NWC Flashcards
EMIF
W
W
1.
W: flying with greater than 110% torque with one engine inop may result in unrecoverable decay of Nr in the event or a dual engine failure.
2. 3. 4.
W: 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.
5. 6
Engine high-side failure in flight
C
N
C: If an Np overspeed condition is reached (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 the auto-ignition system will 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.
N: With high collective settings, Nr may increase slowly, making high-side failure confirmation difficult. Reducingf collective will reveal incresing Nr and verify high-side failure.
Engine Low-side failure
C
C: When an engine is manually controlled with the PCL in lockout, the engine response is much faster and the TGT limiting system is inop. Care must be taken to prevent exceeding TGT limits and keeping NR and Np in their operating ranges; however the Np overspeed system will still be operative.
Engine torque or TGT spiking/fluctuations
W
W: PCL movement during engine fluctuations may precipitate and 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 malfuntioning engine fails.
Compressor Stall
C
C: 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
N C
N: The engine Np sensor is unreliable with Np< 20%. For this reason any DRVSHFT FAIL should be acknowledged and ignored when Np< 20%. no maintenance action is required
C: 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.
Abort Start
C
C: During aborted starts, failure to immediately stop fuel flow may result in engine overtemperature.
Engine Air Restart
C N W
C: For a crossbleed 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.
N: 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
W: 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.
Unusual Vibrations on Deck
C
C: Application of the rotor brake may aggravate lead/lag tendencies and cause a mechanical failure.
Main Transmission Malfunction
W
W: 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.
Tail/Intermediate Transmission malfuntion
W
W
W: High power settings require maximum performance of the tail rotor drive system and may precipitate ultimate drive failure.
W: 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.
Input Chip
N
N: Consideration should be given to returning the engine PCL to fly for a landing
Loss of Tail rotor drive sufficient
AUTO
W
W: Altitude hold will remain engaged unless deselected. If the collective trim release button is not depressed, the AFCS will attempt to maintain aircraft altitude through the collective trim servo. AFCS commanded collective movement can result in an accelerated yaw rate.
Loss of Tail rotor drive insufficient
C
C: Altitude may have to be adjusted based on rate of yaw and/or turn.
Loss of tail rotor control
W N
W W W W
W: Servo hardovers in the yaw channel may result in loss of tail rotor control. Consideration should be given to securing the SAS/BOOST and/or TRIM as necessary
N: A momentary uncommanded right yaw will occur when the tail rotor servo switches from normal to backup in a hover. The rate and magnitude will primarily depend on power required and wind direction and magnitude
W: Following the appearance of the #1 tail rtr servo caustion without the associated backup pump on and #2 tail rtr servo on advisories. the aircraft will demonstrate normal yaw responses in flight regimes that do not require excessive tail rotor performance; however, at slower airspeeds below approximately 40 KIAS, more pronounced effects of loss of tail rotor control may become more apparent.
W: After touchdown, rapid reduction of collective or PCL’s may cause excessive and uncontrollable yaw rates.
W: If an uncontrolled right yaw develops at too low of an airspeed, loss of waveoff capability may result. Increasing collective may increase the yaw to unrecoverable rates. Performing loss of tail rotor drive may be required.
W: If the tail rotor control cables are damaged, the hydraulic transients associated with switching the tail rotor servo from NORM to Backup may cause catastrophic damage to the tail rotor controls.