GB-2 (oz9769)


GB-2 (oz9769) by HS Sayers 1941 - plan thumbnail

About this Plan

GB-2 Flying Boat. Rubber twin-motor flying boat model.

Quote: "The desire to create a flying-boat that would ROW unassisted was aroused on seeing Mr White's flying-boat in the first Roberts Trophy competition for flying-boats, held at Danson Park Lake on July 4th, 1937, and hearing the experts say it couldn't be done. A little later Mr Suggett showed that a model flying-boat (weighing about 4 oz) could get off the water unassisted by setting up the first record for this type with a time of 9 sec. Mr Sayers' interest was in a model somewhat heavier than this, and with some likeness to the Empire flying-boats, but not quite so large and heavy as Mr White's, which weighed 36 oz. The result was G.B.1, which, on Sunday, July 24th, 1938, at 7 a.m., set up a new British record with a time of 22 sec., from the water of a paddling pool in a Crayford recreation ground. The place explains the early hour, and also the absence of thermals.

Experiment, trial and error had found a suitable position for the water planing surface and step, flying trials over land found the weak places in the hull structure, which were remedied, and October 3rd, 1938, saw G.B.1 win the Roberts Trophy for flying-boats with an average of 18 sec. G.B.1 rose to the occasion again in 1939 by winning the Roberts Trophy for the second time, with flights of 29.26 sec., 29 sec. and three delayed flights on the third round. On the last of these it drifted submerged the length of the lake, and in spite of this it flew again, but not that day.

From data and experience gained from this model, G.B.2, the model drawn and described in this article, was built, and in August, 1940, Mr. Sayers won the Roberts Trophy for the third time. This would have been somewhat of a hollow victory, for it was a walk-over, but for the fact that a new British record was set up. The first flight was less than half a second short of the record held by Mr. Lewis, of the Northern Heights, with 33 seconds. However, conditions were good, and the second flight was 42.3 sec. The model crossed the lake and returned to alight on the near bank. This was repeated on the third flight, the time being 40.8 seconds. The next flight the model made an alighting on the water.

A Fleet Air Arm rating who watched it remarked: It's just like the real thing. The same wing was used in the record flight of 22 sec. and the three Roberts Trophy competitions, the tail and fin being replaced, but still to the original design, the only improvements being to the hull design and motor nacelles. Five hundred and ninety-five turns were used on the record flight, but the motors should stand 800, and that should increase the duration to 57 sec., so the minute mark is within reach. Although the model reached a ceiling of 200 ft. on its record flight, being over the lake, it must have been in descending currents and so losing duration. This model must be to the delight of the practical flyer and the despair of the theoretical, as it was built without any calculations, design, data or drawings, with the exception of the propellers, and it does fly..."

Update 06/02/2018: Replaced this plan with a clearer copy (patterned background removed) thanks to rchopper56.

Quote: "Hi, Here is the same file with the background removed, respliced and reduced file size. Used Photoshop to increase contrast and brightened when at gray scale - this removed most of the background. Then changed back to monochrome. Gene"

Update 13/11/2018: Replaced this plan (again) with a clearer copy, thanks to DBHL, theshadow.

Scan from DBHL, cleanup by theshadow.

ref DBHL-5744.

Direct submission to Outerzone.

Supplementary file notes

Previous scan versions.


Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction

GB-2 (oz9769) by HS Sayers 1941 - model pic


GB-2 (oz9769) by HS Sayers 1941 - pic 003.jpg
GB-2 (oz9769) by HS Sayers 1941 - pic 004.jpg
GB-2 (oz9769) by HS Sayers 1941 - pic 005.jpg

Do you have a photo you'd like to submit for this page? Then email

User comments

No comments yet for this plan. Got something to say about this one?
Add a comment



Download File(s):
  • GB-2 (oz9769)
  • Plan File Filesize: 374KB Filename: GB-2_rubber_oz9769.pdf
  • Supplement Filesize: 2586KB Filename: GB-2_rubber_oz9769_article.pdf
  • Supplement Filesize: 4745KB Filename: GB-2_rubber_oz9769_previous.pdf
  • Supplement Filesize: 168KB Filename: GB-2_rubber_oz9769_previous_2.pdf
  • help with downloads


* Credit field

The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.


This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.


Terms of Use

© Outerzone, 2011-2024.

All content is free to download for personal use.

For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.

Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.