Newsletter- Grif Zip Flight Test & World Record Ratification
Last summer’s flight for Distance Without Engine Power has now been ratified as both a British and World Record. I flew the Eurofly Snake and Grif 3DC wing over 34km engine-off, and the take-off was powered by the Cisco C-Max 175 engine.
To get world-beating performance out of an aircraft compliant with our “sub-70” SPHG exemption really demonstrates the advantages of Grif’s modern double-surface wings. I’d like to thank Dario, Italo, Tino and the team for producing such a nice wing, as well as everyone at Eurofly for their continued support.
I’m really pleased that CIMA have ratified my record documented with video & GPS proof, as the previous arrangement was difficult and outdated. This should make it a lot easier to set further records and improve on my distance!
Building on that success, I recently flew Grif’s latest wing design, the Zip. This has been produced specifically with the UK’s sub-70 class in mind. I weighed it on bathroom scales at 27kg in the bag, which includes all the packaging materials and “stinger” keel extension tube (not required for flying). This light weight will allow a bit more leeway for bells & whistles for sub-70 pilots. For example, using this wing should allow fitment of the 33Hp Cisco Bull Max engine whilst still retaining full fuel.
The Zip is a 14m² wing which uses the same basic frame as the 3DC, with a Maximum Take-Off Weight of 190kg. This gives the Snake/Zip combination the highest payload available. It also allows a quick short-pack without tools to only 3.57m length.
The Zip features enough double-surface to enclose the cross-tubes, but eliminates the nosecone and under-surface battens used on the 3DC. My performance tests show that it’s nearly as efficient as the 3DC wing, and offers much higher glide performance than any single-surface wings I’ve tested.
In terms of handling, the Zip is very similar to the 3DC, with a touch more positive feedback in pitch. Both wings respond very well to a light touch and are incredibly pleasant to fly.
The Zip had to be provoked into a very gentle stall at around 20mph indicated air speed. This example didn’t have the optional vortex generators fitted, yet still exhibited a very benign nose-down mush with no tendency to drop a wing.
Hands-off trim speed was 35mph, which coincides nicely with the best glide ratio of the wing. As with all the Grif wings, this cruise speed could be increased if desired by moving the hang-point (I generally fly on the rearmost-but-one position).
As can be seen from the photos, the test-flight took place after the snows began to melt. Hopefully that can put to bed any lingering doubts over the use of the standard light weight wheels on boggy ground. The new alloy drum brake on the 2019 Snake works very well, with a more progressive feel to the brake pedal and better overall stopping power.
The Zip is priced very competitively for a double-surface wing, so fits nicely into our range of wing options. Any immediate orders should still be delivered before Brexit, but you’ll have to be quick!
As always, if you have any questions about the Zip or other aircraft in our range please get in touch.