737 MAX Flight Crew Operations Manual
Air Systems -
Controls and Indicators
2.10.2
MN-FLT-OH-201
OPEN – opens isolation valve.
3
WING–BODY OVERHEAT Light
Illuminated (amber) –
• left light indicates overheat from bleed air duct leak in left engine strut,
left inboard wing leading edge, left air conditioning bay, keel beam or
APU bleed air duct
• right light indicates overheat from bleed air duct leak in right engine
strut, right inboard wing leading edge or right air conditioning bay.
4
Engine BLEED Air Switches
OFF – closes engine bleed air valve.
ON – opens engine bleed air valve when engines are operating.
5
APU BLEED Air Switch
OFF – closes APU bleed air valve.
ON – opens APU bleed air valve when APU is operating.
6
Bleed Air DUCT PRESSURE Indicator
Indicates pressure in L and R (left and right) bleed air ducts.
7
Wing–Body Overheat (OVHT) TEST Switch
Push –
• tests wing–body overheat detector circuits
• illuminates both WING–BODY OVERHEAT lights
• illuminates both MASTER CAUTION lights
• illuminates AIR COND light
8
BLEED Light
Illuminated (amber) – excessive engine bleed air temperature, over-pressure or
under-pressure
• related engine bleed air valve closes automatically
• requires reset.
OR
Illuminated (amber) – a failure within the bleed air system
• bleed system failure may not be resettable
OR
March 1, 2021
