In World War 2 there was a German firm named Blohm und Voss (BV). Under guidance of the technical director Dr.-Ing. Richard Vogt, they produced one of the weirdest airplanes ever.

In 1937 RLM (Reichsluftfahrtministerium) asked for a short range reconnaissance aircraft capable of fulfilling the light bomber, low level attack and smokescreen-laying roles in an emergency. Specifications were:

  1. Three seats
  2. Good all-round view
  3. 850-900 hp for take-off


few of my thoughts


Link to
Scaled Composites
(manufacturor of ARES)

The specification were send by RLM to Arado and Focke-Wulf. Dr.-Ing. Richard Vogt had a unusual idea about all-round view and single engines and made a private-venture proposal. Its name was BV 141.

His idea was to place the fuselage and the engine off center. When you look at the drawing of the airplane, you probably will react with "Huh?". Yes, it looks strange. You might think that this airplane will not be stable in flight. Sorry, you are wrong. It was even a very stable airplane. In fact, it was even more stable than the "normal" single engined airplanes.


BV 141

To understand this you need to look at the following drawings. There you will see what forces are created in a conventional single engined airplane and how the design of Blohm und Voss became more stable.
 

Forces on a conventional airplane
Here you see what forces are present on a conventional airplane. There is a moment created by the rotation of the engine and prop. The airflow that hits the tail creates a left turn.

Forces on the BV 141
The center of gravity, which is placed to the right of the geometrical center, compensates the moment created to the engine and prop. The drag of the fuselage compensates the tendency to turn to the left created by the airflow that hits the tail. There is no longer the tendency to turn to the left.

The plane flew well. Even the critics had to admit that. But the project had some troubles. There were some belly landings due to failure of the hydraulic system, which operates the landinggear. This and the desire to ensure the production of the Focke-Wulf Fw 200 Condor (which took place on 80% of the assembly shop space at Blohm und Voss after a bombing raid on the Focke-Wulf plant) made the RLM choose the reliable Focke-Wulf Fw 189.
The Fw 189 was a surprise to the RLM, because it had two engines. The specification ,made by the RLM, did not mention that the total power had to be delivered by one engine. But everybody, except Focke-Wulf, didn’t consider the choice of two engines.
It is my idea that the RLM made a right choice here due the the unreliability of the BV 141. The Fw 189 proved to be a excellent airplane. It is still on of my favourite "normal" airplanes.

Data of BV 141B-02 (V10)

Seats   3
Power plant (1 BMW 801-A-0)   1560 hp at take-off
Maximum speed 368 km/h 229 mph at sea level
  438 km/h 272 mph at 16400 ft
Range (normal) 1.200 km 745 mls
Range (maximum) 1.900 km 1180 mls
Service ceiling 10.000 m 32 810 ft
Weight (empty equipped) 4.724 kg 10 362 lb
Weight (normal loaded) 5.728 kg 12 566 lb
Weight (maximum) 6.130 kg 13 448 lb
Span 17,45 m 57 ft  3  1/3 in
Length 13,95 m 45 ft  9  1/4 in
Height 3,60 m 11 ft  9  3/4 in
Wing area 52,90 m2 569.41 sq. ft

You will see that the engine in the data is more powerfull than the specification mentioned in this page. The reason for that is that in the development of the BV 141 more power was needed. Luckely Dr.-Ing. Richard Vogt had foreseen this demand and made the original design accessable for larger engines.

In my books I found a article about a similar design, the Da-U. It is a design of prof.-ing.-doctor M. L. Tudha (university of Grönfeldesz). It is a double engined airplane. But here the two engines are placed behind each other. One engine drives a tractor prop, the other a pusher prop. Both engines are placed in the same "nacelle" (don’t know if this is the right word) on the right of the fuselage. It has the advance that the door on the left of the fuselage is totaly free from the props. The noice level in the cockpit should be good if you place the silencers on the rightside of the nacelle.
It is not clear to me if this airplane ever flew. The article mentions another design from the same person but this time with a single seat. At the time of the article (1968) this last airplane was in development.

Another airplane with a asymmetrical layout is the Ares (Agile-Response Effictive Support) from Scaled Composites (the famous Burt Rutan is part of this firm, probably leading part). It is describes as a close-air-support/anti-helicopter fighter.


Ares of Scales Composites (Click picture to get to site of Scaled Composites)
(permission to use picture by Kaye LeFebvre of Scaled Composites Inc.)

The turbofan and the inlet are 8° offset to the left. And the fuselage is offset to the right of the wing centerline. The reason is not stability. The gasses, produced by the firing General Electric GAU-12/U 25 mm cannon (sounds like a big gun to me), may not get into the engine. That is why the inlet is offset.
During flight there is some trim needed when applying more thrust.
This airplane was designed as a low-cost airplane with some low-observable features especially for export.
Scaled Composites has a nice site. Click on the picture of the Ares (at the top or the bottom of the page).
In our site their will be descriptions of some other products of this firm soon.

I made a personal design were I try to combine the stability of a asymmetrical design with the possible benefits of a flying wing. You find at the top of the page a link to that section of the site.

There is another design which uses a asymmetric shape. It is the Boomerang of Burt Rutan. You can see this airplane on several pages of the web. I include some quotes from the nurflugelmailinglist about this airplane.

Interested in seeing this airplane flying. Go to your local videostore and lean the video "Aces: Iron Eagle III" (1992 by John Glen (USA)). The Ares is shown at the end of the film. They mention it as the Me 263 (but you need to know that this refenrence is just a fantasy by the filmmakers). If you need to know more about the real Me 263, go see www.luft46.com! Anyhow, it is a nice view of the Ares.

I got this reaction after showning my idea about a asymmetric flying wing (see section "Few thoughts")

From: Lars Mathiesen Date: Mon, 22 Feb 1999

Hey Koen. I think theres some other approac A 2 engine design like Burt Rutans Boomerang. He uses 2 engine with a silgtly different power output off 200hp and 210hp, this could be a 4 solution. Burt Rutan offcource has to have a asymmetric plane for his personal use. He has some experience in asymmetric design from the AD-1. The scissors wing concept (a fifth solution! with a rotating cockpit/engine nacelle) was originally designed by the designer off the BV 141 (can’t remember his name) Sez Il PS!
BV 141 Picture
http://members.fortunecity.com/braithy/Inbox/bv-141.htm
AD-1 Picture

Boomerang picture

Later I got this reaction.

From: win@writer.win-uk.net (David) Date: Mon, 22 Feb 1999

I was curious about the different power output of the Boomerang's engines, but all became clear when Burt Rutan told me it was really very simple: he already had one engine and got a good deal on the other ! David

It sure was funny to see the rather usual reason to create a unusual airplane. But hey, it must be said. It is a beauty, both in design and in shape.

remark_small.jpg (1234 bytes) On 14-4-2000 I got this remark from Paul Dunlop (www.geocities.com/aerohydro): "You might be interested to know that the first aircraft, the Wright Brother's 1903 Flyer was also a mildly asymmetical craft. Its generally known that the prone pilot and the engine were located side-by-side on the lower wing and hence the Flyer has a tenuous claim to asymmetry due to that layout. What's not so well-known is that the starboard wings were 4 inches longer (than the port wings) to compensate for extra weight of engine. True, thats not very asymmetrical, but the Flyer is lop- sided none-the-less! :-) Check out this URL for the details: http://www.first-to-fly.com/History/1903fly.htm "