I still wonder how they are going to get certified above Fl280. As the million page Cirrus thread pointed out, the current rega make that tough to do on one engine.

I still wonder how they are going to get certified above Fl280. As the million page Cirrus thread pointed out, the current regs make that tough to do on one engine.

In the interminable SF50 thread it's claimed that certification above FL280 now requires maintaining pressurization after an engine failure, obviously hard to do when pressurizing with bleed air from the only engine. The exceptions to this rule (TBM, PC-12) were certified under old rules and grandfathered in. That was the claim (boy, did I just save you a ton of reading!) I'm not a certification guru, I have no idea how true it is. Seems to me it could be handled using electric pressurization a la the 787, then you just need a backup electric source that will last longer than the drift down to breathable air, but Stratos has never said what they're planning.

I've actually met the CEO of Stratos, Michael Lemaire, but it seemed impolite to bring it up. There's no hurry, Stratos says certification is years away, I'm sure it'll be addressed at some point before then.

In the interminable SF50 thread it's claimed that certification above FL280 now requires maintaining pressurization after an engine failure, obviously hard to do when pressurizing with bleed air from the only engine. The exceptions to this rule (TBM, PC-12) were certified under old rules and grandfathered in. That was the claim (boy, did I just save you a ton of reading!) I'm not a certification guru, I have no idea how true it is. Seems to me it could be handled using electric pressurization a la the 787, then you just need a backup electric source that will last longer than the drift down to breathable air, but Stratos has never said what they're planning.

I've actually met the CEO of Stratos, Michael Lemaire, but it seemed impolite to bring it up. There's no hurry, Stratos says certification is years away, I'm sure it'll be addressed at some point before then.

I find this dual-pressurization source requirement very sensible. Loss of bleed air should not be a reason for a plane to turn into a lawn dart because the pilot's time of useful consciousness was a few seconds

...it could be handled using electric pressurization a la the 787, then you just need a backup electric source that will last longer than the glide down to breathable air.

It's a concern either way. Rapid decompression is quite noticeable, but at altitude TUC can leave you only a short time to deal with it. Gradual loss of compression is not so noticeable, but can be just as dangerous, if not more so, for that very reason. At higher altitudes, you really need a backup pressurization system in either case, fast leak or slow.

Stopped by their booth at Oshkosh - walked away very unimpressed.

They went the route of building a POC aircraft, which is of little value towards certification and mainly a marketing tool. They didnt even put the planned engine on the POC but instead used a JT15D. So much of that engineering to this point will be thrown away now. I can't think of a single example of a successful certified aircraft program that started out building a POC, non conforming prototype.

They are privately funded to this point and are now seeking funding for certification. Very small team. I think the fellow I spoke to said there are 16 on the team. The cost is only a guess at this point. "Somewhere around $3M".

The projected stats are interesting but that's where it stops for me. These guys have a LONG way to go. I wish them well but I don't have high hopes for this one.