Platt-LePage XR-1 and XR-1A twin-rotor helicopters

[fishjay]

Has anyone ever seen drawings (patent or 3-v) of the XR-1 helicopter? Numerous photos on the net, but no drawings. Did McDonnell use the XR-1 as the basis for their XHJD-1 design or is this one of those cases where two separate companies designed a similar aircraft simultaneously?

Lester (fishjay)

[Skyblazer]

Platt-Lepage's design was taken over by McDonnell and perfected in the form of the Model 38/Model 65 Whirlaway design.

I don't think I have a three-view of the XR-1 or the XR-1A, but I'll go check.

[fishjay]

Thanks. This confirms my suspicions that these two designs looked too much alike to not have been connected.

fishjay

[Skyblazer]

McDonnell Aircraft Co. which had invested in Platt-LePage Aircraft, in exchange for having McDonnell personnel learn helicopter design, had bought the rights to the PL-9 twin-engine twin-rotor design that became the XHJD-1 Whirlaway the first twin engine helicopter to fly in the USA.

From a very good Platt-Lepage page that can be found here:
http://www.plattlepageaircraft.com/2007/11/platt-lepage-aircraft-co-background.html

[Platt-LePage Aircraft]

McDonnell bought the Platt-LePage PL-9 twin engined design that became the XHJD-1.

In a sense, yes.....the PL-9 / XHJD-1 grew out of the XR-1 layout, though they were in reality two different beasts. (Most Platt-LePage designs were lateral tandems, though they had a couple of intriguing single rotor designs)

McDonnell had an interest in PL-LP, they had engineers at PL-LP learning helicopter design, and a number of ex-PL-LP employees went to McDonnell when Platt-LePage closed down.

The story of Platt-LePage is very complicated, the Wikipedia mess is innaccurate, and Rene Francillon's very dated chapter in the McDonnell book is not very accurate. (The Anigrand model kit is a piece of junk, as well)

[Skyblazer]

The story of Platt-LePage is very complicated, the Wikipedia mess is innaccurate, and Rene Francillon's very dated chapter in the McDonnell book is very dated. (The Anigrand model kit is a piece of junk, as well)

Purrrleeeeaase would you fill the gaps for us!!?? 

[Platt-LePage Aircraft]

I'm working on it. (Someday I'll update my website, so the usual internet suspects can swipe my research   )

I'll answer a few questions here...


First lift off of the XR-1 May 1941

[fishjay]

Assuming there was a single engine in the fuselage, the transmission, drive shafts and gear boxes must have been something to behold!

From what I have read it seems that PL-LP had worked out the lateral stability problems when the plug was pulled. Is this true?

fishjay

[Skyblazer]

Assuming there was a single engine in the fuselage, the transmission, drive shafts and gear boxes must have been something to behold!

Perhaps Bell could have taken some sound advice from Platt-Lepage survivors when they struggled with that problem on the V-22?? 

[Platt-LePage Aircraft]

Assuming there was a single engine in the fuselage, the transmission, drive shafts and gear boxes must have been something to behold!

From what I have read it seems that PL-LP had worked out the lateral stability problems when the plug was pulled. Is this true?

fishjay

Haviland Platt and his team solved a nasty drive shaft failure problem with the Bell P-39 Airacobra, Haviland Platt, also laid out the cross shafting set up in the twin engined XHJD-1 Whirlaway, to transfer power in case of an a failure of one of the engines.


The stability issues were partially solved, unfortunately money and time ran out.
 
It would be nice to see the XR-1 fully re-assembled and displayed at Udvar-Hazy, it's in pretty decent shape.

[Skyblazer]

It would be nice to see the XR-1 fully re-assembled and displayed at Udvar-Hazy, it's in pretty decent shape.

You bet it would!!!

[Platt-LePage Aircraft]

A little rarity to enjoy.

What might have been the PL-12 fuselage, with the XR-1A and XR-1 in the Platt-LePage shop, just after the end of WWII.

[Skyblazer]

Brilliant! So Platt-Lepage actually had ANOTHER type in progress at the same time as the XR-1/XR-1A prototypes? Was this to be a civil version of these? Or something different? It's hard to tell proportions exactly in such a small picture, but it seems to be a little smaller than the PL-3...

[Platt-LePage Aircraft]

The PL-12 would have been larger, holding five people, this would have been the civilian helicopter Platt-LePage was working on producing.

There were a number of projects that had quite a bit of engineering work carried out, plus there were parts stockpiled to build a small number of civil helicopters, however events took over that caused everything to be shut down almost overnight.

(One interview I did with an ex-PL-LP employee, mentioned that they were working on rotary-wing projects literally one day, and the company that took over PL-LP, had them working on non-aircraft engineering the next day)

Others jumped over to McDonnell to work on the XHJD-1 project, but McDonnell wasn't able to move things along fast enough with Frank Piasecki taking the tandem helicopter market. (Frank Piasecki bought the XR-1A in 1947)

 

[Platt-LePage Aircraft]

What you could have bought for fifteen hundred dollars in 1947. (Frank Piasecki bought it)