Emergency Procedures and Limits (Comprehensive)

Question 1

Warning (Definition)

Answer 1

An operating procedure, practice, etc., which, if not correct followed, could result in personal injury or loss of life.

Question 2

Caution (Definition)

Answer 2

An operating procedure, practice, etc…, which, if not strictly observed, could result in damage to or destruction of equipment.

Question 3

Note (Definition)

Answer 3

An operating procedure, condition, etc…, which is essential to highlight.

Question 4

Torquemeter

Answer 4

[Green] 0% to 85% Continuous Operation
[Yellow] >85% to 100% Take-Off Power Range (5 Minute Limit)
[Red] 100% Maximum
Transient Torque Limit is 100% to 110% (5 Seconds Maximum).
INTENTIONAL USE IS PROHIBITED.

Question 5

Turbine Outlet Temperature Gauge

Answer 5

Note: The Red Warning light illuminates when either of the following conditions are exceeded: 810 to 927 degrees Celsius for 10 Seconds, or higher than 927 degrees Celsius.
[Green] 100 to 738 degrees Celsius Continuous Operation.
[Yellow] 738 to 810 degrees Celsius Take-off Power Range (5 Minute Limit)
[Red] 810 degrees Celsius Maximum
810 to 843 degrees Celsius, 6 second transient (Not to be used intentionally).

927 degrees Celsius Maximum during Starting and Shutdown (10 seconds Maximum).

Question 6

Wind Limitations

Answer 6

A) The helicopter can be started in a maximum wind velocity of 45 knots and a maximum gust spread of 15 knots.

Note: Gust spreads are not normally reported. To obtain spread, compare minimum and maximum velocities.

B) Maximum wind for hovering is 35 knots crosswind and 30 knots tailwind.

C) For hover operations at gross weights above 3200 lbs:

• 1) IGE maneuvers - refer to chapter 8.
• 2) OGE maneuvers - calm wind only.

Question 7

Rotor Limitations

Answer 7

[Red] 90% Minimum Operation
[Yellow] 50 to 60% Accelerate through this range
[Green] 90 to 107% Normal Operation
[Red] 107% Maximum

Power on Transient Rotor Droop Limit is 95% (5 seconds Maximum).

Question 8

Engine Starting Limitations

Answer 8

During starting if N1 does not reach 58% in a total time of 45 seconds (or 60 seconds below 10 degrees Celsius FAT), close throttle and press starter button until TOT is below 200 degrees Celsius. If engine fails to start on third attempt, abort start and make an entry on DA Form 2408-13-1. Starter engage time limits above do not apply to engine starting limitations should abort start procedures become necessary.

Question 9

Engine Oil Pressure

Answer 9

[Yellow] 50 PSI Minimum below 78% N1.
[Green] 90 PSI Minimum from 78% to 94% N1.
[Green] 115 PSI Minimum above 94% N1 (double wide arc).
[Red] 50 PSI minimum, 130 PSI Maximum.

Note: During cold temperature operation the oil pressure may exceed the maximum of 130 PSI. Stabilize the engine at idle speed of 60 to 64% until the engine oil temperature is above 0 degrees Celsius and the engine oil pressure is within normal limits.

Question 10

Land as Soon as Possible

Answer 10

Land without delay to the nearest suitable area (i.e. open field) in which a safe approach and landing is reasonably assured. (The primary consideration is to ensure the survival of the occupants).

Question 11

Land as Soon as Practicable

Answer 11

The landing site and duration of the flight are at the discretion of the pilot. Extended flight beyond the nearest approved landing area is not recommended. (The primary consideration is the urgency of the emergency).

Question 12

Gas Producer (N1) Gauge

Answer 12

[Green] 60 to 105% Continuous Operation
[Red] 105% Maximum
105 to 106% Transient - (15 seconds Maximum)

Question 13

Autorotate

Answer 13

The term Autorotate is defined as adjusting the flight controls as necessary to establish an autorotational descent and landing.

1. Collective - Adjust as required to maintain rotor RPM (90 to 107%).
2. Pedals - Adjust. Crab or slip as required.
3. Throttle - Adjust as necessary. Close as required.
4. Airspeed - Adjust as required.

Question 14

Emergency Shutdown

Answer 14

The term Emergency Shutdown is defined as engine shutdown without delay.

1. Throttle - Close.
2. Fuel Valve Switch - OFF.
3. Battery Switch - OFF as desired. Before turning the battery switch off during an in-flight emergency, the pilot should consider a “MAYDAY” call, selecting emergency on the transponder and the possible effects of total electrical failure.

Question 15

Engine Failure at a Hover

Answer 15

Autorotate.

Emergency Shutdown - Accomplish after landing.

Question 16

Emergency Equipment

Answer 16

a. A fire extinguisher is located on the center pedestal between the pilot and the co-pilots stations.
b. A first aid kit is located in one of the pouches by the passenger seat.
c. Emergency Locator Transmitter (ELT): See Chapter 2.

Question 17

Emergency Exits/Entrance

Answer 17

Emergency exit or entrance is through either cabin or crew door. If the door(s) will not open, the windows should pop out if pressure is applied to the outer edges of the window. If the window will not pop out, kick out the plexiglass to exit the aircraft.

Question 18

Engine Fail - Cruise

Answer 18

Autorotate.

Emergency Shutdown - Accomplish during descent if time permits.

Question 19

Hot Start

Answer 19

During starting or shutdown, if TOT limits are exceeded, or it becomes apparent the TOT limits may be exceeded, proceed as follows:

a. Starter button - Press and hold until TURB OUT TEMP is less than 200 degrees Celsius.
b. Throttle - Closed.
c. Fuel Valve Switch - Off.
d. Complete Shutdown.

Question 20

Engine Oil Temperature

Answer 20

[Green] 0 degrees Celsius to 107 degrees Celsius Continuous Operation.

[Red] 107 degrees Celsius Maximum.

Question 21

Engine/Fuselage/Electrical Fire - Ground

Answer 21

Emergency Shutdown.

Question 22

Engine/Fuselage Fire - Flight

Answer 22

If a fire is observed during flight, prevailing circumstances such as VMC, IMC, night, altitude, and landing area available must be considered in order to determine whether to execute a power-on, or power-off landing.

a. If power-on landing:
1. Land as soon as possible.
2. Emergency Shutdown - Accomplish after landing.
b. If power-off landing:
1. Autorotate.
2. Emergency shutdown - Accomplish during descent if time permits.

Question 23

Electrical Fire - Flight

Answer 23

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. In the event of electrical fire or suspected electrical fire in flight:

a. BATT and MAIN GEN switches - Off.
b. IFR STDBY GEN switch - Off.
c. Land as soon as possible.
d. Emergency shutdown - Accomplish after landing.

Question 24

Transmission Oil Pressure

Answer 24

[Green] 30 to 50 PSI Continuous Operation.

[Red] 30 PSI Minimum, 70 PSI Maximum.

Question 25

Transmission Oil Temperature

Answer 25

[Green] 15 degrees Celsius to 110 degrees Celsius Continuous Operation.

[Red] 110 degrees Celsius Maximum.

Question 26

Partial or Complete Power Loss (Indications and Warning)

Answer 26

Warning: Do not respond to the RPM warning system by entering autorotation and reducing the throttle without first confirming engine malfunction by one or more of the other indications. Normal indications signify that 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.

Indications: The indications of an engine malfunction, either a partial or a complete power loss are: left yaw, drop in engine RPM ( N1 and N2), drop in rotor RPM, low RPM audio alarm (steady tone), illumination of the LOW ROTOR RPM caution light, and change in engine noise. If the power loss is total, the ENGINE OUT warning light will activate and an intermittent (warbling) tone will be heard.

Question 27

Engine Restart w/Caution

Answer 27

Caution: Do not attempt air start above 12,000 feet MSL (TURB OUT TEMP rises too fast to control).

After an engine failure in flight, 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. 52 to 60 KIAS is recommended during the descent. Under ideal conditions, approximately one minute is required to regain powered flight from the time the attempted start is begun. If the decision is made to attempt an in-flight start:

Throttle - Close.

Fuel Valve Switch - On

Attempt start.

Land as soon as possible.

Question 28

Airspeed Indicator w/Note

Answer 28

Note: Autorotation above 100 KIAS will result in high rates of descent and low rotor RPM.

Airspeed:

[Green] 0 to 130 Knots Continuous Operation.

[Red] 130 Knots Maximum.

[B] 100 Knots Maximum for Autorotation.

VNE for internal Gross Weight above 3,200 pounds is 78 KIAS, not to exceed placarded VNE.

Question 29

Fuel Pressure Gauge

Answer 29

[Red] 4.0 PSI Minimum.

[Green] 4.0 to 30 PSI Continuous Operation.

[Red] 30 PSI Maximum.

[Red] 8 PSI Minimum - Type A, A-1, JP-5, JP-8 fuel below -18 degrees Celsius (0 degrees Fahrenheit) to -32 degrees Celsius (-25 degrees Fahrenheit)

Question 30

Load Meter

Answer 30

[Red] 70% Maximum

Question 31

Engine Compressor Stall

Answer 31

Engine compressor stall may be characterized by a sharp rumble or a series of loud sharp reports, severe engine vibration and a rapid rise in TURB OUT TEMP. Should engine compressor stall occur:

Collective - Reduce.

Engine Anti-ice and Heater switches - Off.

Land as soon as possible.

Question 32

Fuel Quantity Gauge

Answer 32

[Red] On empty.

Question 33

Power Turbine Indicator

Answer 33

[Red] 97% Minimum Operation.

[Green] 97 to 100% Continuous Operation.

[Red] 100% Maximum.

N2 75 to 88%, 60 seconds Maximum (time not cumulative).

Question 34

N2 Transient Overspeed Limits

Answer 34

0 to 32% Torque = 107 N2 15 seconds Maximum

> 32% to 100% Torque = 103 N2, 15 seconds Maximum.

Anything in between, refer to chart.

Question 35

Engine RPM Limitations - Warning

Answer 35

Use of the throttle to control rpm is not authorized. (Refer to Chapter 9, Emergency Procedures and the USAAWC Flight Training Guide for exceptions).

Question 36

Turbine Outlet Temperature Limits - Caution

Answer 36

Exceeding the limits of 810 degrees Celsius TOT or 100% torque may cause N1 topping with resultant rotor droop.

Question 37

Engine Overspeed

Answer 37

Engine overspeed will be indicated by a right yaw, rapid increase in both rotor and engine RPM, and an increase in engine and rotor noise. If an engine overspeed is experienced:

1. Collective - Increase to load the rotor and sustain engine/rotor RPM below the maximum operating limit.
2. Throttle - Adjust until normal operating RPM is attained.
3. Land as soon as possible. Perform a power-on approach and landing by controlling the RPM manually with the throttle.

If RPM cannot be controlled by throttle adjustment:

4. Autorotate when over a safe landing area.
5. Emergency shutdown - Accomplish during descent if time permits.

Question 38

Engine Underspeed

Answer 38

If an engine underspeed occurs, the collective must be adjusted downward to maintain rotor RPM within limits. If powered flight with rotor in the green can be accomplished:

Land as soon as possible in an area that will permit a run-on landing.

An engine underspeed below 90% results in rotor RPM decay below minimum safe limits. Should this occur:

Autorotate.

Emergency Shutdown - Accomplish during descent if time permits.

Question 39

CG Longitudinal and Lateral Limitations

Answer 39

Longitudinal

VMC Center of gravity limits are from 106.0 to 114.2. Fwd and aft limits are variable depending upon gross weight and aircraft configuration.

Lateral

Note: Lateral CG limits vary depending on longitudinal CG location.

a. 3.0 inches left of helicopter centerline.
b. 4.0 inches right of helicopter centerline.

Question 40

VMC Weight Limits

Answer 40

a. Maximum allowable ramp weight is 3,350 pounds.
b. Maximum allowable gross weight for hover/flight is 3,350 pounds.
c. Minimum front seat weight is 170 pounds.

Question 41

Autorotation - Steady State Factors

Answer 41

Rotor RPM is within limits.

The aircraft is at the correct airspeed.

The aircraft is descending at a normal rate.

The aircraft is in a position to terminate in the intended landing area.

Question 42

AR 40-8 Restrictions

Answer 42

6 hours after Centrifuge runs.

12 hours after alcohol, immunization, anesthesia (local/regional), and simulator sickness.

24 hours after plasma donation, scuba diving, compressed air, hypobaric chamber (>25k feet), and hyperbaric chamber.

48 hours after anesthesia (general/spinal/epidural).

72 hours after blood donations (>200cc).

Question 43

Engine Surges

Answer 43

If surges in engine RPM are experienced:

a. Governor Increase switch - Increase for maximum RPM.
b. Throttle - Adjust to 97% N2.
c. Land as soon as possible.

If engine surges are not controlled in steps a. and b. above, proceed as follows:

a. Auto rotate - When over a safe landing area.
b. Energency Shutdown - Accomplish during descent if time permits.

Question 44

Fuel Boost Pump Limitations

Answer 44

Fuel boost pumps shall be ON during normal operations.

Question 45

Fuel Boost Pump Failures

Answer 45

Warning: Operation with both fuel boost pumps inoperative is not authorized. Due to possible fuel sloshing in unusual attitudes and out of trim conditions and one or both fuel boost pumps inoperative, the unusable fuel is ten gallons.

With one or both fuel boost pumps inoperative:

Note: The engine will operate without boost pump pressure under 6,000 feet pressure altitude and one boost pump will supply sufficient fuel for normal engine operations under all conditions of power and altitude. Both fuel boost pumps shall be operating for all normal operations.

a. Descend to below 6,000 feet pressure altitude if possible.
b. Land as soon as practicable.

Question 46

Spike Knock

Answer 46

a. Spike knock occurs when the round pin in the drag-pin fitting contacts the side of the square hole of the pylon stop, which is mounted to the roof. It creates a loud noise and will occur during a rocking of the pylon. The following factors can cause spike knock; low rotor RPM, extreme asymmetric loading, poor execution of an autorotational landing, and low “G” maneuvers below +0.5 Gs.
b. Spike knock will be more prevalent during zero ground run autorotational landings than for sliding autorotational landings and running landings.
c. Spike knock in itself is not hazardous but is an indicator of a condition that could be hazardous. If spike knock is encountered, an entry must be made on the DA Form 2408-13-1 to include the flight conditions under which the spike knock occurred. An inspection will be performed by maintenance personnel before continuing.
d. During landing, starting, and rotor coastdown, spike knock could also occur, especially if there are high winds and/or the elastomeric damper is deteriorated. This type of spike knock is not considered damaging to the aircraft and does not require an entry on DA Form 2408-13-1.

Question 47

Engine Anti-Ice Limitations

Answer 47

a. Engine anti-ice shall not be used in ambient temperatures above 4 degrees Celsius.
b. Engine anti-icing shall be ON for flight in visible moisture in temperature 4 degrees Celsius or below.

Question 48

Low Inlet Pressure (Caution)

Answer 48

Takeoff with LOW INLET PRESSURE caution light illuminated is prohibited.

Question 49

Engine Starter Limits

Answer 49

a. If there is no rise in TOT within the first 20 seconds of energizing starter, limit starter energizing time to the following:

External Power

25 Seconds ON
30 Seconds OFF
25 Seconds ON
30 Seconds OFF
25 Seconds ON
30 Minutes OFF

Battery

40 Seconds ON
60 Seconds OFF
40 Seconds ON
60 Seconds OFF
40 Seconds ON
30 Minutes OFF

b. If there is a rise in TOT within the first 20 seconds of energizing starter, limit starter energizing time to the following:

External/Battery Power

1 Minute ON
1 Minute OFF
1 Minute ON
1 Minute OFF
1 Minute ON
30 Minutes OFF

Question 50

Air Conditioning Malfunction

Answer 50

The type of malfunction that would create a potential emergency involves a failure of the compressor or drive belt that would cause a noticeable vibration or noise.

Air Conditioning and Fan switch - OFF.

Land as soon as possible.

Question 51

Low Inlet Pressure

Answer 51

a. LOW INLET PRESSURE caution light - ON.
1) Engine Alternate Air Switch - Open.
2) If caution light remains on, land as soon as possible.
3) If caution light goes out, land as soon as practicable. Related engine parameters should be monitored frequently until landing.

Question 52

Engine Icing

Answer 52

Note: When anti-ice system is ON, TOT will rise for same power setting.

1) ENGINE ANTI-ICING switch - ON (if conditions warrant).
2) TURB OUT TEMP - Maintain within limits.

Question 53

Low Engine Oil Pressure/High Engine Oil Temperature

Answer 53

If the engine oil pressure is below 50 PSI or the temperature is above 107 degrees Celsius - Land as soon as possible.

Note: If engine oil pressure is falling or low and the oil temperature is rising or high, a severe leak may be present.

Question 54

Flight Restrictions at Low “G”s

Answer 54

Flight at less than +0.5g is prohibited.

Question 55

Main Drive Shaft Failure

Answer 55

A failure of the main driveshaft will be indicated by a sudden increase in engine RPM, decrease in rotor RPM, a left yaw, activation of the low RPM audio, and illumination of the ROTOR RPM light. A transient overspeed, of N1 and N2 may occur, but will stabilize. In the event of a main driveshaft failure:

Warning: The engine must remain in operation to provide power to the tail rotor. Failure to maintain engine power will result in loss of aircraft control during the autorotation. Adjust throttle as required to maintain engine RPM within normal limits.

a. Autorotate - Establish a Power ON autorotation.
b. Emergency Shutdown - Accomplish after landing.

Question 56

Clutch Fails to Disengage

Answer 56

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

a. Throttle - Open
b. Land as soon as possible.

Question 57

Un-commanded Flight Control Input Malfunction

Answer 57

Un-commanded flight control input malfunctions may be indicated through un-commanded lateral or longitudinal cyclic movements. The magnitude of the event may range from mild to severe. The duration of the event may range from one to several seconds. These conditions should not be mistaken for hydraulic power failure. In the event of an un-commanded flight control input malfunction:

a. Collective - Increase if near the ground to prevent main or tail rotor ground contact.
b. Pedal - Apply in the direction of turn.
c. Direct assistance with flight control inputs to level the aircraft.
d. Land as soon as possible.

Question 58

Smoke and Fume Elimination

Answer 58

Ventilation of the cabin to protect occupants from the effects of toxic fumes, smoke, etc., shall be immediately performed as follows:

a. Vents - Open.
b. Cockpit and Cabin Windows - Open for maximum ventilation.

Question 59

VFR, A+ Generator Failure - No Output

Answer 59

a. A no-output malfunction of the generator will be indicated by a zero indication on the DC Load Meter and an illumination of the MAIN GEN FAIL caution light. An attempt may be made to put the generator back on line by accomplishing the following:
1. GEN FIELD, and GEN RESET Circuit Breakers - Check In.
2. MAIN GEN switch - Reset then MAIN GEN. (Do not hold the switch in the RESET position.)
b. If the generator is not restored, or if it goes off line again.
1. MAIN GEN switch - Off.
2. Turn OFF all unnecessary electrical equipment.
3. Land as soon as practicable.

Question 60

Flight Control Malfunctions

Answer 60

Failure of components within the flight control system may be indicated through varying degrees of feedback, binding, resistance, or sloppiness. These conditions should not be mistaken for hydraulic power failure. In the event of a flight control malfunction.

a. Land as soon as possible.
b. Emergency Shutdown - Accomplish after landing.

Question 61

Slope Landing/Takeoff Limitations

Answer 61

Slope operations shall be limited to slopes of 8 degrees or less.

Caution: Caution is to be exercised for slopes greater than 5 degrees since rigging, loading; terrain and wind conditions may alter the slope landing capability.

Question 62

VMC Airspeed Limitations

Answer 62

Note: All airspeed values are Indicated Airspeed (IAS), except when Calibrated Airspeed (CAS) is specifically stated.

a. At 3,000 pounds gross weight and below:

VMC Vne 130 KIAS sea level to 3,000 feet density altitude. Decrease Vne 3.5 KIAS per 1,000 feet above 3,000 feet density altitude. Maximum density altitude - 20,000 feet.

b. Above 3,000 pounds gross weight:

VMC Vne 122 knots sea level to 3,000 feet density altitude. Decrease Vne 7.0 KIAS per 1,000 feet above 3,000 feet density altitude. Maximum density altitude - 13,500 feet.

c. Vne for internal Gross Weight above 3200 pounds is 78 KIAS, not to exceed placarded Vne.

Question 63

VMC Altitude Limitations

Answer 63

a. 3,000 pounds gross weight and below:

Maximum operating: VFR - 20,000 feet pressure altitude. IFR - 14,000 feet pressure altitude.

b. Above 3,000 pounds gross weight:

Maximum operating: VFR - 13,500 feet pressure altitude. IFR - 8,000 feet pressure altitude.

Question 64

Flight Restriction for High Power

Answer 64

Vne 80 knots with >85% to 100% Torque applied.

Question 65

Aerobatic Maneuvers

Answer 65

Aerobatic maneuvers are prohibited. Aerobatic flight is defined to be any intentional maneuver involving an abrupt change in aircraft attitude, an abnormal attitude, pitch angle greater than 30 degrees or roll angles greater than 60 degrees, or abnormal acceleration not necessary for normal flight.

Question 66

Lightning Strikes

Answer 66

a. Although the possibility of a lightning strike is remote, the helicopter could inadvertently be exposed to lightning damage. Therefore, static tests have been conducted to determine lighting strike effects on rotors.
b. Simulated lightning tests indicated that lightning strikes may damage the helicopter rotor. The degree of damage will depend on the magnitude of the charge and the point of contact. Catastrophic structural failure is not anticipated. However, lightning damage to hub bearings, blade aft section, trim tabs, and blade tips was demonstrated. Also, adhesive bond separations occurred between the blade spar and the aft section between the spar and leading edge abrasion strip. Some portions of blade aft sections deformed to the extent that partial or complete separation of the damaged section could be expected. Such damage can aerodynamically produce severe structural vibration and serious control problems which, if prolonged, could endanger the helicopter and crew.

Warning: Avoid flight in or near thunderstorms, especially in areas of observed or anticipated lightning discharges.

Note: Abnormal operating noises almost always accompany rotor damage, but loudness or pitch are not valid indications of the degree of damage sustained.

c. If lightning strike occurs, or is expected, the following precautions are recommended to minimize further risk.
1. Reduce airspeed as much as practical to maintain safe flight.
2. Avoid abrupt control inputs.

Question 67

Hydraulic Power Failure

Answer 67

a. The first indication of hydraulic boost failure will be an increase in the force required for control movement; feedback forces will be noticed as well as rate limiting. Control motions will result in normal flight reactions in all respects, except for the increase in force required for control movement. In the event of hydraulic power failure, proceed as follows.
1. Airspeed - Adjust as necessary to attain the most comfortable level of control movements.
2. HYD BOOST circuit breaker - Out. Check for restoration of hydraulic power.
b. If hydraulic power is not restored.
1. HYD BOOST circuit breaker - In.

Warning: Do not return the HYDR SYSTEM switch to the ON position for the remainder of the flight. This prevents any possibility of a surge in hydraulic pressure and the resulting loss of control.

2. HYDR SYSTEM switch - OFF.
3. Land as soon as practicable at an area that will permit a run-on landing.

Question 68

Landing in trees

Answer 68

A landing in trees should be made when no other landing area is available. In addition to accomplishing engine malfunction emergency procedures, select a landing area containing the least number of trees of minimum height. Autorotate with the throttle closed using the following procedures:

a. Airspeed - Minimum at treetop level.
b. Descend - Vertically into trees.
c. Collective - Apply remaining collective prior to blades entering trees.

Question 69

Hypoxia

Answer 69

The state of O2 deficiency in the blood cells and tissues significant enough to cause impairment of function. It is generally associated with flights at high altitude. However, other factors such as alcohol abuse, heavy smoking, and various medications can interfere with blood’s ability to carry and absorb O2, thereby reducing the body’s tolerance to hypoxia.

The four types of Hypoxia are:

1. Hypoxic Hypoxia: Occurs when there is not enough O2 in the air or when decreasing atmospheric pressure prevents diffusion of O2 from the lungs to the bloodstream.
2. Hypemic Hypoxia: Caused by a reduction in blood’s O2-carrying capacity. Anemia and blood loss are the most common causes of this type of hypoxia.
3. Stagnant Hypoxia: The blood’s O2-carrying capacity is adequate but circulation is inadequate. Often occurs when a crewmember experiences extreme gravitational forces and blood flow is disrupted, causing blood to stagnate.
4. Histotoxic Hypoxia: Results from an interference with the use of O2 by body tissues. Alcohol, narcotics, or a poison such as cyanide and is delivered to the tissues by the blood where it poisons the tissues, keeping them from using the available O2.

The four stages of Hypoxia are:

1. Indifferent 0-10k feet.
2. Compensatory 10k-15k feet.
3. Disturbance 15k-20k feet.
4. Critical - >20k feet.

Signs:

Hyperventilation, Cyanosis, Mental confusion, Poor judgment, Lack of muscle coordination.

Symptoms:

Increased breathing rate, Apprehension, Fatigue, Headache, Dizziness, Hot and cold flashes, Denial, Euphoria, Belligerence, Blurred vision, Tunnel vision, Numbness, Tingling.

Question 70

Ditching - Power On

Answer 70

If ditching becomes necessary, with power available accomplish an approach to a hover above the water and:

a. Doors - Open.
b. Crew (except pilot) and passengers - Exit.
c. Hover a safe distance away from personnel.
d. Autorotate. Apply all remaining collective as the helicopter enters the water. Maintain a level attitude as the helicopter enters the water. Maintain a level attitude as the helicopter sinks and until it begins to roll, then apply cyclic in direction of the roll.
e. Pilot - Exit when the main rotor stops.

Question 71

Ditching - Power Off.

Answer 71

If an engine failure occurs over water and ditching is imminent, accomplish engine failure emergency procedures and proceed as follows:

a. Autorotate. Decelerate to minimum forward speed as the helicopter nears the water. Apply all remaining collective 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.
b. Doors - Open.
c. Crew and passengers - Exit when the main rotor stops.

Question 72

Loss of Tail Rotor Effectiveness

Answer 72

This is a situation involving a loss of effective tail rotor thrust without a break in the drive system which cannot be stopped with full left pedal application. If LTE is experienced, simultaneously:

1. Pedal - Full Left.
2. Cyclic - Forward.
3. As recovery is affected, adjust controls for normal flight.

Warning: Collective reduction will aid in arresting the yaw rate; however, if a rate of descent has been established, collective reduction may increase the rate of descent to an excessive value. The resultant large and rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate, decrease the rotor RPM and cause an over torque and/or over-temperature condition. Therefore, the decision to reduce collective must be based on the pilot assessment of the altitude available for recovery.

4. If spin cannot be stopped and crash is imminent, an autorotation may be the best course of action. Maintain full left pedal until the spin stops, then adjust to maintain heading.

Question 73

Mast Bumping

Answer 73

Land as soon as possible.

Question 74

Control Movements

Answer 74

Caution: For gross weights greater than 3000 pounds and density altitudes greater than sea level, the directional control margin may be significantly reduced while hovering in winds from the right greater than 20 knots or for right sideward flight at speeds greater than 20 knots.

Abrupt control movements, including rapid and repetitive anti-torque pedals reversals are prohibited to avoid excessive stresses in the structure. This restriction in no way limits normal control application.

Question 75

Spatial Disorientation

Answer 75

A pilot’s erroneous perception of position, attitude, or motion in relation to the gravitational vertical and the Earth’s surface.

3 Types:

1. Unrecognized (the most dangerous).
2. Recognized.
3. Incapacitating.

Question 76

Retreating Blade Stall

Answer 76

Normal cruise lift pattern where the smaller area of the retreating blade, with its high angles of attack, must still produce an amount of lift equal to the larger area of the advancing blade with its lower angles of attack. When forward speed increases, the no-lift areas of the retreating blade grow larger.

Conditions producing RBS:

• High blade loading (high gross weight)
• Low rotor RPM
• High density altitude
• High G-Maneuvers
• Turbulent air

Recovery from RBS:

• Reduce collective
• Reduce airspeed
• Descend to a lower altitude (if possible)
• Increase rotor RPM to normal limits
• Reduce the severity of the maneuver

Question 77

Dynamic Rollover

Answer 77

A helicopter is susceptible to a lateral-rolling tendency called dynamic rollover. This can occur on level ground as well as during a slope or crosswind landing and takeoff. Three conditions are required for dynamic rollover - pivot point, rolling motion, and exceed critical angle.

Physical Factors:

• Main rotor thrust
• CG
• Tail-rotor thrust
• Crosswind component
• Ground surface
• Sloped landing area

Human Factors:

• Inattention
• Inexperience
• Failure to take timely corrective action
• Inappropriate control action
• Loss of visual reference

Question 78

Settling with Power

Answer 78

A condition of powered flight in which the helicopter settles in its own downwash. The following conditions must exist simultaneously for settling with power to occur:

• Vertical or near-vertical descent of at least 300 feet per minute (fpm)
• Slow forward airspeed (less than ETL)
• Rotor system must be using 20 to 100 percent of the available engine power with insufficient power remaining to arrest the descent.

Recovery from settling with power is a large application of collective pitch and applying cyclic to gain airspeed.

Question 79

Vestibular Illusions

Answer 79

Somatogyral Illusions: Give the false sensation of rotation and occur due to the semicircular canal’s inability to accurately register sustained angular velocity.

• Leans
• Graveyard Spiral
• Coriolis Illusion
• Post-Roll Illusion

Somatogravic Illusion: Caused when changes in gravity or linear acceleration stimulate the otolith organ which responds to gravitoinertial force, not gravity alone. These generally result in a false sensation of body tilt as a result of the misperception of the resulting vector of the inertial and gravity as the true vertical.

• G-Excess Illusion
• Elevator Illusion

Oculoargravic Illusion: Visually analogous to the somatogravic illusions and occur under similar conditions. In this case, the illusions occur due to the misperception of movement of a fixed object relative to the pilot during change of direction of gravitoinertial force.

Question 80

Complete Loss of Tail Rotor Thrust

Answer 80

a. This situation involves a break in the drive system, such as a severed driveshaft, causing the tail rotor to lose power.
b. Indications:
1. Pedal input has no effect on helicopter trim.

Warning: Degree of roll and side-slip may be varied by varying throttle and/or collective. (At airspeeds below approximately 50 knots, the side-slip may become uncontrollable, and the helicopter will begin to spin on the vertical axis.)

2. Nose of the helicopter turns to right (left sideslip).
3. Left roll of fuselage along the longitudinal axis.
   c. Procedures:
4. If safe landing area is not immediately available, continue powered flight to suitable landing area at or above minimum rate of descent autorotational speed.
5. When landing are is reached, make an autorotational landing (THROTTLE CLOSED).
6. Use airspeed above minimum rate of descent airspeed.

Note: Airflow around the vertical fin may permit controlled flight at low power levels and sufficient airspeed when a suitable landing area is not available; however, the touchdown shall be accomplished with the throttle in the full closed position.

4. If run-on landing is possible, complete autorotation with touchdown airspeed as required for directional control.
5. If a 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 run.
6. Hover - Perform hovering autorotation.

Question 81

Loss of Tail Rotor Components

Answer 81

a. 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 full autorotational descent and landing should be accomplished with a run-on type termination if to an improved surface, or minimum ground run if to an unimproved surface. Landing should be accomplished in a level attitude.
b. Indications:
1. Varying degrees of right yaw depending on power applied and airspeed at the time of failure.
2. Forward CG shift.
c. Procedures:
1. Enter autorotative descent (THROTTLW CLOSED).
2. Maintain airspeed above minimum rate of descent airspeed.
3. If run-on landing is possible, complete autorotation with touchdown airspeed as required for directional control.
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 run.

Question 82

Transverse Flow Effect

Answer 82

The differences in lift between the fore and aft portions of the rotor disk. The rear portion of the rotor disk has a greater downwash angle than air passing through the forward portion. This causes a reduced AOA resulting in less lift. It occurs between 10 and 20 knots. Gyroscopic precession causes the effects to be manifested 90 degrees in the direction of rotation, resulting in a right rolling motion.