EPs Flashcards
Engine Malfunction in Flight
- Control Nr
Warning: Flying with greater than 110% torque with one engine inoperative may result in unrecoverable decay of Nr in the event of a dual-engine failure. - CONTGCY PWR switch — ON
- Single-engine conditions — Establish
- ENG ANTI-ICE switches — As required
Warning: With engine anti-ice on, up to 18% torque available is lost. Torque may be reduced as much as 49% with improperly operating engine inlet anti-ice valves - External cargo/stores/fuel — Jettison/dump, as required.
- Identify Malfunction.
Engine High Side Failure in Flight
- Engine Malfunction in Flight Emergency Procedure — Perform
Note: Ng does not pass through the EDECU and is a highly reliable signal
Note: Torque signal may be erratic or drop off for high side conditions driven by EDECU failure.
- PCL (malfunctioning engine) — Retard to set:
a. Torque 10% below good engine, or
b. Matched Ng, or
c. Matched TGT. - Land as soon as practicable
Engine Low Side Failure
1/#2 ENG SPEED LOW will display when all of the following conditions exist:
Cause: When an engine is manually controlled with the ENG POWER CONTROL lever in LOCKOUT the engine response is much faster and the TGT-limiting system is inoperative. Exercise caution to prevent exceeding TGT limits and keeping Nr and Np in their operating ranges. The Np overspeed system will still be operative.
1. TRQ is 10% below the good engine. 2. Ng is 5% or less than the good engine. 3. Np is at or below 98% 4. Nr is at or below 97%
- Engine Malfunction in Flight emergency Procedure — Perform
Engine High-Side Failure on Deck
- PCLs—IDLE
Engine Torque or TGT Spiking/Fluctuations
If an engine instrument is spiking/fluctuating and inducing secondary indications in Ng, Np and/or Nr:
1. Engine Malfunction in Flight Emergency Procedure — Perform
If fuel contamination is suspected:
2. Land as soon as possible.
Warning: PCL movement during engine fluctuations may precipitate an engine failure. Consider performing APU Emergency Start procedure prior to manipulating the PCL. Maintaining a low power setting when moving the PCL will minimize the Nr decay rate if the malfunctioning engine fails.
Compressor Stall
Caution: If the Ng decay relight feature attempts to relight the engine, subsequent compressor stalls may occur and damage the engine. A yaw kick may be experienced each time the engine relights. The engine must be manually shut down.
Engine High-Speed Shaft Failure
1/#2 DRVSHAFT FAIL Np is greater than Nr by more than 3% and engine torque is below 10%.
May manifest itself as a high-intensity, medium to high frequency vibration that may be felt throughout the aircraft with a howl.
The Engine Np sensor is unreliable with Np less than 20%
Caution: Following a high-speed shaft failure, the engine will overspeed, the Np overspeed system will flame out the engine and the auto-ignition system will activate the relight feature. The engine Np governor will eventually bring Np down toward 100%. The engine must be manually shut down to prevent further damage.
- Engine Malfunction in Flight emergency procedure — perform.
- PCL (malfunctioning engine) — OFF
Load Demand System malfunction
Roll pin failure will result in max LDS to the HMU.
Jammed or stuck cable may result in the minimum LDS input to the HMU regardless of collective position.
EDECU TMS failure = High Side
LVDT failure = Low Side
Malfunctioning engine will lag the good engine for several seconds.
ABORT START
Causes—
1. Ng does not reach 14% within 6 seconds after starter initiation. 2. No oil pressure within 30 seconds after starter initiation (do not motor engine). 3. No light-off within 30 seconds after moving PCL to IDLE. 4. ENG STARTER advisory disappears before reaching 52% Ng 5. TGT is likely to exceed 851 Degrees C before idle speed is attained.
Caution: During aborted starts, failure to immediately stop fuel flow may result in engine over temperature.
To abort start:
- PCL — Off
- Engine Ignition switch — OFF.
If engine oil pressure is indicated:
- Starter — Engage.
Engine Malfunction During Hover/Takeoff
- Control Nr
- CONTGCY PWR Switch — ON
If a suitable landing site exists or unable to transition to forward flight:
- Set level attitude, eliminate drift, cushion landing.
If able to transition to forward flight:
- Engine Malfunction in Flight Emergency Procedure — Perform.
Dual-Engine Failure
Warning:
1. Rotor rpm decays rapidly following a dual-engine failure or the loss of the second engine after a single-engine failure. Delay in lowering the collective will result in loss of rotor rpm and may cause catastrophic failure of the rotor system due to dynamic instability at low rpm.
2. Altitude hold will remain engaged unless deselected. If the collective TRIM RLSE switch is not depressed, the AFCS will attempt to maintain aircraft altitude. AFCS commanded collective movement could result in a catastrophic loss of Nr. 3. Flying with greater than 110% torque with one engine inoperative, may result in unrecoverable decay of Nr in the event of a dual engine failure. (If both engines fail, generators will drop off line at approximately 80% Nr, resulting in loss of both pilot and copilot mission and flight displays.) 1. Autorotation —Establish 2. Immediate Landing/Ditching emergency procedure — Perform.
If time and altitude permit:
- Engine Air Restart emergency procedure — Perform.
Autorotation
External Cargo should be jettisoned as soon as possible in order to reduce gross weight and drag, thus increasing autorotational performance.
At 60 ft set a level attitude, eliminate drift, cushion the landing.
Single-Engine Failure in Flight
Do not attempt to restart with an engine failure accompanied by an explosion or unusual noise or fire.
ENG OUT will occur with less than 55% Ng
- Engine Malfunction in Flight Emergency procedure — Perform.
Engine Air Restart
Approximately 5000 ft required for APU/ENG start profiles. Most likely cause of dual engine failure is fuel starvation in which case you must prime.
Note: In the event of an alternator failure, the Ng signal may be unavailable. Engine start will not be possible without ac power provided to the ignition exciter.
Caution: For a cross bleed start, the donor engine should indicate the maximum Ng safely obtainable. Receiving engine Ng less than 24% prior to advancing PCL to IDLE may result in a hot start.
Note: either a single or dual-engine restart may be attempted following a dual-engine failure. Decision should be based on applicability of respective start envelopes and considerations of longer time to idle when executing a dual-engine restart.
- APU Emergency Start procedure — As required.
- ENGINE IGNITION switch — NORM
- Fuel selector lever — DIR or XFD
- PCL — OFF
- Starter — Engage, motor engine
- PCL — IDLE (TGT 80 Degrees C or less, if time permits).
- PCL — Advance to FLY after starter dropout.
Warning: If APU is unavailable, and a crossbleed start is necessary, maximum torque available will be reduced during the start sequence. Depending on operating conditions, level flight may not be possible. Ensure AIR SOURCE ECS/START switch is placed to ENG for crossbleed.
Engine Anti-Ice/Start Bleed Valve Malfunction
Temp Hangup of the engine Variable Geometry at the engine anti-ice/start bleed valve may cause engine flameout at low collective settings. As the system is released from any temp hangup, the HMU will schedule maximum fuel flow to the VG actuator, creating a diversion. In a minimum fuel flow flight regimes such as autos/quick stops, this may flame-out the engine.
Malfunction anti-ice/start bleed valve is indicated by any of the following:
- Illumination of the ENG ANTI-ICE ON advisory with above 90% Ng or above 94% Ng if OAT is 15 Degrees C or greater.
- No illumination of the ENG ANTI-ICE ON advisory when Ng drops below approximately 88% Ng. (May vary on a sliding scale with OAT)
- No illumination of the ENG ANTI-ICE ON advisory when the ENG ANTI-ICE switch is selected ON.
- No rise in TGT when ENG ANTI-ICE switch is selected ON.
