B-29 APU?

WIXerGreg · **Posted:** Sat Aug 08, 2009 9:20 am

I've never been in the back of a B-29

and I can't find pictures in any of my books. Does this look right to you guys? (Not that I needed another project in the garage, but...)

http://cgi.ebay.com/ebaymotors/ws/eBayI ... K:MEWAX:IT

Warbird Kid · **Posted:** Sat Aug 08, 2009 9:23 am

Isn't that what killed the Kee Bird?

b29flteng · **Posted:** Sat Aug 08, 2009 9:37 am

It is from a B-29, but the 200 amp generator is missing replaced by the pulley.

DoraNineFan · **Joined:** Fri Aug 12, 2005 3:37 pm **Posts:** 678

Warbird Kid wrote:

Isn't that what killed the Kee Bird?

No, stupidity did.

They ignored advice to bring a fresh carburetor for the APU. When the APU carb wouldn't work. they rigged up a gravity-fed fuel tank above it. A few bumps after getting Kee Bird moving and the fuel splashed all over the hot APU, then whoosh. Leaving the extinguisher in the tail out of reach didn't help.

Taigh Ramey · **Posted:** Sat Aug 08, 2009 9:55 am

I believe it was a fuel pump that died on the APU so instead of waiting for a replacement they took the fuel tank from its mountings and hung it over the APU so the fuel could feed by gravity.

While taxiing around to make a runway the aircraft heaved so strongly the guy in the back was holding on as best he could to keep from getting clobbered. The fuel from the tank sloshed onto the hot APU and started the fire.

WIXerGreg · **Posted:** Sat Aug 08, 2009 10:51 am

Taigh Ramey wrote:

I believe it was a fuel pump that died on the APU so instead of waiting for a replacement they took the fuel tank from its mountings and hung it over the APU so the fuel could feed by gravity.

While taxiing around to make a runway the aircraft heaved so strongly the guy in the back was holding on as best he could to keep from getting clobbered. The fuel from the tank sloshed onto the hot APU and started the fire.

That's the same thing I read. The book Hunting Warbirds is actually way better than the Nova documentary, there is much more information in the book. The documentary leaves out the whole first expedition they made up there and got it out of the lake and up on it's gear.

Ztex · **Posted:** Sat Aug 08, 2009 9:26 pm

There's a good shot of FiFi's APU in this thread.

Gary did a great walk through!

http://warbirdinformationexchange.org/phpBB2/viewtopic.php?p=88686#88686

WIXerGreg · **Posted:** Sat Aug 08, 2009 9:59 pm

You're right, that IS a great walk through! Thanks to Zane for digging that up and thanks to Gary for posting them!

the330thbg · **Joined:** Wed Nov 14, 2007 3:06 pm **Posts:** 2713

http://www.330th.org/

click on the flag on the left side that has 'Aircraft' on it

scroll down to the cut-away of the B-29 (The (11) B-29 Crew Positions)

Click on the blue 'APU" (not my favorite crew position)

Putt-Putt awaits.

Also., why the hell on Kee-Bird were they running the APU after engines started? Once the #3 engine is going.., you have all the power a B-29 could ever want. It was pure stupidity.., these poor guys were just so eager to get her airborne.., they lost site of common sense..,

Matt Gunsch · **Posted:** Mon Aug 10, 2009 12:50 pm

the330thbg wrote:

http://www.330th.org/

click on the flag on the left side that has 'Aircraft' on it

scroll down to the cut-away of the B-29 (The (11) B-29 Crew Positions)

Click on the blue 'APU" (not my favorite crew position)

Putt-Putt awaits.

Also., why the heck on Kee-Bird were they running the APU after engines started? Once the #3 engine is going.., you have all the power a B-29 could ever want. It was pure stupidity.., these poor guys were just so eager to get her airborne.., they lost site of common sense..,

It was not that, they thought the APU was turned off, turned out the operator never did turn it off after engine start, it was a case of miscomunication.

Taigh Ramey · **Posted:** Mon Aug 10, 2009 1:53 pm

The APU, or putt putt, was required to be running for ground ops, take off and prior to landing. The B-29 was essentially an all electric aircraft. The only hydraulics were for the brakes and even the hydraulic pump was driven by an electric motor.

Even though the inboard engines had two 300 amp generators on each engine and 1 and 4 had a single generator if the engines were below a certain RPM (I'm guessing 900 RPM or so) the generators were off line and the only source for electrical power was one regular AN battery the same size as the one used in an AT-6 or a P-51. This battery was also located next to the APU in the aft unpressurized compartment. Just starting one engine would have drained the battery which is why the APU was needed for all ground ops.

The battery was there to start the APU and the APU combined with the battery supplied the power needed for starting, hyd pump and all of the rest of the electrical motors and equipment throughout the B-29 for ground operations through take off and prior to landing.

The flight engineer had remote controls to start the APU and to bring it on line. He could also shut it off. He had a volt meter that could be selected to each engine driven generator and the APU. There were also ammeters and later load meters for each generator and APU so he could keep an eye on the electrical situation which was critical in the B-29.

b29driver · **Posted:** Tue Aug 11, 2009 9:40 pm

As Taigh stated, the APU is required for all ground and traffic pattern flight operations on a B-29 with a normal Boeing electrical system. FIFI has been modified extensively in an attempt to get away from that requirement. The B-29 has no nose wheel steering and less than desirable brakes so ground operations are difficult under ideal conditions. It is not possible to keep engine generators on line while taxiing.
The FE on Kee-Bird told me that the flat landing gear struts taxiing over the rough ground was the main reason for the APU fuel tank failing and starting the fire. The crew didn't have the luxury of ordering parts and being able to postpone the departure. Weather window was a very real factor.
It didn't turn out well, but they did try what many others only speculate about.

the330thbg · **Joined:** Wed Nov 14, 2007 3:06 pm **Posts:** 2713

you are correct.., they lived the dream!!!!!

PbyCat-Guy · **Posted:** Thu Aug 13, 2009 9:59 pm

Was looking at some photos of the wreckage of Kee-Bird. Can some of it be salvaged and used for something? Better this than left to deteriorate in Greenland.

newinertia · **Posted:** Tue Sep 01, 2009 2:24 pm

Hi Guys- I did in fact buy the exact engine in the beginning of the post- I found this thread by serendipity I suppose.... Anyway, I need a manual, and would like to find the service history, like what B-29 it was in, I have found some dates on it from March 1943- mfg date?
I am planning to put it in a WWII commemorative themed motorcycle
project if you guys have no objection... The fairing on the bike will be a greenhouse nose in miniature. How cool to have an American motorcycle with an engine in it that used to drop bombs on Japan...
If we had not dropped those bombs, the japanese motorcycle market would not be what it is now..... How Friggin' Ironic!
I am looking at a complete overhaul, everything is there but I would like to do a 100% refresh. anyone here got any advice? It would be MUCH apreciated! 816-206-7670
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