Jump to content

Flight with APU removed-


HercRep
 Share

Recommended Posts

but we have to fly VMC.

VMC? If I remember correctly, the APU on the commercial Herc (the same one that's on the military C-130) is not certified for use inflight. I tried to find it in my old 382 AOM, but couldn't find the notation.

Don R.

Link to comment
Share on other sites

1- All of our commercial registered airplanes are equipped with APU, but restricted for ground operation only.

Quoting: OM 382G-65C (Sec2 page 162)

“CAUTION”

Do not operate the APU during take-off or in flight.

2- No point on to fly VMC only if APU cannot be used in-flight. (If related avionic instruments (GYROs) are operable before the mission).

3- Basically the APU on military airplane is used during flight for two in-flight emergencies:

During electrical fire and during the loss or suspected malfunction of the Ess Ac Bus.

The concepts are to reduce the load on Ess Ac Bus if the high load is suspected to be the cause and/or to use a deferent routing bath for feeding the Ess Ac Bus).

Link to comment
Share on other sites

  • 2 months later...

No APU = flight required in VMC conditions only, and with no known electrical malfunctions.

According to the good book, the APU may or may not start at or above an altitude of FL20.

Instead of the door opening to 35* (as it does on the ground) it will only open to 15*.

Link to comment
Share on other sites

No APU = flight required in VMC conditions only, and with no known electrical malfunctions.

According to the good book, the APU may or may not start at or above an altitude of FL20.

Instead of the door opening to 35* (as it does on the ground) it will only open to 15*.

Same with the ATM generator. You can fly without it but only on day VMC with no other problems. This is because the APU/ATM are backup electrical sources for a few emergency procedures.

I believe for weight and balance purposes it's any equipment change over 5lbs.

Link to comment
Share on other sites

The additional restriction is placed on by the operator/operator. USAF has their restrictions for day VFR, USNR and USMC have their restrictions but I don't know what their local 3710 dictates. When I was active duty Navy we had no restriction. The Lockheed Flight Manuals for the C-130H and the FAA Approved Flight Manual (AFM) for the commercial L-382E/G have no requirement for a APU. Along with what tenten stated, the AFM has in the limitations section "Do not operate the APU during takeoff or in flight". Also, as stated earlier you should adjust your weight and balance.

Link to comment
Share on other sites

Thanks victorp1 for clearing up the point; so it is an individual operator restriction (MEL) and might be based on some extra equipment added in some aircrafts.

NOTE: The FAA (MMEL) rev.18 dated 1994, and the Belgian air force (MEL) dated JUL 2003, along with our (MEL) allowing us to fly/dispatch the aircraft without APU/ATM generator with NO issue of VMC.

Link to comment
Share on other sites

Am I reading this wrong or is the original question "Can you fly with the APU removed". Not inop. Actually taken out of the aircraft and the aircraft flown. Are you guys quoting the same regs for APU inop without looking at bleed air problems, open electrical, pressurization, weight and balance (kinda addressed) etc. I could be reading it wrong or reading the responses wrong. You know how the internet can be. I have never heard of a plane flying with an open cavity where the APU should be. That area stays slightly pressurized from the small scoop at the bottom but is purged by the venturi of the exhaust stack. If that area was open....? Who knows. I don't. It would be interesting if some one has done this before. I will ask a depot friend tomorrow.

Link to comment
Share on other sites

A little off the subject, but still APU related. Some Herc operators modified their airplanes with an APU from a 727. It was kind of a "Rube Goldberg" contraption and was wired like the GTC in that it could not be started in flight.

I don't know how many were modified this way or how many are still around. Transafrik's 5X-TUF has the 727 APU. The -20 in the attached photo crashed in Angola in November 1989 while being operated by Tepper Aviation.

The Belgians and a few other countries, also modified their early H's with a new APU. I don't remember who the manufacturer is, but it appears to be able to operated in flight.

Don R.

Link to comment
Share on other sites

In '71 we removed the GTC and loaded it in the cargo compartment along with other pieces of scrap.. An E model had been damaged with a satchell charge placed on the left fwd main blowing away left side of the acft.. Hoses were capped, bleed air capped, tires replaced and the area scabbed over with full sheets of T3... Buddy started and flown to the PI from SVN..........

Edited by HercMX
incomplete
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...