Mar 312010

One fighter design that I’d love to see authentic blueprints of is the McDonnell XP-67. Ahead of its time aerodynamically, it suffered from underwhelming engines and came just too late… right at the beginning of the jet age. I’ve heard rumors of jet-powered variant designs, but I’ve never seen any verifiable drawings of such a thing. In lieu of official diagrams, these are the best I have… drawings produced for magazines by non-McDonnell artists. The sources on both of these are unknown to me, but they probably date from the 1950’s. Bjorn Karlstrom, one of the artists, was a designer for Saab, and drew aircraft for magazines starting in the late 1930’s.

A one-sheet XP-67 diagram:


And a three-sheet series:




 Posted by at 9:23 am
  • Michael Holt

    Thanks. This one is a thing of beauty.

  • James

    Good to see my namesake. Is there any chance of kit in the future?


  • Pat Flannery

    Those fuselage slices in the top image could have come right off of a SR-71.
    It would be interesting to know why they designed it with that much blending of the fuselage and nacelle lines – laminar flow?
    There’s already a kit of it out:
    I didn’t realize there was any film footage of it in existence, but YouTube has a five minute video of it:
    Boy, if looks could kill… certainly one of the most attractive aircraft of the WWII era.

  • Ronnie O.

    Never thought I’d see a Karlstrom drawing here, given his dubious reputation wrt. the accuracy of his drawings. Still… a drawing (or two in this case) is better than none.

  • Michael Holt

    What’s this about accuracy? Did Karlstrom make some spectacular and inexcusable errors?

  • admin

    > Is there any chance of kit in the future?

    Not really, since there have been numerous such kits in the past.

    > Still… a drawing (or two in this case) is better than none.

    I’d be thrilled with a large-format McDonnell drawing, but I’ve never seen one.

  • Pat Flannery

    What gets me is the armament…_six_ 37mm cannons.
    The recoil of all those firing at once is probably going to stop the aircraft dead in its tracks.
    This may be one of the few cases I can think of of an aircraft that seems overarmed for any mission other than antitank work or taking on naval vessels.
    You go after a bomber with it, and it’s going to blow it into confetti in a matter of a few seconds.

  • Mike Brickman

    Unfortunately, all drawings, photos, negatives and reports for the XP-67 were destroyed in the late 1980s. Only a half-dozen or so photos were saved into the company’s negative files, and those are the ones you’ve seen over and over.


  • Michael Holt

    The music in the video ( was an odd choice.

  • admin

    > all drawings, photos, negatives and reports for the XP-67 were destroyed in the late 1980s

    Unlikely. Much of the best stuff in my collection comes from private folk who took their work home with them (or got it from family who took their work home with them, etc.). *Somewhere* out there is at least one really good layout of the P-67.

  • Pat Flannery

    I went digging around in my books for info on it today, and found I had more info than I thought I had on it:
    The aircraft was designed as a bomber formation destroyer, and originally was going to carry for 20 mm cannons and six .50 cal. machine guns.
    The 37 mm cannons were Oldsmobile M4s, and had 45 rounds per gun.
    There was consideration given to replacing the six 37 mm guns with a single 75 cannon. Since the M4 had a firing rate of 150 rounds per minute, that meant your were going to be out of ammo in under 20 seconds, so you had better be sure your aim was true before firing a long burst.
    Although flying characteristics were acceptable, pilots thought it was underpowered, particularly during takeoff and initial climb.
    Because of the fact that the Continental XIV-1430-17/19 1,150 hp engines weren’t developing the planned power output, the second prototype was going to be completed with Packard V-1650 license-built Rolls-Royce Merlins of 1,695 hp, as well as a unspecified type of jet engine of 2,300 lb thrust in the back of each nacelle.
    The plan to replace the six 37mm guns with the 75 mm one may give a clue as to where the design was heading after it became obvious that there weren’t going to be hoards of German or Japanese bombers to shoot down; like the B-25H, it would probably be intended for anti-shipping work, and one wonders if that was what the 37mm guns were intended for also, as a long burst with those might be capable of sawing a small ship in half.
    It would have made one hell of a antitank aircraft, as the 37mm rounds would probably have been able to go through the top armor of most wartime tanks.

  • Pat Flannery

    Okay, the turbojets were to be GE I-20s or Westinghouse 9.5″ diameter ones.
    The GE I-20’s would have generated 2,000 lbs thrust each, and the Westinghouse engines would have generated 240-340 lbs thrust each.
    The GE engine seems too big for this use, as you would deplete your fuel fairly quickly while running both those and the Merlins, although speed would have been spectacular when both engines were running.
    The Westinghouse engine seem pretty anemic, but was probably a improvement in thrust over the turbo-supercharger exhaust system that gave so much trouble on the first aircraft.
    One question regards fuel supply – would you run the jets off of gasoline, or put in separate tankage for kerosene?
    In the Ryan Fireball, both ran off of gasoline.

  • Kjell

    Creeping out from the closet.
    Have been a “fan” of you Scott for many years.
    Work as an employee at Swedish Space Corp. We subscribed to APR when it was a paper magazine, but missed you taken over. Admire your effort.
    Anyhow as a flight/space nerd swede, Björn Karlströms drawings was a template to my first “designs”.
    He was not only a brilliant illustrator, he also did a lot of work, designing jetfighters for SAAB, as you wrote, but also lorries for SCANIA. If that has something in common I don’t (wan’t) to know.
    But what I do know is that from 1945 to 1960 there was maybe a hundred different massive balsa kits issued in Sweden, covering most of the airplanes from the 2:nd war and up to F86, MIG-15 and “The Super Sabre” all with a diagram by BK. As a kid back then, it was really thrilling to go to the “hobby-shop” to look for new kits. If I could not find what I wanted I made a “model” myself, always starting with a diagram immitating BK, ending with an airplane and cuts in all fingers. If he was accurate or not did not matter then, but he had a pretty good idea how an airplane should look, but sometime he was wrong. He also did a lot of Si/Fi-stuff.
    I think I could blame him to some extent, me working as a “rocket scientist”.

  • Pat Flannery

    There is a company named Cleveland in the US that made a huge number of plans for flying model aircraft from 1919 forward:

  • Michael Holt

    I just bought the YB-52 and Macchi M.5 plans from Cleveland. The plans are pretty good: easy to read and, as best I can tell, accurate. Delivery is usually slow, though.

    The “top level” of Cleveland plans scales run from 1/32 to 1/4. The plans are printed so that one can cut wood full-size. Some of the aircraft are large enough in 1/4 to give rise to thoughts of riding something like those. Sadly, the B-52 and B-45 plans are a standardized small scale giving wingspans under 24 inches (the PBY at that size has a wingspan of 312 inches, and the B-17, 308 inches). And of course there’s no B-36.