Letters To The Editor
Beautiful & Ugly Planes
I greatly enjoyed Mr. Berliner's article in the October issue of Model Aviation. One of the airplanes in this article caught my eye more than the others—the highly modified An-2 biplane.
This strange-looking contraption actually has an interesting history. It was built about 15 years ago in Poland as a flying laboratory when the Poles were developing a jet-powered agricultural biplane named Lala-1. It has a piston engine in the front and a jet engine in the back (the intake to the jet engine can be seen on the side just forward of the wings, marked by zebra stripes). The jet engine was installed to test the effect of jet blast on chemicals dispersed under the wings. In spite of its unusual appearance, it was a successful test bed.
The airplane that evolved from these tests was the PZL M-15 Belphegor, the only jet-powered biplane in the world. Quite a few were built in Poland in the mid-1970s, mostly for export to the USSR. The biplane configuration was chosen to provide a large wing area for maximum payload and a short wingspan for tight turns as required for crop dusting.
About 10 years ago I started building a model of the Belphegor (1/5-scale, powered by an RK-40 Axiflo fan unit). However, I never finished it—but I haven't given up yet. I am enclosing two photos of the Belphegor model and a photo of the unfinished fuselage in case you want to print them. Thank you for the many wonderful articles in Model Aviation. Each issue is a treat.
Jan P. Koniarek Briarcliff Manor, NY
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McDonnell XF-85 Goblin — A Revised Background
I should like to offer a revised background to the McDonnell XF-85 Goblin as described by Mr. Berliner (page 103, October 1989). I went to work for McDonnell Aircraft Co. in June 1947 and was with them for 37 years. I had the privilege to know Mr. J. S. McDonnell personally, and I have a pretty good insight into what took place there.
Shortly after WWII the military considered trying to reduce long escorted flights by aircraft such as the P-51 with drop tanks and tired pilots, and proposed an on-board fighter similar to that tried during the mid-1930s (remember the Zeppelins with trapezed fighters?). As was the practice in those days, it was a competition among existing U.S. aircraft companies. McDonnell won.
Yes, the XF-85 was hard to fly. So is the Harrier of today. No one was ever killed in the Goblin; not so the Harrier. It was well into the Goblin's development that inflight refueling was successfully developed, which eliminated the need for on-board fighters for aircraft like the B-29, B-47, and B-52.
Launching the Goblin from the mother ship was never a problem, but the extreme turbulence beneath the B-29 when trying to reengage the trapeze was harrowing. It was accomplished, as I recall, but every other flight termination was on land — in this case sand. The Goblin had solid oak wing tips, which served as its designed landing gear.
Mr. Berliner's description of designing a Ferrari to fit in a Buick glove compartment is a bit extreme. The Goblin fit the bomb bay of the mother ship; it was designed to do so. It fit better than some of the "X" planes, and all you could see were the wings sticking out of each side. The pilot did not have to sit cramped in a small cockpit for an interminable time. When called upon he could enter the plane, be extended into the slipstream, and take off. Incidentally, the slipstream helped with engine starting.
Mr. Berliner criticized the fuselage shape and the tail, but he was not privy to the design criteria. Aerodynamics of a short fuselage is very touchy, and the size of the bomb bay dictated much of the design. I believe that when you see the Goblin bobbing, zipping, and maneuvering about the sky, as in a movie, you would call it "cute."
John W. Rawlings St. Charles, MO
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On "Beautiful" vs. "Ugly"
We ask all readers to remember the criterion used by Don Berliner to classify beautiful and ugly airplanes: efficiency or how well a design fulfilled its purpose had nothing to do with it. Pure and simple, it was whether the shapes were pleasing to the eye — whose eye? His. He wouldn't even let the magazine staff cast votes.
While I did not read the previous "Beautiful and Ugly" articles, I'm sure we agree that the Waco taperwing, Ryan STA, P-51D, T-38 Talon, and F-16 Falcon each deserve to be classified as works of art even if they weren't mentioned. Those that did not spend hours drinking in the beautiful, sexy Mustang lines missed out. Ditto the F-16.
However, we disagree on the Pilatus Turbo Porter. Sure, it's not a T-38, but it's not ugly. I still keep an old dog-eared American Aircraft Modeler issue because of a stick-and-tissue Porter article. It just looks good sitting there on that Fairchild-like landing gear.
Also, will you agree that experience plays a role in what we consider pretty? For instance, I will always admire the Parks biplanes and PT-21/22s after having had the privilege of hitching a ride in the front cockpit of the award-winning, meticulous restorations owned by Wayne Ames of Tullahoma, TN.
Stan Jones Huntsville, AL
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Wishes for Blunt Prop Edges
I just finished reading your article about prop safety in the October issue. Like most other RC fliers, I have had my share of nicks, bruises, and cuts from props. What I can't understand is why prop manufacturers put those razor-sharp edges on nylon or glass props.
If I use a nylon prop I always sand down the edges — just in case. The only nylon prop I know of which comes with a blunt edge is the Yoshioka brand. If other companies could follow this example and become safety conscious, more people might be spared unnecessary cuts.
Sasha Pavek Woodland Hills, CA
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Ken Carter Remembered
In the article "Battle for RC Frequencies" in the July 1989 issue, there is a picture on page 60 that identifies Ken Carter as the kneeling judge. For those who might not have known Ken, I am enclosing a note indicating that Ken died on July 16, 1989.
When Ken opened his hobby shop in Burk & Company Department Store after World War II, I worked for him full-time for a year until I started college. After that I worked part-time until completing college.
Milton H. Fanning Nashville, TN
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Safety / Preston (continued)
Some MonoKote repairs.
The moral of this tale is that it is wise to keep a small extinguisher in your field box. As an alternative, it may be possible to smother the fire with a towel, rag, or blanket. When the Cub Yellow engine cowling on my first R/C model (powered by a Cox .09) began to turn first orange, then brown, I was able to smother the fire by wrapping a rag around the front of the model.
Have a safe month.
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Keytwo / Randolph (continued)
When everything is in place, range-check the equipment — and it's time to fly!
Flying: While it has a wide performance envelope compared to the Paskey, Keytwo is basically a very gentle flier. Whether upright or inverted, the stall shows absolutely no tendency to snap. In fact, if the model is balanced correctly it's very difficult to make it snap. If snaps are your bag, move the center of gravity aft about 1/2 in. and increase the elevator throw by 1/4 in.
The roll rate with 3/8 in. of up-and-down movement at the trailing edge of the ailerons is about right for comfortable flying. Landings can be made nose-high and slow, with full aileron control all the way to touchdown.
I had a problem with knife-edge flight at first. The airplane persistently climbed into a half-loop, until I learned that the nose stayed up with just a little rudder. Once I'd mastered the technique, knife-edge loops were included in Keytwo's repertoire of tricks.
And what did Eddie Williams have to say about my latest re-creation? "I see you built another Paskey," said that unsung maestro of the drunken-pilot routine. "It's about time!" Play it again, Eddie?
Transcribed from original scans by AI. Minor OCR errors may remain.
