On Sunday, August 16, 2020 at 11:29:16 AM UTC-7, 2G wrote:
On Sunday, August 16, 2020 at 6:06:14 AM UTC-7, jld wrote:
I did not look at this group for a while (busy flying :-) ), and I am surprised at the amount of discussions and in some cases approximate information concerning the GP15.

From all info provided by GP multiple times, no EASA certification is planned for the GP15. It is going to be registered as UL in key EU countries (and experimental in US).
As far as crossing EU borders with UL, some countries indeed require a permit to fly for foreign UL but that is usually very easy to obtain. As a reminder, which is also applicable to certified gliders, the rules also say that it is necessary to file a flight plan when crossing borders!

Concerning GP15 approval as UL in EU, some countries like Germany have requirements concerning ground/flight tests which are rather time and budget consuming (you can't take the business risk to duplicate these tests). It is therefore logical that GP is eventually converging toward a single stable configuration that can meet approval in all targeted countries.
The haters are going to say that GP should have thought about it sooner but the reality is that the rules in EU, concerning below 600 kg aircraft (UL), have changed while GP was in the middle of the making of their gliders!
GP will now be able to rationalize/industrialize their production tools which shall allow increased production rates, reduce the risk of orphan configurations and help them become profitable (if the later does not happen that would be the end of the story anyway).

For people looking for an electric motor glider with motorized performance close to the gas burning versions, GP15 is the only game in town.
GP is on a virtuous circle: reducing weight and surface while increasing aspect ratio!
This makes possible the design of a high performance electric power plant for a total weight (motor/controller/batteries) similar to gas powered powerplant. This is what GP has done.
One side benefit of the lower power motor, coupled with rather large battery capacity, is that it reduces the max current seen by each battery cell. This allows reduced temperature excursion, simplified temperature management and reduced risks of temperature runaway.

We all would enjoy better communication from GP but, let's be honest, the well established companies are not better while taking much less risks than GP.

I feel GP is on the right path and the family is doing its best to manage the situation, COVID did not help. There has been too many delays, especially for the people who have placed orders 2 or 3 years ago, but they have a unique great design which will become a game changer, we hope pretty soon!
600 kg is considered to be an ultralight in the EU? WOW! In the US a powered ultralight is limited to 115 kg (254 lb). This is the weight of an LSA (1320 lbs):

To be considered an ultralight vehicle, a hang glider must weigh less than 155 pounds; while a powered vehicle must weigh less than 254 pounds; is limited to 5 U.S. gallons of fuel; must have a maximum speed of not more than 55 knots; and must have a poweroff stall speed of no more than 24 knots.
https://www.usua.org/Rules/faa103.ht...n%2024%20knots.

In fact, there are no universal EU regulations governing ultralight aircraft - each country has its own regulations (or none at all):
https://ul-center.com/2016/03/09/ult...t-information/

More guidance on this regulatory issue is in:
https://www.easa.europa.eu/sites/def...20Nov%2010.pdf

But it contains this confusing statement:

Gliders without an engine enabling self-launch if 450kgs (two-seat) or 300kgs
(single-seat) are within the scope of Community regulations. Gliders with engines
enabling self-launch and which are 450 / 300kgs MTOM microlight limits are with
the scope of Community regulations.

GP Gliders lists the MTOW of the GP-15 on their website at 470 kg (who knows what the final number will be), putting it well into the EU regulatory claws by 170 kg. So I don't see how they can fly underneath the EU regulatory radar as an ultralight without losing 170 kg of weight, which seems highly unlikely.

Most gliders imported into the US in the experimental category have a type certificate in the EU. Will the FAA be more hesitant in issuing experimental airworthiness certificates to gliders that have not undergone this certification testing? We will just have to wait and see how this unfolds. To date, I do not know of any GP-15 that has been certified anywhere, although the prototype displayed at the convention had a Slovakian registration number which I have previously shown was assigned to another aircraft. Some have said that that aircraft "could" have been deregistered and, then, reassigned to the GP-15, but have produced exactly zero proof that that had occurred.

You imply that I am a "GP hater." I take exception with this characterization - I don't "hate" GP any more or less than any other startup aircraft manufacturer. Maybe they will ultimately deliver the goods they have promised, and maybe they won't. But I do believe that anyone putting down $105,000 on an unfinished glider deserves to be told the whole truth. And "feeling" that they are on the right path does not count as truth.

Tom

Right after posting this I found that the EU has, indeed, raised the ultralight weight limit to 600 kg:

https://flightdesign.com/easa-new-ba...g-ul-aircraft/

Tom