Slides : 30Time : 10 minutesDate: 22nd January, 2015

Basics of Airplanes

Objectives :

At the end of presentation we all will know,

1. Nomenclature and classification of controls in an airplane (slide # 3-4).

2. Which are the aerodynamic forces acting on airplane (slide # 5).

3. Working principle of an airplane (slide # 6).

4. How an airplane flies (basic motions of an airplane) (slide # 7).

5. How controls play their roles in these motions (slide # 8-22).

6. Simulate a flight in Cessna Skyhawk (slide # 23-28).

7. References and Questions & answers (slide # 30).

2

• Cockpit• Fuselage• Empennage• Wings• Propeller and spinner• Landing gears

Nomenclature : Airplane controls _ Basic

Classification

Primary flight control

- Elevator Control System

- Aileron Control System

- Rudder Control System

Secondary flight control

- Elevator Trim Tab System

- Aileron Trim Tab System

- Rudder Trim Tab System

Auxilliary flight control

- Flap Control System

- High Lift Devices

Advanced flight control

….Limitless

• Ailerons• Horizontal and vertical Stabilizers• Elevators• Rudder• Wing Tip• Flaps

3

Nomenclature : Airplane controls _ Advanced

Flaps

• Inboard Flaps

• Outboard flaps

• Fillet flaps

• Leading edge flaps

Ailerons

• Inboard ailerons

• Outboard ailerons

Spoilers

• Outboard Spoilers

• Inboard spoilers

Horizontal and vertical

Stabilizers

• Stabilizers Control

tabs

Elevator

• Elevators control

tabs

Rudder

• Rudder control

tabs

Vortex Generator

4

Aerodynamic forces

Thrust Drag

Weight

Lift

For straight and control flight

Thrust = Drag

Lift = weight

Aerodynamic force created byan airplane in order toovercomedrag.

Means of thrust• Propellers• Jet Engines• Rockets

Every object on earth has weight (including air).

Aerodynamic force that holds an airplane in air.Most of the lift required to keep the plane aloft is created by the wings.

An aerodynamic force that resist the motion of an object Through a fluid (air and water are fluids)

The amount of drag an airplane creates depends on:•Size and shape of the plane.•Speed of an airplane.•Density of the air.

5

Longer path explanation:

• Particles split at the leading edge, and they come together at the trailing edge of the wing.• Since the particles on top travel longer distance in same amount of time, they must be traveling faster.

Bernoulli’s Theory:

• The speed of a fluid increases, its pressure decreases.• Faster moving air on the top creates a low pressure on the top.• The low pressure on the top essentially “sucks” the plane wings upward.

Working Principle 6

Basic movements of an airplane

1. Pitch2. Roll3. yaw

7

• An elevator is mounted on the back edge of the horizontal stabilizer on each side of the fin in the tail.

• They move up and down together.

• When the pilot pulls the stick backward, the elevators go up.

• Pushing the stick forward causes the elevators to go down. Raised elevators push down on the tail and cause the nose to pitch up.

• This makes the wings fly at a higher angle of attackwhich generates more lift and more drag.

• Many aircraft use a stabilizer — a moveable horizontal stabilizer— in place of an elevator.

• These are used to Dive or climb.

Elevator _ primary flight control system 8

An Elevator Control System of a Commercial Aircraft 9

Figure 1

Figure 2

Figure 3

• Ailerons are mounted on the trailing edge of each wing near the wingtips, and move in opposite directions.

• When the pilot moves the stick left, or turns the wheel counter-clockwise, the left aileron goes up and the right aileron goes down.

• A raised aileron reduces lift on that wing and a lowered one increases lift.

• so moving the stick left causes the left wing to drop and the right wing to rise.

• This causes the plane to bank left and begin to turn to the left.

• Centering the stick returns the ailerons to neutral maintaining the bank angle. The plane will continue to turn until opposite aileronmotion returns the bank angle to zero to fly straight.

• These are used for

• Prevent side slip, skid• Bangking / rolling• Increase and decrease wing cambers• Differentialmechanism

• Greater up than down

Ailerons _ primary flight control system 10

Figure 1

Figure 2

An Aileron Control System of a Commercial Aircraft 11

Figure 1

Figure 2

Figure 3

• The rudder is typically mounted on the back edge of the fin in the empennage.

• When the pilot pushes the left pedal, the rudder deflects left. Pushing the right pedalcauses the rudder to deflect right.

• Deflecting therudder right pushes the tail left and causes the nose to yawright.

• Centering therudder pedals returns the rudder to neutraland stops the yaw.

Rudder _ primary flight controls

Top View of Tail

Isometric View of Tail

12

Figure 1

Figure 2

Figure 3 Figure 4

Figure 5

• Elevator trim balances the control force necessary to maintain theaerodynamicdown force on the tail.

• When aircraft is flying, a lot of trim could be required to maintain the desiredangle of attack.

• This mainly applies to slow flight, where maintaining a nose-up attituderequires a lot of trim.

• An important design parameter for aircraft is the stability of the aircraftwhen trimmed for level flight.

• Any disturbances such as gusts or turbulence will be damped over a shortperiod of time and the aircraft will return to its level flight trimmed airspeed.

Elevator trim tab system _ Secondary flight controls 13

• Trim doesn't only apply to the elevator, as there is also trim for the rudder and ailerons.

• The use of this is to counter the effectsof slip stream, or to counter the effectsof the center of gravity being to one side.

• This can be caused by a larger weight on one side of the aircraft compared to the other, such as when one fuel tank has a lot more fuelin it than the other, or when there are heavier people on one side of the aircraft than the other.

Rudder and Aileron trim tab system _ Secondary flight controls 14

• Flaps are hinged surfaces on the trailing edge of the wings of a fixed-wingaircraft.

• As flaps are extended, thestalling speed of the aircraft is reduced.

• Flaps are also used on the leading edge of the wings of some high-speed jetaircraft, where they may be called Krueger flaps.

• Flaps increase the camber of the wing airfoil, thus raising the lift coefficient.

• This increase in lift coefficient allows the aircraft to generate a given amount oflift with a slower speed.

• Therefore, extending the flaps will reduce the stalling speed of an aircraft.

• They also increase drag which helps to slow the aircraft.

Flaps _ Auxiliary flight controls 15

• Plain flap: rotates on a simple hinge.

• Split flap: upper and lower surfaces are separate, the lowersurface operates like a plain flap, but the upper surface staysimmobile or moves only slightly.

• Fowler flap: slides backwards before hinging downwards,thereby increasing both camber and chord, creating a largerwing surface better tuned for lower speeds.

• Slotted flap: a slot (or gap) between the flap and the wingenables high pressure air from below the wing to re-energizethe boundary layer over the flap. This helps the airflow to stayattached to the flap, delaying the stall.

• Blown flaps: systems that blow engine air over the uppersurface of the flap at certain angles to improve liftcharacteristics.

• Krueger flap: hinged flap on the leading edge.

Types of flap systems: 16

• On low drag aircraft like sailplanes, spoilers are used to disrupt airflow over the wing and greatly increasethe amount of drag.

• This allows a glider pilot to lose altitude without gaining excessiveairspeed.

• Spoilers are sometimes called "lift dumpers".

• Spoilers that can be used asymmetrically are called spoilerons and are able to affect an aircraft's roll.

Spoilers _ Auxiliary flight controls _ High lift devices 17

• Slats, also known as Leading Edge Devices

• are extensions to the front of a wing for lift augmentation, and are intended to reduce the stalling speed by altering the airflow overthe wing.

• Slats may be fixed or retractable• fixed slats give excellent slow speed and STOL capabilities, but compromisehigher speed performance.• Retractable slats, as seen on most airliners, provide reduced stalling speed for take-offand landing, but are retracted for cruising.

Slats _ Advanced flight controls 18

• Leading edge extensions or LEX (also referred to as leading edge root extensions or LERX or strakes orchines) are fillets added to the front of a modern fighter aircraft's wings in order to provide usable airflowat high angles of attack.

• They are typically roughly triangular in shape, running from the leading edge of the wing root to a pointnear the cockpit along the fuselage.

• They tend to be fairly small in span, extending out less than a meter. In effect, they are small delta wingsgrafted onto the front of the normal wings.

Leading Edge Extension _ Advanced flight controls 19

1. To reduce the drag:

1. to increase fuel efficiency by reducing drag from wingtip vortices.2. In lower speed aircraft, the effect of the wingtip shape is less apparent, with only a marginal performance difference between round, square, and Hoerner style tips.

2. To shape airflow:

1. The slowest speed aircraft, STOL aircraft, may use wingtips to shape airflow for controllability at low airspeeds.

3. Miscellaneous mountings:

1. Wing tips are often used by aircraft designers to mount navigation lights, anti-collision strobe lights, landing lights, handholds, and identification markings.

4. Distribution of weight:

1. Wing tip tanks can act as a winglet and distribute weight more evenly across the wing spar.

5. To mount weapon systems:1. On fighter aircraft, they may also be fitted with hard points, for mounting drop tanks and weapons systems, such as missiles and electronic countermeasures.

6. Aerial refueling:

1. Wingtip mounted hose/drogue systems allow Aerial refueling of multiple aircraft with separation.

7. Aerobatics:

1. Aerobatic aircraft use wingtip mounted crosses for visual attitude reference.

2. Wingtip mounted smoke systems and fireworks highlight rolling aerobatic maneuvers.3. Some airshow acts feature the pilot touching or dragging the wingtip along the ground.

8. Landing gear or floats:

1. Aircraft with a single main landing gear or very high aspect ratio wings such as gliders, may place small landing gear in the wingtips.2. Several amphibious aircraft such as the Consolidated PBY Catalina, use retractable wingtips as floats.

9. Movable wingtips:

1. Moveable wingtips can affect the controllability of a wing.2. Wing warping the ends of the wing, produced roll control on the earliest of aircraft such as the Wright Flyer.

3. The North American XB-70 Valkyrie raised and lowered its wingtips in flight to adjust its stability in supersonic and subsonic flight.

10. Power house:1. Wingtips can also house the power plant or thrust of an aircraft. The EWR VJ 101 used tip mounted jets, the V-22 uses tilting wingtip mounted engines, and the Harrier

uses wingtip thrust for stability while hovering.

11. To reduce noise and vibrations:1. Rotary wing aircraft wingtips may be swept or curved to reduce noise and vibration.

Wing tips 20

Wing Tips 21

• To reduce the drag caused bysupersonic flow over portion ofthe wing, small airfoils calledvortex generators are installedperpendicular to the surface ofthe wing.

• Mounted in complementarypairs.

• This causes the vortices beingdeveloped to add one another,thus increasing the effect.

• On some aircraft, fences areinstalled on the wings andelevators. This gives morestability and control of theaircraft, reduces buffeting, andreduces high-speed stallcharacteristics.

Wing vortex generators 22

Flight Simulation

Obtain takeoff clearance fromthe tower or announce yourintentions on the CommonTraffic Advisory Frequency(CTAF), taxi onto the runway andalign the plane with the center-line.

If acceleration from the holdshort line is not possible, taxi tothe takeoff end. Apply your toebrakes and leave the flaps in 0°position

Smoothly apply full power andrelease the brakes once the RPMis in the green arc.

Step 1 _ takeoff Step 2 _ takeoff Step 3 _ takeoff

23

Flight Simulation

Keep the plane centered withthe rudder pedals.

By the point of time you reachabout 20% below rotation speed,set the flaps to the takeoffposition.

Once rotation speed is reachedgently pull back on the yoke .This speed, called Vr, can befound in the Pilot's OperatingHandbook (POH).

Step 4 _ takeoff Step 5 _ takeoff Step 6 _ takeoff

24

Flight Simulation

If the density at altitude andgross weight are both relevant,climb at the best angle of climbspeed, Vx, which can also befound in the POH. Get Flaps tozero degrees again and useelevators to control altitude.

To turn an airplane, move therudder in desired direction alongwith ailerons at relevantelevation. (Relation can befound in POH)

Enter the pattern as you wouldat any airport after contactingthe tower or announcing yourposition on the CTAF.

Step 7 _ takeoff Step 8 _ turning Step 9 _ landing

25

Flight Simulation

Don't forget to lower your gear ifyour aircraft has a retractableundercarriage

• Fly the standard traffic pattern,

beginning your descent on the

downwind leg abeam the

touchdown point of the runway.

• Don't forget to lower 10° of flaps.

When the runway is 45° over your

shoulder, turn base and lower

another 10° of flaps

Turn final to align the plane withthe runway and lower flapscompletely (30° or 40° dependingon the aircraft).

Step 10 _ landing Step 11 _ landing Step 12 _ landing

26

Flight Simulation

• Fly the approach using a point just before the threshold as your

reference.

• Maintain awareness for power lines, trees, fences, or other

obstructions with short field techniques.

• Use power to maintain glide slope and elevator to maintain a

speed that will not allow this point to appear to speed up or

slow down.

• A couple feet before the edge of the runway, pull the power

back to idle and gently flare to lose airspeed and touch down

on the runway.

Raise the flaps and apply brakingwithout locking the wheels.

Step 13 _ landing Step 14 _ landing

27

Flight Simulation

Deploy spoilers to reduce theairspeed before reaching thesafe limit of full braking speed.

Apply full back pressure on theyoke to keep the weight on themain gear.

Exit the runway to make room forother aircraft traffic.

Step 15 _ landing Step 16 _ landing Step 17 _ landing

28

Now we all know

1. Basic nomenclature and classification of controls in an airplane.1. primary , Secondary, Auxiliary, Advanced

2. aerodynamic forces acting on airplane.1. Lift, Weight, Thrust, Drag

3. Working principle of an airplane.1. Longer path explanation and Bernoulli's theorem

4. How an airplane flies (basic motions of an airplane)1. Pitch, roll, yaw

5. How controls play the role in these motions1. Elevators, Ailerons, Rudder 2. Trim tab systems3. Flaps, spoilers4. Slats, leading edge extensions, wing tips, vortex generators

6. We Simulated a flight.1. Takeoff, turning, landing

29Conclusion

References

1. http://functionspace.org2. http://www.aerospaceweb.org3. http://selair.selkirk.bc.ca/training/aerodynamics4. http://www.nomenclaturo.com5. http://en.wikipedia.org6. https://www.google.co.in/imghp7. http://www.wikihow.com8. Games : Crimson skies, pacific navy fighters, Air navy fighters, Rortos Carrier Landing, V22 Osprey.

Questions

30