Turbines 4 Jabirus

[g-lock69]

Hi there guys!!

Apparently some guy fitted a 737 apu to a jabiru!! It had vertical climb capability, and a 25000 ft ceiling. Due to the fact it cruises at such a height it can maintain 150kt indicated which equates to a 250 kt TAS (Ididnt check it on my wizz wheel). So considering it can fly at the height of a jetstream (which for the definition, has to be at least 60kts in magnitude, u can get a 300kt ground speed out of it. Because it has beta mode if one was game, u can descend vertically. The hurdle will be getting it IFR certified.



And keeping the wings on??? :}

Woomera

[Runaway Gun]

I don't suppose that this guy is an American by any chance?

[Squawk7700]

Nice work Dave K, you got my attention with your stupid post.

[Capt Claret]

Geez, that'll give Stiffy a stiffy! :E

[Runaway Gun]

Careful Captain - He'll track you down.

Hell - he'll track us all down, at well over 250kts TAS. ;)

[Kanga767]

Knowing both the 737 APU and most turboprops, I think someone is having a lend of someone here......


Kanga


I'm inclined to agree.............. :}

Woomera

[Mere Mortal]

A turbine plastic maggot flying up in the flightlevels, hope its got a good heater. Will it be Ultralight registed?
And if you ask the ultralight crowd about IFR certifcation, they will use the standard reply of "ahh, it's all GA bulls**t.

MM

[Sunfish]

ummmm as if a) any garrett thing was reliable.

b) Horsepoer and Vne made sense

[Jet_A_Knight]

This might work on a Jabiru.....


http://www.innodyn.com/aviation/products.html

[Deaf]

Long way back (early 70's) there was something about a pre war US biplane with a turbine in a mag. A GAF bloke said the the pair of Allison turbines originally intended for the Nomad (except not enough grunt - sound familiar) came from Victa.

Would have made the Victa less scary on a hot day.

[Kanga767]

Nope.

The 737 Garrett (Honeywell/Allied Signal) APU is a GTCP-85. Smaller/different core engine. The Allied Signal 131-9 in the 737NG is too far removed.

The GTCP 331 with the 'similar' hot section is in the 767/L1011/A300. It, however, has a load compressor which the TPE version would not be very happy with as well as wrong/simplified fuel system, wrong combustion chamber etc etc.

The THERNODYNAMIC rating of the 331 series is anything from 715 SHP for the -1/-2 to 1000 for the -11/-12, (without water meth!) Not to mention the -14 with 1759 SHP. However, the -10/-11/-12/-14 engines are somewhat redesigned from the APU/pre-century versions.

I can tell you right now that converting the APU model of ANY of these into a turboprop is not as easy as unbolting the accessory gearbox and bolting on a prop gearbox!!!! Bear in mind, APUs are designed to run at ONE speed only, I'd like to see a Jabiru taxied around at 100% RPM on one of these suckers. Don't talk about Beta either, the only aircraft I know approved/designed for Beta in-flight is the DHC-6.

Another thought that comes to mind is that if one did manage to shoehorn something like this into a Jabiru, it would empty the fuel tanks shortly after reaching cruise altitude.

Something that IS believable is that there are some single engined Cessnas modified with Allison 250s flying around the USA. (Which BTW were rated at 420 SHP in the Nomad, but apparently only like 250 sucked out of their backside....) Unlike the Nomad, they are a helicopter version with an external driveshaft to a propeller gearbox.

The next thing you're gonna tell me is that Garrett took the original 747 APU and used it to re-engine business jets.........

Now, can I go back to my 737s??!!



Kanga


PS - I am willing to donate funds and my time/experience on Garretts to a 'Mythbusters' 2 Hour special on this.

[Woomera]

The Allison 250-B17 gas turbine (as fitted in the Nomad) has also been installed in a number of Turbine Beech Bonanzas (http://www.pilotjournal.com/content/2004/mayjune/tradewind.html) in the USA - giving rather interesting performance - although the prop diameter appears to require an extended nose leg!

This will make Chuck's eyes water!

"A 300-hp Continental IO-550 A36 will finish its climb to altitude to 600 fpm, whereas the Turbines Bonanza will hold a 25-degree nose-high attitude while climbing at 2,500 fpm well above 10,000 feet."

:ok:

[Kanga767]

Well what do ya know....

http://www.zenithair.com/misc/turbine-power.html

A 737 APU it ain't, it's actually a starter out of an A7 Corsair.

This is a much more interesting application....

http://turbokart.com/turbokart.htm

Kanga

[ur2]

Didn't know a 737 had a turboprop for an APU.
Sounds like an urban myth to me.:ooh:

[g-lock69]

hey boys!

heres a turbine powered jab from overseas

http://www.geocities.com/jimmy_g20/jabiru_turbine.jpg

[Johhny Utah]

You may want to try a little harder with photoshop next time ;) Perhaps you could also pick an engine that didn't have the propeller straps on, and covers over the exhausts. :p

Nice try though...:ok:

For a REAL turbine machine, take a look at this:
http://www.lancair-kits.com/PropJet_images/PropJet_7_lrg.jpg
More info found at Lancair aircraft (http://www.lancair-kits.com/Lancair_PropJet.html)

[Ultralights]

ahh the joys of the experimental catagorie!

[Chadzat]

We had one of those turbine Lancair puppies parked near the Flying School at Parafield not long ago. And it had been telling a few lies too, it had a LOOOONG nose.

"ur2" you are joking about the "I didn't know the APU was a turboprop" comment?

A turboprop is basically a turbine 'jet' engine driving a propeller through a gearbox. Hence "turbo-prop". An APU is just a little jet engine that powers auxilliary stuff.

A question for Kanga- We are having a debate at Uni atm on whether an APU can actually move an aircraft (ie a 737 for example) ?

Chadza

[Kanga767]

Hiya Chadzat,

Taking an educated guess, most of the power developed in an APU is turned into torque by the turbines to drive the accessory gearbox and compressor(s). I would think there is insufficient thrust out the jet pipe to move whatever it is normally mounted in.

Also, bear in mind that some APUs are not necessarily mounted fore/aft, and thus any thrust would not act to move the aircraft in its normal direction.

As an afterthought, some turboprop manufacturers actually take into account jetpipe thrust, even though it may only be a few hundred pounds of thrust........because it makes their thrust specific fuel consumption look better :hmm:

Kanga

[tinpis]

UR2 the 733 I flew had an APU with a switch marked "APU" on the overhead panel.
I never asked anyone WTF model or anything it was.
It coulda been a 455 Chevy.
Also
We had an engine each side under the wings.
Was a CFM -56
They worked
or didnt
We had a book what told us what to do in either case.