For reference, 300 knots in a 5,900 lb plane at 27,000'.

2050 lb ft torque at 1640 rpm is 640 hp.

Cool plane.

I think we've been hearing "Next year" from the DeltaHawk guys for about 20 years now.

But I'm sure this time they really mean it.

This gets into basic market forces. Given no other motivation, the engine that provides the best value is going to be the engine of choice. The only way to move that needle is by artificially influencing the value by doing something like mandating a different fuel type, or discontinuing production of 100LL. Or you could change the value proposition by producing an alternate engine option that performs substantially better at a similar price, or performs better for the same cost or less. Otherwise what's the incentive to change?

The bottom line is that nobody is going to buy a Diesel aircraft engine until it either costs less than what they have, or performs much better at a reasonable premium, or someone forces them to buy it.

the other factor that nobody seems to care about, is insurability

planes with new configurations have no actuarial tables to reference, so insurance rates are not going to be friendly, and coverage is going to be a challenge

why bring that on so you can save a few bucks at the pump?

I think we've been hearing "Next year" from the DeltaHawk guys for about 20 years now.

But I'm sure this time they really mean it.

From comments on the latest video:



[Video Link]

I think I’m going to win my $10 wager. It sure sounds like Peter is going to fly it himself.

Hey, some good news and I wanted to share it- the little "skip ads" button on the Grammarly ad appeared right away on this video. I didn't have to wait for the stupid 5-second countdown.

Hey, some good news and I wanted to share it- the little "skip ads" button on the Grammarly ad appeared right away on this video. I didn't have to wait for the stupid 5-second countdown.

That's what I read as well. If he doesn't do it, I'd make a substantial wager it won't ever happen.

I guess he wasn't willing to split the deposits with WASABI?

I find it especially telling that of all of the skills needed for a successful test flight, Pilotage was called out as the one that needed polish. If you can’t look out the window and find your way back to the airport, how are you going to deal with any of the myriad failure modes this airplane is capable of exhibiting?

He says “Be in prayer for safety and good decision making by all involved.” Maybe a slightly veiled hint that Peter needs to make some good decisions.

I noticed in the Aug 21 video at 4:20 that there's a bolt which appears to be impinging on one of the gas struts. Probably wouldn't cause a problem in flight but accepting something like that raises concerns over what else is wrong. Same with the braided steel hydraulic line he moved for better clearance (@ 3:10) I don't know how bad it was in the first place but now it looks like it could easily flex in flight enough to rub on the bolt next to it (which moves during gear retraction).

Plus I still don't understand why he's working on the air conditioning system at this point in the development.

I don’t think it is a coincidence that experienced professional test pilots universally won’t fly the thing. Help Peter fix what you can, maybe help him polish his flying skills, and then get the heck out of the crash zone when he decides to fly it himself.

If the airplane checked out great and nobody was worried about it flying, it would be risky for someone in Peter’s situation to perform the test flight. The farther from that ideal you get, the more you need a highly skilled test pilot to keep it from becoming a disaster.

The goal of highly trained well disciplined test pilots is to make sure that a flight never happens where their exceptional skill is required.