Fokker (Atlantic) F-11A Flying Yacht

[burunduk]

Dear friends,

don't you know the length and span of Atlantic (Fokker) F-11A Flying Yacht amphibian?

According to Aerofiles site there were 6 F-11A built, including 4 F-11A and 2 F-11AHB with more powerful Hornet engine. The span and length are, respectively, 59' * 45'

http://www.aerofiles.com/_fok.html

The same size is posted in the book
Johnson E.R. American flying boats and amphibious aircraft. McFarland & Co. Inc. 2009 ISBN 978-0-7864-3974-4 p.191.

There is also 3-view, signed L.C.Jones.

BUT! The span/length ratio of the 3 view absolutely doesn't correspond to the data. If the span is correct, the length should be not 45, but 52' - 15% greater.

It's not the only one disagreement in the books of Mr. Johnson. For example, the text data and the scheme of the Fokker XFA-1 parasite fighter in the book
Johnson E.R. United States Naval Aviation, 1919-1941. McFarland & Co., 2011, ISBN 978-0-7864-4550-9 p.80

don't correspond each other. In this case the length is 10% less than should be.

What shoud I believe to, to the text or to the scheme, and are Mr. Johnson's books a reliable source of the information?

And, of course, I'd like to know the right length and span of F-11A

PS. The right length of XFA-1 (20'6") was published in the Matt's book

Matt P.R. United States Navy and Marine corps fighters 1918-1962. Aero Publishers, 1962, p.54

In 1977 L.C.Jones drawn the scheme of this plane and published it in his book

Jones L.S. U.S. Naval fighters 1922 to 1980s. Aero Publishers, 1977, ISBN 0-8168-9254-7, p.89

The proportions of the scheme correspond to the Matt's book but... in the text of Jones's book the span is the same (25'6"), but the length is 22'2'. This doesn't correspond to the scheme. There may be many reasons why it happened - just a mistake, a misprint or something other.

But it seems Mr. Johnson took the data and scheme from the Mr. Jones book and... didn't check it's compatibility. This feel bad and don't permit to look on the Johnson's books as on a reliable information sources.

What do you think about this?

 

[Stargazer]

According to Joseph P. Juptner's U.S. Civil Aircraft (Aero, 1966):

• F-11A Wing span 59.0, Total wing area 550 sq. ft., Length overall 45.10, Height wheels up 13.0, Height wheels down 14.5, Empty weight 4470 lb.
  F-11AHB Speed and climb figures differ, but "all other figures remained same" according to the author.
  A lot more very precise specs are given, which would make me choose Juptner for reliability over the others.

According to Henri Hegener's Fokker - The Man and the Aircraft (Harleyford, 1961):

• F-11A Span 59.0, Length 45.0, Height 13.0. Weight (Empty) 4500, (Gross) 6350. Max. Speed 120.
• XFA-1 Span 25.6, Length 20.3, Height 7.0.

According to Ray Wagner's American Combat Planes (MacDonald, 1960):

• XFA-1 Span 25.6, Length 22.2, Height 9.3, Wing area 175 sq. ft.

According to Paul R. Matt's United States Navy and Marine Corps Fighters (Harleyford, 1962):

• XFA-1 Span 25.6, Length 20.6, Loaded weight 2525 lb.

According to Peter Bowers's Forgotten Fighters Vol.1 (Arco, 1971):

• XFA-1 Span 25.6, Length 22.2 1/2, Wing area 175 sq. ft., Gross weight 2508 lbs., High speed 169.9 mph.

Also, according to the plan I'm attaching below, the length of the F-11A should be 42' 11'', while the wingspan should be 60' 7'' or about (the plan itself seems to have been corrected by its author!).

I probably have other sources still, but these are the ones that came to mind right away. Hope this helps!

 

[burunduk]

Stargazer2006, thank you a lot for this number of sources.

But we see that the dispersion is very sufficient

It seems the plan you posted is from the "Aircraft Year Book" Which year?

 

[Stargazer]

It seems the plan you posted is from the "Aircraft Year Book" Which year?

No idea. I got it from someone else... :-\

 

[Jos Heyman]

The 59' (or 17.98m) span for the Fokker F-11 is confirmed in De Leeuw, R., et al, Fokker Verkeersvliegtuigen, a Dutch publication issued by the Fokker corporation in 1989.
They also state that a new wing was installed at a later date, giving rise to the designation F-11a. No dimension are given for this wing.

 

[Stargazer]

The 59' (or 17.98m) span for the Fokker F-11 is confirmed in De Leeuw, R., et al, Fokker Verkeersvliegtuigen, a Dutch publication issued by the Fokker corporation in 1989.
They also state that a new wing was installed at a later date, giving rise to the designation F-11a. No dimension are given for this wing.

Which adds to the confusion even more... What this says is that the F-11, not the F-11A, had a 59' wing span. All the other sources give that wing span for the F-11A. So unless the new wing had exactly the same length as the old one, the case is far from solved... :-\

This being said, as I stated before, in case of conflicting data I go for the most credible source. Juptner's books were based on the A.T.C. register's data and are literally packed with additional detailed specs that no other book provides, and for these reasons I would tend to consider them favorably.

 

[joncarrfarrelly]

F-11 from The American Fokkers: Part 3, Pete Bowers, AAHS Journal 1967, Vol.12 No. 3.
F-11 and F-14 drawings from Aircraft Year Book 3-view Drawings 1903-1946, J.W. Mc Donald

MODEL 9 - This flying boat/amphibian was the only Fokker to carry separate designations for the American and Dutch versions. The American version was designated F-11 and the Dutch was B-lV in a continuation of the long-established B flying boat and amphibian series. There was also a Dutch F-Xl model at this time. lt had strut-braced wings like the American Universal and was also called "Universal." Like the American F-Vll's, the F-11/B-lV's were a joint Dutch American effort. The metal hulls, direct developments of the metal B-III hulls, were built in Holland. There is no evidence that any complete B-lV's were built in Holland. The Dutch catalog photos and entries in the Dutch section of JANE'S ALL THE WORLD'S AlRCRAFT show an American-registered F-11.

F-11 - This was a logical monoplane development of the B-III pusher biplane flying boat and was assembled at Teterboro. The hull lines were generally the same except that they were developed into a full cabin design. Only one F-11, 7887, C/N 901, was built. (C/N 900 appears in FAA records as a B-II with Napier Lion engine.) The F-11 originally appeared as a six-place amphibian with unique retractable wheel-sponsons in the manner of the German Dornier boats. A wheel was mounted on the end of each sponson, which was lowered for ground operation.
For water operations, the sponson retracted to the horizontal position and the wheel folded back and out of the way. This arrangement was not very satisfactory and was soon abandoned. The F-11 was then converted to a straight flying boat with conventional wing floats mounted much farther inboard than on contemporary designs.
The F-11 originally used a Super Universal wing in what was planned as a neat saving in engineering and tooling costs. The original engine was a 420 hp Pratt & Whitney Wasp. The F-11 was then converted to use a longer 500 square foot wing and a 525 hp Wright Cyclone engine and received Category 2 certificate 2-163 on December 6, 1929.

F-11A - Three 8-place F-11A's (C/N's 902, 903 and 905) were built. These could be purchased as straight flying boats or as amphibians with separate fixed-wing floats and retractable landing gear. The other major difference from the F-11 was the use of a longer wing with 550 square foot area. This was the same wing used on the model F-14. Engines were advertised as the 525 hp Wright Cyclone and the 575 hp P&W Hornet. ATC-222 was issued to the Cyclone-powered F-11A on September 5, 1929. Price of the flying boat was $40,000 and the Amphibian $42,000. These were reduced to $32,500 and $33,775, respectively, when the depression began to affect airplane sales in 1930. The last F-11A was delivered in June 1930.

F-11AHB - This designation shows up in FAA records for two airplanes, C/N's 904 and 905. No documentation has been found to explain the additional letters in the designation. A latter-day collectors photo shows one with a modified vertical tail, but this would hardly cause Fokker to change the designation. Since the FAA records show them fitted with the P&W Hornet engine, a guess would be that the letters HB stood for "Hornet B". C/N 904, which was registered 127M, was licensed 8-place under Category 2 certificate 2-172 and C/N 905 (which later went to Canada) was licensed under 2-200 as 10-place.

F-11A TANDEM - No special designation appears for F-11A, X-148H, C/N 902, when it was temporarily fitted with two Hornet engines in tandem. Again, no documentation is available, but the sequence of photo numbers and dates indicates that the purpose of the twin was not to serve as a test bed for the tandem engine installation of the F-32 transport but rather was an attempt to adapt the F-11 to the Coast Guard's requirements for a twin engine flying boat by fitting an F32 nacelle to an existing single engine aircraft.

F-11
Span:50' 7 3/4" (later increased); Length:42' 11", Area:370 ft2(later increased to 500)

F-11A
Span:59' 0"; Length:45' 0", Area: 550 ft2

The 1929 F-11 drawing shows the original 'retracting sponson' design and Super Universal wing.
Obviously Lloyd Jones copied that drawing when he did 'his' F-11A drawing, which is clearly not
the F-11A. I've included the F-14 3-view for completeness.

 

[Stargazer]

A valuable contribution to the subject, joncarrfarrelly... thanks a lot!!