UH-1H Emergency

For the purpose of standardization the following definitions shall apply:

a. The term LAND AS SOON AS POSSIBLE is defined as executing a landing to the nearest suitable landing area without delay. The primary consideration is to assure the survival of occupants.

b. The term LAND AS SOON AS PRACTICABLE is defined as executing a landing to a suitable airfield, heliport, or other landing area as the situation dictates.

adjusting the flight controls as necessary to establish an autorotational descent. See figure 9-2 and FM 1-203.

1 . COLLECTIVE ADJUST as required to maintain rotor RPM.
2. PEDALS ADJUST as required.
3. THROTTLE ADJUST as required.
4. AIRSPEED ADJUST as required.

Engine stoppage without delay.

1. THROTTLE – OFF.
2. FUEL switches – OFF.
3. BAT switch – OFF.

manual control of the engine RPM with the GOV AUTO/EMER switch in the EMER position.

Because automatic acceleration, deceleration, and overspeed control are not provided with the GOV switch in the EMER position, throttle and collective coordinated control movements must be smooth to prevent compressor stall, overspeed, overtemperature, or engine failure.

CAUTION
No more than 42 PSI torque is available when the GOV AUTO/EMER switch is in the EMER position due to limited fuel flow and may be significantly reduced based on ambient conditions.

1. GOV – switch EMER.
2. Throttle – Adjust as necessary to control RPM.
3. Land as soon as possible.

Emergency exits are shown in figure 9-1. Emergency exit release handles are yellow and black striped.

a. Cockpit Doors.

(1) Pull handle.
(2) Push door out.

b. Cabin Door Windows.

(1) Pull handle.
(2) Lift window inward.

WARNING
Toxic fumes of the extinguishing agent may cause injury, and liquid agent may cause frost bite or low-temperature burns.
Refer to figure 9-1 for fire extinguisher and first aid kit locations.

Minimum Rate of Descent
See figure 9-2

Maximum Glide Distance
See figure 9-2 or 9-8.

If the engine oil temperature exceeds operating limits as specified in Chapter 5,

Land as soon as possible.

a. The indications of an engine malfunction, either a partial or a complete power loss are left yaw, drop in engine rpm, drop in rotor rpm, low rpm audio alarm, illumination of the rpm warning light, change in engine noise.

(1)-Control response with an engine inoperable is similar to a descent with power.

(2)-Airspeed above the minimum rate of descent values (figures 9-2) will result in greater rates of descent and should only be used as necessary to extend glide distance.

(3)-Airspeeds below minimum rate of descent airspeeds will increase rate of descent and decrease glide distance.

(4)-Should the engine malfunction during a left bank maneuver, right cyclic input to level the aircraft must be made simultaneously with collective pitch adjustment. If the collective pitch is decreased without a corresponding right cyclic input, the helicopter will pitch down and the roll rate will increase rapidly, resulting in a significant loss of altitude.

WARNING

Do not close the throttle. Do not respond to the rpm audio and/or warning light illumination without first confirming engine malfunction by one or more of the other indications. Normal indications signify the engine is functioning properly and that there is a tachometer generator failure or an open circuit to the warning system, rather than an actual engine malfunction.

Under partial power conditions, the engine may operate relatively smoothly at reduced power or it may operate erratically with intermittent surges of power. In instances where a power loss is experienced without accompanying power surging, the helicopter may sometimes be flown at reduced power to a favorable landing area. Under these conditions, the pilot should always be prepared for a complete power loss. In the event a partial power condition is accompanied by erratic engine operation or power surging, and flight is to be continued, the GOV switch may be moved to the EMER position and throttle adjusted in an attempt to correct the surging condition. If flight is not possible, close the throttle completely and complete an autorotational landing.

(1) Under a complete power loss condition, delay in recognition of the malfunction, improper technique or excessive maneuvering to reach a suitable landing area reduces the probability of a safe autorotational landing. Flight conducted within the caution area of the height-velocity chart (fig 9-3) or (fig 9-3.1) exposes the helicopter to a high probability of damage despite the best efforts of the pilot.

(2) From conditions of low airspeed and low altitude, the deceleration capability is limited, and caution should be used to avoid striking the ground with the tail rotor. Initial collective reduction will vary after an engine malfunction dependent upon the altitude and airspeed at the time of the occurrence. For example, collective pitch must not be decreased when an engine failure occurs at a hover in ground effect; whereas, during cruise flight conditions, altitude and airspeed are sufficient for a significant reduction in collective pitch, thereby, allowing rotor rpm to be maintained in the safe operating range during autorotational descent. At high gross weights, the rotor may tend to overspeed and require collective pitch application to maintain the rpm below the upper limit. Collective pitch should never be applied to reduce rpm below normal limits for extending glide distance because of the reduction in rpm available for use during autorotational landing.

NOTE

If time permits, during the autorotative descent, transmit a “May Day” call, set transponder to emergency, jettison external stores, and lock shoulder harness.

Autorotate.

1. Autorotate.
2. EMER GOV OPNS

After an engine failure in flight, resulting from a malfunction of fuel control unit, an engine start may be attempted. Because the exact cause of engine failure cannot be determined in flight, the decision to attempt the start will depend on the altitude and time available, rate of descent, potential landing areas, and crew assistance available. Under ideal conditions approximately one minute is required to regain powered flight from time the attempt start is begun.

If the decision is made to attempt an in-flight start:
1. Throttle – Off.
2. STARTER GEN switch – START.
3. FUEL switches – ON.
4. GOV switch – EMER.
5. Attempt start.

a. Starter switch— Press.
b. Throttle- Open slowly to 6400 to 6600 rpm as N1 passes through 8 percent. Control rate of throttle application as necessary to prevent exceeding EQT limits.

c. Starter switch- Release as N1 passes through 40 percent. After the engine is started and powered flight is reestablished, continue with manual control. Turn the START FUEL switch OFF and return the STARTER GEN switch to STANDBY.

6. Land as soon as possible.

Droop compensator failure will be indicated when engine rpm fluctuates excessively during application of collective pitch. The engine will tend to overspeed as collective pitch is decreased and will underspeed as collective pitch is increased. If the droop compensator fails, make minimum collective movements and execute a shallow approach to the landing area. If unable to maintain the operating rpm within limits:

EMER GOV OPNS

Engine compressor stall (surge) is characterized by a sharp rumble or loud sharp reports, severe engine vibration and a rapid rise in exhaust gas temperature (EQT) depending on the severity of the surge. Maneuvers requiring rapid or maximum power applications should be avoided. Should this occur:

1. Collective – Reduce .
2. DE-ICE and BLEED AIR switches – OFF.
3. Land as soon as possible.

a. Closed. If the guide vanes fail in the closed position, a maximum of 20 to 25 psi of torque will be available although N1 may indicate normal. Power applications above 20 to 25 psi will result in deterioration of N2 and rotor rpm while increasing N1 . Placing the GOV switch in the EMER position will not provide any increase power capability and increases the possibility of an N1 overspeed and an engine over- temperature. Should a failure occur, accomplish an approach and landing to the ground with torque not exceeding the maximum available. If possible, a running landing is recommended.

b. Open. If the inlet guide vanes fail in the open position during normal flight, it is likely that no indications will be evidenced. In this situation, increased acceleration times will be experienced. As power applications are made from increasingly lower N1 settings, acceleration times will correspondingly increase.

Engine overspeed will be indicated by a right yaw, rapid increase in both rotor and engine rpm, rpm warning light illuminated, and an increase in engine noise. An engine overspeed may be caused by a malfunctioning N2 governor or fuel control. Although the initial indications of high N2 rpm and rotor rpm are the same in each case, actions that must be taken to control rpr are distinctly different. If the N2 governor malfunctions, throttle reduction will result in a corresponding decrease in N2 rpm. In the event of a fuel control matfunction, throttle reduction will have no effect on N2 rpm. If an overspeed is experienced:

1 . Collective—Increase to load the rotor in an attempt to maintain rpm below the maximum operating limit.

2. Throttle—Reduce until normal operating rpm is attained. Continue with manual throttle control.

If reduction of throttle does not reduce rpm as required:

3. EMER GOV OPNS

If the transmission oil temperature XMSN OIL HOT caution light illuminates, limits on the transmission oil temperature gage are exceeded; XMSN OIL PRESS caution light illuminates, or limits on the transmission oil pressure gage are exceeded (low or high)—

1. Land as soon as possible.
2. EMER SHUTDOWN- After landing.

WARNING

Engine operating RPM, with zero to near zero torque must be maintained throughout the approach. Torque applied for landing should be used at low altitudes to aid in preventing seizure of gears in the transmission.

Should transmission oil pressure drop to zero psi, a valid cross reference cannot be made with the oil temperature indicators. The oil temperature gage and transmission oil hot warning lights are dependent on fluid for valid indications.

Because the many different malfunctions that can occur, it is not possible to provide a solution for every emergency. The success in coping with the emergency depends on quick analysis of the condition.

This situation involves a break in the drive system, such as a severed driveshaft, wherein the tail rotor stops turning or tail rotor controls fail with zero thrust.

a. Indications.

(1 ) Pedal input has no effect on helicopter trim.
(2) Nose of the helicopter turns to the right (left sideslip).
(3) Roll of fuselage along the longitudinal axis.
(4) Nose down tucking will also be present.

WARNING

At airspeeds below 30 to 40 knots, the sideslip may become uncontrollable, and the helicopter will begin to revolve on the vertical axis (right or left depending on power, gross weight, etc).

b. Procedures.

(1) If safe landing area is not immediately available and powered flight is possible, continue flight to a suitable landing area at above minimum rate of descent airspeed. Degree of roll and sideslip may be varied by varying throttle and/or collective.

(2) When landing area is reached, AUTOROTATE using an airspeed above minimum rate of descent airspeed.

(3) If landing area is suitable, touchdown above effective translational lift utilizing throttle as necessary to maintain directional control.

(4) If run-on landing is not possible, start to decelerate at about 75 feet altitude so that forward groundspeed is at a minimum when the helicopter reaches 10 to 20 feet; execute the touchdown with a rapid collective pull just prior to touchdown in a level attitude with minimum groundspeed.

This is a malfunction involving a loss of control resulting in a fixed-pitch setting. Whether the nose of the helicopter yows left or right is dependent upon the amount of pedal applied at the time of the malfunction. Regardless of pedal setting at the time of malfunction, a varying amount of tail rotor thrust will be delivered at all times during flight.

a. Reduced power (low torque).

(1) Indications: The nose of the helicopter will turn right when power is applied.

(2) Procedure: Reduced power situations:

(a) If helicopter control can be maintained in powered flight, the best solution is to maintain control with power and accomplish a run-on landing as soon as practicable.

(b) If helicopter control cannot be maintained, close the throttle immediately and accomplish an autorotational landing.

b. Increased power (high torque) .

(1) Indications: The nose of the helicopter will turn left when power is reduced.

(2) Procedure.

(a) Maintain control with power and airspeed be tween 40 and 70 knots.

(b) If needed, reduce rpm (not below 6000) to control sideslip.

(c) Continue powered flight to a suitable landing area where a run-on landing can be accomplished.

(d) On final, reduce rpm to 6000 and accomplish a run-on landing.

c. Hover.

(1) Indication. Helicopter heading cannot be controlled with pedals.

(2) Procedure.

(a) Fixed Pedal Land.
(b) Loss of tail rotor thrust— AUTOROTATE.

The severity of this situation is dependent upon the amount of weight lost. Any loss of this nature will result in a forward center of gravity shift, requiring aft cyclic.

a. Indications:

(1) Varying degrees of right yaw depending on power applied and airspeed at time of failure.
(2) Forward CQ shift.

b. Procedure:

(1) Enter autorotative descent (power off).
(2) Maintain airspeed above minimum rate of descent airspeed.
(3) If run-on landing is possible, complete autorotation with a touchdown airspeed of between 15 and 25 knots.
(4) If run-on landing is not possible, start to decelerate from about 75 feet altitude, so that forward groundspeed is at a minimum when the helicopter reaches 10 to 20 feet; execute the touchdown with a rapid collective pull just prior to touchdown in a level attitude with minimum ground roll.

This is a situation involving a loss of effective tail rotor thrust without a break in the drive system. The condition is most likely to occur at a hover or low airspeed as a result of one or more of the following:

a. Out-of-ground effect hover.
b. High pressure altitude/high temperature.
c. Adverse wind conditions.
d. Engine/rotor rpm below 6600/324.
e. Improperly rigged tail rotor.
f. High gross weight.

(1) Indications: The first indication of this condition will be a slow starting right turn of the nose of the helicopter which cannot be stopped with full left pedal application. This turn rate will gradually increase until it becomes uncontrollable or, depending upon conditions, the aircraft aligns Itself with the wind.

(2) Procedures. Lower collective to regain control and allow the aircraft to touchdown with little if any forward movement.

A failure of the main driveshaft will be indicated by a left yaw (this is caused by the drop in torque applied to the main illumination of the rpm warning light. This condition will result in complete loss of power to the rotor and a possible engine overspeed. If a failure occurs:

1. Autorotate.
2. EMER SHUTDOWN.

A clutch failing to disengage in flight will be indicated by the rotor rpm decaying with engine rpm as the throttle is reduced to the engine idle position when entering autorotational descent. This condition results in total loss of autorotational capability. If a failure occurs, do the following:

1. Throttle – On.
2. Land as soon as possible.

During recovery from autorotational descent clutch malfunction may occur and will be indicated by a reverse needle split (engine rpm higher than rotor rpm) :

1. Autorotate.
2. EMERGENCY SHUTDOWN.

If collective bounce occurs.

1. Relax pressure on collective. (Do not “stiff arm” the collective.)
2. Make a significant collective application either up or down.
3. Increase collective friction.

The safety of helicopter occupants is the primary consideration when a fire occurs; therefore, it is imperative that every effort be made by the flight crew to put the fire out. On the ground it is essential that the engine be shut down, crew and passengers evacuated and fire fighting begun immediately. If time permits, a “May Day” radio call should be made before the electrical power is OFF to expedite assistance from fire fighting equipment and personnel. If the helicopter is airborne when a fire occurs, the most important single action that can be taken by the pilot Is to land the helicopter. Consideration must be given to jettison external stores prior to landing.

The following procedure is applicable during engine starting if EGT limits are exceeded, or if it becomes apparent that they will be exceeded. Flames emitting from the tailpipe are acceptable if the EGT limits are not exceeded.

1 . Start switch- Press. The starter switch must be held until EGT is in the normal operating range.
2. Throttle— Off. The throttle must be closed im mediately as the starter switch is pressed. 3. FUEL switches-OFF.

EMER SHUTDOWN

If the fire light illuminates and/or fire is observed during flight, prevailing circumstances (such as VFR, IMC, night, altitude, and landing areas available) , must be considered in order to determine whether to execute a power-on, or a power-off landing.

a. Power-On.

1 . Land as soon as possible.
2. EMER SHUTDOWN after landing.

b. Power-Off.

1. Autorotate.
2. EMER SHUTDOWN.

Prior to shutting off all electrical power, the pilot must consider the equipment that is essential to a particular flight environment that will be encountered, e.g., flight instruments, and fuel boost pumps. In the event of electrical fire or suspected electrical fire in flight:

1. BAT, STBY and MAlN GEN switches – OFF.
2. Land as soon as possible.

If landing cannot be made soon as possible and flight must be continued, the defective circuits may be identified and isolated as follows:

3. Circuit breakers- Out. As each of the following steps is accomplished, check for indications of the source of the fire.

4. MAlN GEN switch-ON.

5. STARTER GEN switch-STBY GEN.

6. BAT switch-ON.

7. Circuit breakers In one at a time in the priority required, GEN BUS RESET first. When malfunctioning circuit is identified, pull the applicable circuit breaker out.

WARNING
Do not open battery compartment or at tempt to disconnect or remove overheated battery. Battery fluid will cause burns and overheated battery will cause thermal burns and may explode.

If an overheated battery is suspected or detected:

1. BAT switch OFF.
2. Land as soon as possible.
3. EMER SHUTDOWN after landing.

Smoke and/or toxic fumes entering the cockpit and cabin can be exhausted as follows:

Doors, windows, and vents Open.

CAUTION
Do not jettison doors in flight.

WARNING
During actual or simulated hydraulic failure, do not pull or push circuit breakers or move the HYD CONT switch during takeoff, nap of the earth flying, approach and landing or while the aircraft is not in level flight. This prevents any possibility of a surge in hydraulic pressure and the resulting loss of control.

Hydraulic power failure will be evident when the force required for control movement increases; a moderate feedback in the controls when moved is felt, and/or the HYD PRESSURE caution light illuminates. Control movements will result in normal helicopter response. In the event of hydraulic power failure:

1. Airspeed Adjust as necessary to attain the most comfortable level of control movements.
2. HYD CONT circuit breaker Out.

If hydraulic power is not restored:

3. HYD CONT circuit breaker – In.
4. HYD CONT switch – OFF.
5. Land as soon as practicable at an area that will permit a run-on landing with power. Maintain airspeed at or above effective translational lift until touchdown.

A failure within the irreversible valve may cause extreme stiffness in the collective or two of the four cyclic control quadrants. If the failure is in one of the two cyclic irreversible valves, caution is necessary to avoid over controlling between the failed and operational quadrants.

1. HYD CONT switch – OFF then ON. Check for restoration of normal flight control.

Check for restoration of normal flight control movements. Repeat as necessary.

If control response is not restored:

2. HYD CONT switch — Off if normal operation is not restored.
3. Land as soon as practicable at an area that will permit a run-on landing with power. Maintain airspeed at or above effective translational lift until touchdown.

Cyclic hardover is any erratic movement of the cyclic stick not induced by turbulence or by crew input. During a hydraulics OFF check on the ground, in the event of an irreversible valve failure (hardover), the cyclic stick will move either left rear, right rear, left forward, or right forward, depending on which irreversible fails. In flight with hydraulics ON when a hardover occurs, the cyclic will move left rear, right rear, left forward, or right forward. In flight, with hydraulics OFF (when a hardover occurs), the cyclic will tend to move either right rear or left rear. The cyclic moves toward the rear quadrants due to the main rotor exerting extension forces on the hydraulic servos. A failure in either mode may render the helicopter uncontrollable unless the following corrective action is taken:

1. HYD CONT switch – Select opposite position.
2. Land as soon as practicable at an area that will permit a run-on landing with power. Maintain airspeed at or above effective translational lift at touchdown.

a. Failure of components within the flight control system may be indicated through varying degrees of feedback, binding, resistance, or sloppiness. These malfunctions are normally in isolated controls, i.e. cyclic, cyclic/collective, or antitorque. These conditions should not be mistaken for hydraulic power failure.

b. Imminent failure of main rotor components may be indicated by a sudden increase in main rotor vibration and/or unusual noise. Severe changes in lift characteristics and/or balance condition can occur due to blade strikes, skin separation, shift or loss of balance weights or other material. Malfunctions may result in severe main rotor flapping. In the event of a main rotor system malfunction, proceed as follows:

WARNING
Danger exists that the main rotor system could collapse or separate from the aircraft after landing. A decision must be made whether occupant egress occurs before or after the rotor has stopped.

1. Land as soon as possible.
2. EMER SHUTDOWN after landing.

If mast bumping occurs:

1. Reduce severity of maneuver.
2. Land as soon as possible.

If both FUEL BOOST caution lights come on.

1 . Check fuel pressure. If fuel pressure is zero:
2. Descend to a pressure altitude of 4600 feet or less if possible.
3. Land as soon as practicable.

No attempt should be made to troubleshoot the system while in flight.

Land as soon as practicable.

A malfunction of the main generator will be indicated by zero indication on the Main Generator Loadmeter and DC GENERATOR caution light illumination. An attempt may be made to put the generator back on line as follows:

1 . GEN and BUS RESET circuit breaker – In.
2. MAIN GEN switch RESET then ON.

Do not hold the switch in the RESET POSITION. If the main generator is not restored or if it goes off again:

3. MAIN GEN switch OFF.

NOTE
Check that the standby generator load- meter is indicating a load. Flight may be continued using the standby generator.

A landing in trees should be made when no other landing area is available. Select a landing area containing the least number of trees of minimum height. Decelerate to a zero ground speed at tree-top level and descend into the trees ver tically, applying collective pitch as necessary for mini mum rate of descent. Prior to the main rotor blades entering the trees, ensure throttle is OFF and apply all of the remaining collective pitch.

If it becomes necessary to ditch the helicopter, accomplish an approach to an approximate 3-foot hover above the water and proceed as follows:

1 . Cockpit doors-Jettison at a hover.
2. Cabin doors-Open.
3. Crew (except pilot) and passengers-Exit.
4. Hover a safe distance away from personnel.
5. Throttle-Off and autorotate. Apply full collective pitch prior to the main rotor blades entering the water. Maintain a level attitude as the helicopter sinks and until it begins to roll, then apply cyclic in direction of the roll.
6. Pilot-Exit when the main rotor is stopped.

If ditching is imminent, accomplish engine malfunction emergency proce dures. Decelerate to zero forward speed as the helicopter nears the water. Apply all of the collective pitch as the helicopter enters the water. Maintain a level attitude as the helicopter sinks and until it begins to roll, then apply cyclic in the direction of the roll. Exit when the main rotor is stopped.

1. Cockpit doors Jettison.
2. Cabin Doors Open.
3. Exit when main rotor has stopped.

Check the CAUTION panel for the condition. If master caution only (no segment light) . land as soon as possible.

INT AUX FUEL transfer switches – OFF.

Check GEN AND BUS RESET circuit breaker in MAIN GEN switch RESET then ON. Switch to STBY GEN.

Switch to other inverter.

Close door.

Land as soon as possible. (Ref to para 9-1 9)

Land as soon as possible. (Ref to para 9-19)

Land as soon as practicable.

Land as soon as possible.

Land as soon as practicable.

Land as soon as practicable.

Land as soon as practicable.

Information/System Status.

Land as soon as possible.

Land as soon as possible.

Information/System Status

Land as soon as possible.

Land as soon as possible.

Land as soon as possible.

Land as soon as practicable.

Land as soon as practicable.

Land as soon as possible.