EPs Flashcards
Engine Failure in Flight
Indications:
1. Nr decrease
2. Rapid settling
3. Left yaw
4. ROTOR LOW RPM caution light and audio
5. ENGINE OUT caution light and audio
6. GEN FAIL (B) or MAIN GEN FAIL (C) caution light
Note:
- The best glide airspeed is 72 KIAS. The minimum rate of descent airspeed is 50 KIAS. Do not exceed 100 KIAS in sustained autorotation.
- If time and altitude permit, engine air restart may be attempted. The decision to attempt a restart is the pilots responsibility and is dependent upon the pilots experience and operating altitude.
- All autorotative landings should be made into the wind to a suitable landing site.
- Autorotate
- Shoulder Harness - Lock
If time and altitude permit: - Mayday - Transmit
- Transponder - Emergency
- Engine Restart in Flight Procedure - as required
Engine Failure at High Airspeed and Low Altitude
- Cyclic - Immediately apply aft
Warning: Rapid cyclic movement may cause mast bumping.
- Autorotate
Overtorque
Indications:
1. Torque guage flashes twice per second.
2. TRQ caution light flashes twice per second.
3. Torque limit exceeded.
If overtorque exceeding 120%:
1. Land as soon as possible.
If overtorque of 120% or less:
2. Land as soon as practicable.
Overtemp
Indications:
1. TOT gauge flashes twice per second.
2. TOT caution light flashes twice per second.
3. TOT limit exceeded.
- Land as soon as possible.
Overspeed
Indications:
Ng, Nf, Nr limits exceeded
- Land as soon as possible
Compressor Stall
Indications:
1. Popping, rumbling, or loud banging.
2. Abnormal vibrations.
3. Rapid rise or flictuations in TOT.
4. Torque fluctuations with yaw kicks.
5. Ng fluctuation.
6. Loss of power.
Note (outside of EP): Bleed valve flutter is a mild pop or series of pops and may occur while opening the twist grip. The bleed valve flutter may cause slight momentary TOT or torque changes. Any additional indications should be reason to classify this as a compressor stall.
Warning: This emergency may result in engine failure.
- Collective - Lower
Note: Power (collective) reduction will often eliminate compressor stalls.
- ENG anti ice switch - ON
- Cabin heat valve - ON
- Check power available
Note: Power available is considered sufficient if level flight can be maintained with Nr at 90% or higher without re-aggravating the compressor stall.
If power is insufficient to maintain level flight:
5. Autorotate
6. Twist grip - Flight idle
Note: If some usable power exists but level flight cannot be maintained, that power, if sufficient, may be utilized to effect a landing or minimize rate of descent enroute to suitable site for autorotation.
- Land as soon as possible.
Note: If power available exceeds power required to hover in ground effect, a normal approach to a hover can be executed. If power available is less than power required to hover, but level flight can be maintaiend, fly to a safe landing area and execute a no-hover landing or sliding landing. Terrain permitting, a sliding landing requires the least amount of power.
Note: Depending on time, altitude, and suitability of the landing site the pilot may attempt to increase the twist grip after the compressor stall has cleared to effect a power on landing. Increasing the twist grip may re-aggravate the compressor stall.
Underspeeding Nf/Nr
Indications:
1. Low Nr
2. Low Nf
Warning: This emergency may result in engine failure.
- Collective - Lower as required to maintain a minimum of 90% Nr.
- Twist grip - Full open.
- GOV RPM - Full increase.
If underspeed persists:
4. Check power available.
Note: Power available is considered to be sufficient if level flight can be maintained with Nr at 90% or higher.
If power is not sufficient:
5. Autorotate.
Note: If some usable power exists but level flight cannot be maintained, that power, if sufficient, may be utilized to effect a landing or minimize rate of descent en route to a more suitable site for autorotation.
If sufficient power is available:
6. Land as soon as possible.
Note: If power available exceeds power required to hover in ground effect, a normal approach to a hover can be executed. If power available is less than power required to hover, but level flight can be maintained, fly to a safe landing area and execute a no-hover landing or sliding landing. Terrain permitting, a sliding landing requires the least amount of power.
Engine Overspeed (Nf) Rotor RPM (Nr)
Indications:
1. Nr increase.
2. Nf increase.
3. Ng increase
4. TOT increase.
5. Right yaw.
6. Engine noise increase.
- Twist grip - Reduce (to maintain Nf/Nr in operating range)
- Collective/twist grip - Coordinate
- Land as soon as possible
Fuel Control Failure
Indications:
If TOT is fluctuating, it will be fluctuating in the same direction as Ng due to erratic fuel scheduling.
1. Erratic Nf/Nr
2. Fluctuating Ng and/or TOT
Procedures:
1. Collective - Adjust as required to maintain Nr in operating range
2. Twist grip - Adjust as required to maintain Nf in operating range
3. Land as soon as possible
Warning: This emergency may result in engine failure.
Engine Restart in Flight
- Ng - Note.
If Ng is below 12 %:
Note: Ng will not decrease below minimum starting speed within 10 seconds because of rotational inertia plus possible ram effect. The twist grip can be left full open, since fuel flow during the start will be on the normal start acceleration schedule.
- Twist grip - Close
- Starter - On
- At 12 % Ng, twist grip - full open.
If Ng is 12 % or above:
5. Starter - On
If light off occurs:
6. At 58 % Ng, starter - Off
7. Land as soon as possible
Note: Main generator and BUS/TIE RELAY (C) may beed to be reset.
Main Drive Shaft Failure
Indications:
1. Nr decrease
2. Nf indication higher than Nr
3. Left yaw
4. Loud bang/sound of overspeeding engine
5. Low torque
- Autorotate
- Twist grip - Adjust, if necessary, to maintain Nf in operating range.
Warning: The engine must continue to operate to provide tail rotor drive. Tail rotor authority may be lost if Nf is allowed to go below 80 %.
Note: The Nf governor should bring the Nf back to 100% with the twist grip full open.
When on deck:
3. Emergency shutdown - Complete
Engine Chip
Indications:
1. Illumination of the ENG CHIP and CLEAR CHIP caution lights.
Warning: This emergency may result in engine failure.
- Check for secondary indications.
If secondary indications exist:
2. Land as soon as possible.
If no secondary indications exist, proceed as follows:
First Chip light:
3. Press CLEAR CHIP
If ENG CHIP remains:
4. Land as soon as possible.
If ENG CHIP Extinguishes:
5. Note time and continue flight.
Second Chip Light:
If within 30 minutes of the fitst:
6. Land as soon as possible.
If more than 30 minutes have elapsed since the first light:
7. Proceed as with the first light.
Any subsequent ENG CHIP caution light within 50 hours of the first:
8. Land as soon as possible.
Abort Start
Abort start under the following conditions:
1. Battery voltage stabilized below 17V.
2. TOT fails to rise after twist grip is rotated to flight idle and Ng fails to rise above 20% (igniter failure).
3. TOT rises more slowly than normal and Ng rises slowly and stabilizes (Hung Start).
4. TOT exceeds limits and TOT caution light flashes twice per second (Hot Start)
5. Engine oil pressure remains at 0 psi.
6. Rotors not turning by 25% Ng.
7. Transmission oil pressure not indicated by 30% Nr
Caution (outside EP): An excessive rise in TOT, TOT rapidly accelerating through 840 degrees, and/or the battery voltage stabilized below 17 volts on starter engagement particularly when combine, indicates an increased potential for a hot start and may necessitate aborting the start to preclude an overtemp.
- Twist grip - Close
If light off occurred:
2. Starter - Off after TOT stabilizes at 400 degrees C or below.
If light off did not occur:
3. Motor engine for a minimum of 10 seconds.
Caution:
Failure to use a GPU/Battery cart on subsequent attempts may result in a hot start.
Caution:
Following an aborted start, care must be taken to remove any residual fuel in the combustion chamber. Failure to do so may result in a hot start.
Mast Bumping
Indications:
1. Sharp two-rev knocking
If mast bumping is suspected:
1. Establish positive G load and/or balanced flight (as req)
2. Land immediately
Note: If mast bumping occurs while on deck, maintenance action is required prior to flight.
Transmission Malfunction
Indications:
1. Abnormal tranmission temperature or pressure indications.
2. TRANS OIL PRESS caution light.
3. TRANS OIL TEMP caution light.
4. TRANS CHIP and CLEAR CHIP caution lights
and/or:
5. Abnormal sound from the transmission area.
If failure is imminent:
Warning: Possible indications of an imminent transmission failure may include yaw attitude excursions with no control input, an increase in power required for a fixed collective setting, increased noise, or increased vibration levels.
- Land immediately
- Shoulder harness - Lock
If failure is not imminent
3. Land as soon as possible
Note: Transiting as a minimum power required airspeed and low altitude may permit a quick flare and immediate landing in the event of an imminent transmission failure.
Transmission Chip
Indications:
1. TRANS CHIP and CLEAR CHIP caution lights.
First TRANS CHIP caution light:
1. Check for secondary indications.
If secondary indications exist:
2. Transmission Malfunction Procedure - Perform
If no secondary indications exist:
3. Press CLEAR CHIP
If TRANS CHIP caution light remains illuminated:
4. Transmission Malfunction Procedure - Perform
If TRANS CHIP light extinguishes:
5. Note the time and continue flight.
Second TRANS CHIP caution light.
If within 30 minutes of the first:
6. Transmission Malfunction Procedure - Perform
If more than 30 minutes have elapsed since the first TRANS CHIP caution light:
7. Proceed as with the first TRANs CHIP caution light
Any subsequent TRANS CHIP caution light within 50 hours of the first:
8. Transmission Malfunction Procedure - Perform
Sprag Clutch Slippage
Indications:
When the twist grip is increased to full open, the pilot may experience the following:
1. Nf indication higher than Nr.
2. Low torque indication.
3. Ng and TOT indications lower than normal and not responsive to collective.
- Autorotate
- Twist grip - FLT IDLE
If time and altitude permit:
3. Twist grip - Smoothly rotate to full open
If Nf/Nr are married:
4. Collective - Increase
Note: Multiple attempts to reengage the sprag clutch are permitted dependent on time and altitude.
If sprag clutch continues to slip:
5. Autorotate
6. Twist grip - closed
If sprag clutch reengages:
7. Land as soon as possible
Caution: After completing the autorotative landing, ensure the twist grip is secured. Failure to do so may result in sudden reengagement of the sprag clutch, causing severe damage to the drive system.
Complete Loss of Tail Rotor Thrust
Indications:
1. Pedal input has no effect on helicopter trim.
2. Right yaw (left slideslip)
3. Left roll of fuselage along the longitudinal axis.
4. Loud bang.
Delayed Onset Indications:
1. High frequency vibrations.
2. Whining, grinding.
3. Yaw kicks, often during power changes.
4. Restricted or difficult movement of pedals.
5. Unusual pedal positions.
6. T/R chip and clear chip caution lights.
In a hover:
1. Twist grip - Flight idle
2. Cyclic - Eliminate drift
3. Collective - Increase to cushion landing
Transition to forward flight or hover/air taxi:
1. Twist grip - flight idle
2. Cyclic - Eliminate sideward drift
3. Collective - Increase to cushion landing
At Altitude:
4. Collective - Lower to control yaw
If yaw is not controllable:
5. Autorotate
6. Twist grip - Flight Idle
If yaw is controllable:
7. Continue powered flight and set up to a suitable landing area at or above minimum rate of descent autorotational airspeed.
Warning: Autoration may be the safest option. Attempting to control a loss of tail rotor thrust in powered flight requires considerable skill and may result in loss of aircraft control.
Warning: Airspeed indications during side-slip are unreliable. At airspeeds below approximately 50 Knots, the side-slip may suddenly become uncontrollable, and the helicopter will begin an unrecoverable vertical axis “flat spin”
Warning: If attempting to achieve higher airspeeds, care must be taken to avoid excessive cyclic inputs coupled with large power settings that could lead to mast bumping or rapid nose tucking.
Note: Depending on the nature of the failure and degree of damage, airspeeds between 50 -72 KIAS may provide the best opportunity to maintain level flight.
Note: A non-typical nosedown attitude may be required to achieve a desired airspeed due to increased drag on the tail.
Note: Turns to the right may provide greater controllability of airspeed and potentially minimize altitude loss.
Note: Banking to the left will aid in counteracting torque.
- Autorotate
- Twist grip - Rotate to flight idle prior to touchdown
Warning: In the autorotation, maintain airspeed above minimum rate of descent airspeed until flare to avoid loss of yaw control.
Warning: With the engine at flight idle, in the absence of torque, the lift produced by the vertical fin may tend to yaw the nose to the left at faster speeds. As airspeed slows and Nr decays, the decelerating rotorhead and swashplate friction will create additional left yaw, increase the chance for rollover. Depending on landing profile, consideration should be given to leaving twist grip open until pulling collective at the bottom of the autorotation to allow control of yaw with twist grip.
Tail Rotor Chip Caution
Indications:
1. Illumination of T/R CHIP caution light.
2. Illumination of CLEAR CHIP caution light.
- Land as soon as possible.
Warning: This emergency may result in complete loss of tail rotor thrust.
Note: An autorotative profile or low-powered approach minimizes stress on the tail rotor.
Fixed Pitch in a Hover
Right yaw indication: Pilot unable to control right yaw in a hover with pedal pedal input. If power is increased, it will aggravate the degree of yaw.
Left yaw indication: Pilot unable to control left yaw in a hover with pedal input. If power is decreased, it will aggravate the degree of yaw.
Fixed Pitch Pedal in a Hover - Right Yaw:
If rate of rotation is not excessive and landing surface is smooth and firm:
1. Collective - decrease to affect a power on landing.
If rate of rotation is excessive or landing surface is unsuitable for power on landing:
2. Twist grip - Reduce as nose approaches windline.
3. Cyclic - Eliminate drift
4. Collective - Increase to cushion landing
Fixed Pitch in a Hover - Left Yaw:
If rate or rotation is not excessive and landing surface is smooth and firm:
1, Collective - Decrease to affect a power on landing
If rate of rotation is excessive or landing surface is unsuitable for power on landing:
2. Smoothly increase collective to stop the left yaw
3. When the left yaw has stopped, smoothly decrease collective to set up for a landing
Note: Steps 2 and 3 may need to be repeated until acceptable conditions are established for landing.
Note: Twist grip manipulation may be required to aid recovery.
- Eliminate lateral drift with cyclic as the aircraft settles
- Continue to smoothly lower collective once on deck to control yaw and transfer aircraft weight to the skids
Fixed Pitch at Altitude
Probable cause: see fixed pitch in a hover.
- Collective/Airspeed - Adjust as required to control yaw
- Setup approach to a smooth suitable landing site
- Airspeed - Maintain above 50 knots on final
- Flare - initiate no higher than 50 ft to reach a 5 ft hover
- Use appropriate fixed pitch in a hover procedure
Warning: Attempted wave off, loss of translational lift, or excessive collective input could result in excessive yaw and uncontrolled flight.
Note: Determining torque required to maintain balanced flight will allow crew to determine approximate power settings allowable during landing.
Note: Upon power reduction on final, the nose of the aircraft will tend to be out to the left. The nose of the aircraft may yaw further left during the initial part of the flare.
Loss of Tail Rotor Effectiveness
- Pedals - Full left
- Collective - Lower (as altitude permits)
- Airspeed - Increase
If spin cannot be stopped:
4. Autorotate
High Frequency Vibration
- ECS - OFF
If vibrations continue:
2. Land as soon as possible
If vibrations cease:
3. Land as soon as practicable
Warning: This emergency may result in complete loss of tail rotor thrust.
Note: An autorotative profile or low powered approach minimizes stress on the tail rotor.
Hydraulic Power Cylinder Malfunction
Indications:
1. Cyclic/collective control displaces to abnormal position.
2. Pilot control of cyclic/collective is difficult or impossible.
Note (outside of EP): Odd or unusual stick forces will be felt in boost off situation. Because of excessive forces required for control manipulation, a shallow approach with a sliding landing to a hard, smooth surface is recommended.
- HYDRAULIC BOOST switch - OFF
Warning: Hydraulic system will not secure if HYD BOOST circuit breaker is out and the pilot will be unable to maintain control of the aircraft.
- Helicopter - Regain control
- Airspeed - Adjust (to obtain most comfortable control movement level)
- Land as soon as possible
Warning: In the event of a complete loss of electrical power (B) or a loss of electrical power to the ESS No. 2 Bus (e.g. faulure of the Main Generator and Main Battery) (C), the hydraulic system will reenergize in the malfunction mode. The pilot will be unable to override the hydraulic boost solenoid.
Battery Hot Caution
Indications:
1. BATTERY HOT caution light.
- BAT Switch - OFF
- Land as soon as possible
Note: (C) Switching the Main Battery Off opens the main battery relay, which causes the STBY BATT ON light to illuminate. As long as the ESS No. 1 bus is being powered normally, the standby battery will not be depleted.
Battery Temp Caution
Indications:
1. BATTERY TEMP Caution light
- BAT Switch - Off
- Flight may be continued
Note: (C) Switching the Main Battery Off opens the main battery relay, which causes the STBY BATT ON light to illuminate, As long as the ESS No. 1 bus is being powered normally, the standby battery will not be depleted.
Spare Caution
Indications:
1. SPARE caution light
Illumination of the SPARE caution light indicated improper wiring of the caution panel.
- Check for other indications.
- Land as soon as possible
Fuel Boost Pump Failure
Indications:
1. FUEL PUMP caution light.
2. Indicated fuel pressure of zero (dual pump failure)
- Descent - Initiate if above 6,000 feet PA and flight permits
- Fuel pressure and quantity - Note
Warning: With one of both boost pumps inoperative, 10 gallons is unusable.
If both fuel boost pumps have failed (fuel pressure at zero) or a single pump has failed (fuel pressure 4-30 psi) with fuel quantity below 20 gallons:
Warning: Dual boost pump failure may lead to engine failure.
- Land as soon as possible
If only one boost pump has failed (fuel pressure 4-30 psi):
4. Land as soon as practicable
Airframe Fuel Filter Caution
Indications:
1. A/F Caution light
- Land as soon as possible
Warning: This emergency may result in engine failure.
Suspected Fuel Leakage
Indications:
1. Unusual fuel usage
2. Fuel fumes in cockpit
3. Streaming fuel
- Land as soon as possible
If time and altitude permit:
2. Transmit position and intentions.
3. Unnecessary electrical equipment - Secure
Warning: If an air leak exists in the fuel lines between the boost pumps and engine, turning off all electrical power could cause an engine flameout due to a total loss of boost pump pressure.
When on deck:
4. Emergency shutdown - Complete
Engine Fire in Flight
Indications:
1. Fire light
2. Smoke
3. Flames
Warning: This emergency may result in engine failure.
- Confirm existence of fire
If fire exists:
2. Land immediately
If fire not confirmed:
3. Land as soon as possible
When on deck:
4. Emergency shutdown - Complete
Fuselage Fire
- Land immediately
When on deck
2. Emergency shutdown - Complete
Warning: Fire extinguisher fluid vapors are dangerous; fire extinguisher use should be limited to a well ventilated area. A moving TH-57 with the cabin vents and windows open is considered to be a well ventilated area.
Note: a sideslip may be desirable to keep the flame from spreading.
Electrical Fire - Unknown Origin
Indications:
1. Smoke
2. Fumes
3. Sparks
4. Loadmeter shows excessive load
5. DC voltmeter shows a decrease in voltage
- BAT switch - OFF
- (C) STBY GEN switch - OFF
- (C) If in VMC, STBY ATT IND switch - OFF
- MAIN GEN switch - OFF
If fire persists:
5. Land immediately
If fire extinguishes:
6. Land as soon as possible
When on deck:
7. Emergency shutdown - Complete
Note: Ensure corresponding bus supply circuit breakers are in to provide power to desired electrical equipment.
Note: Voltmeter will not indicate battery voltage until battery bus supply and voltmeter circuit breakers are in.
Note: Flight operation can be maintained without battery and generator. Instruments powered by the 28 Vdc power, however, will be inoperable.
Note: (C) The voltmeter select switch may aid in identifying the location of the fire.
Electrical Fire - Known Origin
Indications:
1. Smoke
2. Fumes
3. Sparks
4. Loadmeter shows excessive load
5. DC voltmeter shows a decrease in voltage
- Affected equipment - Secure
- Affected circuit breakers - Pull
If fire persists:
3. Electrical Fire Unknown Origin procedure - Execute
If fire extinguishes:
4: Land as soon as practicable
Smoke and Fume Elimination
Indications:
1. Fumes in cockpit
2. Smoke in cockpit
- ECS and DEFOG Blower - OFF
- Vents/Windows - Open
If smoke/Fumes persist:
3. Slip or skid aircraft to eliminate smoke and fumes.
If source of the smoke and/or fumes cannot be identified:
4. Land as soon as possible
Post Shutdown Fire (Internal)
Indications:
1. TOT rises above 400 degrees
2. Flames or smoke coming from engine
- Starter - Engage
- Fuel valve - OFF
- Igniter circuit breaker - Pull
- Starter - Secure after fire is extinguished
Immediate Landing/Ditching
Warning: Jettisoning the left cabin door in forward flight may cause catastrophic damage to the tail rotor.
Warning: Failure to remain strapped in the aircraft until all violent motion stops may result in injury or incapacitation.
- Crew and Passengers - Alert
- Shoulder Harness - Lock
- Mayday - Transmit
- Transponder - Emergency
- Doors - Open/Jettison - as req
- Landing Light/Search Light - as req
When on deck:
7. Emergency Shutdown - Complete
If water landing:
8. Underwater Egress - Execute
Underwater Egress
Warning: Inflation of LPU inside of aircraft will impede egress.
Warning: Failure to jettison doors prior to water entry may prevent opening of doors until cabin fills with water. Cabin misalignment due to water landing may also prevent opening of doors.
Warning: Failure to disconnect ICS cords may impede egress.
- SEBD - Don as req
- Communication cords - Disconnect
- Doors - Open/Jettison
- Place hand on known reference point
Once all violent motion has stopped:
5. Shoulder harness/lapbelt - Release
6. Exit helicopter
After egress:
7. Swim clear and inflate LPU
Emergency Shutdown
Indications:
1. Fire warning light illuminated
2. Smoke
3. Fuel flames
4. Fire
5. Indication from ground personnel
6. Grinding noises or apparent drive train damage
- Twist grip - Close
- Fuel valve - OFF
- BAT switch - OFF
- (C) STBY ATT IND switch - OFF
- (C) Rotor brake - Engage immediately
- Helicopter - Egress as req. Use fire bottle or get clear of the aircraft as applicable
Warning: After exiting aircraft, beware of rotor blades.
Icing
Indications:
1. OAT less than 4 degrees C and
2. Visible moisture
- ENG ANTI ICING - ON
- PITOT HEAT switches - HEAT
- (C) Alternate static source knob - As req
- Descend or climb to a warmer temperature or vacate clouds/moisture
If unable to get clear of icing conditions
5. Land as soon as possible
Warning: Monitor engine instruments and be prepared for partial or complete power loss.
Torquemeter Wet Line Rupture
Indications:
1. Low needle indication and digital readout
- Monitor engine oil instruments
- Land as soon as possible
Engine or Transmission Oil Pressures
Indications:
1. Erratic gauge fluctuations, or
2. Engine oil pressure not within normal range, or
3. Transmission oil pressure not 30-70 psi
If engine oil pressure is exhibiting abnormal indications:
1. Land as soon as possible
If transmission oil pressure is exhibiting abnormal indications
2. Transmission Malfunction Procedure - Perform
Warning: Excessive power changes may expedite engine or transmission failure
Note: Illumination of the TRANS OIL PRESS caution light is common, while the twist grip is at flight idle, however, the gauge should indicate positive transmission oil pressure.
Engine or Transmission Oil Temperature Malfunction
Indications:
1. Temperature limit exceeded, or
2. Gauge fluctuates, or
3. Gauge indicates zero
If engine oil temperature gauge exceeds red line limitations:
1. Land as soon as possible.
If transmission oil temperature gauge exceeds red line limitations:
2. Transmission Malfunction Procedure - Perform
If either oil temperature gauge fluctuates or falls to zero:
3. Land as soon as practicable
Pitot Static Instruments
Indications:
1. Airspeed, vertical speed, or altimeter fluctuates erratically or gives false indications, and
2. Power and attitude instruments are normal
- PITOT HEAT switch(es) -HEAT
If pitot heat does not remedy the situation, accomplish the following:
2. (C) Alternate static source knob - Pull
If icing conditions are present:
3. Icing procedures - Execute
If icing conditions are not present
4. Land as soon as practicable
Rotor Blade Stall
Indications:
1. Progressively increasing two-per-revolution vibrations
2. Loss of longitudinal control and severe feedback in the cyclic.
3. Violent vertical nose oscillations independent of cyclic position.
- Severity of maneuver - Decrease
- Collective - Lower
- Airspeed - Decrease
- Altitude - Descend, if flight permits
- Rotor RPM - Increase
Warning: Entry into severe blade stall can result in structural damage to the helicopter
Vortex Ring State
Causes:
1. Rates of descent greater than 800 fpm at airspeeds less than 40 KIAS
2. High, steep, and/or downwind approahes
Indications:
1. Rapid descent rate increase
2. Pitch and roll oscillations
3. Increase in overall vibration level
4. Loss of control effectiveness
- Controls - As req to clear VRS
If impact is imminent:
2. Level skids to conform to terrain
Power Required Exceeds Power Available
Indications:
1. Uncommanded descent with torque at maximum available
2. Rotor droop
3. Loss of tail rotor authority
- Collective - Lower as req to maintain a minimum of 90% Nr
- Twist grip - Full open
- Angle of bank - Level wings
- Airspeed - 50 KIAS (minimum power required airspeed)
- Jettison - As req
If impact is imminent:
6. Level skids to conform to terrain
7. Cushion the landing
Dynamic Rollover
Indications:
1. Excessive roll rates about a pivot point when lift approximately equals weight
2. Lateral control becomes sluggish or ineffective
3. Cyclic contacts lateral stop
- Collective - Lower to stop the roll
- Cyclic - Neutral
Warning: With one skid on the ground and thrust approximately equal to the weight, if the lateral control becomes sluggish or ineffectual, contracts the later stop, or if bank angle or roll rates become excessive (15 or 10 degrees per second respectively) the aircraft may roll over on its side.
Warning: Failure to keep the aircraft in trim during takeoff or landing could result in dynamic rollover.
Uncommanded Right Roll During Flight Below 1G
Indications:
1. Uncommanded right roll
2. Reduced cyclic effectiveness
- Cyclic - Immediately apply aft to establish positive G load on rotor, then center laterally
Warning: LAteral cyclic is decreasingly effective below 1 G and increases main rotor flapping, which can result in mast bumping
When main rotor returns to a positive thrust condition:
2. Controls - As req to regain balanced flight
If mast bumping has occured:
3. Land immediately
Emergency Descent
- Collective - Lower (to minimum pitch)
- Airspeed - 130 KIAS (122 KIAS with FCS on)
Note- During recovery, Nr may tend to overspeed
