Cirrus Design
Section 3A
SR22T
Abnormal Procedures
P/N 13772-005
3A-9
P/N 13772-005
3A-9
Alternate Air Door Open Annunciation
ALT AIR OPEN Caution
1. Manifold Pressure .............................................................. CHECK
If environment suspect as cause (icing or visible debris):
2. Flight Conditions .....................................................CHANGE/EXIT
3. Power .................................... Reduce to 30.5 in.Hg when practical
4. Flight ............................................................................ CONTINUE
Amplification
Alternate induction door has automatically opened, indicating an
obstructed air filter. Potential environmental causes are ice
contamination (icing conditions) or particles (visible debris, heavy
bugs, smoke or ash).
• If ice contamination was cause, unfiltered air won't pose an
operating hazard for the engine, but conditions significant
enough to ice obstruct filters are not suitable conditions for long
duration flight of light aircraft.
• If flying through conditions that have obvious debris
contamination sources, exit those conditions as able; engine
induction is unfiltered when alternate air door is open.
• Reduction to cruise power when able will reduce engine air
consumption, and likely close the alternate air door (restoring
filer protection to induction air).
• Filters likely require maintenance.
When alternate induction door is open, expect 3-5% power loss due to
increased manifold air temperatures and expect lower critical altitude
in climb. Percent Power indication will be accurate, reflecting actual
(reduced) power.
ALT AIR OPEN
Original Issue
