Letters to the Editor
No Christmas cards in the mailbag yet, but there were some fascinating letters that came in.
Whither F5B?
What happened to F5B in the US? Back when I was competing in thermal duration contests in the 90’s, F5B was the pinnacle in soaring innovation. I still see the planes for sale, but cannot seem to find any competitions.
Raymond Wright
Maryland, USA
Great question, Raymond! But I think I had better let the hive mind tackle that one given that my personal recollection is pretty poor, I’m afraid. What say you, hive mind? — Ed.
Looking for Dodgson Anthem Plans
In the January 2022 issue there is mention of the Dodgson Anthem. I like the look of this plane and would like to build one. Can you tell me where I can get a copy of the plan?
Regards,
Norrie Kerr
Thanks for the letter, Norrie. As you already know we had the great pleasure of featuring an extended run of Bob’s articles (see Resources, below). I have it on fairly good authority that he is a regular reader and maybe he can help point you in the right direction. Barring that, perhaps another reader out there can help you out? — Ed.
The Nippi NP-100 and the Pilatus B-4T
I received a very nice enquiry and subsequent email from a reader in Japan who recognised the plane in Glider Patents in the October, 2022 issue (it is linked in Resources). He had some fascinating recollections of the plane and Japanese General Aviation of the period. — Ed.
Thank you for sharing the patent information for the Motor-Glider in the October issue of the New RC Soaring Digest. I recognised the plane but I did not know they obtained a patent. One that was built and flown with the name NP-100 Albatross by Nippi Corp.
I was in the university glider club right after Nippi built and tested the NP-100, and I also had a chance to talk to a person who involved in the project. Nippi is a small aircraft manufacturer who mostly works on Japan and US military aircraft maintenance and repair. They have not had much of a chance to build and fly new aircraft. There was a group of people who wanted to build their own, as an off-work project, and came up with the NP-100.
The NP-100 was tested at Naval Air Facility Atsugi. The story I heard was its climb rate was poor initially. Even with the long Atsugi base runway, it climbed too slowly, getting a bit close to nearby city buildings. Its narrow double wheel main gear seems not be stable, but he mentioned it was okay but only on paved runways. When it was taxing behind an A-4 Skyhawk jet and got its full blast, but it did not fall over! That ducted fan intake was not practical against foreign object damage (FOD), especially given most glider airfields in Japan are unpaved.
The NP-100 was demonstrated at local airshow but never got into manufacturing nor did they have a plan for that. I only saw the real one stored at the Nippi factory.
Later Nippi obtained a manufacturing license for the B-4 glider from Pilatus and built 13. They also built one experimental version as B-4T. Our university receive one of the first five built. It is a good sturdy all metal single seat trainer that I flew a lot. That time I had a chance to talk to somebody from Nippi personally and heard the story of NP-100.
The Nippi B-4T was an interesting project. Nippi obtained a design license together with manufacturing jigs from Pilatus. The B-4 structure was quite unique, using thicker metal skin with less internal structure for a smoother surface. It had a modified fuselage, and added a plug in the root of the wing to extend a little with some forward sweep to be a two seat trainer. I heard it is tested at Sekiyado glider field near Tokyo. I only saw it disassembled. It was eventually donated and stored at Teikyo University.
General aviation in Japan is very minor, there are less general aircraft than passenger jet liners. But these two are good memories of people who struggled to build their own plane.
Thanks and best regards,
Satoru Sasaki
Chiba, Japan
Resources
- The Dodgson Anthology — The collected works of Bob Dodgson as they appeared on the pages of the New RC Soaring Digest.
- Glider Patents | US 4,088,285: Motor-Glider — “In a motor-glider provided with a propeller power system fully encased within the fuselage thereof, outer shapes of the elements adapted for selectively closing air-intakes…”
Links provided by Satoru Sasaki, with our thanks:
- The NP–100 Albatross Factory Brochure — In Japanese, but there are lots of great pictures of the NP–100 Albatross.
- Nippi NP–100 Motor Glider Albatross — More great pictures of this highly unusual and innovative design.
- Nippi NP–100 from Wikipedia. — “The Albatross was the first Japanese motorized glider, unusual in being powered by a ducted fan. Design work started in late 1973 and the first flight of the NP–100 prototype was made on 25 December 1975…”
Send your letter via email to NewRCSoaringDigest@gmail.com with the subject “Letters to the Editor”. We are not obliged to publish any letter we receive and we reserve the right to edit your letter as we see fit to make it suitable for publication. We do not publish letters where the real identity of the author cannot be clearly established.
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