Transcript Slide 1

T-45 Single Engine
Airstart Testing Over
Water
LCDR K. Sproge
LCDR M. Burks
Ms. J. McAteer
Intentional Engine Shutdowns?
The Question: Can single engine airstart testing be safely
conducted over water at Pax river?
T-45 Aircraft Description
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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
We took the BAE Hawk
And Made A Few Minor Changes
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
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
O2 Pallet
• Installed in the aft cockpit
• Approximately 200 lb
• Provides continuous O2 to the
pilot
• Controlled via OBOGS switch
T-45 Flameout Handling Qualities
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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
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)
Stall / Surge Regions
“ACM” Type Surges: High AOA, Fixed or Variable RPM, Cruise Config
“ATSM” Type Surges: Moderate AOA, Variable RPM, PA Configuration
T-45 Engine Testing
• 1987-1993
• T-45 EMD engine tests, follow-on
engine tests, and HAOA tests were
conducted at Edwards AFB
• 1997-1998
• Surge Mitigation Program conducted at
NAS PAX
• 2000-2005
• Integrated Surge Mitigation Program
conducted at NAS PAX
• 2007-Current
• Hot Section Reliability Improvement
Program (HSRIP) conducted at NAS
PAX
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
Initial Surge Mitigation Program
AFO Planning
• Modified NATOPS Precautionary
Approach (PA)
– Based on NATOPS/Contractor provided glide
model
– Pilot carried card
• 32 Engine surges
Integrated Surge Mitigation Program
(2000-2005)
• Modified Inlet / Modified Fuel Control
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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
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)
Hot Section Reliability Improvement
Program (HSRIP), 2005-Current
• HSRIP to replace F405-RR-401
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Adour Mk 951 variant
-401 fan and compressor
Redesigned combustor
Turbine
Nozzle
FADEC
Hydro-mechanical backup fuel control
4,000 hr
HSRIP Test Requirements
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Airworthiness
Full airstart envelope verification
Airstart envelope expansion
Airplane performance verification
Steam ingestion
Carrier Suitability
Intentional Stall/Surges
High AoA
Fleet representative maneuvers
Hot Section Reliability Program
(2005-Current)
• HIGH Potential for AFO
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Intentional Shutdowns
Backup fuel control testing
Airstart envelope expansion
Testing FADEC logic
• Automatic surge detection and recovery
• Automatic flameout detection and recovery
AFO – Parallel Entry
START TURN
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
HIGH KEY
5,000 FEET AGL
195 KCAS
AFO – Perpendicular Entry
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
HIGH KEY
5,000 FEET AGL
195 KCAS
AFO – Abeam Entry
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
ABEAM
3,000 FEET AGL, 195 KCAS
1.5 NM ABEAM
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- 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
The Profile Works!
IDENTIFY HAZARDS
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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
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
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
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
T-45 No Engine Glide (No Wind)
20K / 24NM
30K / 42NM
10K / 8NM
40K / 60NM
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
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Tower/Baywatch training with test team
Tower/Baywatch briefed prior to each flight event
Chase assumes ATC communication
Exclusive use airspace
HSRIP Airstart Example
• Prior to takeoff
– Field Considerations
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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
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
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
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
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
Airstart Communication Example
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
QUESTIONS?