T-45 Single Engine Airstart Testing Over Water LCDR K. Sproge LCDR M. Burks Ms. J. McAteer

1. T-45 Single Engine Airstart Testing Over Water LCDR K. Sproge LCDR M. Burks Ms. J. McAteer

2. Intentional Engine Shutdowns? The Question: Can single engine airstart testing be safely conducted over water at Pax river?

3. T-45 Aircraft Description • Two seat - Tandem • Single engine • Carrier capable jet trainer • Wing • Moderately swept • Full span leading edge slats • Double slotted trailing edge flaps • Flight controls • Hydraulic Stabilator and Ailerons • Mechanical rudder • Control augmentation system • Speed Brake

4. We took the BAE Hawk

5. And Made A Few Minor Changes

6. T-45 Aircraft Emergency Systems • Ram Air Turbine (RAT) • Powers Hydraulic Flight Controls Only • Emergency Flap Extension • Full flaps Only • No Slats • Emergency Landing Gear Extension • Main Landing Gear Doors remain fully opened • Nose Landing Gear Doors actuated electrically to within 10 deg of fully closed • Aircraft essential bus powers: • Limited Aircraft Systems • Instrumentation System

7. Flight Test Aircraft System Modifications • Instrumentation system installed to monitor engine and aircraft parameters • O2 pallet installed for all high risk testing • No OBOGS engine out

8. O2 Pallet • Installed in the aft cockpit • Approximately 200 lb • Provides continuous O2 to the pilot • Controlled via OBOGS switch

9. T-45 Flameout Handling Qualities • Good glide performance • Reasonable approach speed • Arresting hook • Limited maneuverability • Nosewheel steering unavailable • Directional control issues during crosswind landing • No anti-skid • Limited brake applications

10. A History of Stall/Surges • During use as a trainer, two major areas were identified as high risk for engine anomalies • Approach Turn Stall Maneuvers (Fam stage) • Air Combat Maneuvering (ACM stage)

11. Stall / Surge Regions “ACM” Type Surges: High AOA, Fixed or Variable RPM, Cruise Config “ATSM” Type Surges: Moderate AOA, Variable RPM, PA Configuration

12. 1987-1993 1997-1998 2000-2005 2007-Current T-45 EMD engine tests, follow-on engine tests, and HAOA tests were conducted at Edwards AFB Surge Mitigation Program conducted at NAS PAX Integrated Surge Mitigation Program conducted at NAS PAX Hot Section Reliability Improvement Program (HSRIP) conducted at NAS PAX T-45 Engine Testing

13. Initial Surge Mitigation Program(1996-1998) • F405-RR-401 engine with known airstart capabilities • Turbine exit area modification • Abrupt Pulls and Approach Turn Stalls • Airstarts (2) conducted to verify airstart capability • Heart of envelope • Potential for AFO due to surge or flameout

14. Initial Surge Mitigation Program AFO Planning • Modified NATOPS Precautionary Approach (PA) • Based on NATOPS/Contractor provided glide model • Pilot carried card • 32 Engine surges

15. Integrated Surge Mitigation Program(2000-2005) • Modified Inlet / Modified Fuel Control • F405-RR-401 engine with known airstart capabilities • Abrupt pulls • Steam ingestion • High cross-wind testing • Airstarts (3) conducted to verify airstart capability • Heart of envelope • Potential for AFO due to engine surge, flameout or unintentional OCF

16. Integrated Surge Mitigation Program AFO Planning • Developed AFO communication protocol • Control room and test aircraft • Developed glide profile intercept method • Above 20k ft establish 300kt for windmill airstart • Intercept 195 kt below 20k-ft • Modified for different configurations • Verified NATOPS glide profiles • 62 Surges (1 Locked Stall requiring shutdown)

17. Hot Section Reliability Improvement Program (HSRIP), 2005-Current • HSRIP to replace F405-RR-401 • Adour Mk 951 variant • -401 fan and compressor • Redesigned combustor • Turbine • Nozzle • FADEC • Hydro-mechanical backup fuel control • 4,000 hr

18. HSRIP Test Requirements • Airworthiness • Full airstart envelope verification • Airstart envelope expansion • Airplane performance verification • Steam ingestion • Carrier Suitability • Intentional Stall/Surges • High AoA • Fleet representative maneuvers

19. Hot Section Reliability Program(2005-Current) • HIGH Potential for AFO • Intentional Shutdowns • Backup fuel control testing • Airstart envelope expansion • Testing FADEC logic • Automatic surge detection and recovery • Automatic flameout detection and recovery

20. START TURN 5,000 FEET AGL 195 KCAS HIGH KEY 5,000 FEET AGL 195 KCAS LOW KEY 3,000 FEET AGL, 180 KCAS BANK ANGLE – 35 DEGREES 1.5 NM ABEAM 1750 FEET DOWNWIND FROM END OF RUNWAY EMERGENCY EXTEND LANDING GEAR 90 – DEGREE POSITION 1,500 FEET AGL, 170 KCAS BANK ANGLE 35 DEGREES EMERGENCY FLAPS - DOWN 45 – DEGREE POSITION 1,000 FEET AGL, 165 KCAS BANK ANGLE 25 DEGREES AFO – Parallel Entry

21. AFO – Perpendicular Entry START TURN 5,000 FEET AGL, 195 KCAS BANK ANGLE 25-35 DEG HIGH KEY 5,000 FEET AGL 195 KCAS LOW KEY 3,000 FEET AGL, 180 KCAS BANK ANGLE – 35 DEGREES 1.5 NM ABEAM 1750 FEET DOWNWIND FROM END OF RUNWAY EMERGENCY EXTEND LANDING GEAR 90 – DEGREE POSITION 1,500 FEET AGL, 170 KCAS BANK ANGLE 35 DEGREES EMERGENCY FLAPS - DOWN 45 – DEGREE POSITION 1,000 FEET AGL, 165 KCAS BANK ANGLE 25 DEGREES

22. AFO – Abeam Entry ABEAM 3,000 FEET AGL, 195 KCAS 1.5 NM ABEAM LOW KEY 3,000 FEET AGL, 180 KCAS BANK ANGLE – 35 DEGREES 1.5 NM ABEAM 1750 FEET DOWNWIND FROM END OF RUNWAY EMERGENCY EXTEND LANDING GEAR 90 – DEGREE POSITION 1,500 FEET AGL, 170 KCAS BANK ANGLE 35 DEGREES EMERGENCY FLAPS - DOWN 45 – DEGREE POSITION 1,000 FEET AGL, 165 KCAS BANK ANGLE 25 DEGREES

23. AFO- Straight In 5,000 FEET AGL 5 NM FROM END OF RUNWAY 195 KCAS 3,000 FEET AGL 3 NM 180 KCAS EMERGENCY EXTEND LANDING GEAR 1,500 FEET AGL, 1.5NM FROM END OF RUNWAY, 165 KNOTS, EMERGENCY FLAPS - DOWN

24. The Profile Works!

25. IDENTIFY HAZARDS • T-45 AFO approaches prohibited • AFO over water with one available field • Decompression sickness • Airspace/traffic conflicts when returning AFO • T-45 ground handling characteristics

26. HSRIP Risk Mitigation Procedures • T-45 AFO prohibited • CNAF waiver required • Provided evidence of safe profiles and training/currency measures • Referenced in NAVAIR flight clearance • Waiver allowed for pilot training/proficiency

27. HSRIP Risk Mitigation Procedures • AFO over water with one available field • Test procedures refined over the course of several programs. • Simulator • Communication protocol • AFO profile intercept method • Pilot/Test Team training • Pilot Currency • SFO training flight • At least one SFO in a 14 day period • SFO following takeoff for all flights with high risk test points

28. HSRIP Risk Mitigation Procedures • AFO over water with one available field • Glide profile monitor • Required for all high risk testing • All high risk test points must be conducted within glide distance to the field • Must be conducted within exclusive use airspace • Modified AFO communication protocol (DME) and profile intercept method • Wind considerations

29. T-45 No Engine Glide (No Wind) 30K / 42NM 20K / 24NM 10K / 8NM 40K / 60NM

30. HSRIP Risk Mitigation Procedures • Decompression sickness • 1 shutdown above 25k per day • Pre-breathe 100% 02 30 min prior to shutdown • Airspace/traffic conflicts when returning AFO • Tower/Baywatch training with test team • Tower/Baywatch briefed prior to each flight event • Chase assumes ATC communication • Exclusive use airspace

31. HSRIP Airstart Example • Prior to takeoff • Field Considerations • Crosswind limits (< 10 kt) • Arresting gear (short and long field) • Available runways (RWY 32 required for straight-in) • SAR Condition • Area Considerations • Exclusive use for “high-risk” test points

32. HSRIP Airstart Example • Communication checks • Direct radio between test aircraft, chase, TC, FTE’s, and DME monitor • Hot mic from test aircraft • Hot mic broadcast from telemetry center to chase (hot mic to chase) • Post takeoff • Execute SFO

33. HSRIP Airstart Example • Test point setup • Winds • Test aircraft provides winds • at test condition • max altitude (test point setup) • Glide monitor determines maximum DME • aircraft configuration • wind speed/direction • TC relays • Test point executed with less than 90 deg turn to make field

34. HSRIP Airstart Example • TC, Test aircraft, and chase make ready call • Propulsion FTE takes comm lead for test point • Provides clearance to conduct test point, • Executed when on conditions and within DME

35. HSRIP Airstart Example • After FTE clears throttle off ... • Chase calls DME every 2 nm • Glide monitor reports minimum altitude • Propulsion monitors airstart parameters and engine status • Unsuccessful airstart • Propulsion recommends airstart type • Chase and glide monitor continue comm sequence • Test aircraft monitors profile • Option to change to straight-in • Return to field for AFO approach • Chase handles all ATC comms

36. Airstart Communication Example

37. SFO/AFO Lessons Learned • Glide performance • Data dropout • Test point location corresponds to drop out area • Several airstarts with no data • Telemetry center implemented best-source select with multiple receiving antennas • Loss of comm • Backups ready • Verify continuously • Winds • New personnel

38. QUESTIONS?