[MilAir] P-3C Talon 63

[AllanStern at aol.com]

Many thanks for the information, Tom.  
I photograph at least one P-3 every day over Patrick, and I will be looking 
 for that APU air intake port now.
 
May I have your permission to post this information to my MilRadioComms  
group?
 
 
AL STERN  Satellite Beach FL
AllanStern at aol.com
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"Clarke, Tom   AIR4.0P NATOPS" _frederic.clarke at navy.mil_ 
(mailto:frederic.clarke at navy.mil)   writes:

I wonder  why he has his APU running?  Notice the small door open, just
aft of  the nose wheel well (gear doors are closed), that is the APU air
intake.  Exhaust comes out of a door just aft/below the copilot's side
windshield.  We don't usually run it in flight, unless it is a generator
out situation.  Since this is a training flight, that might explain it.

More info than  needed department: The P-3 has 3 engine driven
generators. Since the  engines are constant RPM, a CSD is not required.
#2 and #3 gens power the  main and essential AC busses.  #4 runs in
standby and automatically  picks up the load if 2 or 3 go offline.  The
APU gen (same gen as on  the engine- a 60/90 KVA, 400 Hz, 3 Phase) can
pick up load if #4 isn't  available. The APU (a.k.a, "the Ape"!) is run
on the ground for power and  air conditioning, when the engines are in
low RPM (less noise and lower  fuel consumption) and the gens are
offline.  It is basically an AC  airplane and any DC needed comes from a
couple of Transformer/Rectifiers  and a 24 v battery if all else fails.