06 nimrod mra4 natural icing trials
DESCRIPTION
qTRANSCRIPT
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Knowing when to ask for help.
Nimrod MRA4 Natural Icing ProgrammeNashville TN, USA - Feb 2008
Ed Townshend- Nimrod Test & Evaluation
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Scope
• Background to Trial• Trial Planning• Trial Execution• Results• The Outcome• Lessons learnt
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Background – The Requirement
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Background – The Requirement
ICING CLEARANCE
ICE SHAPES
FULL ENVELOPE
HANDLING
NATURAL ICING
ANTI ICE SYSTEM
PERFORMANCE
ACCRETION MODEL
BASIC HANDLING
PERFORMANCE
DRY AIR TESTS
ANTI ICE SYSTEM
PERFORMANCE
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Background – Certification Requirements
PRE DEPLOYMENT
CONFIRM WEATHER
CHARACTERISATION
PROBES HAVE NO
EFFECT ON HANDLING
Def-Stan Requirements & JAA Guidance
DEMONSTRATE ICING PROTECTION
•DEMONSTRATE ICE PROTECTION ACROSS RANGE OF
ICING CONDITIONS (APPENDIX C)
•DEMONSTRATE ICE PROTECTION SYSTEM UNDER SINGLE
FAILURE STATE
•VALIDATE ENGINE AND AIRFRAME ICE PROTECTION
SYSTEM MODELSDEMONSTRATE TOLERANCE TO ICING
•CONFIRM ICE ACCRETION MODEL CORRECT
•DEMONSTRATE BASIC HANDLING & SYSTEM
PERFORMANCE UNDER FULL AND PARTIAL PROTECTION.
•CONFIRM ICE RELATED PERFORMANCE PENALTIES
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Background – The Aircraft
• PA1 used as primary programme handling aircraft.• Fully instrumented Anti Ice System • No Mission System Radar, but standalone Weather radar fitted
Horizontal stabiliseranti-icing
Engine intakeAnti-icing
Wing leading edgeanti-icing
Ice detectionprobe
Visual ice accretion vane
Heated Windscreenpanels
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning – Start point
ZERO
Pre trial Company Military aircraft icing experience:
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Logic
DEFINED &
UNDERSTOOD
REQUIREMENTS
MANAGE ICE
ENCOUNTERS
IDENTIFY
RISKS
MAXIMISE
EFFICIENCY
CERTIFICATION
MINIMISE
EXPOSURE
TO RISKS
Programme Timescales Maximise Safety
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning – Gathering experience
HOW TO MEET
CERTIFICATION
REQUIREMENTS
HOW TO CAPTURE
RESULTS
HOW TO FIND ICING
DESIGN AUTHORITY
WORKS WITH
CUSTOMER EXPERTS
CONTRACT WEATHER
CHARACTERISATION
EXPERT
CONTRACT
METEOROLOGIST
WITH ICING EXPERTISE
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning – Finding Icing
• Identify time of year trial programme planned• Identify list of potential venues from experience• Identify factors for scoring locations and weighting:
• Daytime available
• Frequency of Icing encounters within range
• Base Weather / facilities
• Availability of diversions
• Air Traffic Density
• Quality / Availability / Cost of Forecasting data
• Nashville chosen from list of Prestwick, Keflavik, St Johns & Central USA• Extensive dialogue with FAA to build understanding with US ATC
Picture courtesy of NASA
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Accurate Meteorology
• Weather out of our control• Response to weather is under our control
• In depth knowledge of icing weather systems• Maximise understanding of forecast• Target weather and plan Escape routes• Continue to monitor weather as it evolves• Track aircraft throughout flight• Compare route with forecast and results• Refine onward approach
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Instrumentation
• Wing pylon with two instruments for droplet
diameter measurement and identification:• Forward Scattering Spectrometer Probe (FSSP)
• 2 Dimensional Cloud optical array probe (2DC)
• Window mounted King Probe to measure Liquid
water content
• System partially integrated into existing FTI
• Existing FTI records aircraft system performance
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Instrumentation
• Four video cameras mounted in windows / pylon• Window mounted periscope with camera mount for tail observation• Multiple handheld stills and video cameras for crew use• Ice depth gauges mounted on wings and tail
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Instrumented Aircraft
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Informed Meteorologist
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Communication
sortie plan Conduct TestEncounters feedback
Traditional Open Loop method
Remaining testing
Weather forecast Takeoff Land
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Communications
THE GAP
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Communication
sortie plan Conduct TestEncounters feedback
Traditional Open Loop method
Closed Loop method
Conduct Test Encounters feedback
Remaining testing
Weather forecast
Weather update / PIREPS / Aircraft LocationPIREPS – Pilot Icing REPorts
Takeoff
Takeoff
Land
LandMeteorologist
sortie plan
Remaining testing
Weather forecast
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Satellite Communications
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning – Crew roles
• 10 Crew • 2 pilots, Navigator, Comms to fly aircraft safely• 3 FTOs to monitor icing build up and anti ice system status &
performance• 1 Weather Characterisation Expert, Design Authority FTO & Customer
Representative FTO to provide on board expertise and test validation.• Second Team of 5 FTOs to enable concurrent reporting
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning - Summary
HOW TO MEET
CERTIFICATION
REQUIREMENTS
DESIGN AUTHORITY
WORKS WITH
CUSTOMER EXPERTS
HOW TO CAPTURE
RESULTS
CONTRACT WEATHER
CHARACTERISATION
EXPERT
HOW TO FIND
ICING
CONTRACT
METEOROLOGIST WITH
ICING EXPERTISE
PLAN FOR TRACKING
WEATHER AND A/C
INSTRUMENTED
AIRCRAFT TO RECORD
WEATHER
CLEAR TEST
REQUIREMENTS AND
SUCCESS CRITERIA
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning – Trial approval
• Two main documents required:• Flight Test Programme document • Operational Management Plan
• Trial assessed as High / Medium Risk• Concept and Safety Reviews mandated
• Required approval from the Company, UK Military
Flying Regulator, & FAA
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning – Considered Risks• Ice accretion on unprotected surfaces not as expected• Ice accretion on protected surfaces due to poor system performance or
severe conditions• Ice induced Landing gear / flap system malfunctions• Reduced directional stability leading to increased sideslip / fin loads• Stalling with ice is new untested configuration• Engine flameout or damage due to intake ice shedding• Damage on ground due to ice shedding
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Planning – Logic Summary
DEFINED &
UNDERSTOOD
REQUIREMENTS
MANAGE ICE
ENCOUNTERS
IDENTIFY
RISKS
MAXIMISE
EFFICIENCY
CERTIFICATION
MINIMISE
RISKS
Programme Timescales Maximise Safety
Combine knowledge of Specialists & Operators
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Execution
• Departed UK 29th Jan – date set 1 year previously• Fitted External Instrumentation• Redeployed briefly to avoid Severe Weather• Flew 11 sorties over next 21 days • Flying only curtailed by:
• 1 day President Bush visit to storm victims
• 1 day servicing
• 1 day aircraft snag
• 6 days unsuitable weather
• Removed external instrumentation• Arrived back in UK 4th March, again within plan
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Execution – Incremental Approach
Experience
Time
Full AI = Airframe + Engine Anti Ice ON
Part AI = Airframe OFF + Engine Anti Ice ON
Full AI handling - 0.5”
Dry Air Rehearsal
Part AI handling – 0.5”
Part AI handling - 1.0”
Full AI handling - 2.0”
Full AI handling - 1.0”
Part AI handling - 1.5”
Full AI Systems Tests - 2.0”
Appendix C completion
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Execution – Area covered
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Results – Wing – Protection On
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Results – Wing – Protection Off
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Results – Wing and Tail
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Results - Fin
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Results – System Failure Test
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Results – Runback
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Results – Probes
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Results – Probes
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Results – Post flight observations
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Results – Encounter Envelope
Continuous Maximum (Stratiform Clouds) CS25 Appendix C - Nimrod MRA4 Trials Data
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
10 12.5 15 17.5 20 22.5 25 27.5 30 32.5 35 37.5 40
Mean Effective Drop Diameter (Microns)
LW
C g
/m3
F132F133F134F135F136F137F138F139F140F141Series12Series4Series11Series5Series3Series2LWCAir Temp 0°C
(+32°F)
-30°C (-22°F)
-10°C (+14°F)
-20°C (-4°F)
LIQ
UID
WA
TE
R C
ON
TE
NT
MEAN DROPLET DIAMETER (Microns)
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
The OutcomeHOW TO MEET
CERTIFICATION
REQUIREMENTS
HOW TO CAPTURE
RESULTS
HOW TO FIND
ICING
TASK AGREED COMPLETE BY ALL PARTIES BEFORE DEPARTURE
ICE WAS FOUND AND SAFELY CHARACTERISED ON EVERY TEST FLIGHT
11 FLIGHTS
61 HOURS
21 DAYS
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Lessons Learnt
• Get help for areas where you are lacking knowledge and experience
• Planned Concept of Ops worked extremely well:• Meteorologist and Weather Characterisation experts• Satellite telephone communications• Design Authority and Customer direct involvement
GO OUT AND GATHER THE BEST POOL OF EXPERIENCE TO GET THE BEST RESULTS
RAeS 4th SFTE FTSW – 28 September 2010 - UNCLASSIFIED
Questions