To all pilots who it might concern.
Just for Your information- there will be an oral hearing in Court in Cz Republic, regarding the VL-3 ultralight Aircraft. Usti na Orlici. on September 5.10:00
The hearing is Public and of great interest to anybody who might want to attend and get important information about this Aircraft and the factory.
Tom Lindberg.
VL3, could you give us more background?
Anyone have any up to date info or experience with the VL3? Someone mentioned it to me yesterday and it looks like an amazing aircraft, especially in its non-LSA, retractable version – 160 KIAS on 145 hp.
johnh wrote:
its non-LSA, retractable version – 160 KIAS on 145 hp
I see specs are 1042lbs weight and 105ft2 wing area? wing load is 10lbs/ft2, 160IAS is a bit too fast no?
The max speed before losing wings is usually about = 1.5*33*sqrt(10lbs/ft2) = 156KIAS
Nothing to do with engine or cruise flying, it’s the limit for dives in gliders, including with full metal ones !
“Nothing to do with engine or cruise flying, it’s the limit for dives in gliders, including with full metal ones !”
Surely wing strength can be increased? The Bjorn Andreason design I fly has a 153 kts VNE but the F16 wing he worked on in the US has a much higher VNE.
Interesting article here includes calculation of design certification speeds based on wing loading. Also makes mention of the VL-3 design.
The certification procedures include calculation of arbitrary “cruise” and “dive” and “never exceed” speeds as an exercise in what the author describes as “a purely formal requirement, used to provide a framework for structural and other decisions.”
The certified Vne for my plane lines up exactly with the cook book calculation. I wonder what would happen if the manufacturer wanted a higher Vne with a given wing loading than the certification formula specifies, and designed the plane to achieve it.
F16 has a huge wing load but surpersonic with load of thermal heating that would burn fibreglass & plastic 
seriously, I was referring to FAR23/CS23 SEP and maybe LSA aircrafts, VNE is tightly linked to wing load & elasticity less way more less than static strength, the limiting factor for high speeds is vibrations from light weight rather than material strength, the Mooney wing was tested to 9G (pilot neck break first) but it can’t fly more than 200KIAS due to low wing load & flutter…
http://www.mooneyevents.com/wingld.htm
Also while googling “VNE wing load” to find the boring Section 335 of CFR Part 23, I found this article from 2010 on flying mag, it talks about design speeds & flutter and how it relates to wing load, then to my surprise it mentions VL3 !!!
https://www.flyingmag.com/technique/proficiency/technicalities-are-you-feeling-lucky/
CFR_2017_title14_vol1_sec23_335_pdf
Edit: Silvaire posted the same article ;)
johnh wrote:
Anyone have any up to date info or experience with the VL3? Someone mentioned it to me yesterday and it looks like an amazing aircraft, especially in its non-LSA, retractable version – 160 KIAS on 145 hp.
They are now claiming close to 200KTAS at FL140 with the 915iS engine – if it was an EASA LSA, I’d buy one but microlight? Too much hassle. There is a 915iS powered model for FS 2020, it’s an incredible machine….
What would the hearing (or rather, the court case) be about?
