UH-1N FAM-113

Goal Introduction to unlit field operations.

Requirement 1. Brief and discuss all previously introduced emergency procedures. 2. Introduce landing to an unlit area. 2. Review (at a light airfield) basic air work, normal approach, steep approach, low work, sliding takeoff and landing, no hover takeoff and landings, autorotations, simulated engine failure (single/dual), SCAS off flight/landing, manual fuel operation, and tail rotor malfunctions.

Emergency Procedures See NATOPS Ch 14

Landing to an unlit area Use of landing light & searchlight (NATOPS 8.26): For night approaches and landings, set the landing light approx 15 deg down from horizontal. This will give the pilot a reference point during takeoff and also light the approx touchdown area following a normal approach. The landing light and searchlight should be positioned for immediate use in the event of an immediate landing. Use the searchlight as desired to illuminate the intended flight path. The searchlight can be placed directly on the landing spot/LZ or offset and still provide sufficient illumination.

Engine Failures Indications: Nr/Nf/Ng decrease, left yaw, DC GENERATOR/ENG OIL PRESS/PARTICAL SEP caution lights (affected engine(s)) Single Engine Failure
 * 1. Nr – Maintain
 * 2. RPM switch – Full increase
 * 3. Airspeed – Adjust as necessary
 * 4. Jettison – As necessary

Engine Failures at low altitude
 * 1. Level the aircraft
 * 2. Cushion the landing

Engine Failures at altitude
 * 1. Autorotation – Accomplish

Autorotative Landing
 * 1. Controls – Adjust (maintain Nr and desired airspeed)
 * 2. Jettison – As necessary

MDG Ch 3: Dual engine Failure A simulated dual engine failure at altitude is performed in the same manner as an autorotation discussed in the familiarization section except as noted below: (1) A simulated dual engine failure at altitude may be initiated and simultaneously announced by the instructor pilot provided that a preflight brief was conducted to discuss all aspects of this simulated emergency situation. (2) Recovery shall be complete at a minimum of 300 feet AGL and 60 knots unless performed at an airfield with an available crash / fire / rescue. If a crash/fire/rescue is available, a simulated dual engine failure may be flown to the completion of a power recovery auto. See paragraph 2015, steps (b) thru (i) of the practice autorotation maneuver description for further details.

Single Engine Failure The altitude, airspeed, gross weight, and wind conditions at which an actual engine failure occurs will dictate the action to be followed to affect a safe landing. Level flight can be maintained at low altitude and normal gross weights with standard day conditions. At high gross weights / high altitude, level flight cannot be maintained when hovering or operating at low airspeed. The maximum gross weight at which level flight can be maintained decreases as altitude above sea level increases. b. Simulated single engine takeoffs are prohibited. c. Simulated single engine flight for the purpose of practicing single engine emergencies is authorized under the following conditions: (1) Power available is sufficient for single engine flight. (2) A suitable landing area is accessible. d. Simulated single engine emergencies shall not be initiated below 200 feet of altitude and 80 knots on takeoff, and 200 feet of altitude and 70 knots on landing. Indicated torque at the time of initiating the simulated single engine failure shall not be more than single engine maximum power (Q, ITT, Ng) available. e. A single engine waveoff shall not be initiated below 300 feet. If a waveoff below 300 feet is required the engine at flight idle will be increased to the full open position. f. A simulated single engine failure may be taken to a sliding landing to the right grass at MCAS, Camp Pendleton.

SCAS off flight/landing (MDG Ch 3) If the SCAS mode of the AFCS becomes inoperative, adequate control of the aircraft can be maintained to a safe landing. The instructor pilot may initiate this simulated emergency at any time during the flight. b. The emphasis should be on small smooth control inputs to avoid over controlling the aircraft. c. A normal approach profile is flown to practice SCAS off flight.

Indications of SCAS failure will be felt in the controls as the A/C becomes more unstable. The NULL lights will also illuminate. Force Trim and higher airspeeds (weathervane effect) will help stabilize the A/C. Time permitting, have the PNAC check the circuit breaker and try to reengage SCAS. Land as soon as practical.

SCAS Hardover: 2. Identify affected channel(s) 3. Power switch(es) – Off 4. SCAS – Reengage (if applicable) 5. Land as soon as practical.
 * 1. AFCS release switch – Press

AFCS four channels of operation are: pitch, roll, yaw and altitude hold. SCAS powered by 28 VDC Essential bus and 115 VAC Essential bus. No. 1 hydraulic system provides hydraulic power for yaw and altitude channels. No. 2 hydraulic system provides hydraulic power for pitch and roll channels. In the event of either hydraulic system failure, the AFCS will automatically disengage.

Each stabilized axis (pitch, roll & yaw) has an electro-hydraulic actuator installed in series that extends/retracts its respective control linkage to operate the flight control power cylinders.

The actuators are limited in available control travel to: Pitch	16% Roll	19% Yaw	30% This enables the pilot to override a SCAS hardover in any channel. In the non-energized condition the actuators are mechanically locked in a centered position, becoming fixed links in the flight controls.

AFCS will automatically disengage if: 1.	hydraulic power is lost for more than 0.5 second 2.	AC voltage is too low or too high or if power is removed Manual channel engagement is required after any channel disengages. Failure of the channel to reengage or remain engaged indicates that the fault is still present.

Manual Fuel Operation (MDG Ch 3) Actual malfunction of the fuel control will be evidenced by an abnormal change in gas producer (Ng), inter turbine temperature (ITT), fuel flow, and free power turbine (Nf). (1) If a Nf governor or automatic fuel control unit (AFCU) fails, it will either lead to an underspeed (rollback) or overspeed situation. If one engine is underspeeding, initial indications will be a torque split caused by the underspeed and low Nr and Nf. The low torque and low Ng (as low as 40%) indicate the underspeeding engine.

(2) If the engine is overspeeding, initial indications will be a torque split and high Nr and Nf. The higher torque needle indicates the overspeeding engine. Incidentally, the Nf governor for the good engine sees the high Nf condition and attempts to control the overspeed by spooling down, causing low Ng on the good engine.

The key is determining which engine is causing the problem. When flying straight and level with a normal power setting, low Nr means the engine with low torque and low Ng is underspeeding. High Nr means the engine with high torque and high Ng is overspeeding. In every instance, the appropriate corrective action for fuel control malfunction is to roll the affected engine to flight idle and switch from the AUTOMATIC to MANUAL fuel control mode. Therefore, it is essential that all pilots be familiar with the manual mode of operation, and that they develop proficiency in actually flying in the manual mode.

CAUTION: Failure to roll the throttle of the affected engine to the flight idle position prior to switching to manual mode will result in rapid overspeed and damage to the engine. Note that it is the throttle position, not Ng reading, that is critical when switching to manual fuel.

Manual fuel control operations shall be prebriefed and discussed prior to and during the switch into the manual fuel control mode.

In order to reduce the chance of severely overspeeding an engine, switching from automatic to manual fuel and back shall be performed while on the deck with both throttles at flight idle while in the training command.

While on the deck, the PUI (PAC) will roll both throttles down to flight idle. Then the PUI will direct the instructor to place his/her finger on the appropriate governor switch. The PUI will concur with the correct switch, at which time the instructor will switch to manual fuel. The PUI shall note and announce a flux in Ng, ITT, fuel flow, and that the appropriate governor manual caution light has illuminated.

While the PUI is still holding the manual throttle at flight idle, the instructor will roll up the automatic throttle to the full open position. Once full open, the throttle friction of the automatic engine may be tightened down.

The PUI should now roll the manual throttle up to approximately 4% below the automatic throttle. While flying in manual fuel, the torque needle of the engine in manual fuel should remain within 4% (approximate width of the transmission Q needle) and below the torque needle of the engine in automatic.

The pattern is flown the same as for a normal approach. Terminate the approach in a stabilized hover. Once on deck, smoothly roll both throttles to flight idle. The instructor will again get dual concurrence before switching the governor switch back to automatic.

CAUTION While operating in the Manual Fuel mode, the engine will respond directly to your inputs without automatic protection features. To prevent exceeding limitations, aggressively scan engine/Nr instruments throughout the maneuver. Any time the manual torque comes above the automatic torque, Nr will tend to overspeed.

As a general rule, while operating in the Manual Fuel mode, when increasing power, lead with collective increase and follow with rolling up throttle. When decreasing power, lead with throttle decrease and follow with collective reduction.

Anticipate power changes in three areas: leveling off from climbout, at the abeam position, and on short final. Start the power change earlier than normal to give you more time to make a smooth, gradual power change. Adjust the collective and throttles in small increments at a time to keep the torque split under control.

The automatic torque needle moves up and down as you move the collective. The manual torque does not respond to collective. Rather, it moves as you roll the throttle up and down.

Torque splits are controlled by manipulating either the manual throttle (to affect the manual torque) or the collective (to affect the automatic torque), depending on if the manual torque is high or low, and if more or less power is needed.

(1) Large torque splits with the manual torque low are undesirable because the automatic engine assumes the entire load. If this happens on climbout, smoothly roll up the manual throttle to bring up the manual torque. If this happens on descent, reduce the collective to bring down the automatic torque. (2) Large torque splits with the manual torque high are undesirable because Nr tends to overspeed. If this happens on climbout, increase collective to put more pitch on the blades to prevent the overspeed and raise the governed torque up above the manual torque. If this happens on descent, reduce the manual throttle to bring manual torque down below the automatic torque.

Landing and rolling both throttles to idle is a HMT-303 maneuver training restriction only. Realize that if an actual governor failure is experienced in flight, the good throttle will stay full open and only the bad throttle will be rolled to flight idle. It will be switched to manual and rolled back up while in flight. The aircraft will be flown in manual mode only far enough to land as soon as practical.

Reduce the throttle on what you believe to be the good engine. If Nf for that engine decreases then it is the good engine. The other engine has the malfunction. Tail rotor malfunctions RIGHT Yaw - Opposite of an engine failure, tail rotor thrust deficiencies will result in nose-right yaw. Quick reaction is required to prevent the aircraft from entering uncontrolled flight. Maintain airspeed to prevent right yaw of more than 30 deg from direction of travel. LEFT Yaw – max of 75 deg of left yaw from direction of travel. As airspeed decreases, use collective to control rate of descent and use throttle to maintain RPM. Pull more collective as translational lift is lost and use throttle reduction to align the A/C with direction of travel.

Loss of tail rotor effectiveness 1. Reduce collective (altitude permitting) 2. As right rotation decreases, apply forward and right cyclic to accelerate through translational lift. 3. After accelerating through translational lift, collective pitch may be increased as required. WARNING – Increasing collective pitch with full left pedal will aggravate the situation by causing a decrease in Nr thereby further decreasing the effectiveness of the tail rotor, causing increased right rotation, loss of altitude and possible ground contact

Tail rotor driveshaft hanger failure May be evident as an electrical fire odor of the bearings overheating. Momentary high-freq vibration, metallic grinding or scraping located aft of the main transmission. LAND AS SOON AS POSSIBLE, maintaining higher than normal approach airspeed. Failure will be noted by a loud bang, a high freq vibration, and a loss of tail rotor rpm. WARNING: Tail rotor driveshaft hanger assembly failure and associated loss of tail rotor rpm may occur immediately after indications of bearing failure. Complete Loss of tail rotor thrust while hovering at low altitude
 * 1. Throttles – flight idle
 * 2. Level the aircraft
 * 3. Cushion the landing

Complete loss of tailrotor thrust in flight WARNING: Failure to immediately reduce throttles can result in unrecoverable right yaw. NOTE: When the situation permits, control aircraft yaw/heading with a down-up collective pulse (recover from right yaw) or throttle increase (recover from left yaw) as appropriate. NOTE: If altitude permits, with airspeed above 60 knots, throttle and collective may be gently applied to see if some degree of powered flight can be resumed. 4. On short final, execute a flare 5. Execute a sliding landing in a slightly nose-high attitude CAUTION: The flare and the abrupt use of collective will cause left yaw, but throttles should not be used to correct. Rotation upon landing should not be severe. Slight application of cyclic in the direction of yaw with a slight aft-skid landing will help prevent the aircraft from rolling over on touchdown.
 * 1. Autorotation – Enter (maintain slightly above normal autorotation airspeed)
 * 2. Throttles – Flight Idle
 * 3. Throttles – Close prior to flare (time permitting)

Loss of tail rotor pitch change control while hovering at low altitude 2. Throttles – adjust to control yaw as necessary 3. Land as soon as possible
 * 1. Collective – Reduce or Freeze as required

Loss of tail rotor pitch change control (right yaw) in flight (ball will be out to the Left) 1. Adjust power and airspeed to maintain a comfortable yaw angle (60 to 80 knots, 100% rpm) MDG – 500AGL and 60 – 80 KTS on downwind. Do NOT exceed 1 ball width deflection until on final approach. 2. Plan landing to a smooth, level surface with a prevailing left crosswind if possible 3. Establish a long, shallow approach 4. Maintain sufficient airspeed to avoid excessive right yaw (30) on final approach MDG – Maintain 60 – 80 KTS on final until reaching 50AGL to keep the A/C aligned with the Left half of the runway. 5. At 10 to 25 feet AGL when landing area is assured, begin a slow deceleration but maintain translational lift 6. At 2 to 3 feet, reduce throttles and increase collective as required to align the aircraft with the direction of landing MDG – Approaching 25AGL begin a deceleration (nose will yaw to the Right as A/C decelerates). When the nose has yawed approx 15 – 20 deg from the RW centerline, reduce throttles as necessary to align the A/C with the runway prior to a simulated touchdown at 10 AGL. CAUTION: The PUI will announce “Reducing Throttles” prior to reducing throttles. Do NOT reduce throttles below 25 AGL or the 10 AGL minimum altitude may be exceeded. NOTE: To recover from a Right yaw situation, the throttles must be reduced sharply, however the amount of reduction is minimal. 7. Maintain heading on the ground with throttle and collective. (Follow a right yaw with smooth cyclic input.) WARNING: Attempted waveoff, loss of translational lift, or excessive collective input could result in excessive right yaw and uncontrolled flight.

In an actual low power fixed pitch RIGHT YAW situation the Cyclic is the primary wave-off flight control.

Loss of tail rotor pitch change (left yaw) in flight (ball will be out to the Right) 1. Adjust power and airspeed to maintain a comfortable yaw angle MDG – downwind is 500 AGL and 60 – 80 KTS (left downwind is desirable). Do NOT exceed 1 ball width deflection until on final approach. 2. Plan landing to a smooth, level surface with prevailing winds as desired (left crosswind is desirable) 3. Establish a long, shallow, powered approach (maximum left yaw 75) MDG – maintain 60 – 80 KTS on final to keep the A/C aligned with the runway. 4. Throttles may be reduced to attain a rate of descent within a comfortable sideslip angle (minimum 91% Nr) 5. At 10 to 25 feet AGL when landing area is assured, begin a slow deceleration but maintain translational lift 6. At 2 to 3 feet, apply collective to stop rate of descent, adjust forward airspeed, and align the aircraft. MDG – At 25 AGL begin a deceleration of the A/C (nose will initially yaw Left as the A/C decelerates). As power is increased the rate of Left yaw will either slow, stop or the A/C will begin to yaw Right. Coordinate cyclic, collective and throttles to terminate at a 10 AGL hover or hover-taxi aligned with the runway. NOTE: At no time shall RPM be allowed to decay below 91% Nf or Nr. 7. Coordinate cyclic, collective, and throttle to level the touchdown or slide, as conditions require. NOTE: In many cases, the nose will yaw right (past the centerline) with increase in power to stop the descent. Throttle reduction may be necessary to control the yaw.

In a high power fixed pitch LEFT YAW situation, a combination of cyclic and collective can be used for a safe climbout.