T45 Single Engine Airstart Testing Over Water

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

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

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We took the BAE Hawk
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And Made A Few Minor Changes
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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

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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

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O2 Pallet

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

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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

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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)

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Stall / Surge Regions
ACM Type Surges High AOA, Fixed or Variable
RPM, Cruise Config ATSM Type Surges Moderate
AOA, Variable RPM, PA Configuration
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T-45 Engine Testing

• 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

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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

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Initial Surge Mitigation Program AFO Planning

• Modified NATOPS Precautionary Approach (PA)
• Based on NATOPS/Contractor provided glide model
• Pilot carried card
• 32 Engine surges

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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

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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)

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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

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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

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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

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AFO Parallel Entry
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AFO Perpendicular Entry
HIGH KEY 5,000 FEET AGL 195 KCAS
START TURN 5,000 FEET AGL, 195 KCAS BANK ANGLE
25-35 DEG
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
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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
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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
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The Profile Works!
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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

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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

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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

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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

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

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HSRIP Airstart Example

• Prior to takeoff
• Field Considerations
• Crosswind limits (lt 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

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HSRIP Airstart Example

• Communication checks
• Direct radio between test aircraft, chase, TC,
  FTEs, and DME monitor
• Hot mic from test aircraft
• Hot mic broadcast from telemetry center to chase
  (hot mic to chase)
• Post takeoff
• Execute SFO

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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

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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

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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

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Airstart Communication Example
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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

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• QUESTIONS?