HIGH ALTITUDE HIGH SPEED FLIGHT
· The airplane exhibits excellent stability throughout the high altitude / high Mach range. Mach buffet
is not normally encountered at high Mach cruise. However, even in Mach buffet, control response
is smooth and normal. The airplane does not have a Mach tuck tendency.
· With Mach trim inoperative, the airplane exhibits a slight nose down trim change when accelerating
to speeds approaching MMO, however, control force changes are light and easily managed. When
the Mach trim system is operative, the nose down trim change is nearly imperceptible except by
referencing the control column position.
· As speed nears MMO, drag increases rapidly. At high weights, sufficient thrust may not be
available to accelerate to MMO in level flight at normal cruising altitudes.
HIGH ALTITUDE MANEUVERING, "G" BUFFET
· During turbulent flight conditions, it is possible to experience high altitude "g" buffet at speeds less
than MMO. In training, buffet is induced to demonstrate the airplane's response to control inputs
during flight in buffet.
· Establish airspeed of Mach.80 Induce "g" buffet by smoothly increasing the bank angle until the
buffet is noticeable. Increase the rate of descent while increasing the bank angle to maintain
airspeed.
· Do not exceed 45 degrees of bank. If buffet does not occur by 45 degrees of bank, increase control
column back pressure until buffet occurs. When buffet is felt, relax back pressure and smoothly roll
out to straight and level. Notice that the controls are fully effective at all times.
ACCELERATION TO AND DECELERATION FROM VMO
· This maneuver demonstrates performance capabilities and response to speed, thrust, and
configuration changes throughout the medium altitude speed range of the airplane.
· VMO is a structural limitation and is the maximum operating indicated speed. It varies from sea
level to approximately 26,000 feet, where VMO and MMO coincide. Compressibility effects account
for the difference in VMO airspeed with altitude. VMO and MMO are displayed by a maximum
operating indication on the airspeed indicator. Exceeding VMO/MMO is indicated by an aural
warning. Sufficient thrust is available to exceed VMO in level flight at lower altitudes.
· Failure to reduce to cruise thrust in level flight can result in excessive airspeed.
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· Establish an airspeed of 250 knots. Set Maximum Continuous Thrust (MCT), maintain level flight
and keep the airplane in trim. As airspeed increases nose-down trim is required. Stabilize at just
below VMO and execute turns at high speed while maintaining altitude. Continue by accelerating
above VMO and note the VMO aural warning.
· Start the deceleration by reducing the thrust to idle. Since the airplane is aerodynamically clean,
any residual thrust will result in a longer deceleration time. Start timing when the aural warning
stops. Check distance, and maintain in-trim level flight. Note deceleration time passing through
280 knots. Decelerate and stabilize at flaps up speed. Check timing and distance.
· This maneuver may be repeated using speedbrakes to compare deceleration times and distances.
DECELERATION TIME
· For average landing gross weight it takes:
1) approximately 60 seconds to decelerate from VMO to 280 knots
2) approximately 60 seconds from 280 knots to 210 knots in level flight, with speedbrakes down
and thrust at idle. These lead times are useful in approach planning to determine the
time/distance required to slow to flap extension speed.
· Airplanes at maximum landing weight require:
1) approximately 12 NM to slow from VMO to flaps up speed in level flight without speedbrakes (8
NM with speedbrakes).
2) approximately 14 NM to slow from VMO to flaps 5 speed in level flight without speedbrakes (10
NM with speedbrakes).
STEEP TURNS
· The objective of the steep turn maneuver is to familiarize the pilot with airplane handling
characteristics and improve the instrument cross check.
· During training, 45 degrees of bank will be used. It is not intended that the pilot should bank greater
than 30 degrees for normal, or non-normal procedures. If so equipped, the GPWS will give
momentary bank angle alerts up to 45 degrees.
Entry
· Stabilize airspeed at 250 knots on heading and altitude. Use a normal turn entry. An increase in lift
is required as the bank angle is increased at a constant airspeed and altitude to balance the
increase in load factor ("g"). An increase in thrust is required to maintain airspeed. Stabilizer trim is
not recommended when maintaining altitude during the turn because of increased workload during
rollout.
During turn
· Pitch and thrust control are the same as for a normal turn; however, larger pitch adjustments will be
required for a given altitude deviation. Varying the angle of bank while turning makes pitch control
more difficult.
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· If altitude loss becomes excessive, reduce the angle of bank as necessary to regain positive pitch
control.
· Smooth and positive control is required. A rapid instrument scan is required to detect deviations
early enough to be corrected by small adjustments.
Attitude Director Indicator (ADI)
· The ADI is reliable for accurate pitch and bank information throughout the turn. Precession error is
not apparent because the IRS is the source of attitude information.
· If the IRS is not the source of attitude information, the ADI has cyclical precession in pitch during
steep turns. Although the actual airplane pitch attitude will remain constant in a perfect steep turn,
the instrument indication of pitch attitude will slowly vary throughout the turn. Do not rely upon it for
pitch attitude other than for small corrections based on short period observations.
Vertical Speed Indicator
· IRS vertical speed indications are reliable during the turn.
Altimeter
· Crosscheck the direction and rate of altimeter needle movement, and make smooth minor changes
to the pitch attitude for corrections.
Airspeed
· Airspeed changes very slowly because of small changes in thrust and drag. Anticipate thrust
changes and apply them at the first indication of change on the airspeed indicator, or speed tape
(as installed). An increase in thrust will be required as bank angle increases.
Note: If the airspeed cursor is set to 250 knots on the airspeed indicator, the Airspeed Fast/Slow indicator (as
installed) on the ADI will indicate thrust change required.
Rollout
· Higher than normal pitch attitude and thrust will be used during the turn. Roll out at the same rate
as used with normal turns. Normally rollout should begin 15 to 20 degrees prior to the desired
heading.作者: bocome 时间: 2011-7-30 20:32:57