Frans wrote:
Same thoughts. I’ve seen several VL3 machines now, and they seem really well build, but without LSA approval, it remains a kind of “toy”. I’m also a bit sceptic of their retractable gear, it looks a bit “cheap” when you see how it works in-flight with cameras.
I’m not too concerned about the gear, it works and there’s been no reports of failures. The issue for me is solely that as I’m german resident, it would need to be D-Mxxx registered → no autopilot. Having said that, if you look at certain D-Mxxx registered aircraft on tracking websites, there are those whose path through the air resembles George Best after chucking out time whereas others most definitely have an Autopilot fitted because both track and altitude are rock steady.
I’ve asked on other ultralight forums how they cope with the examiners being told to ground any aircraft fitted with an autopilot and fail it, what they do to avoid this consequence but no-one wants to share any info…. I do think it’s absurd though – the LBA banning autopilots on ULs in Germany, even though a significant number of the higher performance machines will have them fitted….
Steve6443 wrote:
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.Same thoughts. I’ve seen several VL3 machines now, and they seem really well build, but without LSA approval, it remains a kind of “toy”. I’m also a bit sceptic of their retractable gear, it looks a bit “cheap” when you see how it works in-flight with cameras.
What would the hearing (or rather, the court case) be about?
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….
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 ;)
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.
“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.
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 !
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.
