Turboprop conversions – built and unbuilt

[Kokoro]

Re: Turboprop conversions – built and unbuilt


Has the RevCon 6G (Hawk 6G) been mentioned in this thread yet? incase I missed it when flicking through pages.

http://www.aviastar.org/helicopters_eng/groen_revcon.php

 

[AeroFranz]

Most probable enigine is a TPE331, though it could be an Allsion 250 which would be a lighter engine. After all, someone replaced the Lycoming IO360 in a Great Lakes sport biplane with an Allison 250 and got, IIRC, twice the horespower at no significant change in weight. From everything I read, it put on stunnign displays.

I thnk (not 100% sure!) on the 250, the exhaust would end up pointing down or up, whereas this is on the side. TPE331 might be more likely

 

[elmayerle]

You're correct about the Allison. The engine must be a TPE331, then.

 

[RyanC]

JB-17 photos found at NARA.

 

[fightingirish]

XC-123 -- R-2800s
XC-123A -- 4 x J-47s

XC-123 -- R-2800s
Link: http://www.flickr.com/search/?s=rec&ss=2&w=49487266%40N07&q=XC-123&m=text

XC-123A -- 4 x J-47s

Link: http://www.flickr.com/search/?s=rec&ss=2&w=49487266%40N07&q=XC-123A&m=text

 

[Hood]

A little additional info on the ENAER T-35T Aucan (Blithe Spirit).
The engine was the 420shp Allison 250-B17D turboprop with a max speed of 367kmh (228mph). The weight (I assume loaded) was 1315kg (2800lbs) to improve payload especailly for weapon training. Plans to start production in 1988 were stopped and the type was cancelled in 1987. The single-seat T-37S aerobatic display variant first flew in March 1988 with a piston engine but the Allison turboprop was planned for production aircraft.

 

[Jemiba]

Found in InterAvia May 1957, this C-124 testbed with a Pratt & Whitney
T-57 turboprop engine:

 

[gatoraptor]

Grumman S-2 Tracker - Conair Turbo-Firecat (PT6), Marsh Turbo Tracker (TPE331), Israel Aircraft Industries S-2UP (TPE331)

Grumman also converted S-2s to TPE331 power for Taiwan. A couple of aircraft were done in Bethpage and the rest were done in Taiwan using supplied kits. I think that the total quantity was around 30, and I do not know their current status.

 

[Apophenia]

Cheers folks. Groen RevCon 6G added to lists as a Cessna 337 conversion. Also Aucan details and I've added the planned Grumman Turbo Trader for Brazil as a (so far) unbuilt project.

[Waaay back, the Cessna 337 pusher came up but I can't remember if the attached image was shown.]

gatoraptor: thanks for the nudge on the Turbo Trackers. I'd thought that Grumman's Taiwan conversions used Marsh kits (like IAI) but the timing is off. That section has been revised (and engine details for the individual projects added).

 

[firepilot]

I dont think that Cessna 337 with just the rear engine, is actually a turboprop. At least it was not last time I was at CIRPAS

 

[Apophenia]

firepilot: thanks for that correction. A little background on those CIRPAS aircraft. Two Skymasters, one 337H (N84NX, US Navy 167782), one ex-USAF O-2A (68-111550, US Navy 167783), converted into Pelican OPV (Optionally Piloted aircraft) by General Atomics (contract March 1996, first flight as a UAV, 10 Dec 1998).

There's lots of detail out there about Pelican payloads and flights but nothing about the engine. Someone on a discussion group suggested that Pelican OPVs have rear 310hp TSIO-520s (Riley Rocket style) in place of the original 195hp IO360. In any case, not a turboprop.

However, another 337 conversion, the Conroy STOLifter has now been added (not sure how I left that one off the list).

Can anyone confirm that the Robertson O-2ST conversion to PT6A was never completed (I've got it listed as 'Unbuilt'). I assume that the attached image shows the 250-C30-powered O-2ST.

 

[JimK]

Apophenia: I don't see your attached image of the O-2ST, and, as I can't attach an image I had scanned from the March 7, 1983 issue of AW&ST, I'll refer you to these pages of Flight International:

http://www.flightglobal.com/pdfarchive/view/1983/1983%20-%200383.html?search=Cessna%20O-2%20conversion
http://www.flightglobal.com/pdfarchive/view/1983/1983%20-%200722.html?search=Cessna%20O-2%20conversion

The registration number doesn't appear clearly in the first reference, but the copy I have shows N987CJ. The second reference is a letter from one of the firms involved in the modification of the 0-2 and mitigates the sinister tone of the first article.

 

[robunos]

The second reference is a letter from one of the firms involved in the modification of the 0-2 and mitigates the sinister tone of the first article.

I think that the second article is just mis-information, and that the first, 'sinister', article is correct. As I posted here,

http://www.secretprojects.co.uk/forum/index.php/topic,9987.msg93055.html#msg93055

with regard to the Mississippi Marvel,

' "...as a proof-of-concept aircraft for a desert
utility aircraft able to take off from soft sand,
and possessing LO features."
What was this aircraft project, what was the
requirement, for what mission, and what customer?'

I have to say, I smell something rat shaped and fishy tasting.......


cheers,
Robin.

 

[Apophenia]

JimK: Sorry, I don't know what happened to my O-2ST attachment but it showed the same, ringed conversion shown in the Flight images (and of equally poor quality).

... I smell something rat shaped and fishy tasting...

;D

 

[Apophenia]

Drawing from Jacques Moulin's Aerophile blog, I've added the following:
http://aerophile.over-blog.com/

Beech UC-45 conversion to Beech-SFERMA PD-18-9 (Turboméca Bastan III)

Max Holste MH-152 conversion to MH-153 Turboméca Astazou II testbed

Nord 1102 Noralpha conversion to SFERMA N-1110 Turboméca, Astazou testbed

Beech 95 Travel Air conversion to Beechcraft-SFERMA PD-146 Turbo-Travel Air and production as PD-146 Marquis 1961

 

[Apophenia]

http://www.secretprojects.co.uk/forum/index.php/topic,1070.msg24965.html#msg24965
PISTON-TO-TURBOPROP -- TRANSPORTS sections updated with more details on Fairchild C-123 Provider turboprops. Iincludes the Mancro C-123T prototype and planned conversions in the US, a current US-South African joint venture proposal, and (thanks boxkite!) an early '90s US-Bulgarian joint venture project.

 

[Bill Walker]

Didn't see this on in the lists yet. Avro Canada converted a Lancaster X to take two Orenda jet engines in 1950. It was destroyed in a hanger fire in 1956, along with some other experimental aircraft.

http://www.flickr.com/photos/78215847@N00/3707441029/sizes/z/in/photostream/

 

[Apophenia]

Thanks Bill! FM209 has now been added under PISTON WITH JET TESTBEDS
http://www.secretprojects.co.uk/forum/index.php/topic,1070.msg24962.html#msg24962

I was surprised to read that a Lancaster X PS-13 testbed was also considered (although I'd like to see a better source for that info).

 

[Jemiba]

Riley, Florida, US planned a turboprop conversion of the DH 104 Dove with
two Astazou engine with 560 hp each, only other external modification would
have been the swept fin. Estimated cruising speed : 480 km/h

(drawing and data from Der Flieger, October 1963)

 

[Jemiba]

A turboprop powered version of the trusted Do 28 was planned, too, but not realised.
http://www.secretprojects.co.uk/forum/index.php/topic,1911.msg187255.html#msg187255

 

[Jemiba]

Already mentioned, but fightingirish and GTX found some photos of the Boeing YC-97J :
http://www.secretprojects.co.uk/forum/index.php/topic,11267.msg202415.html#new

 

[hesham]

Riley, Florida, US planned a turboprop conversion of the DH 104 Dove with
two Astazou engine with 560 hp each, only other external modification would
have been the swept fin. Estimated cruising speed : 480 km/h

(drawing and data from Der Flieger, October 1963)

Great find my dear Jemiba,


sorry,I never saw this post before.

 

[fightingirish]

Turbo Connie: Four R7V-1 Super Constellation transports ordered by the US Navy were modified during assembly as experimental turboprop-powered R7V-2s with four 5,550 shaft horsepower Pratt & Whitney YT34-P-12A engines. The aircraft was first flown in September 1954. Lockheed leased one of the R7V-2s back from the Navy to serve as a testbed for the Allison 501 turboprop engines used to power the L-188 Electra airliner. Nicknamed Elation (derived from combing Electra and Constellation), that aircraft was later delivered to the US Air Force as a YC-121F.

Picture & Source: Code One Magazines Photos - Turbo Connie

 

[GTX]

Lockheed P2V-7 (N7060X) [Conv] to Hawkins & Powers 'turbine Neptune' (Allison T-56-A-14s, N138HP) "incomplete, project on hold." http://www.ruudleeuw.com/greybull-rp-may03.htm

Image of what this might have looked like.

 

[CostasTT]

SFERMA SF-60 Marquis:
http://www.airliners.net/photo/Air-Lorient/SFERMA-SF-60-Marquis/1445802/L/
http://www.airliners.net/photo/SFERMA-SF-60-Marquis/1158465/L/

 

[Apophenia]

Thanks for the additions folks! The Beech-SFERMA Maquis series, Dornier Do 28C, and Riley Turbo Executive have been added ... along with a pair of Canadian Seabee conversions to turboprop power.

 

[wybenga]

A picture of an organization planning to convert Cessna P337s to apparent twin turboprop has been making the rounds in the Skymaster forum, I wonder if anyone here has any insight

 

[Apophenia]

Added: Vazar Aerospace's proposed Turbo Husky, a PT6A conversion of the Canadian Fairchild F-11 Husky bush aircraft.
http://www.secretprojects.co.uk/forum/index.php/topic,1070.msg24965.html#msg24965

 

[LowObservable]

I saw the mention of the O-2ST above...

http://www.flightglobal.com/pdfarchive/view/1983/1983%20-%200383.html?search=337

I would not bet any part of my anatomy on the completeness or accuracy of that article, however, as it produced a letter from the company involved:

http://www.flightglobal.com/pdfarchive/view/1983/1983%20-%200722.html?search=brico


Jack Bridges (Brico) definitely had some Saudi and national security connections, but died at 60 the following year.

http://newspaperarchive.com/us/maryland/annapolis/annapolis-capital/1984/03-10/page-4

It was also known as the Desert Utility Aircraft or Sandcrab. Walt Shiel's Cessna Warbirds book probably has something on it. but my copy has gone walkies.

The remains of the aircraft are at the Quonset Air Museum on R.I.

http://secure.wickfordwebworks.com/~theqamo/aircraft-cessna-02a.html

 

[CostasTT]

On the subject of the 0-2/337 turboprop conversions, I'll add links to the Conroy Stolifter and Basler's Spectrum SA-550:
http://www.network54.com/Forum/149674/thread/1271630450/O-2+Turbine
http://en.wikipedia.org/wiki/Conroy_Stolifter
http://www.337skymaster.com/messages/showthread.php?t=2888
http://i163.photobucket.com/albums/t320/hawkeyes_bucket/Real%20Aircraft/n337bf.jpg
http://www.allaboutguppys.com/cl44/barry_scrap/stol_lifter.jpg
http://www.air-and-space.com/Conroy%20Turbo%20Mods/19740612%20Stolifter%20a%20l.jpg

And a couple of O-2TT images:

 

[famvburg]

Sorry if this one has been posted, but a piston twin to a turboprop single, the Speedstar, formerly an Aerostar.
http://www.schemedesigners.com/Sample-Speedstar850.htm

 

[blackstar]

Grumman S-2 Tracker - Conair Turbo-Firecat (PT6), Marsh Turbo Tracker (TPE331), Israel Aircraft Industries S-2UP (TPE331)

Grumman also converted S-2s to TPE331 power for Taiwan. A couple of aircraft were done in Bethpage and the rest were done in Taiwan using supplied kits. I think that the total quantity was around 30, and I do not know their current status.

The new issue of Combat Aircraft magazine has an article about the Taiwan Trackers. I have not read it yet, but I'll provide an update.

 

[JohnR]

The MKII variant of the Bristol Brabazon was to have had it's Centaurus replaced by Proteus Turboprops.

http://en.wikipedia.org/wiki/Bristol_Brabazon

Regards

 

[masher47]

The Convair listing is incomplete without the original, the Allison Turboliner, which was the prototype CV-240 converted by Convair for Allison with two T38's. This aircraft served many years with Allison in demonstrating the feasibility of turboprops to the airlines and military with several tours throughout the states. It was eventually converted back to radial engines and sold.
The first twin turbine helicopter was the conversion of the Piasecki YH-16 into the YH-16A, again with the replacement of its radial engines with two T28, one mounted behind the cockpit, the other in the tail. Near the end of its flight test program a failure of test equipment mounted on the connecting drive shaft sheared the shaft causing the blades to mesh, killing both pilots and terminating the program

 

[masher47]

Here's the YH-16

 

[terryjohnson]

The dart 17 was converted in Twin Falls Idaho. Ray Elgin of Cody Wyoming was the owner. We took the engines off a Viscount and installed on 17. I worked about two weeks on the project, then went back to flying duties down the line a ways at Feeders. I watched the maiden voyage. That summer Ray and John Bastin died in it.

 

[Stargazer]

I have found mention of a Fairchild C-119 modified by Conroy with turboprops as one of his early post-ASI conversions (circa 1968) but somehow I can't find any photo or specs for this prototype, not even its name. Can anyone confirm that this prototype did indeed exist, and that they have seen photos of it? Thanks for any help on this.

 

[Apophenia]

A few updates ... mostly ag aircraft and the Allison Turboliner.

Brabazon Mk.II with coupled Proteus was covered:
http://www.secretprojects.co.uk/forum/index.php/topic,1070.msg24476/topicseen.html#msg24476

Any other mention of that Conroy Fairchild C-119 turboprop conversion?
-- http://www.aviastar.org/manufacturers/0603.html

 

[LowObservable]

Footage of the B-17T...


https://www.youtube.com/watch?v=ANuDjDJWdtE

 

[Apophenia]

A few changes and corrections to:

Ag aircraft (Ayres Thrush conversions) - http://www.secretprojects.co.uk/forum/index.php/topic,1070.msg24966.html#msg24966

and the addition of Cascade Aircraft Conversions' M601-powered Max Holste MH.1521 Broussard -
http://www.secretprojects.co.uk/forum/index.php/topic,1070.msg24963.html#msg24963