Raptor Aircraft

[donjohnston]

Guys... c'mon now. There is absolutely no need to "explore" anything like that. The computer says what the stall speed is and that it's benign.

The computer also said it would weigh 2,000lbs empty and go 250kts. But the computer was only wrong on those two things so he's okay with that.

 

[Omalley1537]

My favorite part is when he discovers his stall characteristics are not benign after his belts snap and he looses all power outside of gliding distance to the airport. Oh wait.... that happens in an upcoming video

Im reading this in the voice of Johnny Carson as Art Fern announcing one of his black and white short films, and laughing way more than I should...

 

[kyleb]

My concern is he finds out the stall characteristics on about a 1/2 mile final. You explore the edges of the envelope at a safe altitude, so you know where they are at all times.

He doesn't appear to have a plan. Like when he tried the slip on final a few days ago. You don't do that for the first time when you're on short final. I just hope he doesn't come to a bad end.

 

[schmookeeg]

My favorite part is when he discovers his stall characteristics are not benign after his belts snap and he looses all power outside of gliding distance to the airport. Oh wait.... that happens in an upcoming video

Spoilers!

 

[iamtheari]

Spoilers!

Spoilers are among the few things that the Raptor doesn't have.

 

[midwestpa24]

He doesn't appear to have a plan. Like when he tried the slip on final a few days ago. You don't do that for the first time when you're on short final. I just hope he doesn't come to a bad end.

That truly is the problem and why he has become such a mockery. He only got as far as he did in design and production because of the help of the people he later cut ties with. He has thrown every conceivable notion of aircraft design and testing out of the window and is blazing along blind. The only reason this aircraft is still being talked about is the Youtube videos are like watching a Nascar race, everyone is just waiting for the next wreck.

 

[Racerx]

Is his plan really to fly in circles for 40 hours then deem it production worthy?

 

[Jeff767]

He can’t do that. He is required to have a flight test plan. It requires he explore and test the entire envelope of the aircraft in order to remove the aircraft from phase one.

 

[nauga]

He can’t do that. He is required to have a flight test plan. It requires he explore and test the entire envelope of the aircraft in order to remove the aircraft from phase one.

There is no such "entire envelope" requirement for experimental/R&D cert airplanes. There isn't really for amateur-built either, but that doesn't apply to the Raptor. Heck, there isn't even a requirement to demonstrate that it's capable of *flying* before going to market on the ex/ab side.

Nauga,
above and beyond

 

[iamtheari]

There is no such "entire envelope" requirement for experimental/R&D cert airplanes. There isn't really for amateur-built either, but that doesn't apply to the Raptor. Heck, there isn't even a requirement to demonstrate that it's capable of *flying* before going to market on the ex/ab side.

Nauga,
above and beyond

This is something I’ve been curious about, actually. How does the kit approval process go? I’ve only built (not quite that yet, actually) a kit for EAB airworthiness. I think the Raptor is aimed at becoming an EAB kit plane, albeit one that can only be built under supervision at a build center. Does a kit manufacturer have a different airworthiness/test flying regime than a kit-built or plans-built EAB? Is the Raptor prototype being done to those rules, or is it being done as a straight EAB homebuilt that he will later seek kit approval for?

 

[DaleB]

I don't think there is a difference between EAB from a kit and EAB not from a kit, other than a checklist of tasks to prove that the builder of the kit will still qualify as having completed the majority of the build (the "51% rule"). E-LSA kits are a different animal altogether, but this is far from LSA. The FAA does not, as afar as I know, "approve" anything about EAB kits other than the abovementioned checklist.

 

[nauga]

This is something I’ve been curious about, actually. How does the kit approval process go? I’ve only built (not quite that yet, actually) a kit for EAB airworthiness. I think the Raptor is aimed at becoming an EAB kit plane, albeit one that can only be built under supervision at a build center. Does a kit manufacturer have a different airworthiness/test flying regime than a kit-built or plans-built EAB?

EAB does not differentiate between kit and scratch in terms of test requirements. The 'kit approval process' is only to ensure that a builder will complete the majority of the tasks (or is it skills now?) to build the airplane, AKA the '51% rule', and has nothing to do with flight characteristics, as has been readily demonstrated by several popular designs. It is possible, if not practical, to market kits for an airplane that has never flown and let the builders be your source of flight test data. In terms of what's required for the Raptor's flight test program, even though (AFAIK) the goal is to market EAB kits, the airworthiness cert hes operating on is experimental - research and development.

Nauga,
from either side of the line

 

[Brad Smith]

Now would be a good time for PM to bring in a professional test pilot. He has an aircraft that does fly that will allow a test pilot to nibble at the envelope and determine the limits of the aircraft. I hope that he doesn’t hurt himself by exercising a skill set that is best left to professionals.

 

[Jeff767]

There is no such "entire envelope" requirement for experimental/R&D cert airplanes. There isn't really for amateur-built either, but that doesn't apply to the Raptor. Heck, there isn't even a requirement to demonstrate that it's capable of *flying* before going to market on the ex/ab side.

Nauga,
above and beyond

Here is just part of the index on the FAA advisory circular on how flight testing should be done for a experimental aircraft.


4-5. General .........................................................................................................................56
4-6. Gear Retraction ............................................................................................................56
4-7. Climbs and Descent .....................................................................................................57
4-8. Airspeed In-Flight Accuracy Check ............................................................................58
CHAPTER 5. EXPANDING THE ENVELOPE...........................................................................61
Section 5-1.
Section 5-2. 5-3.
Section 5-4. 5-5. 5-6.
Section 5-7. 5-8.
Section 6. Accelerated Stalls..........................................................................................................74 5-12. Objective ......................................................................................................................74
CHAPTER 6. PUTTING IT ALL TOGETHER: 36 HOURS TO —————?..........................77
Section 1. Maximum Gross Weight Tests .....................................................................................77 6-1. Objective ......................................................................................................................77
Section 2. Service Ceiling Tests ....................................................................................................78 6-2. Objective ......................................................................................................................78
Section 3. Navigation, Fuel Consumption, and Night Flying........................................................79 6-3. Objectives ....................................................................................................................80
CHAPTER 7. THOUGHTS ON TESTING CANARD TYPE AMATEUR-BUILT
AIRCRAFT ............................................................................................................83
Section 1. Canards .........................................................................................................................83 7-1. Objective ......................................................................................................................83
1. General..........................................................................................................................61 Objective ......................................................................................................................61
2. Hours 11 through 20 .....................................................................................................61 Objective ......................................................................................................................61 Stalls.............................................................................................................................63
3. Hours 21 through 35: Stability and Control Checks.....................................................66 Objective ......................................................................................................................66 General .........................................................................................................................66 Definitions....................................................................................................................67
4. A Word or Two about Flutter .......................................................................................70 Objective ......................................................................................................................70 Description ...................................................................................................................71
5. Spins..............................................................................................................................72 Objective ......................................................................................................................72
5-10. Caution .........................................................................................................................73
5-11. Planning the Flight.......................................................................................................

 

[Racerx]

Here is just part of the index on the FAA advisory circular on how flight testing should be done for a experimental aircraft.


4-5. General .........................................................................................................................56
4-6. Gear Retraction ............................................................................................................56
4-7. Climbs and Descent .....................................................................................................57
4-8. Airspeed In-Flight Accuracy Check ............................................................................58
CHAPTER 5. EXPANDING THE ENVELOPE...........................................................................61
Section 5-1.
Section 5-2. 5-3.
Section 5-4. 5-5. 5-6.
Section 5-7. 5-8.
Section 6. Accelerated Stalls..........................................................................................................74 5-12. Objective ......................................................................................................................74
CHAPTER 6. PUTTING IT ALL TOGETHER: 36 HOURS TO —————?..........................77
Section 1. Maximum Gross Weight Tests .....................................................................................77 6-1. Objective ......................................................................................................................77
Section 2. Service Ceiling Tests ....................................................................................................78 6-2. Objective ......................................................................................................................78
Section 3. Navigation, Fuel Consumption, and Night Flying........................................................79 6-3. Objectives ....................................................................................................................80
CHAPTER 7. THOUGHTS ON TESTING CANARD TYPE AMATEUR-BUILT
AIRCRAFT ............................................................................................................83
Section 1. Canards .........................................................................................................................83 7-1. Objective ......................................................................................................................83
1. General..........................................................................................................................61 Objective ......................................................................................................................61
2. Hours 11 through 20 .....................................................................................................61 Objective ......................................................................................................................61 Stalls.............................................................................................................................63
3. Hours 21 through 35: Stability and Control Checks.....................................................66 Objective ......................................................................................................................66 General .........................................................................................................................66 Definitions....................................................................................................................67
4. A Word or Two about Flutter .......................................................................................70 Objective ......................................................................................................................70 Description ...................................................................................................................71
5. Spins..............................................................................................................................72 Objective ......................................................................................................................72
5-10. Caution .........................................................................................................................73
5-11. Planning the Flight.......................................................................................................

Advisory on how it SHOULD be done. Nothing is absolutely required except flying for 40 hours. It's why he uses the term "fly off" so frequently. He's already said he doesn't see the need to stall test. So the rest of that advisory is pretty useless if you're not going to read it.

Did anyone catch what he said about pitot static? Did he really say the pitot tube itself could be faulty and not the location? And blame a bad altimeter setting the tower reported for the hundreds of feet altitude difference?

His autopilot kicks off when he engages. Probably because the controls are so heavy. And if you look close, the stick still shakes pretty good with any input. I suspect nothing is nearly as smooth as he reports.

 

[German guy]

Is his plan really to fly in circles for 40 hours then deem it production worthy?

...seems like this is the plan. And so that he can fly it to California, as he mentioned in one of his recent videos.

I'm not sure, though, how he wants to achieve this, given the fact that he can currently make it only up to around 3,000 ft or so, before the engine overheats.

The best performance he appears to be able to sustain, at this point, is to putter around at 2,500 ft., doing around 120 kts TAS. (according to Flightaware). In one of his past videos, in which he showed the logged data, it was quite obvious that he still needs a lot power (if I remember correctly over 60%) and that the temperatures only stabilize at a high level, to achieve this rather poor level of performance.

I also understand that he is still flying with the heater fully on and that the coolant temperature goes up quite significantly, every time he turns it off.

I'm betting that his plan is to somehow, at least slightly, improve cooling and to fly it to California as a publicity stunt, as soon as he has 'flown off' the 40 hours.
It will then be available for purchase with the promise that the series production version will be much lighter and much faster!

Frankly, though, reading through the very positive comments on Youtube and looking at the really high ratio between 'likes' and 'dislikes', I am pretty sure that some people will believe his promises and move forward with the purchase of a kit.

 

[nauga]

Here is just part of the index on the FAA advisory circular on how flight testing should be done for a experimental aircraft

That looks like it's out of AC90-89B, which is intended for experimental/amateur built aircraft. Despite what you might think of the builder's skills, the Raptor is certified as experimental/research and development. The FAA did not intend for this AC to apply to EX/R&D. Further, from the front matter in the AC, "This advisory circular (AC) provides suggestions and safety related recommendations primarily to assist amateur and ultralight builders in developing individualized aircraft flight-test plans." So where is the requirement to "explore and test the entire envelope..."?

I have no issue with recommending it, I think it's an excellent idea, but let's be realistic about what is actually required. There's way too much scope creep going on in this thread when the reality of it is bad enough already.

Nauga,
who went well beyond the recommendations but was not required to

 

[Lindberg]

Ok, I've never designed or built or test flown anything. But he's flying prototype #1. It seems to be built mostly with bandaids and bailing wire, but it flies. What's wrong with calling that a proof-of-concept and designing prototype #2 based on lessons learned?

 

[Tantalum]

Ok, I've never designed or built or test flown anything. But he's flying prototype #1. It seems to be built mostly with bandaids and bailing wire, but it flies. What's wrong with calling that a proof-of-concept and designing prototype #2 based on lessons learned?

if this plane is to be successful, at least as far as achieving some of its design goals, I think that's really the only path to realistically take..

and that's not all doom and gloom either, several modern successful designs had a fairly pathetic "V1" .. hell the first test sr20 crashed when the controls got jammed..

My issue with Peter is his attitude. The dude's entire house could be burning down and he would tell you there's nothing wrong with it and that it's great because it will provide free heating and he'd start building another addition while the kitchen burns

 

[Racerx]

Ok, I've never designed or built or test flown anything. But he's flying prototype #1. It seems to be built mostly with bandaids and bailing wire, but it flies. What's wrong with calling that a proof-of-concept and designing prototype #2 based on lessons learned?

Nothing. The problem is I have zero confidence prototype 2 would be any better if the builder of prototype 1 is doing the work. I actually think Peter alienated or got rid of the guys that actually got prototype 1 in the air. So I have my doubts anything was actually learned on this one. Look at his last fix with the tensioner. Still not chamfering inside corners.

 

[Tarheelpilot]

Nothing. The problem is I have zero confidence prototype 2 would be any better if the builder of prototype 1 is doing the work. I actually think Peter alienated or got rid of the guys that actually got prototype 1 in the air. So I have my doubts anything was actually learned on this one. Look at his last fix with the tensioner. Still not chamfering inside corners.

Oh sweet Jesus. That will bring it down in flames. Lol

 

[donjohnston]

The dude's entire house could be burning down and he would tell you there's nothing wrong with it and that it's great because it will provide free heating and he'd start building another addition while the kitchen burns

Is it possible that this guy is actually Bagdad Bob???

 

[Racerx]

Oh sweet Jesus. That will bring it down in flames. Lol

A small probably insignificant detail. But the totality of all those seemingly insignificant details is what makes this build quality poor. Leaky fitting...paper towels and zip ties. Let's go flying! Hes learned nothing. Or at least isn't showing hes learned anything. So what makes anyone think the build quality on number 2 would be superior in any way? Realistically he needs to shed 500 plus pounds. Im not sure thats possible for one. And I'm not sure he could get the weight and balance right without prototype 3. Again, nothing wrong with it. Just suspect subsequent models would be any better without help.

 

[kyleb]

The weight of the Raptor is a big issue and a decent portion of it apparently comes from the engine and its associated systems. The airframe is heavy because of his pressurization goals, but his window attach scheme will not work, so without a redesign, pressurization is off the table.

He's promised too many things. A turbodiesel with great efficiency. Not demonstrated at this point, but let's say he gets there. Unfortunately, that blows the weight budget. Which kills the payload and range figures. Unless he gives up pressurization to save weight. In the end, it may fly, and it is possible to develop the concept into something that works (although he probably isn't the one to make that happen). But it'll never come close to the list of claims he made initially.

 

[231TC]

New video: Autopilot Testing

That would be pretty far down my list of things to test, especially with everything else still wrong with the aircraft. I'm starting to think he really will try to fly it to the west coast as soon as he "flies off" 40 hours.

 

[FastEddieB]

I realize there are huge, possibly insurmountable problems to overcome, with cooling, weight and performance, not to mention actually going into production.

Still, I am impressed with his recent progress.

 

[jaxcessnadriver]

So the belt on the re-drive started skipping teeth and he had to limp back reduced power to the field. But that’s OK

 

[SoonerAviator]

So the belt on the re-drive started skipping teeth and he had to limp back reduced power to the field. But that’s OK

Autopilot will correct for that, lol.

 

[donjohnston]

OMG... where to start. He's "testing" the autopilot but he hasn't bothered to read the manual. So he's not sure what that "Trim up" message means.

Still got the static port error causing a 100' gain in altitude while rolling down the runway. And he seems confused as to why the GPS altitude and the altimeter don't "sync up".

And testing the autopilot before doing any stall testing.

You can't make this stuff up.

 

[231TC]

OMG... where to start. He's "testing" the autopilot but he hasn't bothered to read the manual.

Haha, I just said the same thing at HBA. I don't know why I'm still surprised by the things that guy does, but I am.

 

[Katamarino]

If I hear him say "dial it in" one more time, I think I'll scream.

 

[iamtheari]

If I hear him say "dial it in" one more time, I think I'll scream.

 

[jrcox19]

OMG... where to start. He's "testing" the autopilot but he hasn't bothered to read the manual. So he's not sure what that "Trim up" message means.

I had to watch to see what he said.. That's incredible. He doesn't know what TRIM UP means, but he also admitted he didn't even know what mode he was in (PIT was active, ALTS was armed).

 

[Racerx]

I had to watch to see what he said.. That's incredible. He doesn't know what TRIM UP means, but he also admitted he didn't even know what mode he was in (PIT was active, ALTS was armed).

Would anyone hire him to be your CFI? You'd think he'd have some previous experience with the equipment since he's a cfii. And you'd think being the guy that installed the equipment he'd have read the damn manual.

 

[Omalley1537]

Would anyone hire him to be your CFI? You'd think he'd have some previous experience with the equipment since he's a cfii. And you'd think being the guy that installed the equipment he'd have read the damn manual.

Can you imagine being HIS CFI?

 

[Z06_Mir]

Can you imagine being HIS CFI?

Maybe Jerry is his CFI... he has been giving instruction lately. Perhaps they can meet up when Peter flies to the West Coast in 38 more hours.

 

[painless]

Meh..... All the comments here are beginning to be rather repetitive. Peter is going to do what Peter is going to do. Or not do.

My main interest in this whole spectacle is if he will learn anything from prototype 1 and apply it to P2 and get the weight down. If he sticks with the Audi conversion, I have my doubts. I’m also interested if the design ever hits the market. Again, I have doubts.

Regardless of my disagreement with his methodology, I admire him for taking a stab at it.

 

[NHWannabe]

Meh..... All the comments here are beginning to be rather repetitive. Peter is going to do what Peter is going to do. Or not do.

My main interest in this whole spectacle is if he will learn anything from prototype 1 and apply it to P2 and get the weight down. If he sticks with the Audi conversion, I have my doubts. I’m also interested if the design ever hits the market. Again, I have doubts.

Regardless of my disagreement with his methodology, I admire him for taking a stab at it.

He has only alluded to his "backers" but I'm wondering if at some point he runs out of money does someone come in and buy him out at bankruptcy pricing and re-engineers the design to get closer to his original intent.
I've posted this before in this thread but as someone who can't draw a straight line with a ruler I'm pretty impressed at what Peter has been able to build warts and all.

 

[Racerx]

He has only alluded to his "backers" but I'm wondering if at some point he runs out of money does someone come in and buy him out at bankruptcy pricing and re-engineers the design to get closer to his original intent.
I've posted this before in this thread but as someone who can't draw a straight line with a ruler I'm pretty impressed at what Peter has been able to build warts and all.

What he designed in CAD and had someone build the shell is pretty impressive. What Peter has built from there, it could have been so much nicer...and safer.

 

[NHWannabe]

What he designed in CAD and had someone build the shell is pretty impressive. What Peter has built from there, it could have been so much nicer...and safer.

No disagreement that Peter has done a lot of bubble gum and duck tape fixes and some of his decisions have been, I'll be generous here, questionable but he's still gotten an aircraft off the ground. I don't think I could do that and that may be a low bar but I give him credit nonetheless.