Notes / Warnings / Cautions (JAN2023) Flashcards
EMIF
2 Warning
WARNING: Flying with greater than 110% torque with one engine inoperative may result in an unrecoverable decay of Nr in the event of a dual engine failure.
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.
Engine High-Side Failure in Flight (3)
-Indications
-1 C
-2 N
INDICATIONS: all of the following exist
1. TRQ is 10% or greater than the other engine.
2. Ng is 5% or greater than the other engine.
3. Np is matches within 5% of the other engine.
4. Nr is at or above 103%.
CAUTION: If an Np overspeed condition exists (120%), the overspeed system will flame out the engine and the auto-ignition system will relight the engine. If Nr is not controlled and Np accelerates back to 120%, the overspeed system will flame out the engine again and reset the igniter 5-second timer. The Np overspeed/auto-ignition system will continue cycling until Np/Nr is controlled. A yaw kick may be experienced each time the engine relights.
NOTE: With high collective settings, Nr may increase slowly, making high-side failure confirmation difficult. Reducing collective will reveal increasing Nr and verify high-side failure.
Note: Ng does not pass through the EDECU and is a highly reliable signal
Engine Low-Side Failure 1 C
INDICATIONS: all of the following indications exist
- TRQ is 10% below the good engine.
- Ng is 5% or less than the good engine.
- Np is at or below 98%.
- Nr is at or below 97%.
CAUTION: When an engine is manually controlled with the ENG POWER CONT lever in LOCKOUT,
1. The engine response is much faster
2. The TGT-limiting system is inoperative.
3. Np and Nr governing is lost
4. Care must be taken to prevent exceeding TGT limits and keeping Nr and Np in their operating;
5. the Np overspeed system will still be operative.
Actual application: CRM intensive due to manual manipulation of PCL (we don’t really practice that all that often)
Engine Torque or TGT Spiking/Fluctuations 1 W
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.
If fuel contamination, assume it is in BOTH engines
Compressor Stall NWC and Indications
-Indications
-NWC: 1 C
- Salt Encrustation
Indications: Indications: rapid rise in TGT, hang-up or rapid decrease of Ng, muffled explosions, loss of power
CAUTION:
1. If the Ng decay relight feature attempts to relight the engine, subsequent compressor stalls may occur and damage the engine.
2. A yaw kick may be experienced each time the engine relights.
3. The engine must be manually shut down.
TGT rise of 20C for constant torque is indication of degraded engine. Rise of 40 C may lead to compressor stalls
Engine High-Speed Shaft Failure NWC and Indications
-NWC: 1 C, 1 N
-Indications
Indications:
-Np > Nr by 3%, TRQ < 10%
-Imminent: High Intensity, Medium-High Frequency Vibrations
-Secondaries: XMSN Oil PX or Temp out of limits
CAUTION: Following a high-speed shaft failure, the engine will overspeed,
1. the Np overspeed system will flame out the engine,
2. and the auto-ignition system will activate the relight feature.
3. The engine Np governor will eventually bring Np down toward 100%.
4. The engine must be manually shut down to prevent further damage.
NOTE: The engine Np sensor is unreliable with Np < 20%. For this reason any (#1/#2) DRVSHAFT FAIL should be acknowledged and ignored when engine Np < 20%. No maintenance action is required when in this condition.
Indications:
-Np > Nr by more than 3% and engine torque below 10%
-Impending failure: high-intensity, medium to high frequency vibrations, “howl” from the engine
-Secondary Indications: transmission oil px or temp
Abort Start
-NWC: 1 C
-Reasons to abort
CAUTION: During aborted starts, failure to secure fuel flow may result in engine overtemperature.
Abort engine start if any of the following occur:
1. Ng does not reach 14% within 6 seconds after starter initiation
2. No oil pressure within 30 seconds after starter initiation
3. No light-off within 30 seconds after moving the PCL to IDLE
4. ENG STARTER advisory disappears before reaching 52% Ng
5. TGT is likely to exceed 851* Celsius before idle speed is attained
Dual Engine Failure
-NWC: 3 W
WARNING: 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 the dynamic instability at low RPM.
WARNING: 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.
WARNING: Flying with greater than 110% torque with one engine inoperative may result in an unrecoverable decay of Nr in the event of a dual-engine failure.
-If both engines fail, generators will drop offline at approximately 80% Nr, resulting in the loss of both pilot and copilot mission and flight displays ie turn on APU.)
-Approximately 5000’ AGL will be required to accomplish an engine restart. Based on APU and engine start cycle and autorotative descent rate
Single Engine Failure in Flight
-NWC: 1 W
WARNING: Engine failure accompanied by an explosion or unusual noise indicates damage to the engine. There is a possibility that any attempt to restart the engine may result in a fire. Under such circumstances, do not try to restart the engine unless it is needed to maintain level flight.
Engine Air Restart
NWC: 1 W, 1 C, 1 N
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 starts.
CAUTION: For a crossbleed start, the donor engine should indicated 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 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. Don’t restart if failure was accompanied by explosion or unusual noise
Note: in the event of an alternator failure, Ng may be unavailable. Without AC power, engine start will not be possible
Unusual Vibrations on Deck/Ground Resonance
2 Warnings
2 Cautions
Airspeed
Landing preferences
WARNING : Ground resonance can occur withing 3 seconds and produce violent vibrations resulting in difficulty reaching PCLs, Pilot-induced oscillations and possible dynamic rollover
WARNING: Failure to ensure ground personnel are clear of rotor arc and aircraft is free from deck or chains may result in loss or aircraft or ground personnel
CAUTION: Application of the rotor brake may aggravate the lead/lag tendencies and cause a mechanical failure.
CAUTION: continued operations with unusual on deck vibrations may result in rotor system damage or mechanical failures
Airspeed to minimize vibrations: 80 KIAS
Landing:
1. Runway/Pad Ashore
2. Large Deck
3. Single Ship Deck
Running landing is NOT recommended due to rotor instability and possible loss of helicopter.
Unusual Vibration in Flight
1 WARNING
1 CAUTION
PREFERRED LANDINGS:
WARNING: Abnormal vibrations in flight may result in ground resonance upon landing
CAUTION: Unusual vibrations may be indicative of a
1. degraded or failed damper system,
2. separated tip cap,
3. rotor overspeed,
4. bird strike or AFCS failure
1. Runway / Pad Ashore
2. Large Deck
3. Small Deck
*Running landing is NOT recommended due to possible loss of helicopter control
Hung Droop Stops
1 NOTE
NOTE: While operating in cold weather, consideration should be given to turning the BLADE DE-ICE control panel POWER switch to the POWER ON position. This will activate the droop-stop heaters and aid the droop stops in seating.
Main Transmission Malfunction
2 Warnings
3 Notes
WARNING: Possible indications of main transmission imminent failure may include: yaw attitude excursions with no control input, an increase in power required for a fixed collective setting, failure of a main generator or hydraulic pump, increased noise, increased vibration levels, or abnormal fumes in the cabin.
WARNING: Operation of the main gearbox with no oil pressure may result in failure of the tail rotor drive takeoff pinion gear and subsequent loss of tail rotor drive in as little as 8 minutes
NOTE: Consideration should be given to performing the applicable steps of the Immediate Landing/Ditching emergency procedure and transiting at a minimum power airspeed and low altitude profile (approximately 80 feet and 80 KIAS) to permit a quick flare followed by and immediate landing/ditching.
NOTE: A loss of all main transmission lubricating oil may result in unreliable temperature indications from the main transmission temperature gauge and temperature sensor (caution).
NOTE: Continued operations in the precautionary range for temperature and pressure are acceptable provided that the ambient conditions and flight regime of the aircraft correspond with the guidance set for in the transmission limitations section of Chapter 4.
Tail/Intermediate Transmission Malfunction (2)
WARNING: High power settings require maximum performance of the tail rotor drive system and may precipitate ultimate drive failure.
WARNING: Consideration should be given to transiting at an altitude sufficient to enter an autorotation and performing the applicable steps of the Immediate Landing/Ditching emergency procedure.
Landing: Running or No-Hover Landing
Imminent: Strong Medium Frequency Vibrations, Hot Metal Fumes or buzzing in pedals
INT XMSN OIL HOT / TAIL XMSN OIL HOT and WCA miscompare alert may be indication of mission computer/backup computer failure
