Fam 9 Discuss Items

During 4202 The IP will Demonstrate Tail Rotor Malfunctions Studs should be familiar with the procedures.

=Fixed Pitch Right Pedal Applied=

In A Hover
Maneuver Description
 * 1. To develop the proper procedures required enabling the pilot to recover from a fixed pitch  tail rotor malfunction in a hover.
 * 2. Refer to the NATOPS Manual Emergency Procedures chapter.

Procedures
 * 1. Review NATOPS procedures for fixed pitch right pedal in a hover.
 * 2. The maneuver will be initiated from a five-foot hover.  The instructor will make a right  pedal input to initiate a right rotation.  During the right rotation, determine the slowest and fastest  portion of the turn.  in addition, be conscious of the wind direction.
 * 3. The recovery will be initiated as follows:  As the nose of the aircraft passes through the  windline, reduce the twist grip to slow the rotation.    NOTE    This portion of the maneuver may require several attempts to get  the aircraft to stop its rotation.
 * 4. Adjust cyclic to maintain a level attitude and eliminate drift.
 * 5. Cushion the landing with collective.

At Altitude
Maneuver Description
 * 1. To familiarize the SNA/IUT with situations likely to be encountered in the event of loss of  tail rotor control.
 * 2. Refer to the NATOPS Manual Emergency Procedures chapter.

Procedures
 * 1. Review the NATOPS procedures for fixed pitch pedals at altitude.
 * 2. The pattern will be flown at 500 feet.  On downwind establish aircraft at 50 KIAS, set  power at 30% torque and center the ball to simulate a stuck right pedal condition.  Resume  normal pattern at 500 feet and minimum 60 KIAS.
 * 3. Fly a shallow approach, maintain 60 KIAS.
 * 4. On final, the winds will be centerline or left of centerline.  At 50 to 75 feet, set a  deceleration.  Arrive over intended landing surface at 2 to 3 feet at or slightly above translational  lift.
 * 5. At 2 to 3 feet add collective to cushion the landing and level the skids.  As the nose of the  aircraft rotates to the right reduce the twist grip as necessary to maintain alignment with the  direction of travel and cushion the landing.  Recover in a five-foot, five-knot air taxi or to a hard  surface runway.

=Fixed Pitch Left Pedal Applied=

In a Hover
Maneuver Description
 * 1. To develop the proper procedures required enabling the pilot to recover from a fixed pitch  tail rotor malfunction in a hover.
 * 2. Refer to the NATOPS Manual Emergency Procedures chapter.

Procedures NOTE   This portion of the maneuver may require several attempts to  actually get the aircraft to stop its rotation.
 * 1. Review the NATOPS procedures for fixed pitch left pedal in a hover.
 * 2. The maneuver will be initiated from a five-foot hover.  The instructor will make a left pedal  input to initiate a left rotation.  During the left rotation, determine the slowest and fastest portion  of the turn.  In addition, be conscious of the wind direction.
 * 3. The recovery will be initiated as follows:  As the nose approaches 90° prior to the windline,  slowly reduce the twist grip and increase the collective until the aircraft rotation has stopped.
 * 4. Coordinate collective and the twist grip to maintain heading and allow the aircraft to settle.   Monitor Nr and eliminate drift with cyclic.
 * 5. After touchdown, continue reducing twist grip until weight is greater than thrust.

At Altitude
Maneuver Description
 * 1. To familiarize the SNA/IUT with situations likely to be encountered in the event of loss of  tail rotor control.
 * 2. Refer to the NATOPS Manual Emergency Procedures chapter.

Procedures
 * 1. Review the NATOPS procedures for fixed pitch pedals at altitude.
 * 2. Establish aircraft at 50 KIAS, set power at 70% torque and center the ball to simulate a stuck  left pedal condition.  Resume normal pattern at 500 feet and minimum 60 KIAS.
 * 3. Fly a normal approach and maintain 60 KIAS.
 * 4. On final approach, begin a slow deceleration in order to arrive at a point about two feet  above the intended touchdown area as translational lift is lost.  Align the helicopter with the  intended landing path.  If the aircraft is not aligned after collective application, adjust the twist  grip to further help with the alignment.
 * 5. Allow the aircraft to touchdown at near zero groundspeed or recover in a five-foot, five KTS  hover taxi, maintaining runway alignment with the twist grip.  If the aircraft has an excessive yaw  to the left after terminating in a hover, execute the procedures for fixed pitch left pedal applied in  a hover.

====A good ditty for remembering the stuck pedal in a hover procedures is: "Lead the left, crack, pull" and "Right on, reduce." Remember that a stuck left pedal requires a cooridnation of twist grip and collective, executed 90 degrees prior to the windline. A stuck right pedal requires a reduction of the twist grip as the nose passes the windline. The wind should stabilize the rotation, all thats left for you to do is allow the helicopter to settle.

=Complete Loss of Tail Rotor Thrust in a Hover= Maneuver Description
 * 1. To develop the proper procedures required enabling the pilot to recover from a tail rotor  failure in a hover.
 * 2. Refer to the NATOPS Manual Emergency Procedures chapter.

Procedures
 * 1. Discuss the necessity for a skids level attitude.
 * 2. Stabilize the helicopter in a hover, heading 90 degrees to the left of the windline.
 * 3. Instructor will neutralize the pedals (simulating loss of tail rotor thrust) to commence a  right rotation about a vertical axis.
 * 4. As the aircraft comes into the windline, rotate the twist grip to flight idle, hold the pedals  and collective position constant.  The rotation should slow to a stop shortly after reducing the  twist grip to flight idle.  Additional aerodynamic stability is gained as the tailboom and vertical  stabilizer approach the windline at nine o'clock position.
 * 5. Cushion with collective, follow rotation on the ground with right forward cyclic as  necessary or hold cyclic constant.

=ROTOR BLADE STALL LOSS OF TAIL ROTOR EFFECTIVENESS (UNANTICIPATED RIGHT YAW)= Five aircraft characteristics during low-speed flight have been identified through extensive flight and wind tunnel tests as contributing factors in unanticipated right yaw. For this occurrence, certain relative wind velocities and azimuth (direction of relative wind) must be present. The aircraft characteristics and relative wind azimuth regions are: The aircraft can be operated safely in the above relative wind regions if proper attention is given to controlling the aircraft. However, if the pilot is inattentive for some reason and a right yaw is initiated in one of the above relative wind regions, the yaw rate may increase unless suitable corrective action is taken.
 * 1. Weathercock stability (120 to 240°)
 * 2. Tail rotor vortex ring state (210 to 330°)
 * 3. Main rotor vortex disk interference (285 to 315°)
 * 4. Loss of translational lift (all azimuths).
 * 5. Angle of Attack Reduction (060-120°). (out of Aero book pg. 6-11)

Weathercock Stability (120 to 240°).
Winds within this region will attempt to weathervane the nose of the aircraft into the relative wind. This characteristic comes from the fuselage and vertical fin. The helicopter will make an uncommanded turn either to the right or left depending upon the exact wind direction unless a resisting pedal input is made. If a yawrate has been established in either direction, it will be accelerated in the same direction when the relative wind enters the 120 to 240° shaded area of Figure 11-3 unless corrective pedal action is made. The importance of timely corrective action by the pilot to prevent high yaw rates from occurring cannot be overstressed.

Tail Rotor Vortex Ring State (210 to 330°).
Winds within this region, as shown in Figure 11-4, will result in the development of the vortex ring state of the tail rotor. The tail rotor vortex ring state causes tail rotor thrust variations that result in yaw rates. Since these tail rotor thrust variations do not have a specific period, the pilot must make corrective pedal inputs as the changes in yaw acceleration are recognized. The resulting high pedal workload in tail rotor vortex ring state is well known and helicopters are operated routinely in this region. This characteristic presents no significant problems unless corrective action is not timely. If a right yaw rate is allowed to build, the helicopter can rotate into the wind azimuth region where weathercock stability will then accelerate the right turn rate. Pilot workload during tail rotor vortex ring state will be high; therefore, the pilot must concentrate fully on flying the aircraft and not allow a right yaw rate to build.

Main Rotor Disk Vortex (285 to 315°).
Winds within this region, as shown in Figure 11-5, can cause the main rotor vortex to be directed onto the tail rotor. The effect of this main rotor disk vortex is to change the tail rotor angle of attack. Initially, as the tail rotor comes into the area of the main rotor disk vortex during a right turn, the angle of attack of the tail rotor is increased. This increase in angle of attack requires the pilot to add right pedal (reduce thrust) to maintain the same rate of turn. As the main rotor vortex passes the tail rotor, the tail rotor angle of attack is reduced. The reduction in angle of attack causes a reduction in thrust and a right yaw acceleration begins. This acceleration can be surprising, since the pilot was previously adding right pedal to maintain the right turn rate. Analysis of flight test data during this time verifies that the tail rotor does not stall. The helicopter will exhibit a tendency to make a sudden, uncommanded right yaw which, if uncorrected, will develop into a high right turn rate. When operating in this region, the pilot must anticipate the need for sudden left pedal inputs.

Loss of Translational Lift.
The loss of translational lift results in increased power demand and additional anti-torque requirements. If the loss of translational lift occurs when the aircraft is experiencing a right turn rate, the right turn rate will be accelerated as power is increased, unless corrective action is taken by the pilot. When operating at or near maximum power, this increased power demand could result in rotor rpm decay. This characteristic is most significant when operating at or near maximum power and is associated with unanticipated right yaw for two reasons. First, if the pilot’s attention is diverted as a result of the increasing right yaw rate, he may not recognize that he is losing relative wind and, hence, losing translational lift. Second, if the pilot does not maintain airspeed while making a right downwind turn, the aircraft can experience an increasing right yaw rate as the power demand increases and the aircraft develops a sink rate. Insufficient pilot attention to wind direction and velocity can lead to an unexpected loss of translational lift. The pilot must continually consider aircraft heading, groundtrack, and apparent groundspeed, all of which contribute to wind drift and airspeed sensations. Allowing the helicopter to drift over the ground with the wind results in a loss of relative windspeed and a corresponding decrease in the translational lift produced by the wind. Any reduction in translational lift will result in an increase in power demand and anti-torque requirements.

Angle of Attack Reduction (060 to 120°).
In a right crosswind, the relative wind shifts toward the rail rotor blade's chordline because of effectively increased induced velocity. The shifted relative wind impacts at a lower angle of attack, which develops lower lift and results in less thrust. The pilot will automatically compensate by adding more left pedal, but in some cases can reach pedal travel limits before adequate thrust can be generated.

=Low RPM (Nr) Recovery (IUT ONLY)= Maneuver Description: A low RPM recovery demonstrates a proper method of recovering from a low RPM situation. Procedures:
 * 1. Enter an autorotation.
 * 2. At 75 to 100 feet, flare and simulate forgetting the twist grip.
 * 3. At 15 TO 20 feet crack open the throttle slightly, then simultaneously increase the collective bleeding rotor rpm no lower than 90%, smoothly rotate the twist grip to the full open position, and lower the nose toward the level attitude.
 * 4. Complete the recovery in a 5 to 10 KTS, five-foot hover taxi before transitioning to forward flight.