UH-1N FAM-104

FAM 104 Review previous work and introduce alternate approaches and landing. Preflight inspection to be evaluated per NATOPS. Requirement 1. Brief and discuss generator failure, inverter failures, battery thermal runaway, SCAS malfunctions, Nf governor failures, hydraulics system, fuel system, auxiliary fuel system, fuel servicing, tail rotor malfunctions, applications of high angle of bank maneuvering, related effects of high density altitudes and g-loading. 2. Introduce SCAS off flight/landing, high angle of bank maneuvering, and manual fuel operation. 3. Review start/shutdown, normal approach, steep approach, autorotations (including 180 degree autorotations and hovering/taxiing), sliding landing/takeoff, no hover takeoffs/landings, simulated single/dual engine failures, takeoff from a hover, and maximum power takeoff. 4. Demonstrate high speed/low level approach, quick stop, low level autorotation and low rotor RPM hover.

Generator failure Indications: DC GENERATOR caution light, ammeter reads zero 30 VDC, 200 Amp ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ give regulated power at approx 71% Ng. Voltage regulator output voltage of 27-28.5 DC. Reverse current relay automatically opens from the generator to the main 28 DC bus when battery voltage is greater than generator voltage (prevents the generators from draining the battery). If non-essential bus switch is in NORMAL, the non-ess bus will drop offline when either generator is lost. With the non-ess bus switch in MANUAL, non-essential bus will retain power if either generator is lost. This will ensure no break in AC power either, as the STBY inverter and in turn AC non-essential bus is powered by the DC non-essential bus.

1. Starter ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ OFF 2. Appropriate GEN FIELD circuit breaker(s) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ In 3.  Generator ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Reset, then ON (if reset fails, then OFF) 4. MASTER caution light ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Reset 5. Land as soon as practical NOTE: When both generators fail or if an excessive ammeter reading is noted, turn off unnecessary electrical equipment.

Inverter failures Indications: AC FAIL & ALT ENCODE caution lights, SCAS disengagement (NULL lights illuminated) and loss of attitude gyro Main inverter powered by 28 VDC Essential bus and supplies power to the AC Essential bus. STBY inverter failure in Non-AFCS A/C will be recognized by radalt failure & UHF-DF. STBY inverter failure in AFCS A/C will be recognized by the ALT ENCODE caution light.

With either inverter failure, the AC nonessential bus power will be lost link building and cannot be regained. If the MAIN inverter fails, switching the MAIN-STBY switch to STBY will cause the STBY inverter to power the AC essential bus. If the STBY inverter fails, the MAIN inverter will continue to power the essential bus.

2. MAIN INVTR circuit breaker ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ In 3.  Inverter switch ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ MAIN (as required) 4. MASTER caution light ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Reset 5. SCAS ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Reengage (as required) 6. Land as soon as practical
 * 1. Inverter switch ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ STBY

Battery thermal runaway Indications: increase in ammeter reading, smoke, fumes, noise & electrolyte leakage from battery compartment 24 VDC, 34 Amp battery. With an 85% charged battery, 12 minutes of power is available for the essential DC loads. With the Non-Essential Bus switch in the MANUAL position, emergency DC power (from the battery) is provided to the DC Non-Essential bus.

2. Land as soon as possible WARNING: To avoid a possible explosion, CO2 or halon shall not be directed into a battery compartment unless a visible flame is present. Water fog may be used to cool the battery or displace explosive gases. CAUTION: After shutdown, do not turn the battery on until corrective maintenance action has been completed.
 * 1. Battery ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ OFF

SCAS malfunctions SCAS Hardover: 2. Identify affected channel(s) 3. Power switch(es) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Off 4. SCAS ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Reengage (if applicable) 5. Land as soon as practical.
 * 1. AFCS release switch ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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.

Nf governor failure CAUTION: With constant power settings, random power fluctuations indicated by torque splits of as little as 5% may indicate impending fuel control failure.

2. Complete Manual Fuel Control Actuation procedures or SINGLE ENGINE FAILURE procedures as appropriate.
 * 1. RPM ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Control using throttle/collective

Hydraulics system Main rotor collective and cyclic controls receive control power from two completely separate hydraulic systems. Each system includes the reservoir, transmission-driven pump, integrated valve and filter assembly, directional flow check valves, a pressure switch, an accumulator, and connecting hoses and tubes. Two quick-disconnect couplings are provided in each system for an external hydraulic power source for ground operations.

System # 1 supplies power to the UPPER section of the cyclic & collective power cylinders and the entire T/R power cylinder. AFCS A/C - yaw and altitude SCAS channels. System # 2 supplies power to the LOWER section of the cyclic & collective power cylinders. AFCS A/C - pitch and roll SCAS channels. Each section of the cyclic & collective power cylinders has full control authority in case of failure of the other. In the event of a single system hydraulic failure a fail-safe mechanism is designed into the HYD CONTROL switch circuit that prevents you from inadvertently securing the good system.

Other than what they control, the pump operating speed, and system capacity, the #1 & 2 systems are the same. Pump 1 spins at 4302 rpm (T/R driveshaft) & Pump 2 spins at 6600 rpm (main driveshaft). Each pump has a minimum delivery rate of 6 gal per minute and is driven by the transmission. # 1 System capacity is 1.56 gal and # 2 system capacity is 1.17 gal. Total system capacity is 2.75 gal. Each hydraulic reservoir holds 5.25 pints.

The pump draws fluid from the reservoir to deliver it under pressure through an external line and check valve to the integrated valve and filter assembly. The pump has internal pressure compensation and supplies flow based on system demand. In the valve and filter assembly, the fluid passes though a pressure line filter to the solenoid-operated shutoff valve. link building services The system shutoff valve is normally open except when energized closed by the 28VDC circuit energized by the shutoff switch. When the valve is open, normal pressure of 1000 psi is provided to flight control actuators and flow will occur as actuator servo valves are moved by linkage from the control sticks or pedals. Fluid returns to the reservoir through the shutoff valve and return-line filter. When the shutoff valve is closed or after shutdown, the pressure-operated shutoff valve will close as the pressure drops below 600 psi. The HYD SYS caution light will illuminate at 650 psi. The pressure-operated shutoff valve isolates the control actuators and lines from the rest of the system, retaining fluid pressure in the actuators providing irreversibility to maintain a stiff control column. When pressure is reapplied, the caution segment will extinguish and the pressure-operated shutoff valve will reopen at 750 psi

Spring-loaded accumulators make up for fluid lost by leakage and seepage past seals. The accumulators prevent entry of air into the lines and power cylinders by pressurizing the system when the pump is not operating or the system is electrically secured. They also damp out pressure surges from the pumps.

There are two non-electric devices, one on each filter (pressure and return) of each system. These provide visual warning of a partial filter clogging by popout red indicator buttons. The indicators are actuated when a 70 psi difference across the filter element is detected and must be reset manually. An electrically operated indicator in the nose will turn from green to red when any of the four filter elements is partially clogged (checked on pre-flight).

With a complete loss of hydraulic boost, turns should be initiated to the RIGHT (which are more difficult) to ensure that enough left cyclic is available to stop the turn. A balance spring attached to the stationary swashplate mechanically balances the aerodynamic forces generated in flight and facilitates moving the cyclic in the right forward quadrant.

Fuel system Consists of five interconnected self-sealing cells. Each of the forward (underfloor) cells is divided into two compartments by a lateral baffle fitted with a flapper valve to allow fuel flow from the front to the rear.

FORWARD RIGHT CELL		CENTER AFT CELL				FORWARD LEFT CELL Quantity XMTR (frnt & aft)		Quantity XMTR 				Fuel Low Float Switch Automatic high-low float switch 		(100-300 lbs indicated) (1300 lbs ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ aux trans pump OFF		(aft compartment)					1100 lbs ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ aux trans pump ON) Fuel Flow: Fuel cell ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ boost pump ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ check valve ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ crossfeed ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ shutoff valve (thermal relief valve returns unused fuel to cells) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ airframe fuel filter (or bypass) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ oil to fuel heat exchanger (80 +/- 10 deg F) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ fuel pump (600 psi) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ MFCU (solenoid transfer valve) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ AFCU ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ MFCU ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ fuel flow transmitter (gauge in pph) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ fuel flow divider (with dump ports and surge dampener) ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 14 fuel nozzles (7 primary & 7 secondary).

Fuel Control Switches control the following (HIBS): H - Control line heaters ON (>40 deg F) I ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Ignition circuits energized B ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Boost pumps (both) ON S ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Fuel shutoff valve (respective eng) OPEN

Auxiliary fuel system Two 150 gal fuel bladders (approx 1000 lbs each). Each bladder has a filler cap, an electric transfer pump and float switch assembly. Connected to main fuel cells through T-fittings. Check valves ensure fuel flow from aux bags to main fuel cells.

Fuel servicing 195.5 gal total, 193 useable; 150 gal per aux bag. Aux bag pump will come ON when main fuel cell capacity is 1100 lbs or less and should shut OFF when capacity is 1300 lbs. If the float switch fails to function, fuel will vent overboard. Fuel can be refilled through either pressure (hot) refueling or gravity (cold) refueling. JP-5, 4, 8, or other fuels as listed in the PCL can be used. During hot refueling, 65 gpm can be delivered at 55 psi. Gravity refueling with engines operating is PROHIBITED.

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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Enter (maintain slightly above normal autorotation airspeed)
 * 2. Throttles ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Flight Idle
 * 3. Throttles ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Close prior to flare (time permitting)

Loss of tail rotor pitch change control while hovering at low altitude 2. Throttles ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ adjust to control yaw as necessary 3. Land as soon as possible
 * 1. Collective ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 500AGL and 60 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 (30ÃÂÃÂ¯ÃÂÃÂÃÂÃÂ°) on final approach MDG ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Maintain 60 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ Approaching 25AGL begin a deceleration (nose will yaw to the Right as A/C decelerates). When the nose has yawed approx 15 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂReducing ThrottlesÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ downwind is 500 AGL and 60 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 75ÃÂÃÂ¯ÃÂÃÂÃÂÃÂ°) MDG ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ maintain 60 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ 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 link building and throttles  link building service 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.

Applications of high angle of bank maneuvering 180ÃÂÃÂ¯ÃÂÃÂÃÂÃÂ° autorotation MDG ÃÂÃÂ¢ÃÂÃÂÃÂÃÂ min 1000 AGL and 90 KIAS; turn for 180 deg (maintaining alt) with max of + 2.2 g.s

Related effects of high density altitude and g-loading Decreased performance anytime high/hot/heavy/humidÃÂÃÂ¢ÃÂÃÂÃÂÃÂ¦density altitude increases as alt/temp/humidity increases. G-loading the aircraft requires greater performance as more power is required to hold the aircraft in level flight. As density altitude increases and aircraft performance decreases, it is possible for power required to exceed power available as the aircraft is g-loaded and can cause settling with power. The pilot can see this by a rapid descent rate increase or loss of rotor rpm. The technique to recover from this is to: 1. Reduce collective to increase rotor rpm 2. Forward cyclic to gain airspeed WARNING: Increasing collective has no effect toward recovery and will aggravate settling with power. g load is 0.5 - 3.5 g for A/C weighing less than 6600 lbs g load is 0.5 - 2.2 g for A/C weighing 6600 lbs or more.