May 2010Approval of Experimental Aircraft for Instrument Flight APPROVAL OF EXPERIMENTAL AIRCRAFT...

May 2010 Approval of Experimental Aircraft for Instrument Flight

APPROVAL OF EXPERIMENTAL AIRCRAFT FOR INSTRUMENT FLIGHT

Richard L (Dick) Newman (M) and Benjamin K (Ben) JohnsonNAVAIR, Pax River

Presented at SETP Flight Test Safety WorkshopSan Jose, California

May 2010


OUTLINE

• Introduction

• Instrument Flight Approval

• Pathway to Approval

• Lessons Learned

DISCLAIMER: The material in this presentation is intended to promotesafety discussion. The opinions expressed are those of the authors andnot those of any organization with whom the authors may be affiliated.


INTRODUCTION

• Background

• Criteria

• Philosophy


INTRODUCTION

• Background– New Generation of Electronic Displays– Implicit Assumptions– Highly Integrated Avionics Systems

• Criteria

• Philosophy


INTRODUCTION

• Background

• Criteria– Acceptable Level of Risk

• General population• Other aircraft• Own aircraft

– Overall Mission Effectiveness

• Philosophy


INTRODUCTION

• Background

• Criteria

• Philosophy– Test Pilots versus Operational Pilots– Ultimate Tester is the User– Final Operational Testing Should Use

Operational Pilots


INSTRUMENT FLIGHT APPROVAL

• Test using mission scenarios– Can not separate

• safety• performance• workload

• It is important to test the entire display system– Medium (the display itself)– Symbology– Software– Supporting hardware – Sensors



• Test using mission scenarios– Can not separate

• safety• performance• workload

• It is important to test the entire display system– Medium (the display itself)– Symbology– Software– Hardware – Sensors


STATEMENT OF THE PROBLEM

• Traditional Instrument Suites• Reliable• Independent• Known failure modes• Standard displays

• Modern Instrument Suites• Unknown reliability• Highly integrated• Uncertain failure modes• Novel displays



• Approach

• Safety Standards

• Evaluation Pilots

• Hazard Assessment

• Results



• Approach• AFFSA-style endorsement or equivalent

– Representative mission tasks– Typical performance standards




• Results



• Approach• Safety Standards

• Appropriate level of safety– General population– Other aircraft– Aircraft passengers and crew

• Safety standards vary with aircraft type– Transport vs non-transport– GA, commercial, or military

• Evaluation Pilots• Hazard Assessment• Results



• Approach


• Evaluation Pilots• Eval pilots should represent the users• Use appropriate skill levels• Include experienced and inexperienced pilots


• Results



• Approach• Safety Standards• Evaluation Pilots• Hazard Assessment

• Safety standards vary with aircraft type• Include reliability standards• Complete software clearance

– Removal of error injection routines

• Results



• Approach




• Results• All test results documented• Configuration change history• Final report


PATHWAY TO APPROVAL

• Design Process

• Supporting Analyses

• Testing Buildup

• Interim Approvals

• Operating in Weather

• Final Approval


PATHWAY TO APPROVAL


PATHWAY TO APPROVAL

Do we have todo these testsin order? Lab tests before sim Sim tests before flight


PATHWAY TO APPROVAL

Do we have todo these testsin order? Lab tests before sim Sim tests before flight

Of course not, but this approachreduces program risk.


PATHWAY TO APPROVAL

Do we need all these preliminarysoftware releases?


PATHWAY TO APPROVAL

Do we need all these preliminarysoftware releases?

Of course not, but waiting until softwareis fully tested would lead to unnecessarydelays.


TESTING BUILDUP

Lab and SILTests


TESTING BUILDUP

Lab and SILTests

Do we really needto use a SIL?


TESTING BUILDUP

Lab and SILTests


No, but a SIL wouldsave a lot of $$$$.


TESTING BUILDUP

Lab and SILTests


No, but a SIL wouldsave a lot of $$$$.

You can pay me now,

or

You can pay me later.


TESTING BUILDUP

Lab and SILTests

Simulator Tests

Do we really needsimulator tests?


TESTING BUILDUP

Lab and SILTests

Do we really needsimulator tests?

Simulator TestsAgain, it reducesrisk later in theprogram.


WHY AN INTERIM APPROVAL

• Minimize impact on schedule

• Allow positioning flights

• Need to test in weather• Low visibility testing• HUD/HMD testing• Ice protection testing


INTERIM APPROVALS

• Approach




• Reasonable Restrictions


INTERIM APPROVALS

• Approach• Same approach as final approval• AFFSA-style protocol






INTERIM APPROVALS

• Approach

• Safety Standards• Primary emphasis on non test participants

– General population– Non-participating aircraft





INTERIM APPROVALS

• Approach


• Evaluation Pilots• Use project test pilots




INTERIM APPROVALS

• Approach



• Hazard Assessment• Assessment appropriate for flight testing• Don’t wait for full reliability/safety assessment• Don’t wait for final software clearance



INTERIM APPROVALS

• Approach• Safety Standards• Evaluation Pilots• Hazard Assessment• Reasonable Restrictions

• Use chase aircraft typical• Avoid populated areas flight test• Avoid high traffic areas restrictions• Limit duration in clouds


LESSONS LEARNED

• Precede flight test with simulator test

• Build up• Reduce incremental risk• Reduce schedule risk

• Systems Integration Laboratory (SIL)• Saving cost of SIL is false economy


LESSONS BEING LEARNED

• There’s more to approval for flight into weather than evaluating symbology.


LESSONS TO BE LEARNED

• For prototype airplanes with novel or non-traditional instrument suites



• For prototype airplanes with novel or non-traditional instrument suites– Consider using a simple “steam gauge” panel

for the initial prototypes.– Program risk reduction



• For prototype airplanes with novel or non-traditional instrument suites– Consider using a simple “steam gauge” panel

for the initial prototypes.– Program risk reduction

– If there are two pilot stations, consider fitting the second pilot station with “steam gauges”


QUESTIONS?

May 2010Approval of Experimental Aircraft for Instrument Flight APPROVAL OF EXPERIMENTAL AIRCRAFT...

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