From conversations I’ve had, I get the impression that very few owners of LAA aircraft actually do the VNE test and just fill in the paperwork indicating that they have.
That is what I would do in this circumstance.
I’d base arguments on there being no benefit to performing it.
Given that as discussed Vne is a design parameter that is properly validated in manufacturer conforming prototype testing, I wonder what fraction of e.g. Cessna 172s have ever been to Vne in their lifetime? Obviously you could do it, but why would you?
Silvaire wrote:
I wonder what fraction of e.g. Cessna 172s have ever been to Vne in their lifetime? Obviously you could do it, but why would you?
Well, the talk is about LAA, aka homebuilt aircraft. Now, there are homebuilts, and there are homebuilts. A biplane à la Starduster Stolp, or a monoplane à la MiniMax, will normally offer the same resistance as a C172, and need some persuasion to go anywhere near their respective Vne. Let’s call it natural protection 
But as we all know, they are also some very slick homebuilts out there. Lancairs, Glasairs, Falcos, Turbine Legend (we have one flying around here) and even some of the Vans, can reach their design limit Vne rather fast. For example there’s unfortunately been 6 or 7 RV-7 lost to flying over their Vne, mostly associated with some accelerations.
Another factor is that the mere fact of indulging in 3D flying, as in aeros, will place one at an increased risk regarding Vne.
Again, I am in no way protecting or defending the LAA’s requirement, which I find useless, maybe even placing the pilot performing at risk. Since the vast majority of the LAA’s member seem against that requirement, why is there no push within the association to have it questioned and maybe removed?
But the fact remains that flying within the speed envelope, from say 1.3Vs up to Vne, is a normal flight regime. There’s a white, a green, and a yellow speed range on basically all speedometers, this is the usable range, with given constraints. If an aircraft is being endangered whilst respecting the given constraints in any of its allowable flight regime, then the very airworthiness of the subject aircraft should be scrutinised.
Again, when in a hurry, most airliners do fly at their Vmo/Mmo (their “Vne”), or slightly below. Will you ask the captain of your next flight what speed he/she’ll be flying, and then get off that flight if told that “they” will fly at Vmo/Mmo or 5kts below as they’re late for dinner?
The same probably applies to bizjet ops, any intel about that @Yeager?
Given that UK has no Experimental Amateur Built airworthiness category, and that the government delegates to LAA a kind of quasi-certification of LAA defined ‘types’, I could see that it is justified by the legal process (whether of not that process is appropriate) to validate Vne compliance in the initial test program of a given ‘LAA certified’ type. It is not correct or justified under that process to subject every aircraft built to the LAA conforming spec to Vne (otherwise the LAA type certification is pointless) and it makes no sense on any level to repeat an unjustified test on a conforming aircraft that is inspected annually to verify conformance. This is basic 20th century aircraft engineering process, and the LAA approach here strikes me as something at a pre WWI level of engineering.
Dan wrote:
Again, when in a hurry, most airliners do fly at their Vmo/Mmo (their “Vne”), or slightly below. Will you ask the captain of your next flight what speed he/she’ll be flying, and then get off that flight if told that “they” will fly at Vmo/Mmo or 5kts below as they’re late for dinner?
The same probably applies to bizjet ops, any intel about that @Yeager?
@Dan See attached.
It´s not uncommon for G500/600/G650/G700 to cruise at High Speed Cruise Mach.90 prevailing conditions and forecasts allowing for this to be comfortable. At the first hint of turbulence or upsetting wind/temp changes, I reduce without hesitation to Mach .88 and revise. I´m not concerned about the structural integrity of the airframe, but it would require paperwork etc. if it goes 5 kts into the red, and I´d rather go to bed or whatever.
Strong rumors’ have it that the G650 was tested beyond Mach 1. The pictured envelope is the normal Fight Envelope and Mmo is Mach .925 from around 35K FT and up.
FYI, Long Range cruise is around Mach .86 which is obviously “significantly” more fuel efficient – commercial charter ops will usually opt for .87.
I´ll update you on G700 early next year! 
Silvaire wrote:
Given that UK has no Experimental Amateur Built airworthiness category, and that the government delegates to LAA a kind of quasi-certification of LAA defined ‘types’, I could see that it is justified by the legal process (whether of not that process is appropriate) to validate Vne compliance in the initial test program of a given ‘LAA certified’ type.
I think this process is applied in a similar way in different EU countries. Our association in CH oversees the build, and the flight tests, as required for a new aircraft. One of the flight test tasks is to fly the aircraft up to 1.1 Vne and assess possible vibrations and stability issues. This has to be done once for every aircraft, only during the initial testing.
It is true that newer designs, which entail assembling rather than building a kit, should level out differences in build quality. An RV-14 kit with its final size prepunched airframe, finished spars, precise KAIs, and accessory kits, should lead to repeatable finished product. The next step being the quick built options as offered by different kit manufacturers, where the self proclaimed builder is more of a systems installer. But I digress…
OTOH we still have older kits being finished, or even started. On some of them, mostly those out of wood or composite, the build quality attained can differ. Same is valid for early non-punched aluminum designs. I recall one of my first visits to KOSH, must have been around 1990, when I saw an RV-4 which had a sub-standard build. I certainly would not have tempted fate flying it. Obviously the FAA thought the same, as a couple of days later same RV-4 got grounded by them on the spot.
Also when flying older homebuilts of the same type, same as for Harleys, one will notice that they’re all different, and some do fly quite differently too.
But yes, the LAA’s requirement sounds obsolete enough.
Yeager wrote:
I´m not concerned about the structural integrity of the airframe, but it would require paperwork etc. if it goes 5 kts into the red, and I´d rather go to bed or whatever.
Thanks @Yeager, we had the same kind of thinking But, inevitably we had the odd overspeed, maybe once every 2nd year (but flying way more sectors and hours than standbyers do ) and during descent.
Interesting to note the lower (than the Airbus I was familiar with) Vmo of 300-340 against 350… probably bird impact protection?
I stand to be corrected, but since I have read through 40-odd posts my summary for anyone who does not feel like reading through it all is:
Thx @Dan, @Pilot_DAR , @Yeager, @RobertL18C and everyone who contributed for your insights
Antonio wrote:
UK LAA is still requiring annual Vne+10% check flights for permit aircraft under their oversight
No, the annual requirement is Vne itself rather than Vne +10%.
It is under review.
One clarification, as per my post above is that DVT (design verification testing) such as a Vne-related test is not appropriate for individual aircraft that are built to an approved type design, as is the case for UK LAA amateur built aircraft. That means it is an inappropriate precondition for even initial airworthiness approval of a new example of a given approved type, never mind repetitive periodic retesting. DVT is properly done on a conforming prototype only, in accordance with an approved test plan and with a qualified test pilot, and never again. That’s why type certification exists, even when delegated to e.g. LAA and applied to non factory-built aircraft.
Further, complete design verification on even the first example of a type that has Experimental airworthiness certification is not a necessary or appropriate precondition to issuing an airworthiness certificate or renewal, because Experimental airworthiness does not by its intent assure that the plane meets any certification standard. That situation is not relevant under UK regs where individual amateur built aircraft must conform to LAA type requirements, but would apply to countries where Experimental Amateur Built airworthiness exists. If it is Experimental, then it is properly viewed as an experiment not a wrung-out and proven design.
All of this is basic stuff, and it amazes me that LAA and perhaps some other organizations like them don’t seem to understand the basics.
Pre-EASA, UK certified aircraft underwent a check flight when the Certificate of Airworthiness was renewed – this was known as a Star Annual and occurred every three years. Contrary to popular belief, the physical inspection on a Star Annual was identical to a ‘normal’ Annual inspection.
On the check flight, aircraft were flown to Vne. NOT Vne +% – which I believe is Vd in most cases. It is/was a ‘check flight’ not a ‘test flight’ and checked the aircraft within its normal flight envelope. Aircraft that were cleared for spinning were spun on the check flights. No one called for either Vne ‘dive’ or spins to be banned at the time… The check flights were performed by pilots authorised by the CAA who, I recall had a briefing and >1500 flight hours.
With the LAA check flight, it’s really not difficult or dangerous. For some of the older types, Vne has been reduced on request by LAA Engineering. The LAA is not just about amateur built aircraft but also vintage/orphaned types as well.
Vne dangerous? Really? I speak as one who was an observer on dozens of CofA renewal check flights, piloted a few dozen LAA check flights on aircraft I (co-)assembled and co-owned. Seemed to survive so far. And in a previous life, I looked at around 14,000 LAA Permit to Fly revalidation applications and the associated check flight results, we used to get one or two people a year who didn’t like flying to Vne out of around 2,800 annual revalidations – probably more didn’t like stalling. Owners can always get someone else to fly it if they don’t like doing it.
