Supplementary Procedures -Airplane General, Emer. Equip., Doors, Windows
Disengage from door support, depress latch at base of forward extension to permit retraction within upper segment of handrail. Slide extension down along the upper rail. Stowing in appropriate stowage points provides circuit continuity for energizing retract relay.
WARNING:Step down the airstair as the forward entry door moves to the cocked position to prevent injuries to personnel.
Forward entry door ......................................Close to cocked position
Aft handrail extension ........................................................ Disengage
Disengage from door support, depress latch at base of forward extension to permit retraction within upper segment of handrail. Slide extension down along the upper rail. Stowing in appropriate stowage points provides circuit continuity for energizing retract relay.
Forward entry door ........................................................... Fully close
CAUTION: Use of the standby control switch bypasses all safety circuits. Airstair handrail extension must be stowed or substantial damage could result.
Control Handle ......................................................... Rotate to Retract
When airstair is retracted and airstair door is fully closed, release
and stow handle.
Copyright . The Boeing Company. See title page for details.
SP.1.6 June 4, 2004
737 Operations Manual
Wing–Body Overheat Test
Wing–body OVHT TEST switch .....................................................Push Hold for a minimum of 5 seconds. Both WING–BODY OVERHEAT lights – illuminated MASTER CAUTION – illuminated AIR COND system annunciator – illuminated Wing–body OVHT TEST switch ................................................ Release Both WING–BODY OVERHEAT lights – extinguished MASTER CAUTION lights – extinguished AIR COND system annunciator – extinguished
External Air Cart Use
CAUTION: The BAT switch should always be on when using the airplane air conditioning system since the protective circuits are DC. This ensures protection in the event of loss of AC power.
Note: For engine start with a ground air source, see section SP. 7.
APU BLEED air switch .................................................................... OFF
ISOLATION VALVE switch ......................................................... OPEN
RECIRC FAN switch .....................................................................AUTO
PACK switch(es)............................................................AUTO or HIGH
The operation of two packs from one air source is permitted provided the external air cart can maintain 20 psi minimum with both packs operating.
Cabin temperature selectors...........................................................AUTO Set for desired temperature. Duct pressure ..........................................................................20 psi min.
Supplementary Procedures -Air Systems 737 Operations Manual
If external air cannot hold 20 psi minimum and the APU is operating:
ISOLATION VALVE switch ................................................... AUTO APU BLEED air switch ................................................................ ON APU supplies left pack and external air source supplies right pack.
Ground Air Conditioning Cart Use
Before connecting ground air conditioning cart: PACK switches ............................................................................OFF Allows cart to operate at maximum efficiency. After disconnecting ground air conditioning cart: PACK switches ................................................................ As required
Using the APU for Heating (on the ground/engines shut down)
Under extremely cold conditions, both packs may be used for more rapid heating.
ISOLATION VALVE switch ..........................................................OPEN
During right pack operation only, under cold conditions, if the left PACK TRIP OFF light illuminates, position the recirculation fan OFF until the cabin temperature stabilizes.
Isolated Pack Operation during Engine Start
To improve cabin air quality between starting the first and second engine:
CAUTION: Moving engine BLEED air switches while a starter is engaged can damage the starter.
Engine No. 2 .....................................................................................Start
After engine No. 2 stabilized: ISOLATION VALVE switch ................................................. CLOSE Right PACK switch .................................................................. AUTO Duct pressure ...................................................................... Stabilized 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300机组操作手册Flight Crew Operations Manual FCOM 1(50)
