曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
in the pilot’s altimeter.
The copilot’s altimeter is a pneumatic counter-drumpointer
type which displays altitude in the same manner
as the pilot’s altimeter. It also incorporates a barometric
pressure setting knob and an internal vibrator powered
by the No. 2 DC bus. A minimum of 1 minute of vibrator
operation is require before setting or checking the altimeter.
At ambient pressure, both altimeters should agree within
± 70 feet of the field elevation when the proper barometric
pressure setting is set in the altimeter. If the internal
vibrator of either altimeter becomes inoperative due to
DC power failure, the pointer drum may momentarily
hang up when passing from 9 through 0 (climbing) or
from 0 to 9 (descending). This will cause a lag of magnitude
which will depend on the vertical velocity of the
aircraft and the friction in the altimeter.
2-14-9. Radar Altimeter (AN/APN-209A).
Radar altimeters are provided for the pilot and copilot and
filght engineer (fig. 2-14-3). The altimeters provide a continuous
indication of the height of the helicopter above
the surface from 0 to 1,500 feet. Altimeter indications are
reliable with pitch and roll attitude up to 45.
Altitude is displayed by a dial, pointer, and a digital display.
Each altimeter has HI and LO caution lights. The
caution lights on each altimeter can be set independently
of the other altimeter. The caution lights are set by rotating
the LO SET and HI SET knobs until the L index and
H index on the perimeter of the altimeter are at the desired
altitudes.
TM 1-1520-240-10
2-14-3
When the helicopter descends below the low index setting
or rises above the high index setting, the corresponding
HI or LO caution light will illuminate. If helicopter
altitude exceeds 1,500 feet, pitch or roll angle exceeds
45, or the system is unreliable, the following will occur.
The OFF flag will appear, the pointer will move through
1,500 feet behind the dial mask, and the digital display
and LO and HI caution lights will extinguish.
If power to the system is lost, the following will occur. The
OFF flag will appear, the digital display and caution lights
will go out, and the pointer will remain at the last valid
indication when power was lost. The altimeters have a
self-test feature. Pressing the PUSH-TO-TEST knob will
cause the pointer and digital display to indicate between
900 and1,100 feet. If LO set and HI set are indexed
below 900 feet, the LO caution light goes out, and the HI
caution light comes on. Power to operate the radar altimeter
is supplied by the No. 2 DC bus through the NAV
RAD ALT circuit breaker on the No. 2 PDP.
Figure 2-14-3. Radar Altimeter (AN/APN-209)
2-14-10. Controls and Functions, Radar Altimeter
(AN/ APN-209A).
CONTROLS/
INDICATOR FUNCTION
LO SET knob Either pilot’s LO SET knob
applies power to altimeter
system. LO set index on
both altimeters can be set
independently. Both LO set
indices must be masked to
turn the set off.
HI SET knob Sets position of HI set index
and tests altimeter system
when pressed.
CONTROLS/
INDICATOR FUNCTION
LO set index Indicates altitude trip point
for LO caution light.
HI set index Indicates altitude trip point
for HI caution light.
Indicator pointer Indicates absolute altitude
from 0 to 1,500 feet.
Digital indicator Provides direct reading four
digit indication of absolute
altitude from 0 to 1,500.
LO caution light Comes on when helicopter
descends below altitude on
LO set index.
TM 1-1520-240-10
2-14-4
CONTROLS/
INDICATOR FUNCTION
HI caution light Light comes on when helicopter
rises above altitude
on HI set index.
OFF flag Flag is displayed when power
is removed from set,
when indications are unreliable,
or when altitude exceeds
approximately 1,500
feet.
RAD ALT dimming
controls
On right side of both instrument
panels. Controls light
intensity of digital display
and HI and LO caution light.
2-14-11. Normal Operation - Radar Altimeter (AN/
APN-209A).
a. Starting.
(1) Rotate the LO SET knob on the altimeter
until LO index is at 100 feet. Rotate the HI set knob until
the HI index at at 800 feet. Allow 1 minute for warmup.
(2) Check for the following indications:
(a) The pointer indicate between -5 and 5
feet.
(b) The digital displays indicate between 0
and 3 feet.
(c) LO caution light is on.
(d) HI caution light is off.
(e) OFF flag not in view.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
支奴干运输直升机操作手册1(56)
