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A more elegant, nevertheless quite unusual concept fom Bell:
A tandem stowable rotor.

(from AviationWeek 5/67)


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Thanks my dears,

and there was also retractable rotors from Sud Aviation.


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I would be very interested in any information or pictures that anyone might have regarding the Bell Ducted fan efforts.
jemiba- Thanks! I had not seen that concept before. Of all the Commercial VTOL concepts I have seen over the years, the D-2240 seems to be one that might actually have met with passenger acceptance. It does not have the look of an aircraft with lots of moving parts etc., that seems to be crucial to passenger acceptance. Of course it is doubtful that the technologies of the mid-60's would have allowed for the crucial cost per seat/mile to be realized to make the aircraft finacially viable.
"..and do you know Bell D-196 ?"

Sorry, I don't know this designation, but many projects were just published
with designations as "transport with tiltable ducted fans" or something like
that. If you can describe the D-196, maybe we find a project, that fits into
this description. ;)
Breathtaking Orion..
Can jou give us more info of the book ?

Obrienblam(2) - Thank you for the fantastic info. The chart alone was a tremendous surprise. I was not aware of two thirds of the concepts on the diagram.

A question for the veterans here. When doing the patent search, do you go with specific nomenclature, or is a 'hit or miss' ordeal? I tried to search specific nomenclature for the designs from Obrienblamblam's chart post to no avail. While 'ducted fan' and 'four post ducted fan' bring up some aircraft, I have not found many of the designs. I assume they never progressed to patent stage or I am missing the mark.

Thanks in advance.
yasotay said:
I tried to search specific nomenclature for the designs from Obrienblamblam's chart post to no avail. While 'ducted fan' and 'four post ducted fan' bring up some aircraft, I have not found many of the designs.

These are Design Patents. As such, the patent contians naught but the basic drawings... and has a very basic title. For instance, as memory serves, both of these patents were titled "Aircraft."

I'm finding google Patents to be both very useful... and very limitted. One patent that I had a photocopy of (from the Denver public library, pre-Web days of manual searching of microfilm) was a Bell Aircraft patent for a VTOL tailsitter fighter from WWII; I had misplaced the copies, and decided to use Google to hunt it down, based on the few snippets of info that I could recall. A few days of searching failed to turn it up. I finally located the paper copy, and then went back to Google: even with a patent number search... Google couldn't find it. The patent office server had the patent, but Google does not. Strange. I can only assume that there are a *lot* of gaps.
Thanks my dears about all informations and drawings.
Thanks for the reply. I suspected something of the sort as you suggest might be one of the possiblilities as the service is relatively new.
Ok my dears,

I left the English language in 1983,excuse me.

The Bell D-318 was also designed for LAMPS program (Light Airborne Multi-Puropose
System) as Boeing-Vertol BV-237,do you have a drawing to this project ? please.

I heard that the Bell D-137 was a fighter project,
is that right ? please help.

The Bell proposed to develope a civilian transport version of BOMI
rocket bomber in 1957,and the straight wing was replaced by a delta
wing and the estimated range was 4800 km.

The Bell D-116 was a civilian version project of HSL-1,and the D-216 &
D-238 were the development of the same helicopter.

Can I ask about the Bell D-138 & D-143,were those aircraft a
twin boom fighters or not ?.

What was that Bell aircraft ?.


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To me, it looks like a jet aircraft with the inlets in the nose, covered by metal mesh
or grid to retain the profile. The jet pipes seem to be on the underside under the wing.
Yes my dear Jemiba,

and R. Hall was also designed a several projects to Bell
Aircraft Corporation,such as this design;,M1


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hesham said:

What was that Bell aircraft ?.

Perhaps related to a Bell X-14 development?


the Bell D-104 was twin engine anti-submarine helicopter project,
does anyone know more about the D-261 attack helicopter
project ?.

there are also a several of unknown convertiplanes projects,
the D-212,D-240 and D-250,if anybody can help.The Bell D-200
was turbine-powered helicopter project.
This Bell project really looks like a sort o mix-up between an Heinkel 176 (in plant) and a Percival Provost (in profile), not counting the weird disposition of the engines....

the Bell Model-323 and Model-604 were tilt rotor aircraft
projects and the D-276 was light twin helicopter project,
but the more interesting the Bell did built the mock-up
of D-306 helicopter,but no more informations.
According to The Bell Helicopter Textron Story by David A. Brown,

D-200 is Bell number for the XV-3 convertiplane.

D-261 was an attack two seater for AAFSS contest (1964).

From Bell Aircraft by A J Pelletier (Putnam),

Model 212 is the UH-1N

Model 240 was Bell UTTAS contender (1972)

Model 250 is a project from Model 206 (1962)

Please note that Bell Model designations are different from Bell Design Numbers. I don't have info for D-212, D-240 or D-250 design numbers.

no info available about Model 323, 604 or Design number D-276 but I found that Bell submitted two designs to AAFSS: D-261 and D-262


Thank you my dear pometablava,

and finally I found in Internet from a many months a small
info about Bell Model-215 helicopter project which was
submitted to a competition as a proposal,also Model-216
attack helicopter and Model-217G for a competitions
during 1970s,with no explainations in that site,I don't
remember its name.

I heard that the Bell X-5 was redesigned as interceptor
aircraft,is that right ?.
Source: Bell Aircraft. AJ Pelletier. Ed. Putnam

US troops discovered a Messerschmitt P.1011 prototype on 29 April 1945. It was 80% completed. Bell borrowed it in 1948 and decided to fly it with a J35 engine but the aircraft was too damaged. Then, the Bell team decided to produce a design based on it and show their proposal to the Air Force in late 1948 but the Engineering Division stated that it was unable to carry enough fuel and armament to be a good interceptor. Bell proposed building two experimental aircraft to prove the validity of the concept, that was the Bell Model 60 / NACA X-5. Several fighter projects were studied from 1949 to 1951. A single 5,200 lb J35-A-17 would have been the powerplant (720 mph at sea level). Armament: 46 rockets and nose mounted AN/APS-19A radar.
Thank you my dear pometablava,

and there is the Bell D-218 cargi helicopter of 1956 and
powered by two R-1820-34 engines.


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Hi Maveric,

unfortunately, the answer is no. All drawings were included for pure ornamental purpose to illustrate an article about the Bell XV-15.
BELL *All Wing* helicopter project dated 1954!


The text mentioned: "The prototype is now being built" ???

It seems related with the D-218 cargo helicopter project.,1222.msg24342/highlight,bell+d-218.html#msg24342


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