View Full Version : A few unique "Push-me/Pull-you" birds that didn't quite hatch...

03-31-2012, 11:37 PM
Here's a pair of interesting Push-Pull aircraft that would have been great to see fly in person, perferably NOT by extending the war though... ;)


This was going to be Germany's "Twin-Mustang", made from combining 2 DO-335's....Four V-12s, Four props, and lots of GO-GO-GOOOOO......and JUNKERS was going to make it too! Weird how things happen, or DON'T happen in this case.

(The twin horizontal stabilizers and airframes joined only at the main wing remind me a lot of Burt Rutan's White Knight aircraft...)

..................... Junkers JU635 ....................


Did I say "JUNKERS"? Oh yaz.
Read on...

In mid-1944, Junkers inherited the Dornier 335Z long-range reconnaissance (Z for Zwilling, or twin) program from Heinkel, who were brought in to assist Dornier because they lacked the experience in building such aircraft.

After meeting with engineers from Dornier and Heinkel, Professor Heinrich Hertel decided that it would be late 1945 before the first prototype of the Do 335Z would be ready. He then referred back to Project 1075.01-21/W 00304, which would involve a lot less redesign and modification, and gave the date of Febuary 1945 for the first prototype to be ready.

After a few more modifications (new main wheels, lengthened fuselages and an increased center wing both in chord and length), the RLM authorized the use of the 635 number, thus becoming the Ju 635. A purchase order for four prototypes and six pre-production aircraft was received.

The Ju 635 used two modified Do 335 fuselages, joined by a center wing section of constant chord. The outer wing panels were tapered back, and two 1200 liter drop tanks could be carried beneath the wings to increase range.

Four Daimler Benz 603E-1 engines supplied the power, one in each forward fuselage pulling and two in each rear fuselage driving a pusher propeller via a long drive shaft. Fuel was to be carried in ten internal wing tanks, four in the fuselages and possibly one in each fuselage bay. The port fuselage bay carried the two Rb 50/30 cameras (or one camera and one 250 liter (66 gallon) tank for GM 1 power boost) and the starboard bay contained five 60 kg (132 lbs) marker bombs.

A crew of three was envisioned, although this could be stretched to four eventually. The pilot and radio operator sat in the port fuselage and a second pilot sat in the starboard fuselage. The fourth crew member (navigator) was to also sit in the starboard fuselage.

The landing gear was to consist of two nose wheels (one under each fuselage nose), two main wheels which were fitted with mud guards to protect the rear radiator intakes, and a jettisonable fifth wheel located beneath the center wing, which was fitted with a parachute for recovery. The main wheels were modified from the Ju 352 B-1 transport's wheels.

That would make for one lightning-fast machine, but where is it? :dunno:

"It" isn't. The airframe was never built...

In early 1945, a wind-tunnel model was tested, and a cockpits mock-up was constructed, but in February 1945, due to the desperate war situation, the project was cancelled.

.................................................. .................................................. ..........

The second flyer is another push-pull configuration, this time an interesting design from France. At least this one was built in prototype form, twice.

......... Moynet JUPITER ...........Is that a baby B-25 or an oversize Ercoupe? .........




The Jupiter was an executive transport with between four and seven seats, depending on engine power. It was designed by André Moynet, a member of the National Assembly of France and a former government minister, while also a test-pilot, and built by S.S. Engins Matra (so it is sometimes referred to as the Matra Moynet Jupiter)

The prototype first flew on 17 December 1963 with the designer and Lucien Tieles at the controls. Its wing had a straight trailing edge, but the centre section had strong taper on the leading edge which continued more weakly outboard. It was of two spar, stressed skin construction, carrying mass balanced ailerons and slotted flaps. The main undercarriage legs, placed at the end of the centre section each carried a single wheel and retracted inwards electrically. A retractable nosewheel completed the landing gear.

One horizontally opposed Lycoming engine was conventionally placed in the nose. The rear fuselage was quite short, and it lacked the normal taper, giving it a boxy look, so that the second, pusher Lycoming could be mounted in the extreme tail. This was cooled by air from rectangular intakes on the upper sides of the rear fuselage.

The straight edged, tapered tailplane was mounted on the fuselage top above the engine, with small end-plate fins carrying balanced rudders. These fins extended above and below the tailplane, with arrow shaped leading edges and straight, swept trailing edges. There was also a long, shallow strake over the rear fuselage.

Only two Jupiters were built. The first, designated 360-4 and initially registered as F-WLKE had two 200 hp (150 kW) Lycoming IO-360-A1A engines driving two-bladed propellers and was configured as a 4-5 seater.

The second prototype was of a more powerful and slightly larger variant designated the model 360-6. This model had a choice of engines, either 290 hp (216 kW) Lycoming IO-540 six cylinder engines driving constant speed, three-bladed propellers, or 310 hp (231 kW) Lycoming TIO-541 engines. The span was increased by 0.37 m (15 in) and length by 0.64 m (25 in). The increased length allowed seats for 6-7, with two rows of two single seats and a bench seat at the rear that could accommodate 2 or 3.

Here's photos of a Jupiter prototype undergoing restoration, clearly showing the engine layout...


Defiant...eat yer heart out.


First time Juke
04-03-2012, 12:16 PM
You forgot Bellanca TES.


04-03-2012, 11:53 PM
You forgot Bellanca TES.


That Bellanca was more of a one-of-a-kind, purpose-built aircraft (like Rutan's Voyager) and was never intended to go into mass production like those I was featuring.

The Bellanca TES (Tandem Experimental Sesquiplane) was originally built in 1929 for the price of $25,000 price for the first non-stop flight from Seattle to Tokyo.

It has two Pratt & Whitney Wasp motors mounted tandem in the nose, one driving an ordinary tractor propeller, the other driving a shaft connected to a pusher propeller at the rear end. The tail of the plane is held out behind this rear propeller by two outriggers from the wings.

Interesting plane though. I never heard of the TES before. Thx for posting/sharing it.

First time Juke
04-04-2012, 01:24 AM
Okay...first I was gonna post Star Kraft...but it hatched; http://www.aircraftdesigns.com/starkraft.html

04-05-2012, 03:17 AM
No biggie. The Star Craft is a fascinating machine.

Go ahead and make this a "Push-pull aircraft" topic now if you will and display other planes of this species type with a prop on each end..http://img444.imageshack.us/img444/1636/newt1.jpg.That could prove interesting and informative. :thumbsup:

We all already know of Burt Rutan's Defiant and Voyager, Cessna's 337 Skymaster and Dornier's DO-335, shown here in respective order:

I got to see one of these in person at Stead in the early 80's, possibly Burt's own...




What else is there? :dunno: .....lemme seeeee.....

Atom Aircraft created both the tandem prop Adam A500 AND a no-tandem jet-propelled version (A700). They never made it to production:


There's an assortment of Dornier seaplanes that qualify, but I'll just post a D18:




Schweizer RU-38B:


That's a good start. Let's see if anyone else comes up with some additions.

No pusher-prop-only planes please, nor mixed-power aircraft such as those with a jet engine or rocket in the tail and a prop on the nose. Just propeller-tandems if you would. :thumbsup:

To finish...it would be VERY interesting if this one had ever been tried (It hasn't as far as I know of):



First time Juke
04-10-2012, 02:03 AM
No biggie. The Star Craft is a fascinating machine.



Just think about this AC with modern day solar panels with 1 kg/5 m2 weight and 2 hp/5 m2 output !

Making the rear engine work with solar power alone. Loose the 2500 kg and the other lycosaurus...you get 30 kg/m2 wing loading..instead of the 133 kg/m2..at take off. Also you can actually put the rear lyco at the front..and save more weight.

04-10-2012, 10:13 AM


04-10-2012, 02:43 PM
He had me at Lycosaurus, although I don't see how moving the dinosaur up front would save weight. Maybe ya hafta be a paleontologist of Rutan caliber to understand....:dunno:

04-10-2012, 05:17 PM
He had me at Lycosaurus, although I don't see how moving the dinosaur up front would save weight. Maybe ya hafta be a paleontologist of Rutan caliber to understand....:dunno:

Rutan put an engine in back for better efficiency. The 2nd beast up front was for safety of redundancy. I too wonder how moving one from the back to the front saves weight.

Maybe move the dinosaur to the middle instead... :D


(Thx to Bill Watterson for the artwork...)


First time Juke
04-11-2012, 01:49 AM
Rutan put an engine in back for better efficiency. The 2nd beast up front was for safety of redundancy. I too wonder how moving one from the back to the front saves weight.

Maybe move the dinosaur to the middle instead... :D


Awesome T-Rex there !

Well just in princip the aft engine was lighter lyco...and replacing 2500 kg of the 3000 kg fuel with just 5 kilos of solapanel will give you 16 hp ( another 4 hp when paneling the fuse too )....which is not much but when you also get cleaner airframe and better l/d ( Roncz told me the canard foil is 20% and main wing foil 18 % thick to get all fuel on board ) when getting canard into 17% and main 15 % ( for instance )...above the clouds there is always sunshine and front engine could be applied when the aft electric sustainer engine isn't enough...at start and getting into cruising altitude of 12 000 ft for instance.

20 hp electric power in clean low wing loading ac is enough in a glider..in fact 5 hp is also enough in a gliders.

Originally Voyager was a bit over 400 kg the airframe...if you have 100 kg engine at the front and 200 kg people + 200 kg fuel payload you get 33,5 m2 winged plane a 27 kg/m2 wing loading....and 0.022 hp/kg power to weight ratio ( almost 8 times better than in HPA planes )...and 0.12 hp/kg running on lyco alone...which is twice more power to weight ratio than what Dick and Jaena had on their take off in 1986..in a cleaner air frame.

What this actually means in that plane cruises at lot faster speed when on lyco alone...and for the economy drive approximately at 60 mph ( which is slower )...if the sustainer engine wasn't a lyco at all but much smaller like a 25-30 hp 4 stroke you might be able to make it around the globe nonstop...it might also mean that you pedal electricity during the nite for the rear engine..since it is not operational. Pedalling only produces 1 hp for 2 people and 1.5 hp for 3 people at max...it just might help a tad in the glide ratio...from 30 to 45 perhaps. From 16 000 ft to 220 km..that is around 2 hours..not using the lyco...then a burst of the lyco again to gain 16 000 ft again for 30 minutes..this would mean that during the nite the lyco ( or smaller 30 hp ) would be used 2,5 hours burning 25 liters of LL100 a nite. I estimate around 10 nites endurance with 200 kg of fuel.

How far do you go in 11 days at 60-80 mph ? It is 252 hours...only 24 000 km and at 100 mph just around the globe ! So you might need 350 liters then.

yes we made it !....virtually. ;)


05-11-2012, 09:09 PM
Getting back on topic, I ran across an 8-minute video with some of the best footage of the Dornier DO-335 I have come across yet.


It even shows a drawing near the end of the clip of an un-built variant that replaced the rear V-12 and propeller with a turbojet engine:

Screen capture...

02-09-2017, 04:56 PM
And then, there was Dave Garber's DG1 unlimited raceplane, from back in the 1970's...completed, test-flown once or twice but never raced. About the size of a F-1 raceplane but with two 330 HP engines.The story I heard was that Dave did one lap of the pattern and had to land immediately because the engines were overheating.... then later found that the coolant pumps were being driven too fast and were cavitating and not moving coolant through the radiators....