Romeiko-Gurko RMK-1 powered-glider transport aircraft

Hi,

the Romeiko-Gurko RMK-1 was a powered-glider transport aircraft of
1936,it was a high-wing pusher with tail carried on slim lower boom on
centreline.Welded AMTs fuel tank was in nacelle ahead of engine,fixed
spatted main gears braced to fuselage,well-glazed fuselage nacelle with
pilot on centreline at front and six-passengers in three rows,it was powered
by one M-11 engine,probably never completed.

By powered-glider you mean a glider converted to a powered aircraft (like the Go244)? The alternative would be an aircraft that alternates between powered flight and gliding. I assume the main limitations on large gliders for transport are the relatively slow speeds and the dependence on favourable atmospheric conditions. Is there any other reason why one couldn't make a moderate sized transport aircraft with wings optimised for gliding that would alternate between the two flight modes? I assume some long endurance UAV designs may be relevant to the question.

Thanks,

Avimimus said:

By powered-glider you mean a glider converted to a powered aircraft (like the Go244)? The alternative would be an aircraft that alternates between powered flight and gliding.

Click to expand...

Rather your second guess is right. RMK-1 was so-called Planerlet (Планерлет), which can be translated as “gliderplane”. This concept and the term itself are inventions of Lev P. Malinovsky, the Osoaviakhim vice-president and Civil Airfleet (GVF) chief of Scientific & Technical Department. He published his ideas in Samolet magazine, No.12/1933, under title “New Ways of Gliding” (Новые пути планеризма). His main idea was that permanent increase of flight speeds conflicts with economical reasons; it isn’t always necessary (sometimes even harmful, as in agricultural aviation) but very expensive (as it requires more and more powerful engines which burn plenty of fuel). Therefore he proposed a new, optimized kind of flying machine combining the best features of a conventional airplane and a glider. As “normal” aircraft, the Planerlet could maneuver independently of thermals; but it would have such “glider” features as: high L/D ratio, low landing speed, limited wing load. Empty Planerlet could takeoff by its own power, but with full payload it could need an assist of towing aircraft.

Malinovsky considered that his “gliderplane” would be much more costeffective in service than classic transport airplane, and their wide introduction would yield large economic benefits. But not all the specialists agreed with him. In 1934-35 there was a discussion about this in “Samolet” magazine: both supporters and opponents of planerlet put their arguments. Among the supporters there were Eng. Viktor Belyaev (later renowned designer of many unconventional aircraft, the best-known of which is DB-LK bomber), Pavel Ivensen, and Sergei Korolev (future “father” of Soviet space program); the main opponents were Eng. Ramm and V. Markin, deputy editor of "Samolet" magazine. As a result, it was decided not to introduce Planerlets widely for a while, but to build some experimental types and test them.

Three types of Planerlets were built and flown; probably the best known of them is Kharkov-built KhAI-Aviavnito-3 Sergei Kirov flying wing, designed by A. Lazarev and A. Krol. It was first flown at September 23, 1936 (pilot E. Schwarz), and was actually used in 1937-38 on Moscow Oblast regional airlines for cargo and passenger transport (it was the world’s first flying wing really used as transport aircraft!). Two other prototypes even obtained “LEM” designations – for Lev Malinovsky. The LEM-2 (OKA-33) was designed by Oleg Antonov, and became the first powered aircraft by him; its first flight was at April 20, 1937 (pilot N. Fedoseev). Another was Leningrad-built LEM-3 (LIG-6) designed by Yu. Domrachev and L. Vildgrube; it was also tested in 1937 but crashed during overfly to Moscow. Also there was one military Planerlet – it was powered version of Grokhovsky G-31 assault glider called G-31A and tested in 1935. Like its motorless prototype, G-31A could carry 16 troops in special sections inside thick wing. All Planerlets were powered by 100-hp M-11 engine.

The construction of two other Planerlet types was beginned but never finished. One of them was 6-seat SK-7 designed by Sergei Korolev (with assistance of Petr Flerov). And the second was subject of this topic – the RMK-1. Romeiko-Gurko designed it together with Dmitry Kolesnikov, renowned glider designer (his DK-2 established new Soviet Union record of flight range for gliders at September 20, 1934). So, “R” and “K” letters in the designation are for two designers; “M” is perhaps in honor of Malinovsky?

Unfortunately I don't have RMK-1 pictures now. I attach some pictures of other Planerlets.

Sources:
http://www.airwar.ru/enc/cw1/hai3.html
http://www.airwar.ru/enc/law1/lem2.html
http://www.airwar.ru/enc/cw1/lig6.html
http://www.airwar.ru/enc/glider/g31.html
Krasilschikov A.P. Gliders of USSR. - Moscow, 1990. - P.165-168
Sobolev D.A. 100-year history of Flying Wing. - Moscow, 1998. - P.68-71
Vetrov G.S. S.P.Korolev in aviation: Ideas, Projects, Designs. - Moscow, 1988. - P.70-83
Shavrov V.B. History of aircraft designs in USSR before 1938. - Moscow, 1986 (3rd edition). - P.560-561, 586-590. (http://eroplan.boom.ru/shavrov/chr10/civil/planer.htm)

Hi redstar72,

from your last source: ХАИ-8 — это тот же планерлет ХАИ-3, но с двумя двигателями М-11, установленными на стойках над крылом, с тянущими винтами. Строился в 1936—1937 гг., но не был закончен..

Do you have a drawing and technical data for this bird?

Thanks Maveric

Maveric
Unfortunately not. I also want to find a picture of KhAI-8...

Thanks redstar72.

-"Flieger Revue"
-Vetrov G.S. "S.P.Korolev in aviation"
-Unknown sources.
Images PMK-1 for the time being no.
P.S. Alex, thanks for the text.

Thank you my dear Borovik very much.

Yes borovik, two times THANK´s... ;D

Borovik, thank you a lot.

Here is a very intriguing picture of G-31A with M-25. According to "Last Hope" article (M.Orlov. The Last Hope. Wings of Motherland, #3 2002, p.10) this variant wasn't built. Is this a real photo or just an artist impression?

BTW, the scheme and photo of HAI-3 don't correspond. On the photo one can see two fuselages. On the scheme there are no fuselages at all, just small cabins above the wing. Could you comment it?

Äëÿ óâåëè÷åíèÿ ñêîðîñòè òðåáîâàëñÿ áîëåå ìîùíûé ìîòîð, ÷òî ïåðåâîäèëî ìàøèíó èç ïëàíåðëåòîâ â ðàçðÿä ïîëíîöåííûõ òðàíñïîðòíûõ ñàìîëåòîâ, íî ñ î÷åíü íåóäîáíûì ðàçìåùåíèåì äåñàíòíèêîâ è ãðóçà. Ïðåèìóùåñòâî ïëàíåðîâ èñ÷åçàëî, à íåäîñòàòêè îñòàâàëèñü. Òàêîé ñàìîëåò âðÿä ëè èìåë áû ïåðñïåêòèâó ñåðèéíîé ïîñòðîéêè è ýòî ïðåêðàñíî ïîíèìàë Ãðîõîâñêèé. Ïîýòîìó ïðîåêò ñ 700-ñèëüíûì ìîòîðîì Ì-25 íå áûë ðåàëèçîâàí

Hello Yuri,
G-31A with a strengthened structure matched to the 700hp M-25, an imported (later licensed) Wright R-1820 Cyclone yet been built. According to Ye. Gordon - it is believed that later a three-blade flight variable Hamilton Standard was fitted.
KhAI-Aviavnito-3 to (the scheme) and after (photo) modifications, initially (1936) was a short version - 5 meter cabin for 6 persons each, in 1937 they have been lengthened, thus increasing the payload.

Borovik, thank you very much for interesting info, especially for G-31A photos and KhAI-8 picture!

RMK-1 drawing is finally found!
It was published in Tekhnika Vozdushnogo Flota (Airfleet Technique) magazine No.6/1935, in the “Planerlets” article written by the author of the whole concept - Lev Malinovsky!

And technical data for RMK-1 (calculated):
Wing span – 30.0 m
Length – 12.4 m
Height – 3.0 m
Wing area – 64 m2
Empty weight – 1170 kg
Payload – 985 kg
Takeoff weight – 2500 kg
Powerplant – one Shvetsov M-11, 5-cylinder radial, 100 hp
Maximum speed – 130 km/h
Cruise speed – 95…100 km/h
Landing speed – 56 km/h
Flight durability – 10 hours with full payload

And some more pictures of other Planerlets from the same source (all of them still weren’t built at that time). Note unusual early configuration of KhAI-3, much different from its final layout. In case of Korolev SK-7 - drawing is the same but in bigger resolution.

P.S. It’s curious that Malinovsky in his article calls the designer “Gurko-Romeiko”, instead of more common “Romeiko-Gurko”; therefore the aircraft is also called here “GMK-1” instead of “RMK”. It’s even more amusing that the designer published his own article about some problems of gliders’ designing in the same issue of the magazine – and it is signed “Romeiko-Gurko” .

Additional response to Reply # 9
Cosakov V.B. "Heaven ... remember:" The Story Chronicle (1988)

Later on he found a more powerful engine, "Wright-Cyclone F-3", and later the domestic engine M-25. Glider, which put the metal variable-pitch propeller, increased its full load speed of up to 150 kilometers per hour and was the altitude. Grokhovsky used it for stratospheric research and test flights with different weights. In fact, G-31 with M-25 became the first aircraft designed specifically for airborne troops.

Click to expand...

There is an article, with drawings, in les Ailes of 17 October 1935 concerning the GMK-1, LEM-2, CK-7, KHAI-3 and LEM-3.

avion ancien said:

There is an article, with drawings, in les Ailes of 17 October 1935 concerning the GMK-1, LEM-2, CK-7, KHAI-3 and LEM-3.

Click to expand...

Could you take a digital photo of it? (I'm not asking for a scan as I know how fragile these old Les Ailes can be...).

I would if I could - but I have my copies of les Ailes as pdf files on a DVD and try as I might, I can't work out how to transfer individual pages from this onto my PC - if this can be done - in order that I might upload them to this forum. I regret to say that I never have been very proficient in this sphere! But if someone can tell me whether and, if so, how I can do this, firstly I'll be grateful to them and secondly I'll do as you wish, Stargazer2006!

Attached is a copy of the article in les Ailes of 17 October 1935. I apologise if the quality leaves something to be desired. Stargazer2006 knows the reason why!

You can use PDF-XChange viewer
http://www.tracker-software.com/product/pdf-xchange-viewer
Load the PDF into it and then export it as an image (15 different image formats are supported) and you can save each page as a separate single page image file.

Thank you, bigvlada.

Not quite the same concept, but some slightly later motor glider transports:

Gribovski M-11M
https://www.secretprojects.co.uk/forum/index.php/topic,17784.msg245721.html#msg245721

Gribovski G-30/G-11M variants:
https://www.secretprojects.co.uk/forum/index.php/topic,10105.msg190211.html#msg190211

Polikarpov MP
https://www.secretprojects.co.uk/forum/index.php/topic,17877.msg312831.html#msg312831

SAM22/SAM28
https://www.secretprojects.co.uk/forum/index.php/topic,516.msg93405.html#msg93405

Here is a question:

How were gliders with centrally mounted tractor propellers supposed to be towed? The LEM-3 appears to have a frame to keep the cable below the propeller - but what about the LEM-2? The same goes for the KhAI-3 variants which had the engine mounted at wing level, the SK-7, G-31 and the LIG!

Don't know for sure, if the engine of such gliders was intended to be used, when the glider was
towed. Maybe it was installed only to increase the range of the released glider, or to allow for an
easy return after the payload was delivered ?

Jemiba said:

Don't know for sure, if the engine of such gliders was intended to be used, when the glider was
towed. Maybe it was installed only to increase the range of the released glider, or to allow for an
easy return after the payload was delivered ?

Click to expand...

Looks like the original designer never figured out the problem with keeping the tow rope clear of the propeller.
During WW2, British GAL. 49 Hamilcar assault gliders used a bifruncated ("Y" for the proleteriats) tow rope attached to wing roots. When they later added radial engines to a handful of Hamilcars, they installed engines near the tow rope hooks.

Avimimus said:

By powered-glider you mean a glider converted to a powered aircraft (like the Go244)? The alternative would be an aircraft that alternates between powered flight and gliding. I assume the main limitations on large gliders for transport are the relatively slow speeds and the dependence on favourable atmospheric conditions. Is there any other reason why one couldn't make a moderate sized transport aircraft with wings optimised for gliding that would alternate between the two flight modes? I assume some long endurance UAV designs may be relevant to the question.

Thanks,

Click to expand...

It is more about the debate of whether to install enough power for short take-offs or just enough power for cruise flight. Consider that Cessnas throttle back to 75 percent or even 55 percent power to extend endurance (loiter time). The USSR only had a tiny petroleum industry during the 1930s, so low fuel consumption was a big issue.

Wings are essentially the same planform for both gliders and long-range transports, with high aspect ratio and low wing loading. Low wing loading translates to slow rate of descent (power off) and the ability to exploit even slow thermals. On powered airplanes, low wing loading translates to less excess power needed for climb.
This high aspect ratio planform still holds true on modern, long range, jet airliners because you need essentially the same wing for climbing, soaring and high altitude cruising. Modern jet airliners benefit from fuel efficient turbo-fans that can be throttled back for low fuel consumption during cruise.
A disadvantage of this whole powered glider transport concept is that it works great in the flat, open steppes of Ukraine, but is woefully under-powered when trying to take off from small lakes high in the mountains.

About the LEM-3, its says that it did its own take-offs , only by heavy load eg... it needed towing to get up in air.