FAA Safety Presentations

8/11/2019 FAA Safety Presentations

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FEDERAL AVIATION ADMINISTRATION

TRANSPORT AIRPLANE AND ENGINESAFETY REQUIREMENTS

A GENERAL OVERVIEW

Certification Process Study Team Meeting #6

Museum of Flight, Seattle WA

June 26-27, 2001


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TABLE OF CONTENTS

Introductory Remarks (D. Cheney) Flight: Airplane Performance, Stability and

Control, Related Support (T. Archer/J. Neff)

Structures: Loads, Design and Construction

(H. Offerman)

Equipment: Mechanical (R. Jones)

Equipment: General, Electrical, Avionics

(S. Boyd) Propulsion: Engine/APU (M. Fulmer)

Propulsion: Engine Installation (K. Rask)

Cabin Safety (F. Tiangsing)

Human Factors (S. Boyd)


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CERTIFICATION FLIGHT TEST

Tom Archer - FAA Flight Test Pilot

John Neff - FAA Flight Test Engineer

Flight Test Branch

Seattle Aircraft Certification Office


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Overview Flying Qualities

Systems and Equipment

Aero. Performance Airplane Flight Manual

CDL

Operations Manual / MMEL


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Flying Qualities (FAR 25, Subpart B)

Aircraft Systems (FAR 25, Subparts D, E, & F)

Aircraft Systems Installed Equipment

Performance (FAR 25, Subpart B)

Airplane Flight Manual (FAR 25 Subpart G)


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FLIGHT TEST - GOAL

Ensure aircraft meets minimum standards Fully operational aircraft or

with any foreseeable failures (more probable

than 1x10E-9)

with a pilot of average skills throughout the operational envelope:

Speed

Altitude

Gross Weight / Center of Gravity Temperature

Limit head/tail/cross winds


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FLYING QUALITIES (FQ)

General Requirements- The airplane must:

Be safely controllable and maneuverable

Not require exceptional piloting skill,alertness or strength

Be capable of continued safe flight and

landing following any single failure or

combination of failures not shown to be

extremely improbable. The flying qualities requirements must be

demonstrated throughout the flight envelope


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FLYING QUALITIES (FQ) (contd)

Stability Static

Dynamic

Controllability Maneuverability

Stall Characteristics

High Speed Characteristics

Degraded Modes


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C.G./GROSS WEIGHT ENVELOPE

GrossWeight(Pounds)

Center of Gravity (%MAC)


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FLIGHT ENVELOPE

P

ressureAltit

ude(Feet)

Airspeed (KCAS)


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V-N DIAGRAM


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SPECIFIC FQ FLIGHT TESTS

General (25.101-.143)

Maneuvering stability

(25.143, .251, .255)

Longitudinal control(25.145)

Directional and lateral

control (25.147)

Minimum control speed

(25.149)

Trim (25.161)

Static longitudinalstability (25.173-.175)

Static lateral-directional

stability (25.177)


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SPECIFIC FQ FLIGHT TESTS (Cont)

Dynamic stability

(25.181)

Stall characteristics

(25.203) Ground handling

(25.231-.235)

Cross wind (25.237)

Vibration and buffeting

(25.251)

High-speed

characteristics (25.253) Out-of-trim

characteristics (25.255)


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TEST CONDITIONS

TEST LOADING

(wt/cg)DATA

General Full range Qual, forces

Man stab Fs/g

Long control Heavy/fwd, aft Qual, forces

Lat-dir control Heavy/fwd, aft


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TEST CONDITIONS (Cont)

TEST LOADING DATA

Min cont spd Light/aft Hdg, grd track

Trim Full range Control forces

Stat long stab Light/aft Fe/V

Stat lat/dir stab Light/aft Fa/, Fr/


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TEST LOADING DATA

Dyn stability Light/aft Oscillations

Grd handling Full range Qualitative

Stall char Light/aft , response

Vib/buffet Heavy/aft Fs/g, Vc, Mach


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TEST LOADING DATA

High spd char Full range Fs/g, Vc, Mach

Out-of-trimcharacteristics

Full range Fs/g, Vc, Mach


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ADDITIONAL APPROVALS

Human Factors- continuous evaluations

conducted concurrently with other tests

Operating Limitations (FAR 25, Subpart G)-

sufficient to define the envelope

demonstrated during flight tests

Airplane Flight Manual (FAR 25, Subpart G)-

information validated during flight testing


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SYSTEMS

Systems and equipment evaluated by

Flight Test All Systems

Virtually every piece of equipment on the A/C Three categories of equipment

> Equip. required by FAR Part 25

> Equip. NOT required by FAR 25, but IS by FAR 91,

121, 125, or 135,

>

Equip. not required by any FAR


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SYSTEMS

ALL equip. MUST meet the following rules Perform its intended function/function

properly

Not provide any misleading information tocrew

Not interfere with any other equipment

Specifically applicable rules (if any)

No failure condition may preclude continuedsafe flight and landing


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AIRCRAFT SYSTEMS

Flight Controls

Landing Gear

Powerplant

Fuel Auto Flight

Flight Director

Auto Pilot

Auto Throttle

HUD

Hydraulics

Electrical

Pressurization/Environ.

Fire Protection

Flight Deck Controls

Displays

Lights

Safety

Comm/Nav

De-ice/Anti-ice


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FLIGHT TEST - FIRE/SMOKE


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WATER IMPINGEMENT


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COLD / HOT ENVIRONMENT


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WINDOWS / DOORS


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INSTALLED EQUIPMENT

Operational

Requirement TCAS

GPWS/EGPWS

RWS/PWS

CVR

FDR

HF

3rd Comm/Nav Standby Instruments

Optional ACARS

GPS

IFE Telephones

SAT Comm

Lavatories

Prayer Rooms


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PERFORMANCE

Phase of Flight Takeoff (FAR 25.105 - .107)

Accelerate - Go

Accelerate - Stop (FAR 25.109)

Climb (FAR 25.113 - .117, .121) First / Second / Third / Final segment

En Route (FAR 25.123)

Descent

Approach

Approach climb (FAR 25.121)

Landing (FAR 25.125)

Landing climb (FAR 25.119)


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T.O. PERFORMANCE

Takeoff Speed Schedule Development

(FAR 25.107)

Takeoff Field Length Requirements

(FAR 25.113)


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HIGH ALTITUDE TAKEOFF PERF.

LaPaz, Bolivia, field elevation 13,100 ft. MSL


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TAKEOFF SPEEDS

Definitions for speed scheduledevelopment V1 Takeoff decision speed

Min. speed, following critical engine failure, from which

T.O. can continue and achieve 35 within T.O. distance Max speed to initiate the first action in an abort and

stop within accel-stop distance

less than V1MBE

Brake Release Vef Vr >V2VlofV1

35 feetVmcg Vmca

Vmu

Max. tire

speed

Vmbe(15 if wet)


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TAKEOFF SPEEDS (contd)

Definitions for speed schedule development Vr Rotation speed

Equal to, or greater than, V1, and 1.05 Vmca

result in a minimum Vlof of 1.05 OEI Vmu & 1.1 AEO Vmu

Allow reaching V2min by 35, OEI

5 knot abuse (OEI) will not significantly extend the

takeoff distance

Brake Release Vef Vr

>V2

VlofV1 35 feet

Vmca Vmu


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TAKEOFF SPEEDS (contd)

Definitions for speed scheduledevelopment V2 Takeoff Safety Speed

Meet minimum EO climb gradient

Greater than V2min V2min

1.1Vmca

1.13Vs

Brake Release Vr

V2

V1 35 feet

VmcaVs


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ADDITIONAL SAFETY MARGINS

T.O. Tests @ each flap setting Light / mid / heavy weights

All engine / one engine inoperative

Several T/W at each flap setting

Fuel cut conditions Overspeed

Abuses

Rapid rotations (rate)

Over rotations

5 knot Vr abuse

Mis-trim

Over 60 Takeoffs


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FAR TAKEOFF FIELD LENGTH

AFM Takeoff Distance Required

Vr Vlof

35 feet

Demonstrated All Engine Distance

Takeoff Distance= 1.15X All Eng. Dist. To 35 feet

>V2

All engine, full up airplane

FAR TAKEOFF FIELD LENGTH


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FAR TAKEOFF FIELD LENGTH(contd)

Critical Engine Fails at VefBalanced field length

GO

V2

VlofVr35 feet

Vef

V1

RTO

Throttles / max. brakes, speed brakes

AFM expansion, incl. 2 sec. At V1

Dry Runway - NO credit for thrust reversers

Wet Runway - Credit given for thrust reversers


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REFUSED TAKEOFF - STOPPING

100% MBE RTO Demonstrated performance with:

90% (min.) worn brakes (accident

investigation)> FAR 25.109

Pre-heated, 3 mile taxi w/ three stops full stop - 5 minutes


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ANTI SKID - INOPERATIVE


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CLIMB PERFORMANCE

Takeoff Path Segments (FAR 25.115) 1st = Liftoff to gear up

2nd = gear up to 400 ft.

3rd = 400 ft. to 1500 ft. (accel/cleanup)

Enroute = Greater of: 1500 ft. or clean, MCT &at final climb speed

Min. climb requirements based on:

Weight Altitude

Temperature

Most unfavorable CG


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TAKEOFF PATH

Minimum Climb Gradient (FAR 25.117) Based on total number of engines

Takeoff segment

All engine / OEI, and two EI for quads

Operational Requirements (FAR 121,

Subpart I)


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ENROUTE PERFORMANCE

Enroute (FAR 25.123) Following data must be determined and

published

Climb performance, all engine and OEI

Drift down Procedures associated with the above


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APPROACH PERFORMANCE

Approach Climb (FAR 25.121) Min. climb gradient, based on:

Approach configuration

Total number of engines

Critical engine inoperative

Max. landing weight


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FAR LANDING FIELD LENGTH

Vref landing threshold speedVref min = 1.23Vsr

FAR 121 FACTORED Landing Distance (121.195)

Touch down

FAR 121 Landing Distance= demonstrated

0.6

50 feet

transition deceleration in full braking config.

Full stop

FAR 25 Landing Field Length

landing flare

Vref

FAR 25.125


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AIRPLANE FLIGHT MANUAL

AFM (FAR 25.1581) Four sections

Limitations

Normal procedures

Non-normal procedures

Performance

Appendices

Configuration Deviation List

Derated thrust operations Engine intermix

Alternate Weight

/ C


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AFM / CDL

CDL contains additional limitations

required for operations with missing

secondary parts

PIC notified and provided a list of all parts Each limitation listed by placard in flight deck

Logbook entry

Cumulative performance decrements via

weight penalty

OPERATIONS MANUAL / MMEL


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OPERATIONS MANUAL / MMEL

Flight Crew Operations Manual (FCOM)(FAR 121.141) Permits OM in lieu of the FAR Part 25 AFM

Must contain Limitations from AFM

Perf. data / procedures can be modified fromAFM

NOT FAA Approved, Accepted by POI

Master Minimum Equipment List (FAR121.627) Permits operation of the aircraft in a non-

standard configuration

owned by AEG

FLIGHT TEST CONCLUSION


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FLIGHT TEST - CONCLUSION

Huge improvements in recent years Analytical Methods

Dynamometer Testing

Simulation

Only Flight Test Total Integrated Package

Real World Environment

Human Factors

Questions?


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PART 25 STRUCTURES RULES

Hank OffermanAirframe Branch

Transport Airplane Directorate

CERTIFICATION OF STRUCTURE


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CERTIFICATION OF STRUCTURE

CFR 14, Part 25 - Airworthiness Standards Subpart C, Structure

Loads, design conditions, proof of structure

Subpart D - Design & Construction (Structure)

Material & process specifications, specialfactors, design criteria, special considerations

Subpart G - Operating Limitations & Information

Airspeed, weight, center of gravity> Limits can not exceed values used for design in

Subpart C Instructions for Continued Airworthiness

> Inspection requirements

Locations, intervals, methods, acceptance criteria

DESIGN LOADS


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DESIGN LOADS

Flight Maneuver & Gust (25.331 - 25.351) Ground Loads (25.471 - 25.519)

Landing loads Ground handling loads

Taxi & ground maneuver Towing loads Jacking & tie-down loads

Control Surface & System Lds (25.391 -25.459)

Emergency Landing Conditions (25.561 -25.563) Supplementary Conditions (25.361 - 25.373) Fatigue Evaluation (25.571) Lightning Protection (25.581)

MANEUVER LOADS


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MANEUVER LOADS

Response to Control Input or Command Pilot

Automatic flight control system

Symmetric Balanced maneuvers

Steady state> Zero pitching acceleration

Checked maneuvers Rational pitch vs. time profile

Unchecked maneuvers

Maximum control deflection

MANEUVER LOADS


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MANEUVER LOADS

Asymmetric Rolling conditions

Sudden deflection of controls

Steady state roll maximum control deflection

Yaw maneuver conditions Sudden deflection of controls

Overswing yaw maximum control deflection

Steady sideslip maximum control deflection

Sudden return to neutral

MANEUVER LOADS


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MANEUVER LOADS

Airplane Flight Configuration Cruise configuration

With and without in-flight lift and drag

devices

Takeoff, approach & landing Airplane Weight Configuration

All critical weight & center of gravity

combinations on or within the C.G. envelope

All critical fuel load combinations

Airplane Speed & Load Factor All critical speed & load factor combinations

on or within the maneuver envelope

MANEUVER LOADS


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MANEUVER LOADS

Load Factor - n The inertial or acceleration forces acting on a

body (f) is the load factor times the weight (w)

of the body

f = n x w

Sign Convention - Airplane Axis System Positive - push you into your seat

Negative - lift you out of your seat

DESIGN V N ENVELOPES


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DESIGN V-N ENVELOPES

Defined by Experience Based upon extensive flight measurement

60 year history - on-going programs

Values selected such that probability of

exceedance is small

Relationships defined to ensure safe operation

in usage environment

Does not constrain airplane usage in the

operational environment Enables minimum weight design

MANEUVER LOADS


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MANEUVER LOADS

Maneuver Design Load Factors V-n diagram

GUST LOADS


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GUST LOADS

Gust is an Atmospheric Disturbance Direction - change in angle of attack

Velocity - change in local airspeed

Result of Gust is Change in AerodynamicForce Acting on Airplane Acceleration - change in load factor

Two Structural Load Components Rigid body response

Dynamic response due to airplane flexibility

and gust velocity profile

GUST LOADS


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GUST LOADS

Present Evaluation Requirements Discrete gust

Excites rigid body response> Provides a dynamic component

Single encounter - defined gust profile

Includes airplane dynamic response

Continuous gust

Atmosphere model - power spectral density> Atmospheric energy vs. frequency

Excites dynamic components> Provides a rigid body component

Envelope design - high loads

Mission analysis - fatigue spectrum

GUST ENVELOPE


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GUST ENVELOPE

Gust Design Load Factors V-n diagram

GROUND LOADS


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GROUND LOADS

Ground Loads are Computed using

Weights and Centers of Gravity Which

Result in Maximum Design Loads in Each

Landing Gear Element Forward, aft, vertical and lateral centers of

gravity locations must be considered

GROUND LOADS


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GROUND LOADS

Landing Loads Applied to landing gear and airplane

Landing Parameters Descent velocity

Maximum landing weight - 10 feet per

second

Maximum takeoff weight - 6 feet per second

Landing load factors Function of landing gear energy absorption

characteristics

Must be validated by tests

GROUND LOADS


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GROUND LOADS

Landing Conditions Level landing (nose landing gear arrangement)

Main gear in contact, nose gear clear

All three gear in contact

Tail down landing One-gear landing

Drift landing

Rebound landing

GROUND LOADS


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GROUND LOADS

Ground Handling Loads Taxi, takeoff and landing roll

Roughest ground reasonably expected

Braked roll

Main gear in contact, nose gear clear

All three gear in contact

Turning

Side load due to centrifugal load factor

Nose wheel yaw & steering

Side load on nose gear Pivoting

Landing gear torque

Reversed braking

GROUND LOADS


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GROUND LOADS

Towing Loads Defines loads to be applied to the towing

fittings

30% of the towed weight for airplanes

weighing less than 30,000 pounds 15% of the towed weight for airplanes

weighing more than 100,000 pounds

Linearly varying between 30,000 and 100,000

pounds

GROUND LOADS


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GROUND LOADS

Jacking & Tie-Down Loads Airplanes must have jacking provisions

Loads computed at maximum ramp weight

Airplane

Loads resulting from a vertical load factor of

1.33 plus a horizontal load factor of 0.33 in anydirection

Fittings & local structure

Loads resulting from a vertical load factor of

2.00 plus a horizontal load factor of 0.33 in anydirection

Tie-down fittings and local structure (IF provided)

Loads resulting from a 65 knot horizontal

wind in any direction

CONTROL SURFACE & SYSTEM


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LOADS Control Surfaces Must be Designed for

Loads Resulting From Flight conditions

Loads need not exceed those resulting from

the application of maximum pilot effort loads

Ground gust conditions Loads parallel to hinge line

Load factor of 12 for horizontal surfaces and

24 for vertical surfaces

Must Consider Pilot effort effects

Trim tab effects

Unsymmetrical loading


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EMERGENCY LANDING


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CONDITIONS

Protection of Occupants Protection of Systems Which Could Cause

Fire or Explosion

Design Load Factors Up - 3.0

Forward - 9.0

Sideward - 3.0 for airframe, 4.0 for seats

Downward - 6.0

Aft - 1.5 Dynamic Conditions for Seats

16 g seats

SUPPLEMENTARY CONDITIONS


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SUPPLEMENTARY CONDITIONS

Engine Torque Operating torque

Engine acceleration

Sudden engine stoppage

Side Loads on Engine Mounts

Pressurized Compartments

Unsymmetrical Loads Due to Engine

Failure Gyroscopic Loads

Speed Control Devices

DAMAGE TOLERANCE & FATIGUE


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EVALUATION OF STRUCTURE

An evaluation of the strength, detail

design, and fabrication must show that

catastrophic failure due to fatigue,

corrosion, manufacturing defects, oraccidental damage, will be avoided

throughout the operational life of the

airplane FAR 25.571(a)



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Damage Tolerance Evaluation Address catastrophic failures due to fatigue,

corrosion & accidental damage

Crack growth analysis and/or tests

Residual strength evaluation Inspection & maintenance procedures

Applied to single load path structure

Applied to multiple load path and crack arrest

fail safe structure where it cannot bedemonstrated that failure will be detected

during normal maintenance



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Damage Tolerance Evaluation (Contd) Wide spread fatigue damage will not occur

during the design service life of the airplane

Supported by full scale fatigue test evidence

Damage Tolerance (Discrete Source) Bird impact

Uncontained fan blade impact

Uncontained engine failure

Uncontained high energy rotating machineryfailure



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Fatigue (Safe Life) Evaluation May be used when the application of the damage

tolerance requirements is impractical

Sonic Fatigue Strength

Sonic fatigue cracks are are not probable inflight structure subject to sonic excitation, or

Catastrophic failure is not probable if sonic

fatigue cracking occurs

Instructions for Continued Airworthiness The data developed to demonstrate compliance

with this requirement forms the basis for the

airframe instructions for continued airworthiness

LIGHTNING PROTECTION


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LIGHTNING PROTECTION

The Airplane Must be Protected Against

Catastrophic Effects of Lightning Electrical bonding

Design of components to preclude the effect ofa strike

Diverting electrical current

PROOF OF STRUCTURE


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PROOF OF STRUCTURE

25.303 through 25.307 Computed Loads - Limit Loads

Limit Loads Times Factor of Safety -

Ultimate Loads Factor of safety - 1.5

Very low number - commercial machine

design applications use 6 and up

Usage is justified by material and process

controls imposed by Subpart D andmaintenance programs required by

operating rules> Part 91, 121, 125, 135

PROOF OF STRUCTURE


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PROOF OF STRUCTURE

Requirement Limit load

No detrimental permanent deformation

Deflections may not interfere with safe

operation

Ultimate load

Structure must be able to support the load

for 3 seconds

Dynamic testing may be used

PROOF OF STRUCTURE


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PROOF OF STRUCTURE

Compliance Demonstration Static tests to limit load

May require ultimate load testing where limit

load testing is determined to be inadequate

Structural analysis May only be used if the structure conforms

to that for which this method has been

shown to be reliable

DESIGN AND CONSTRUCTION


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DESIGN AND CONSTRUCTION

Material & Process Specifications 25.603, 25.605, 25.613

Special Factors

25.619 - 25.625 Design Criteria

25.607 - 25.611, 25.651 - 25.735

Special Considerations 25.629 - 25.631, 25.843(a)

MATERIAL & PROCESS


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SPECIFICATIONS

The Suitability and Durability of Materials

Must - Be established on the basis of experience or

tests

Conform to approved specifications

Ensure having the strength and other

properties assumed in the design data

Take into account environmental conditions

expected in service> Temperature

> Humidity

MATERIAL & PROCESS


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SPECIFICATIONS

Manufacturing Processes The method of fabrication used must produce

a consistently sound structure

If a fabrication process requires close control

to produce consistently sound results it must

be performed under an approved process

specification

Each new fabrication method must be

substantiated by tests

MATERIAL & PROCESS


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SPECIFICATIONS

Material Specifications Material strength properties must be based on

enough tests of material meeting approved

specifications to establish design values on a

statistical basis A-basis 99% probability, 90% confidence

B-basis 90% probability, 90% confidence

Effects of temperature must be considered

where thermal effects are significant undernormal operating conditions

SPECIAL FACTORS


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SPECIAL FACTORS

The Factor of Safety of 1.5 Must be

Multiplied by the Highest Pertinent Special

Factor of Safety for Each Part of the

Structure Whose Strength is Uncertain

Likely to deteriorate in service

Subject to appreciable variability

Uncertainties in manufacturing process

Uncertainties in inspection methods

SPECIAL FACTORS


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SPECIAL FACTORS

Casting FactorProcess Variables Critical castings

Failure would preclude continued safe flight

and landing or cause injury

1.25 to 1.5> Based upon testing and inspection

Noncritical castings

All others

1.0 to 2.0> Based upon testing and inspection

SPECIAL FACTORS


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SPECIAL FACTORS

Fitting FactorUncertainties in Stress

Analysis Applied to fittings whose strength has not been

proven by limit and ultimate load tests 1.15

Fitting FactorWear and Deterioration Seats, seatbelt fittings

1.33

Bearing FactorWear and Deterioration Control surface hinges

6.67

SPECIAL FACTORS


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SPECIAL FACTORS

Bearing FactorClearance Fits Subject to

Vibration Judgment

Joints Subject to Angular MotionWear 3.33

Not applicable to ball or roller bearings

DESIGN CRITERIA


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DESIGN CRITERIA

Fasteners Locking devices

Protection of Structure Protection against loss of strength in service

due to any cause, including

Weathering

Corrosion

Abrasion Provisions for ventilation and drainage

DESIGN CRITERIA


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DESIGN CRITERIA

Control Surfaces Limit load tests required

Compliance with special factor requirements

must be shown by analysis or test

Control System Stops Must be able to withstand any load

corresponding to design conditions for the

control system

Control system Limit Load Static Tests Testing required in which

Each fitting, pulley and bracket is loaded

Compliance with special factors may be by

analysis

DESIGN CRITERIA


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DESIGN CRITERIA

Landing Gear Shock absorption tests

Limit drop tests> Landing load factors

Reserve energy absorption drop tests> 12 foot per second descent velocity

Landing Gear Retracting Mechanisms Loads from flight conditions, gear retracted

Loads from flight conditions in landing

configuration, gear retraction operating

DESIGN CRITERIA


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DESIGN CRITERIA

Landing Gear Doors Design for yawing conditions

Wheels and Tires Requirements for load ratings

SPECIAL CONSIDERATIONS


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Aeroelastic Stability Requirements Flutter, divergence, control reversal

Loss of stability and control as a result of

structural deformation Must be shown by

Analysis

Wind tunnel tests

Ground vibration tests

Flight tests

Other means found necessary by the

Administrator



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Aeroelastic Stability Requirements

(Contd) Aeroelastic stability envelope

Normal conditions> VD+ 15%

Failure, malfunction & adverse conditions> VC+ 15%

> Failures, malfunctions & adverse conditions

defined

Flight test requirements

Bird Strike Empennage

8 pound bird at VC

MECHANICAL SYSTEMS


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Robert C. Jones

Mechanical Systems Branch


C C S S S

MECHANICAL SYSTEMS


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MECHANICAL SYSTEMS

Flight Controls

Hydraulic Systems

Landing Gear Systems

Cabin Environmental Systems

Cargo Fire Protection Systems

Ice Protection Systems

FLIGHT CONTROL SYSTEMS


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Flight Control Systems (25.629, .671, .672, .1309 et al) Ensure airplane controllability for

All flight and load conditions in flight envelope

Environmental conditions (temp, precip, salt, deice contamination, etc)

In the presence of failures (including A/P) All single failures & combinations of

failures Pf > 10^-9 and certain dual failures

Jams Pj > 10^-9

Ensure availability of functions that rely on FC

Stability: Flutter, speed, mach, dutch roll; loadallev.

Safe pilot interface (feel systems, disconnects,

indications, warnings, motions, procedures)

Methods:Test, analysis redundancy, separation, monitoring,maintenance



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Safety Objectives Provide control system capable of safely maneuvering airplane

through all phases of flight within the flight envelope and that

has effective residual control for safe flight and landing after

failures and jams.

The system must be designed to allow to control airplane

without exceptional piloting skill or strength even after failures. System design must account for human factors to ensure pilot

has suitable warnings, can disconnect or override interfacing

systems, and that movement of controls in the normal sense

results in normal airplane response.

Where automated functions (A/P, SAS, LAS) implemented thruflight controls ensure system has acceptable reliability,

annunciation, disconnects, and that procedures are available to

permit CSF&L.

Ensure the airplane without engines remains controllable

down to certain landing speeds.



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Upcoming Improvements

Harmonized flight control rule (25.671/672) Addresses NTSB recommendation for reliable

redundancy Ensure that failures of dual redundant control

paths do not fail latent without meeting specific

guidelines

HYDRAULIC SYSTEMS


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U C S S S

Hydraulic Systems (25.1309, 1435, 1438, 1461)

Ensure hydraulics for critical & essentialservices

Equipment reqd to meet specific pressure

loads in combination with limit structural loadsand to withstand 1.5 X design operating

pressure load

Fire safety requirements

Integrity of pressure vessels

Containment of failed rotors

Methods:Test, analysis, separation, redundancy,monitoring, maintenance

HYDRAULIC SYSTEMS


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Safety Objective

Ensure hydraulics for critical & essential

services, as required, to allow continued safe

flight and landing even after hydraulic failures

LANDING GEAR SYSTEMS


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Landing Gear Systems (25.721, 729, 735, 1309,JAR 25.745)

Provide capability for airplane ground

maneuvering, Braking/stopping,

Gear retraction and gear extension in the

air.



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Safety Objective

Provide capability for airplane ground

maneuvering, braking/stopping, plus gear

retraction and gear extension in the air Landing gear systems include nose and main

gear retraction/extension mechanisms

including doors, wheels, tires, brakes and

brake controls (antiskid), steering, brake wear& temperature monitoring, and tire pressure

indication systems



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Note

Worn Brake Rejected Take-Off (RTO)

A DC-10 went off the runway. Brakes had been

tested in a new condition for RTO in accordance

with the certification rules in effect at that time.

AD required airplanes over 75,000 pounds to

perform a worn brake demonstration

(dynamometer)

Latest rule requires airplane demonstration for

all gross weights

CABIN ENVIRONMENTAL SYSTEMS


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Cabin Environment (25.831, 25.832, 25.841,25.1438, 25.1441, 25.1443, 25.1445, 25.1447,

25.1450, 25.1309)

Ensure passengers and crewmembers have:

an acceptable environment during normal

operating conditions

adequate protection to enable survival

without permanent physiological damageafter any system failure

Methods:Test, analysis, redundancy, maintenance



104/208

Safety Objective

Provide the means to keep the occupants

of the aircraft alive and comfortable

Oxygen, pressurization, pneumatic, heating,

ventilation, and air conditioning systems



105/208

The pressurization and temperaturecontrolled environments protect the

occupants from the cold temperatures at

high altitudes and provides an atmosphere

with enough oxygen to maintain life

The high operating altitudes of modern

aircraft necessitate oxygen systems that

can sustain life for a limited period of timeshould cabin pressurization fail

CARGO FIRE PROTECTIONSYSTEMS


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Cargo Fire Protection (25.851(b), 25.855,25.857, 25.858, 1309)

Ensure that -

Detection systems detect a fire before itdamages airplane structure & provides visual

indication within 1 minute

Built-in fire extinguishing system does not

introduce a hazard to occupants or theairplane structure & is adequate to control any

fire likely to occur

Methods:Test, analysis, redundancy, maintenance

SYSTEMS



107/208

Safety Objectives

Provide safety features to detect/combat fires

Minimize the impact of fire and extinguishing

agent on occupants

SYSTEMS



108/208

Cargo Compartments

Requirements to keep hazardous quantities of

smoke/flame from entering into crew/passenger

compartments

Most are required to have smoke/fire detectors and

an annunciator in the flightdeck

Fire Suppression

Cargo compartment fires are not extinguished,

they are suppressed and controlled

The suppressing agent is Halon

SYSTEMS



109/208

SYSTEMS

Information on Class D to C Cargo Compartments

FAA eliminated Class D cargo compartments for future type

certification from commercial transport airplanes

March 19, 2001

Class D cargo compartments must meet the standards for

Class C or Class E compartments

These changes came about because of a number of

accidents, including Valujet

ICE PROTECTION SYSTEMS


110/208

Ice Protection (25.1419, 1403, 1309)

Ensure Airplane Safety by: Detection ice or icing conditions

Anti-ice or deice capability Windshield and probes heating

Provide acceptable flight characteristics for

intercycle ice and ice accreted on

unprotected surfaces

Methods:Test, analysis, redundancy, separations



111/208

Safety Objectives

For airplanes that intend to operate in icingconditions the ice detection and protections

systems must be designed to ensure timely

activation and capability of ice protection system,

the airplane must be shown to safely operate withice accreted on unprotected surfaces and

intercycle ice on protected surfaces, and the

airplane must be shown safe for trajectories of

shed ice to ensure they do not negatively impactpropulsion, instruments, or structures

Clear windshield in icing conditions

Instruments operable in icing conditions



112/208

Developments Definition of SLD conditions for certification.

Current FAR/JAR do not cover this condition.

(rule in development)

Detection of ice formations aft of the protectedsurfaces. Current FAR/JAR do not require

this. (OPS rule in development)

Ensuring stall margins met with intercycle ice

and ice on unprotected surfaces (SFAR in

work)

PART 25 EQUIPMENT RULES


113/208

Steve BoydSystems & Flight Crew Interface Branch


OVERVIEW


114/208

General Remarks Equipment Installation Requirements

Safety Standards and Objectives

Operational Environment

Instruments

Electrical Systems

Lighting

Recording Systems

GENERAL REMARKS


115/208

Subpart F addresses most systems

installed in the airplane

Examples include avionics flight and navigational equipment

environmental control

lighting

power generation

EQUIPMENT INSTALLATIONREQUIREMENTS


116/208

REQUIREMENTS

Overall Purposes Establish safety standards for installed

equipment

Equipment must perform its intended

functions

Regulate frequency of failures based on theirseverity

Protect aircraft and persons against effects of

environmental and operational hazards

Provide means to alert the crew Standardize certain flight deck display

information

Provide airworthiness standards for certain

equipment required by operating rules

SAFETY STANDARDS: PERFORMINTENDED FUNCTION


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INTENDED FUNCTION

The equipments functionality, capability,

and limitation must be deliberately

incorporated, i.e. no hidden functionality

(25.1301) Certain levels of reliability for safety-

critical systems are required,

However, equipment is not expected to

alwayswork Therefore, the effects of failures are also

regulated (25.1309)

SAFETY OBJECTIVES


118/208

CatastrophicEffect

Minor Effect

Extremely

Improbable

More

Frequent

Reduced Crew

Ability to Cope

with Adversity

Improbable

Failure effects are regulated by requiring

an inverse relationship between the

severity of the failures and their frequency

of occurrence

SAFETY OBJECTIVES(continued)


119/208

In addition

Fail Safe Design = No single failure

can result in a catastrophic condition(AC25.1309-1A)



120/208

The regulations governing system safetyare based on the fail-safe design

concepts which typically include: Design integrity and quality (design practices)

System redundancy (protect from first failure) Proven reliability (service experience)

Error tolerance (designer, maintainer,

operator)

Flight/maintenance crew procedures (mitigatefailure effects)

Others (not listed for brevity)



121/208

The safety objectives are defined at the

airplane level, not at the components

themselves [a component failure does not

always result in a hazard to the airplane,crew, or occupants]

To meet these objectives, the methods of

compliance routinely involve qualifying

components by rigorous industry-wideguidelines: Hardware RTCA/DO-160D

Software RTCA/DO-178B



122/208

Alerting is necessary to meet the overallsafety objectives (25.1309 (c)) When flight crews are expected in intervene to

mitigate the effects of failures

Alerting can be by design (warnings/cautions)or by intrinsic characteristics (e.g. deterrent

buffet)

Lighted messages are standardized by

color coding: red or Amber, depending onthe hazard level and urgency (25.1322)

SAFETY OBJECTIVES(end)


123/208

Certification Maintenance Requirements

(CMR) are established during certificationas an operating limitation of the Type

Certificate (AC25-19) CMR is failure finding task to detect safety-

significant latent system failures that, incombination with other failures, result in a

hazardous or catastrophic condition

CMR is not MSG-3 which are tasks that prevent

failures CMR is not structural inspection required by

25.571, 25.1529, Appendix H25.4

THE OPERATING ENVIRONMENT


124/208

Effects due to operational and

environmental conditions (internal and

external) are considered Specific rules for:

lightning protection (25.1316)

ice detection and protection (25.1403, 1419)

life support systems (25.1438-1453)

Other conditions (altitude, temperature, rain,

wind, vibration, glare, etc) are considered in

specific methods of compliance whichtypically involve testing

INSTRUMENTS


125/208

The regulations provide the minimumstandards for displaying safety-critical

information in the flight deck (25.1303,

1305)

Certain instruments must be installed Safety-critical flight and navigation

instruments (specific navigation systems are

required by operating rules)

Powerplant instruments The basic T arrangement (25.1321)

INSTRUMENTS


126/208

Specific regulations levied against flightcritical system to ensure: Safety of design (under failure conditions, for

flammability, system status indications, etc.)

Human factors issues (control accessibility,consistency of operation, consistent use of

color, etc.) have been addressed

Adequate means to detect system failures

Adequate system capacity (for electrical

power)

INSTRUMENTS


127/208

General requirements levied against flightcritical instruments ensure: Means are provided to connect required

instruments to opposite side of cockpit

Display of information essential to safety offlight will remain available to pilots after single

failure

Other systems may not be connected to these

flight critical systems, unless provisions are

made to ensure correct operation after failure

AIRSPEED INDICATING (25.1323)STATIC PRESSURE (25.1325)


128/208

( )

Other specific instrumentationrequirements intended to deal with past

problem areas: System arrangement to prevent malfunction

due to entry of moisture, dirt, or othersubstances

Heated to prevent malfunction due to icing

Redundant systems separated to prevent

single event (e.g., birdstrike) from disablingmultiple systems

Positive drainage to avoid corrosion, correct

use of materials, correct installation to avoid

chafing

AUTOPILOT/FLIGHT DIRECTORSYSTEMS (25.1329)


129/208

( )

Must be able to be disengaged quickly andpositively to prevent interference with pilot

control of airplane

Must be designed to prevent hazardous loads

on airframe or hazardous flight path deviationsduring normal flight or failure condition

Must be designed to provide positive and

unambiguous annunciation of current operating

mode Human factors issues (operation of controls,

location of displays and controls, etc.)

POWERPLANT INSTRUMENTS(25.1337)


130/208

( )

Provides installation requirements for theinstruments required by other sections Minimize hazards from escape of flammable

fluids

Ensure proper calibration of fuel quantity

indication systems

Minimize affects of fuel flowmeter

malfunctions

Other specific issues associated with oil

quantity, propeller position, and fuel pressureindication systems

ELECTRICAL SYSTEMS


131/208

General Requirements

Generating Systems

Distribution System

Circuit Breakers

GENERAL REQUIREMENTS


132/208

The airplane must be capable of operation

without normal electrical power sources at

maximum altitude for at least 5 minutes

(25.1351d)

Electrical equipment, controls and wiringmust be installed to ensure non-interference

with other electrical units and systems

essential to safe operations (25.1353a)

Electrical cables must be grouped, spacedand routed to minimize damage to essential

systems due to faults in heavy current-

carrying cables (25.1353b)

GENERAL REQUIREMENTS


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Electrical Systems Laboratory Tests

(25.1363) system should have a high degree of fidelity

with actual equipment installed on the airplane

for flight conditions not simulated adequately

in the laboratory, flight tests must be made

example: effect of zero g and negative gs on

generator function

GENERATING SYSTEMS (25.1351)


134/208

Electrical Loads analysis determines thegenerating capacity and number and kind

of power sources

No failure of a power source can create a

hazard or impair the ability of remaining

sources to supply essential loads

There must be a means to disconnect

power sources from the system andindicate power available

BATTERIES (25.1353C)


135/208

Most aircraft need a battery to power criticalsystems or start the auxiliary power unit in

case normal generator power is lost in flight

Battery requirements include: temperature and pressure safeguards protection from explosion and toxic gas

emissions

meet 5 minute loss of primary power requirement

charge rate, temperature monitored withassociated warning to crew and ability to

disconnect

CIRCUIT PROTECTION (25.1357)


136/208

Circuit breakers or fuses are required toprotect wiring and airplane power busses automatic devices required to minimize hazard

to airplane in event of wiring faults

protective devices necessary for generatingsystem

if resetting is required for safety of flight,

circuit breaker must be located and identified

so it can be easily reset in flight

LIGHTING REQUIREMENTS


137/208

External requirements include: Position lights (red, green, white on tail)

(25.1385, 1387, 1389)

Anti-collision lights (25.1401)

Wing ice detection lights (25.1403)

Landing lights (25.1383)

Specific requirements for coverage, color,

position and intensity (25.1389, 1391,

1393, 1395, 1397)

LIGHTING REQUIREMENTS


138/208

Internal lighting requirements include: means provided to control intensity (25.1381)

meet intended function (25.1301)

emergency lightning for evacuation (25.812)

Cockpit lighting evaluation by pilots for alloperational conditions

No requirements for cabin lights, except

for emergency lighting

RECORDING SYSTEMS


139/208

Recording systems must not impact thesafe operation of the airplane and are

mandated by the operating rules (91.609

c,e)

Design and installation requirementsaddressed in Part 25, subsection F Cockpit Voice Recorder (CVR)

Flight Data Recorder (FDR)

Additional requirements in operating rules(121.359, 121.343)


140/208

ENGINES AND APUS


141/208

Mark Fulmer

Manager, Engine Certification Office

Engine and Propeller Directorate

FUNDAMENTAL CERTIFICATION CONCEPTSENGINES AND APUS


142/208

Safety is defined at the Aircraft level Engine and APU Contributors

Burst

Fire Loads

Loss of Thrust Control

Toxic Products in Bleeds

In-flight Shutdown

Propeller Release

THE OLD WAYResources Expended on Initial & Ongoing Evaluation (Type & Production)


143/208

Typical average

by PAH type

Wide variation

subjective criteria

Priority

Resource

Expenditure

(degree ofattention

paid)

No Distinction for Same Production Approval

Holder (PAH) types PMA/TSO/PC)

THE NEW WAYResources Expended on Initial & Ongoing Evaluation

(Type & Production)


144/208

Smaller variation

defined by resourcetargeting

Resource

Expenditure(degree of

safety based

attentionpaid)

Priority

Old Avg.

Non-Priority

Non-Critical

Designees &Self Audit

Priority

Non-Critical

PI/PE

Evaluations

Priority

Critical

ACSEP & ProductSpecific Evaluations

Focus

Eval. Method

System AdequacyCriteria

{{

{

Determined by: - SVC Exper Safety Data

- Product Safety Assessment

Causal Factors of Disk Fractures


145/208

Accident (level 4)

Part Fractures

Hazardous events:~ 16 per 100 M flights

All uncontained:

~ 32 per 100 M flights

low cycle

fatigue

high cycle

fatigue

manufact.

defect

material

defect

maint. &

overhaul

fretting/

rubbing

erosion/

corrosion

bearing

failure

overspeed overtemp FOD

Forging

Machining

Peening

Titanium

Inconel

Steel

Other

Assembly error

Inspection

Repair

troubleshooting

Loss of disk

cooling,

Limitation

exceeded

Shaft failure

Fuel Control

Closed VSVs

Examples

Opportunities

~ 5 per 100 Million Flights

Opportunities

Design

Prod.

Maint.

Birds

A/C ice shed

Blue ice

BMOD



146/208

Some common considerations

Likely single and multiple failures

Likely improper operation

Likely improper maintenance

Likely inservice damage

Minimize and cover latent failures

Human factors assessed


147/208



148/208

Fire Minimize occurrence and spread

Contain flammable fluids

>

Assess structural integrity and materials ofcomponents and fire wall

Isolate ignition sources

Control usage of flammable materials such

as Titanium and Magnesium

Coordination with aircraft installation to

minimize effects



149/208

Loads Ultimate and limit capability defined

Mounts

Major load carrying structure

Vibratory (internal and external effects)

Component criticals and induced

Failure conditions

Instantaneous, rundown, windmilling

Engine induced loads coordinated with aircraft

installation



150/208

Loss of Thrust Control Control system reliability and safety

assessment (hardware and software)

Redundancy

channels, mode, models, hydro-mechanicalbackup

Auto-shutdown for APUs

Limiting topping, overspeed, overtemp

Fail safe options



151/208

Toxic Products in Bleeds

Bleed air quality testing

HazMats and VOC assessment

Minimize ingress for likely failures

Aircraft level isolation



152/208

In-flight Shutdown Reliability and durability

Random independent vs. common cause threat

Damage tolerance

ETOPS Control system time limited dispatch

Environmental

Weather, birds, HIRF, lightning

Stability Fan and compressor stall

Combustor stability

Human factors in operations and maintenance



153/208

Propeller Release Propeller mount flange and shaft loads

Propeller installation and flight strain

survey evaluated for suitability



154/208

Outcomes of Certification Ratings and Operating Limitations

Power

Rotor speeds

Temperatures and pressures (gas path, fuel,

oil, etc.)

Installation Requirements

Component temperatures Loads (steady & vibratory)

Inputs/Outputs



155/208

Outcomes of Certification

Operating instructions

Altitude, attitude, speed, temperature

Procedures (in-flight relight, environmental,

ground handling, etc.)

Airworthiness Limits

Component life, inspections, maintenance

Instructions for Continued Airworthiness On-wing preventative maintenance and

off-wing overhaul



156/208

Production Certification

Production process definition, process

controls, defect characterization, inspectability,surveillance

Operational and Maintenance Certifications

Based on ability to adhere to type certification

data, limitations, and conditions

Ongoing Management of Production,

Operability and Maintainability


157/208

PERFORMANCE OF MAINTENANCEAND ALTERATION


158/208

Repair Stations must perform work in accordance with

the manufacturers ICA (FAR 43.13a), an aircarrier'smanuals (FAR 145.2) or other FAA approved data.

Maintenance may be conducted using other methods,

techniques and practices acceptable to the

Administrator that accomplish the same end resultwith respect to airworthiness i.e.; conformity to the

type design and safe for operation

Repairs, alterations, or deviations from the

Manufacturers ICA which are major require FAAapproved data

Maintenance must return the product to either its

original or properly altered configuration

(FAR 43.13b)



159/208

In Closing:

Dont confuse compliance with safe nor

non-compliance with unsafe

There is no such thing as an isolated event

POWERPLANT INSTALLATIONS


160/208

Kathrine Rask

Senior Engineer, Propulsion Branch

Seattle Aircraft Certification Office

PROPULSION SYSTEM


161/208

Overview System Definitions

Fundamental Certification Concepts

Fuel Systems

Engine Ice Protection

Thrust Reverser

Engine Operating Characteristics

Fire Protection

Uncontained Engine Failure

Powerplant Instruments

SYSTEM DEFINITIONS


162/208

Multi-Engine Installation Engines are Part 33 certified

Objective is stand alone type certificate;

generally not airframe specific

Auxiliary Power Unit (APU) Installation APUs qualified to technical standard order

Also stand alone certification objective

Fuel System Tanks, pumps, plumbing, wiring, etc.

25.901(a), 25.903

FUNDAMENTAL CERTIFICATIONCONCEPTS


163/208

No Single Failure or Probable

Combination of Failures will Jeopardize

Safe Operation A single failure is assumed without

consideration as to its probability of failing

If a failure event cannot be readily detected, itis counted as a latent existing failure in

addition to the first failure

Probable - expected or foreseeable

Term often confused with 25.1309terminology; quantitatively means not

extremely improbable

25.901(c)



164/208

Jeopardize safe operation Continued safe flight and landing from brake

release through ground deceleration to stop

Safe flight is determined by both qualitative

and quantitative analysis Consider service experience of similar failures

25.901(c)



165/208

No Single Failure or Probable Combination

of Failures will Jeopardize Safe Operation Accomplished By

Isolation

Independence

Redundancy Reliability

Four Exceptions To Rule

Uncontained Engine Failures

Combustor Case Burn Through

Propeller Failure

Certain Structural Failures

25.901(c), 25.903(b), 25.903(d)(1), 25.905(d)

FUEL SYSTEMS


166/208

Fuel System Independence/Redundancy

Fuel Flow Normal operation

Hot/cold weather, negative G, gravity feed

Lightning Protection

Crashworthiness Failure Modes

Ignition sources/flammability

Function of automated fuel system

25.943, 25.951-25.1001

FUEL SYSTEM


167/208

New Outlook on Fuel System Safety Part 21 Special Federal Aviation Regulation

Retroactive design review of in-service

airplanes

New Part 25 Regulation Changes

Improved safety analysis Minimized fuel tank flammability

Operating Rule Changes

Mandate improved maintenance

SFAR No. 88; 25.981, 91.410, 121.370, 125.248, 129.32

ENGINE ICE PROTECTION


168/208

Engine Installation Shall Continue to

Operate in Severe EnvironmentalConditions Review ice accumulations on engine, inlet, and

other airframe surfaces that could be ingested

Freezing fog on ground Falling and blowing snow on ground

Late activation of ice protection by crew in

flight

Fan ice shedding and procedures No engine icing limitations

Engine power/thrust always required to exit

inadvertent icing conditions 25.1093

THRUST REVERSER

Demonstrate compatibility with engine


169/208

Demonstrate compatibility with engine

Demonstrate compatibility with airplane Significant change in philosophy since the

Lauda 767 accident

Exposed vulnerability to certain aircraft

during high speed flightLong Strut/Low Mount Short Strut/High Mount

T/R pattern under wing - no stall T/R pattern over wing - stall

THRUST REVERSER


170/208

Two Options to Meet Part 25 Safety Intent: To demonstrate that the airplane must be

controllable under any possible position of the

thrust reverser

Thorough flight test controllability

demonstration Demonstrate operable reverser can be

restored to the forward thrust position

Minimize potential for in-flight deployment

25.933

THRUST REVERSER


171/208

Two Options to Meet Part 25 Safety Intent

(continued): To demonstrate the possibility of an inflight

thrust reverser deployment will not occur

within the life of the airplane fleet

Rigorous qualitative and quantitativeanalysis with more conservative

assumptions

Typically results in three independent

thrust reverser restraints Review minimum dispatch configurations

THRUST REVERSER

M i t h l d i ifi t l i


172/208

Maintenance has played a significant role in

the majority of inflight thrust reverserincidents

Review safety analysis assumptions to ensure

they are tolerant to human error

Review general thrust reverser maintenanceprocedures

In depth review of thrust reverser lock-out

configuration and procedures

Vast majority of in-service thrust reverser

uncommanded deployments resulted from

improperly de-activating system

associated with MEL activity

ENGINE OPERATINGCHARACTERISTICS


173/208

Engines should continue to safely operate

throughout the airplane flight envelope Engine operation demonstrated at

airplanes limits of :

Ambient temperature

Altitude/airspeed/angle of attack

Tailwind/crosswind

Rapid and slow power lever movements

Mechanical/electrical loading

25.939, 25.931

POWERPLANT FIRE PROTECTION

G l i t t i t id d d t


174/208

General intent is to provide redundant

design: Minimize potential for fire

Ventilation required to minimize potential of

flammable vapor

Managing zone temperatures and sourcesof ignition

Minimize effects/duration if a fire should occur

Fire walls

Quick acting detectors

Flammable fluid shut off provisions

Drainage provisions

Extinguishing

25.863-25.869, 25.1181-25.1207

UNCONTAINED ENGINE FAILURE


175/208

DC-10; 1973

B-747; 2000


Uncontained engine failure threat too


176/208

Uncontained engine failure threat too

great to be completely addressed byfailsafe philosophy Some of the threat addressed by prescriptive

requirements

Differential compartment loads Damage tolerant structure

Decompression

25.365(e)(1), 25.571(e)(2)-(3), 25.841(a)(3), 25.903(d)(1)


Remainder of airplane threat minimized in the


177/208

Remainder of airplane threat minimized in the

event of an uncontained engine or APU failure Isolation

> hydraulic check valves

> flammable fluid shut-off provisions & dry bays

Redundancy & Separation

> hydraulic line, flight control wires/cables & electricpower

> flammable fluid shut-off valves

Shielding> critical structure & systems

> auxiliary fuel tanks> APU containment devices

POWERPLANT INSTRUMENTS

Intent is to provide indication of engine


178/208

Intent is to provide indication of engine

parameters, limits, and failures to enablethe crew to always maintain control of

engine Limit exceedances (protect rotor integrity)

Fault enunciation - critical failures Messaging system consistent with flight

deck philosophy

Minimize flight crew workload

Pop-up displays Standby indication

Trend monitoring

25.1305

OTHER SYSTEM REQUIREMENTS

P t 25 l dd


179/208

Propeller installation

Oil system

Thrust augmentation

Starting

Component cooling

Controls

APU

Performance

Powerplant accessories

Inlets/Exhaust

All follow the fundamental conceptof fail-safe and isolation

Part 25 also addresses:

CABIN SAFETY


180/208

Frank Tiangsing

Manager, Airframe/Cabin Safety Branch


DEFINITION


181/208

Cabin Safety,the discipline that dealswith:

Occupant protection/survival

Escape from crashes or other emergencyevents

Electrical

Systems


182/208

Mechanical

SystemsCabin Safety

Airframe

Systems

Operations(Flight Standards)

MAIN ELEMENTS


183/208

Occupant protection

Evacuation

Fire protection

Emergency equipment

OCCUPANT PROTECTION


184/208

Occupant protection is provided byhaving: Seats approved to static and dynamic loads

( 25.561, 25.562, 25.785)

Items of mass retained ( 25.789) Padding on projecting objects ( 25.785(k))

Handholds along aisles ( 25.785(j))

Slip resistant floors ( 25.793)

Access to oxygen during a decompression event

( 25.1447)

OCCUPANT PROTECTION

St ti t ti f t


185/208

Static testing of seats Seats are tested to loads in the forward, aft,

sideward, up and down directions

Maximum loads from the ground, flight and

emergency landing conditions are applied

OCCUPANT PROTECTION


186/208

Dynamic testing of seats Two test conditions

16g forward load

14g downward load

Includes occupant injury criteria Head Injury Criteria (HIC)

Lumbar load

Femur load

TSO-C127 prescribes minimum performance

standards for dynamically tested seats

MAIN ELEMENTS


187/208

Occupant protection

EVACUATION

Fire protection

Emergency equipment

EVACUATION

Evacuation addresses the means for


188/208

Evacuation addresses the means for

occupants to safely travel from their seats

to the ground or water

EVACUATION

Effective evacuation is accomplished by


189/208

p y

providing: Appropriate type and number of exits ( 25.807)

Access to exits ( 25.813)

Assist means from the aircraft to ground or water

( 25.810, TSO C69c)

EVACUATION

Effective evacuation is accomplished by


190/208

p y

providing: Emergency lighting ( 25.812)

Emergency evacuation demonstration ( 25.803, App. J)

Ditching capability ( 25.801)

MAIN ELEMENTS


191/208

Occupant protection

Evacuation

FIRE PROTECTION

Emergency equipment

FIRE PROTECTION

I t i fi t ti i li h d


192/208

Interior fire protection is accomplished

by addressing the following areas:

Interior materials ( 25.853, App. F)

Bunsen burner test (Part I)

Seat cushion test (Part II) Heat release test (Part IV)

Smoke emission test (Part V)

Cargo compartments ( 25.855, App. F)

Bunsen burner test Oil burner test for Class C compartment liners

(Part III)

FIRE PROTECTION

L i ( 2 8 3(h) 2 8 4)


193/208

Lavatories ( 25.853(h), 25.854)

Waste receptacles> Must have built-in fire extinguishers

> Must be capable of containing fire

Smoke detectors are required

Portable fire extinguishers must be distributed

throughout the aircraft ( 25.851)

MAIN ELEMENTS


194/208

Occupant protection

Evacuation

Fire protection

EMERGENCY EQUIPMENT

EMERGENCY EQUIPMENT


195/208

Emergency Equipment Required byPart 25 Fire extinguishers, oxygen bottles, floatation seat

cushions or life vests ( 25.851, 25.1415, 25.1447,

121.333(e)) Overwater operation: life rafts, life vests, survival

kits, emergency transmitters, life lines ( 25.1415)

Emergency Equipment Required by

Part 121 Megaphones, first aid kits, smoke hoods, crash ax,

flashlights ( 121.309, 121.337, 121.549)

EMERGENCY EQUIPMENT

Emergenc eq ipment m st be


196/208

Emergency equipment must be: Readily accessible ( 25.1411(a))

Reasonably distributed and arranged so that

its location is obvious, well identified and

appropriate for its intended use

( 25.851(a), 25.1411) Protected from inadvertent damage

(25.1411(b))

HUMAN FACTORS IN PART 25


197/208

Steve Boyd

Airplane & Flight Crew Interface Branch


HUMAN FACTORS IN PART 25


198/208

Definition (unofficial) - Human Factors, as itapplies to aircraft certification: The application of scientific theory, principles,

data and methods...

about human abilities, limitations, and other

characteristics...

to the establishment of minimum safety-related

design requirements for flight crew interfaces,

tasks, and procedures,...

and then ensuring that those requirements aremet,

in order to promote overall system performance

and safety

UNDERPINNING FOR THE CREWINTERFACE REQUIREMENTS


199/208

We base the requirements on knowledgeand/or assumptions about: The human capabilities and limitations of the

people who will fly the airplanes

Their level of training Their roles and responsibilities

The demands of the mission

Note: Requirements for items 2 and 3 are

contained in the operating rules

PRIMARY HF AREAS


200/208

Human factors issues are integrated into

the rules in various subparts

Main areas include:

The controls and displays that the pilots use The physical geometry of the flight deck

Integrated aspects of the flight crew interfaces

The evaluation of performance and handling

qualities

COMPETING REQUIREMENTS

All controls

W i ht P l


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reachable,

displays readable

Space necessary

for controls and

displays

Situation

Awareness

Information

Overload

Commonality

Additional

functionality

16g seats

External vision Short Pilots

Weight. Panel

space

Comfortable

seats

Tall Pilots

CONTROLS AND DISPLAYS

Specific controls and displays are called


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Specific controls and displays are called

out for certain functions

Some are based on assumed pilot

responsibilities

Some are required to deal with failures Driven by failure modes and effects Pilot actions are intended to mitigate the

failure effects

CONTROLS AND DISPLAYS

Design to support pilot performance and


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Design to support pilot performance and

reduce errors in the use of controls/displays Arrangement - convenient accessibility and use,

no confusion, standardization

Direction of movement - matches the function

Control shape - standardization for certaincontrols

Control labeling - except when function is

obvious

Preventing inadvertent activation - location,guarding

Color coding - standardization for alerts/limits

FLIGHT DISPLAYARRANGEMENT

The technology and formats change,


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The technology and formats change,

but.

Airspeed

Heading

Altitude

Attitude

FLIGHT DECK GEOMETRY


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Accommodate a range of pilot sizes Short pilots can reach everything they need

Tall pilots can fit in the flight deck

Pilots can see what they need to see

Installation location of the displays/controls Windows provide adequate visibility

Reflections and glare

Emergency egress

INTEGRATION ASPECTS OF THEFLIGHT DECK

Workload


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Workload Workload must be acceptable for the minimum

flight crew

No unreasonable concentration or fatigue

Crew response to failures

Environmental conditions Noise and vibration

Lighting

Intended function - assessed in context

EVALUATION OF PERFORMANCEAND HANDLING QUALITIES


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HF considerations are embedded innumerous requirements related to

performance and handling qualities.

Examples:

...can be consistently executed in service bycrews of average skill.

may not require exceptional piloting or

alertness.

Reasonably expected variations in service

from the established takeoff procedures may

not result in unsafe flight characteristics

Requirements are based on experience

EVALUATION OF PERFORMANCEAND HANDLING QUALITIES


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Requirements are based on experience Human performance margins are usually in

guidance material

Test pilots are the key players in

evaluating performance/HQ Subjective assessment (including

consideration of line pilot capabilities and line

operations)

Performance data - measuring airplane

FAA Safety Presentations

Documents

Transcript of FAA Safety Presentations