Term
| 1. LOSS OF VISUAL REFERENCE DURING LANDING |
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Definition
1. Collective — Increase to climb.
WARNING
-Not only must descent be stopped to prevent impact with the surface, but also a positive rapid climb is necessary to regain visual flight conditions. Any delay may allow drift to develop, which could cause impact with ground/obstacles.
-Consideration should be given to external cargo jettison.
2.Cyclic — Hover attitude (on instruments).
3.Selected heading — Maintain. |
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Term
| 2. EXTERNAL CARGO JETTISON |
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Definition
1.Area — Cleared if possible.
2.Cargo release — Activated.
WARNING
-Prior to jettison of external cargo, alert the crew to prevent injury. |
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Term
| 3. SINGLE- OR DUAL-ENGINE FAILURE |
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Definition
WARNING
-Pilot response to single- or dual-engine failure is dictated by gross weight, ambient conditions, relative wind, and height above the surface. These factors will determine whether an immediate landing or a flyaway recovery should be attempted. Based on the pilot’s knowledge of aircraft single- or dual-engine power available and power required, the pilot should decide which procedure he intends to follow before the emergency occurs. Indecision following the single- or dual-engine failure may prevent the success of either procedure.
-If the altitude hold feature of AFCS is engaged, it will increase collective pitch in an attempt to hold altitude. The collective must be positively controlled by the pilot to prevent excessive loss of rotor speed.
-Jettison of Auxillary Fuel Tanks at rates-of-descent greater than 1,500 fpm and forward airspeeds greater than 120 KIAS may result in aircraft or rotor strike due to the aerodynamic and stability characteristics of jettisoned tanks. The risk of an aircraft strike is highest for empty tanks. Jettison characteristics improve with increasing auxiliary fuel tank weight (fuel state).
CAUTION
-Nose-high attitudes shall be avoided near the surface or the tail rotor blades may strike the ground or water. Tail rotor contact may occur with nose attitudes above 5_ when on the water. The altitude, airspeed, and gross weight at which a single- or dual-engine failure occurs will dictate the action to be followed to effect a safe landing. Refer to the height-velocity diagram, one- or two-engine failure. During mission planning, the engine torque available can be determined from the maximum and military power-available charts. The minimum and maximum indicated airspeed at which level flight can be maintained is determined from the Ability to Maintain Level Flight chart. The maximum gross weight at which a hover or level flight can be maintained decreases as density altitude increases. Therefore, mission planning should include a thorough analysis of the performance data in Part X.
NOTE
-If altitude cannot be maintained or a safe single- or dual-engine landing is not feasible, decrease gross weight by releasing external cargo, dumping fuel, or jettisoning auxiliary fuel tanks if required. Stop dumping before landing.
NOTE
-Careful monitoring of main fuel tank quantities is required on flights where fuel transfer from range extension fuel tanks is being conducted, and fuel is not being depleted from all main tanks. Main fuel tank expansion volume can diminish and ultimately result in overboard vent spillage due to constant flow of fuel through helicopter fuel system precheck lines.
1.Collective — Maintain Nr.
2.Airspeed — As required.
3.Pickle — External load as required.
4.Tanks — Jettison as required.
5.Speed control levers — As required (shut off affected engine, conditions permitting).
6.Land as soon as practical.
WARNING
-Refer to Height-Velocity Diagram, Dual-Engine Failure and Height- Velocity Diagram, Single-Engine Failure in Part X.
NOTE
-A roll on landing will normally decrease power required. Minimize drift and yaw on landing.
-Determine which engine has failed by reference to engine torquemeters, T5 indicators, Nf or Ng tachometers, and proceed as instructed in Engine Shutdown In Flight in this section. If a restart is advisable, refer to Engine Restart During Flight in this chapter. |
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Term
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Definition
SYMPTOM: AFF ENG-T5 increase — All other parameters decrease. As long as the affected engine is producing any usable torque, Nf will remain matched with the normal Nf/Nr. If torque drops to zero, Nf will likely split off and decay.
:NORM ENGINE: All parameters increase except for steady Nf/Nr. If the normal engine power available is not sufficient for the affected engine power loss (i.e., the total torque requirement cannot be met), Nf/Nr, may droop/decay excessively depending on the degree of power deficit. Also, if the normal engines have sufficient power available to compensate for the affected engine power loss (i.e., the total torque requirement can be met), it is normal for Nf/Nr to droop about 1% to 2% as the normal engines are forced to assume the additional load.
NOTE
-Compressor stall is normally accompanied by unusual engine sounds/slight yaw kick. Illumination of ENGINE FUEL BOOST and FUEL FILTER CAUTION lights is possible due to decay of Ng.
1.Collective — Maintain Nr.
2.Airspeed — As required.
3.Pickle — External load as required.
4.Tanks — Jettison as required.
5.Speed control levers-As required. (If compressor stall of No. 2 eng is indicated, reduce airspeed to 85 KlAS and immediately secure SCL and continue with Engine Shutdown in Flight procedures. If No. 1 or No. 3 engs, affected SCL below MIN GOV.)
WARNING
-With a compressor stall in the No. 2 engine, any delay in shutdown of the engine can result in hot exhaust gas backflow into the engine compartment, creating a fire hazard. If a No. 2 engine stall is suspected, reduce airspeed to less than 85 KlAS to reduce backflow and shut down the engine. |
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Term
| 5. ENGINE POWER LOSS (FLAME OUT) |
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Definition
SYMPTOM: 1. (NOT FLAME OUT) -All engine parameters decreasing. As long as the affected engine is producing any usable torque, Nf will remain matched with the normal Nf/Nr. If torque drops to zero, Nf will likely split off and decay.
2. FLAMEOUT- All parameters decreasing.
1.Collective — Maintain Nr.
2.Airspeed — As required.
3.Pickle — External load as required.
4.Tanks — Jettison as required.
5.Speed control levers — As required
6.Continue to use affected engine if engine is producing some torque and all engine parameters are within limits.
WARNING
-If the No. 2 engine is operating at a low power condition and the Ng is less than 75%, hot exhaust gas may backflow into the engine compartment creating a fire hazard. Limit airspeed to less than 85 KlAS to reduce backflow. If dual-engine flight can be maintained, consideration should be given to securing the No. 2 engine.
NOTE
-If engine power loss takes place following fuel system transfer, selected fuel source is suspect for contamination or insufficient fuel. |
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Term
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Definition
SYMPTOM-All parameters increasing, fuel flow may jump to 1,700 pounds or more.
NOTE
-Engine may accelerate to maximum power. If engine attempts to deliver uncommanded power exceeding the total torque requirements, Nf/Nr will increase/overspeed depending on the degree of power surplus. Also, if the engine attempts to deliver uncommanded power less than the total torque requirements, Nf/Nr can be expected to increase slightly, about 1% to 2%
1.Collective — Maintain Nr.
2.Airspeed — As required.
3.Pickle — External load as required.
4.Tanks — Jettison as required.
5.Speed control levers — As required. Attempt to regain control of affected engine power by retarding affected engine speed control lever below MIN GOV.
WARNING
-If the No. 2 engine speed control lever is at or below MIN GOV and the Ng is less than 75 percent, hot exhaust gas may backflow into the engine compartment, creating a fire hazard. Limit airspeed to less than 85 KlAS to reduce backflow. If dual-engine flight can be maintained, consideration should be given to securing the No. 2 engine. |
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Term
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Definition
SYMPTOM: (FAIL BETWEEN Nf AND NGB)
a.Sudden decrease to zero on Nf and torque indicators.
b. Ng and T5 increasing until overspeed system actuation, then T5 decreasing and Ng decreasing to flight idle.
c. Grinding/howling noise may be heard.
:(FAIL OF TRANS) -a. Ng, T5 — Decrease.
b.Nf — May increase to overspeed cut in (110% ±2%), then decrease with Ng stabilizing at flight idle speed.
c.Torque — Decrease to zero.
1.Collective — Maintain Nr.
2.Airspeed — As required.
3.Pickle — External load as required.
4.Tanks — Jettison as required.
5.Speed control levers — As required (secure engine(s))
CAUTION
-Do not attempt to restart affected engine. |
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Term
| 8. ENGINE CHIP LOCATOR LIGHT |
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Definition
An engine chip locator light accompanied by unusual vibrations and/or low oil pressure/high oil temperature, or an engine chip locator light returning after resetting circuit breaker without the above indications, is cause to suspect probable engine failure. If an engine chip detector light goes on, do this:
1.Instruments/caution lights — Check.
If malfunction verified:
2.Perform Single- or Dual-Engine Failure procedures.
3.4.5. (non-memory)
WARNING
-Level single- or dual-engine flight and/or safe single- or dual-engine hover landings may not be possible at certain combinations of helicopter gross weight and density altitude. Flight conditions may require that the decision to establish single- or dual-engine flight be deferred until a safe descent is possible. Select landing site suitable for running landing if available. |
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Term
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Definition
If an emergency situation such as fire, control failure, transmission failure, etc. dictates immediate discontinuation of engine or rotor system operation, stop the aircraft if moving, request assistance as necessary, and proceed as follows:
1.High pressure rotor brake switch — EMERGENCY.
2.All engine speed control levers — SHUT OFF.
3.APP — As required.
4.Fuel selector levers — SHUT OFF.
WARNING
-A fire hazard exists during emergency brake application due to the heat generated and the presence of debris and oil in the rotor brake area.
-Personnel should not exit the cabin section during emergency shutdown until the rotor head has stopped.
NOTE
-Underfrequency protection may cause loss of electrical power due to rapid Nr decay prior to complete pressurization of the emergency rotor brake. |
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Term
| 10. ENGINE SHUTDOWN IN FLIGHT |
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Definition
1.Speed control lever — Shut off. If No. 2 engine is being secured, reduce airspeed to less than 85 KIAS.
WARNING
-If an operating engine and a failed or secured engine have the same tank selected, the operating engine may flame out if the failed or secured engine fuel selector lever was not placed to SHUT OFF.
-Failure to reduce airspeed below 85 KIAS when securing the No. 2 engine increases the hot exhaust backflow component and likelihood of a subsequent engine compartment fire.
2.Fuel selector lever — Shut off.
CAUTION
-If an engine post shutdown fire should occur, as indicated by a continuous T5 above 320 °C, motor engine with starter to extinguish fire.
3.4. (non memory) |
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Term
| 11. Three-Engine Failure (Hover and Takeoff) |
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Definition
1.Collective — Reduce (if altitude permits, to maintain Nr).
2.Airspeed — As required.
3.Pickle — External load as required.
4.Tanks — Jettison as required.
5.Speed control levers — As required
6.Collective — Increase (cushion landing). |
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Term
| 12. Three-Engine Failure (Cruise) |
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Definition
1.Collective — Reduce (to maintain Nr at 95 percent to 100 percent).
2. Airspeed — As required (maximum glide distance airspeed provides improved flare effectiveness).
3. Pickle — External load as required.
4. Tanks — Jettison as required.
5. Speed control levers — As required.
6. Execute autorotative landing (Figure 12-9). |
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Term
| 13. Tail Rotor Drive System Failure (Hover and Takeoff) |
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Definition
1. Collective — Reduce (if altitude permits) to initiate a moderate rate of descent and retard rotation.
2. Airspeed — As required (land in level attitude).
3. Pickle — External load as required.
4. Tanks — Jettison as required.
5. Speed control levers — Shut off at 5 to 20 feet AGL.
6. Collective — Increase (cushion landing). |
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Term
| 14. Tail Rotor Drive System Failure (Cruise) |
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Definition
1. Collective — Reduce (enough to stop fuselage rotation). 2. Airspeed — 100 to 120 KIAS.
3. Pickle — External load as required.
4. Tanks — Jettison as required.
5. Rudder pedals — Centered.
6. If directional control is not regained — Autorotate.
WARNING
-If steps 1. through 5. are unsuccessful in regaining directional control of the helicopter, the pilot should immediately enter autorotation and perform an autorotative descent and landing as outlined under Three-Engine Failure (Autorotative Landing) in this chapter. Secure all engines before increasing collective to cushion landing.
-If the tail rotor/tail rotor gearbox/tail section has (have) departed the aircraft, absence of the autorotating tail rotor will necessitate an autorotative descent and landing. However, due to the forward shift of cg under such conditions, the pilot should use extreme caution during the flare recovery to avoid excessive forward pitch rates which may become uncontrollable.
7. (non memory) |
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Term
| 15. PYLON UNSAFE FOR FLIGHT Light |
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Definition
If illumination of the PYLON UNSAFE FOR FLIGHT light while operating at 100 percent Nr may provide warning of a malfunctioning tail rotor disconnect fitting. Total failure of the tail rotor disconnect fitting will result in loss of tail rotor drive. Failure to retract or premature extension of the tail rotor actuator could result in damage to the tail rotor head or tail rotor gearbox. Extension or cycling of the tail rotor disconnect disengage flag may also indicate a malfunctioning tail rotor disconnect fitting.
If illumination of the PYLON UNSAFE FOR FLIGHT light or extension/cycling of the tail rotor disengage flag occurs, execute the following procedures:
1. If accompanied by abnormal vibration, noise in the tail section, or yaw kicks — Land immediately.
2. If not accompanied by these indications—Land as soon as possible,minimize tail rotor stress,execute running landing if possible.
NOTE
-A PYLON UNSAFE FOR FLIGHT caution light may be accompanied by loss of AFCS servos. |
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Term
| 16. BEARING TEMP DETECT Caution Light |
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Definition
If the BEARING TEMP DETECT caution light comes on:
1. Aircrew — Alert.
*2. Land as soon as possible. |
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Term
| 17. BEARING TEMP LIMIT Caution Light |
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Definition
If the BEARING TEMP LIMIT caution light comes on:
1. Aircrew — Alert.
*2. Land immediately. |
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Term
| 18. Bearing Monitor System Fault Isolation |
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Definition
The bearing monitor panel (BMP) shows bearing monitor system (BMS) fault indications to the aircrew. If a fault indication shows more than a maintenance condition, the pilots have to know immediately. This is normally done by the BEARING VIB LIMIT, BEARING TEMP DETECT, or BEARING TEMP LIMIT lights on the caution/advisory panel. If the aircrew sees a system, WOW, or bearing fault condition on the BMP:
1. Land as soon as practical if a system fault occurs which precludes monitoring of swashplate vibrations/temper- atures as indicated by any of the following conditions:
a. Illumination of a TEMP or VIB system status light, and SP1 and SP2 fault indications appearing in the BMP alphanumeric display.
b. Illumination of the PANEL system status light and PNL NG fault indication appearing in the BMP alphanumeric display.
c. Failure of the BMP display or loss of system power.
WARNING
-(ON AIRCRAFT NOT MODIFIED by AFC 491 PT3) Because the threshold for attenuation induced vibration sensor failure is below the TEMP DET limitation, the first indication of swash plate thermal imbalance may be the VIB SYSTEM status light accompanied by SP1 or SP2 fault indications appearing on the alphanumeric display.
NOTE
-(ON AIRCRAFT MODIFIED by AFC 491 PT3) A swashplate thermal imbalance may be indicated by a VIB system status light, accompanied by SP1 OR SP2 fault indication appearing on the alphanumeric display.
-Failure of both the SP1 and SP2 sensors or failure of the bearing monitor panel (BMP) will result in loss of swashplate monitoring capabilities. |
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Term
| 19. BIM CAUTION LIGHT-IN FLIGHT |
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Definition
If BIM® caution light goes on, have a crewmember check if BIM® circuit breaker is in (on right cabin circuit breaker panel). Due to the sensitivity of the system, the caution light may go on due to Electromagnetic Interference (EMI), giving the pilot a false indication of impending spar failure. If the caution light remains on with the circuit breaker in, and EMI is not verified:
1. Airspeed — 80 KIAS, minimize maneuvering.
2. Altitude — Minimum safe.
3.4. (non memory)
WARNING
-Flight operations outside a level cruise flight regime of 80 ±5 KIAS and operations in a hover produce blade flight loads that will increase potential crack stresses and accelerate crack propagation rates. Continuous flight outside this recommend flight profile will compromise the safety margin incorporated into the maximum prescribed flight duration and lower the allotted 1.5 hour interval. |
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Term
| 20. Engine Compartment Fire(s) on the Ground |
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Definition
1. Speed control levers — As required (affected engine(s) shut off).
2. Engine emergency T-handle(s) — Pull aft (affected engine(s)).
3. Main engine fire extinguisher switch — Main, reserve if necessary.
4. Groundcrew — Alerted. |
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Term
| 21. Single- or Dual-Engine Compartment Fire(s) in Flight |
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Definition
Engine fires are usually the result of an engine malfunction or failure of one of its component systems. Ruptured fuel and oil lines will usually be detected by engine instrument indications. To be sure the engine fire detection system is not being activated by the rays of the sun, turn the helicopter 90_ to its flight path. When possible, confirm presence of fire by sight or smell; then do this:
1. Collective — Maintain Nr.
2. Airspeed — As required.
3. Pickle — External load as required.
4. Tanks — Jettison as required.
5. Speed control levers — As required (affected engine(s) shut off).
6. Engine emergency T-handles — Pull aft (affected engine(s)).
7. Main engine fire extinguisher switch — Main, reserve if necessary.
NOTE
-If two bottles were discharged into one engine compartment, the remaining bottle can be discharged into either of the remaining compartments. The last bottle will be discharged by either the MAIN or RESERVE selection, depending on which two bottles have already been discharged, and which compartment has been selected. In this case, the most expeditious thing to do is to select MAIN and then RESERVE.
8. If fire continues, land immediately.
9. If fire extinguished, refer to Single- or Dual-Engine Failure in this chapter. |
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Term
| 22. Engine Postshutdown Fire |
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Definition
An engine postshutdown fire in the combustion chamber after shutdown may continue to feed itself unless it is blown out by compressor air. Indications would be a rise in T5 above 320 _C after shutdown and/or excessive smoke from the engine exhaust outlet.
1. Speed control lever — SHUTOFF.
2. Fuel selector lever — SHUTOFF.
3. Emergency start switch — EMER.
4. Starter button — Press. Motorize engine until fire is put out, and observe T5.
NOTE
-If all engines have been shut down, APP should be operating.
5.-8. (non memory) |
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Term
| 23. Three Simultaneous Engine Compartment Fires in Flight |
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Definition
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Term
| 24. APP or Cabin Heater Fire |
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Definition
A fire in either the APP or cabin heater will be indicated by the fire warning master lights and the fire warning lights in the APP emergency T-handle. Whenever the APP and cabin heater fire warning light is on, do this:
1. APP emergency T-handle — Pull aft (to discharge fire extinguisher and shut off APP and heater fuel).
2. If fire persists — Land immediately.
3.-5. (non memory) |
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Term
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Definition
1. Cockpit circular vents — Closed.
2. Vent fan switch — Off.
3. If fire persists — Land immediately. |
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Term
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Definition
In case of an electrical fire, attempt to isolate the affected circuits by selectively securing electrical equipment or pulling circuit breakers. If fire persists, land immediately; while in flight, do as follows:
WARNING
-Turning all generators off will result in immediate loss of all electrical instruments, warning systems, ICS, and AFCS, except servo 1. Helicopter response to total electrical loss may be violent. Landing gear may only be extended by the emergency method, and a positive gear down check will not be possible. Consideration should be given to all problems before turning all generators off.
1. Circuit breaker (for affected circuit) — Pull.
2. Fight fire with portable fire extinguisher.
3. If fire persists — Land immediately. |
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Term
| 27. Hydraulic Fire in Main Rotor Pylon |
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Definition
Hydraulic fire in the main rotor pylon area is most likely to occur during taxi, hover, or low airspeed operations. Hydraulic fire may be indicated by white smoke and/or flames in the vicinity of the main transmission and/or by illumination of a number of unassociated caution lights. Because of the intense heat generated, flight control components may disintegrate rapidly, causing the aircraft to become uncontrollable. If a hydraulic fire is detected/suspected:
1. Land immediately.
NOTE
-If feasible, accomplish a running landing at 40 knots ground speed to maintain airflow through the rotary wing pylon.
2. Secure helicopter — Immediately.
WARNING
-Delay in shutting down the helicopter may give the fire time to burn through a flight control component, causing the helicopter to roll over.
3. Portable fire extinguisher — Use. |
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Term
| 28. No. 2 ENGINE OVERHEAT Caution Light |
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Definition
When the temperature inside the No. 2 engine compartment rises above approximately 575 _F, a signal is sent to illuminate the NO. 2 ENGINE OVERHEAT caution light. If No. 2 ENGINE OVERHEAT caution light illuminates in flight other than during an in-flight No. 2 engine start, check engine instruments and proceed as follows:
NOTE
-The No. 2 ENGINE OVERHEAT light may illuminate for a short time (up to 30 seconds) during restart of the No. 2 engine at any airspeed. Monitor engine start for hot or hung starts. If a hot or hung start is experienced, immediately secure engine.
1. Collective — Maintain Nr.
2. Airspeed — As required.
3. Pickle — External load as required.
4. Tanks — Jettison as required.
5. Speed control levers — No. 2 engine shutoff.
6.-7. (non memory) |
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Term
| 29. Auxiliary Fuel Tank Jettison |
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Definition
External auxiliary fuel tank jettison may be required in case of single-or dual-engine operation. If tank jettison is to be done, do this:
1. Airspeed — 0 to 150 knots. (Maximum airspeed in descent: 120 knots.)
2. Rate of descent — Less than 1,500 feet per minute.
3. Bank angle — 0°.
4. Area — Cleared if possible.
5. Place desired AUX TANK JTSN switch — ON. |
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Term
| 30. AFCS Computer Malfunction |
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Definition
An AFCS caution light means both computers are off and no AFCS functions are being performed. If recycling computer power OFF and then ON does not make the AFCS caution light go out, do the following:
1. Instrument meteorological conditions (IMC) — Land as soon as possible.
(non m)2. Visual meteorological conditions (VMC) — Land as soon as practical. |
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Term
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Definition
An AFCS servo hardover is an uncommanded movement of the flight controls which cannot be easily overridden by the pilot. The rate at which the control moves may vary from a relatively slow rate (about 1 inch per second) to full travel in less than one second (100 percent per second). When potentially high rates of control change are experienced, and pressing the trim release does not override the drive, suspect an AFCS servo hardover. A rapid response to this emergency will be required to retain control. If a hardover is experienced, do the following:
1.Transfer to other AFCS servo .If servo hard over condition goes away—Proceed and land as soon as practical.
CAUTION
-High control forces may change to normal at AFCS servo changeover.
2. If servo hardover condition continues — Secure AFCS servos.
3. VMC — Land as soon as practical.
4. IMC — Land as soon as possible. |
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Term
| 32. Utility Hydraulic System Failure |
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Definition
The primary visual indications of system malfunctions are: (1) The UTIL HYD PRESS gauge on the instrument panel, redlined at 2,600 psi minimum or 3,300 maximum; (2) the UTILITY PRESS caution light that goes on when hydraulic pressure drops below 1,500 psi; (3) the UTILITY OIL HOT caution light that goes on when the hydraulic fluid temperature rises to 107 _C; and (4) the UTILITY QTY T/R caution light that goes on when reservoir quantity drops to an unsatisfactory level.
The utility hydraulic system receives pressure from a pump driven by the accessory gearbox, and failure will be indicated by the pressure gauge or temperature caution light. The engine starting system, APP starting system, landing gear system, cargo ramp and door system, main wheel power brake system, blade/pylon fold systems, rotor head positioning for engine start, second stage side of tail rotor servo, AFCS SERVO 2 pitch, altitude, roll, and yaw servos, utility hoist, and cargo winch will be inoperative if the utility hydraulic system pump should fail, or if pressure is lost from the system.
If utility hydraulic system failure is indicated by either the UTILITY PRESS caution light or the pressure gauge is at zero or fluctuating near or below 1,000 psi, proceed as follows:
WARNING
-Extended flight with utility hydraulic system failure is not recommended due to possible loss of first stage hydraulic system and subsequent loss of tail rotor control.
1. Landing gear — Extend.
CAUTION
-Should utility hydraulic failure occur with ramp at or below level position, ramp to ground contact may occur during landing.
2. Land as soon as possible. |
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Term
| 33. Flight Control Hydraulic System Failure |
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Definition
The primary visual indications of system malfunctions are: (1) 1ST and 2ND STAGE HYD PRESS gauges on the instrument panel redlined at 2,600 psi minimum or 3,300 psi maximum, (2) the 1 STG PRESS M/R T/R and 2 STG PRESS M/R caution lights that go on when pressure drops below 2,000 psi, (3) the 1 STG QTY M/R T/R and 2 STG QTY M/R caution lights that go on when reservoir fluid quantity drops to an unsatisfactory low level, and (4) the 2 STG OIL HOT caution light that goes on when the second stage hydraulic fluid temperature rises to 107 _C.
WARNING
-Failure of first and second stages of flight control system will result in loss of control of helicopter.
-Rapid or abrupt movement of flight controls with only one primary flight control hydraulic system operating can result in control restrictions due to a reduction of pressure in operating system.
NOTE
-Do not turn a flight control system off if a constant abnormally high pressure is indicated. Land as soon as practical.
-In case of loss of pressure in first or second stage hydraulic system, check that both collective flight control servo switches are ON.
-In the event of a pending 2nd stage failure (pressure fluctuations), consideration should be given to securing AFCS SERVO 1 to allow smooth operation of AFCS servo functions.
1. Reduce airspeed to 80 to 100 knots.
2. Land as soon as possible. |
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Term
| 34. Primary Tandem Servo Malfunction |
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Definition
The primary visual indications of a primary tandem servo malfunction are the 1 STG M/R SERVO BYPASS or 2 STG M/R SERVO BYPASS caution lights that go on when a servo has malfunctioned in such a manner to cause it to bypass hydraulic pressure or it has lost system pressure.
WARNING
-When the 1 STG M/R SERVO BYPASS caution light is observed after a utility hydraulic system failure, securing first stage flight control system will result in loss of tail rotor control. There are no interlocks to prevent turning off pressure to first or second stage hydraulic systems when a servo in the other stage is in bypass. Turning off pressure to the nonbypassed stage results in loss of control of the servo.
An individual primary tandem servo malfunction will be indicated by a servo bypass caution light that indicates which flight control hydraulic system has the failed servo. The caution light does not indicate the individual servo that has failed. The servo bypass caution light will indicate a servo has failed in a manner that has subjected it to a loss of hydraulic pressure. The servo bypass caution light may go off with certain positions of the servo piston, even though the malfunction still exists. In this case, check the appropriate flight control hydraulic system pressure gauge to determine if the system has failed or the failure is within the servo.
When a servo bypass caution light is observed, do not turn off the corresponding servo system unless there is a definite restriction of controls and do the following:
1. Airspeed — Reduce.
2. Land as soon as possible. |
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Term
| 35. Tail Rotor Tandem Servo Malfunction |
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Definition
The primary visual indications of tail rotor tandem servo malfunction are the 1 STG T/R SERVO BYPASS and 2 STG T/R SERVO BYPASS caution lights that go on when the servo has malfunctioned in such a manner to cause it to bypass hydraulic pressure or it has lost system pressure.
When a tail rotor servo bypass caution light is observed, do not turn off the corresponding servo system unless there is a definite restriction of controls and perform the following:
1. Airspeed — Reduce.
2. Land as soon as possible. |
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Term
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Definition
Main gearbox failure may be indicated by any abnormal noise. At that time, check all instruments, and monitor for adverse indications. If the instruments should show any unusual indications, make an emergency landing. Main gearbox failure may also be indicated by an unusual yaw kick accompanied by fluctuations in the torquemeters. If indications of main gearbox failure are noted, do this:
1. Land immediately.
WARNING
-An increase in torque for a given flight condition is an indication of a main gearbox impending failure. |
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Term
| 37. Main Gearbox Chip Locator Light |
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Definition
When the CHIP DETECTED caution light is accompanied by the MAIN GB chip locator light on the chip locator panel, progressive failure of the main gearbox may be occurring.
1. Instruments and caution lights — Check.
2. If malfunction verified — Perform main gearbox failure procedures.
3.-5. (non memory) |
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Term
| 38. Main Gearbox Oil System Failure |
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Definition
If the MGB OIL PRESS and the MGB AUX lube pump caution lights both illuminate and the MGB oil pressure drops rapidly or decreases below minimum, the main gearbox has lost all means of lubrication and an immediate landing shall be made. In this case:
1. Land immediately. |
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Term
| 39. Free Wheeling Unit Failure |
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Definition
A Free Wheeling Unit (FWU) failure is a slippage condition which allows the Nf to exceed Nr with no usable torque transmitted to the MGB. This condition, usually caused by FWU bearing spitout, may be momentary (sometimes repeatedly) or permanent and may also result in breakup of the FWU. Slippage is indicated by any/all of the following symptoms: Nf exceeding Nr torque dropping to zero, and a slight to moderate left yaw kick as the FWU slips. Sudden FWU reengagement causes a jolt in the airframe. If momentary slippage and reengagement occur to rapidly, symptoms may not be fully reflected in the cockpit quad tach and torque indicator; therefore, pilots should carefully monitor their instruments if FWU malfunction is suspected. In addition, a FWU may lock up following a momentary slippage, wherein the MGB can backdrive the engine. This will be indicated by Nf not splitting off from Nr upon retarding the affected engine SCL to MIN GOV.
If a momentary slippage is indicated:
1. Collective — Maintain Nr.
2. Airspeed — Establish dual- or single-engine airspeed. 3. Pickle — External load as required.
4. Tanks — Jettison as required.
5. SCL — Affected engine to MIN GOV.
WARNING
-If the No. 2 engine speed control lever is at or below MIN GOV and the Ng is less than 75 percent, hot exhaust gas may backflow into the engine compartment creating a fire hazard. Limit airspeed to less than 85 KIAS to reduce backflow. If a FWU slippage has occurred and dual-engine flight can be maintained, consideration should be given to securing the No. 2 engine. If a FWU lockup is suspected, maintain No. 2 engine at no less than 75 percent Ng to reduce possibility of backflow and to ensure engine lubrication.
CAUTION
-In the event of a No. 1 or No. 3 FWU lockup, maintain the affected engine at or above ground idle to ensure lubrication of the power turbine shaft bearings.
6.-7. (non memory) |
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Term
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Definition
Nose gearbox failure may be indicated by an abnormal noise or change in noise frequency. A malfunction that would cause a binding or restriction within the gearbox will cause a high engine torque reading to be observed. A malfunction that would cause a no-load condition on the engine should produce a tendency for the engine to overspeed. If indications of nose gearbox failure are noted, do this:
1. Instruments and caution lights — Check.
2. Collective — Maintain Nr.
3. Airspeed — As required.
4. Pickle — External load as required.
5. Tanks — Jettison as required.
6. Speed control levers — As required (shut off affected engine, conditions permitting).
7. Land as soon as practical. |
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Term
| 41. Nose Gearbox Chip Locator Light |
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Definition
When the CHIP DETECTED caution light is accompanied by either of the nose gearbox chip locator lights, check all other nose gearbox caution lights and gauges and engines torquemeters to verify malfunction.
1. Instruments and caution lights — Check.
2. If malfunction verified — Perform Nose Gearbox Failure procedures.
3.-5. (non memory)
NOTE
-An increase in torque for a given flight condition is a positive sign of nose gearbox internal binding or restriction. |
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Term
| 42. Nose Gearbox Oil System Failure |
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Definition
Loss of nose gearbox lubrication will be indicated by the nose gearbox oil temperature gauge and oil temperature and pressure caution lights. If indications of a nose gearbox oil system failure are noted, do this:
1. Instruments and caution lights — Check.
2. Perform Nose Gearbox Failure procedures. |
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Term
| 43.Intermediate or Tail Gearbox Failure and Chip Light |
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Definition
Other than the chip light and the TGB/IGB OIL PRESS caution lights, there are no other instruments or caution lights with which to verify impending failures. A combination of chip light and corresponding OIL PRESS caution light confirms an impending failure. Additional flight indications of impending failure may include heading control difficulty, yaw kick, high frequency vibrations, and unusual or loud grinding noises from the tail section.
If impending failure is imminent as noted by combination of chip and corresponding OIL PRESS light, illumination of any caution light with additional flight indications discussed above, or any of the flight indications discussed above, proceed as follows:
1. Land immediately.
If only a single caution light illuminates without any additional indication of failure, proceed as follows:
(non memory) |
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Term
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Definition
Lightning strike can occur while flying in the vicinity of thunderstorms. Damage to main and tail rotor blades in the form of arcing, erosion and heat annealing will result. Engineering analysis of blades subjected to an actual in-flight lightning strike concluded that the damage to the blades can be so severe that the fatigue life would be reduced to a few hours or even minutes. If a lightning strike is suspected, the helicopter should be landed and inspected. In past cases, major hidden damage was inflicted and was associated with minor appearing visible/external damage to the spot or pockets; however, no hidden damage was found without visible/external indications of some kind.
If lightning strike suspected:
1. Airspeed — 80 KIAS.
2. Land as soon as possible. |
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Term
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Definition
1. If able — Take off.
2. If unable to take off — Emergency shutdown. |
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Term
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Definition
1. Flight control — Release. If oscillations do not dampen within several seconds:
2. External cargo — Jettison. |
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Term
| 47. Water Autorotative Landings |
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Definition
Autorotative landings on water differ from land, in that touchdown speed must be held to a minimum. The helicopter should enter the water with a near vertical descent if possible. Refer to Three-Engine Failure (Autorotative Landing) in this chapter.
1. Autorotate as described under Three-Engine Failure.
2. Enter water tail rotor first. |
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Term
| 48. Helicopter Rolls Over or Does Not Float |
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Definition
All personnel shall remain strapped in until rotors stop. Passengers shall not inflate life vest while in helicopter.
1. When rotors stop — ABANDON HELICOPTER.
2. Check — All passengers out.
3. Flotation devices — Inflate when clear of obstructions.
4. Assist passengers into raft (if required).
NOTE
-If time permits, launch rafts through any escape point.
-If the helicopter is inverted, use of the single-point suspension hatch should be considered for exit. |
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