Raptor Aircraft

the fact that he cannot even keep the engine within temp parameters on the ground at idle tells me that he either didn't do a thermodynamic workup on his cooling system, or it was very flawed. Ive seen pete law (legendary thermo guy from lockheed and reno racing fame) just look at a airframe and determine almost exactly what it needs to get rid of heat.
 
231TC said:
They rolled an ARFF truck out of the station to stand by during his flight.
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kyleb said:
I don’t think his cooling and intake air are ducted and separated. He’s not exhausting all the hot air and it is recirculating and mixing with his intake and cooling air. Basically a heat adding feedback loop.
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Oh, he’s exhausting plenty of hot air...


...but the plane’s not...
 
From watching all of his videos, and how popular this topic is on multiple pilot boards on the interwebs, I'm really surprised someone from the FAA hasn't intervened at some point. His methodology for development and testing is non-existent, and downright dangerous not just to himself but others. During the flight video all I could think of was the innocent people on the ground under him that had no idea what was flying just hundreds of feet over their heads.
 
midwestpa24 said:
From watching all of his videos, and how popular this topic is on multiple pilot boards on the interwebs, I'm really surprised someone from the FAA hasn't intervened at some point. His methodology for development and testing is non-existent, and downright dangerous not just to himself but others. During the flight video all I could think of was the innocent people on the ground under him that had no idea what was flying just hundreds of feet over their heads.
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Yep. As he was making the turn towards the airport, that freeway caught my attention.
 
midwestpa24 said:
From watching all of his videos, and how popular this topic is on multiple pilot boards on the interwebs, I'm really surprised someone from the FAA hasn't intervened at some point. His methodology for development and testing is non-existent, and downright dangerous not just to himself but others. During the flight video all I could think of was the innocent people on the ground under him that had no idea what was flying just hundreds of feet over their heads.
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My wife (non pilot) commented on that. She got one look at the plane wobbling around in flight and said what an *******. He’s gonna kill innocent people on the ground. It’s crazy to me that someone with zero aerodynamic knowledge like her can even see how dangerous this is.


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Peter Anderson said:
My wife (non pilot) commented on that. She got one look at the plane wobbling around in flight and said what an *******. He’s gonna kill innocent people on the ground. It’s crazy to me that someone with zero aerodynamic knowledge like her can even see how dangerous this is.


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In fairness, people with zero aerodynamic knowledge see all small planes as obscenely dangerous. But this is one of the times when the proverbial broken clock is dead-on accurate.
 
unsafervguy said:
the fact that he cannot even keep the engine within temp parameters on the ground at idle tells me that he either didn't do a thermodynamic workup on his cooling system, or it was very flawed. Ive seen pete law (legendary thermo guy from lockheed and reno racing fame) just look at a airframe and determine almost exactly what it needs to get rid of heat.
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One of the true geniuses of aviation, and certainly of air racing.
 
Shepherd said:
Ladies and gentlemen instead of snarking at the bears dance style, you should be amazed that the bear can dance at all.
A lot of people, with a lot more resources, have done far worse than this guy.
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No. The man has refused every iota of advice from highly qualified people. His data is made up as every part of the design has been changed. Nothing works as it should or even close to what he was hoping for. His engine and cooling has been untested and it's showing that it's completely flawed. He has flight control surfaces that are literally coming unglued. The thing is a lead sled that is going to kill himself or someone else.

Kudos for getting it off the ground but he needs to walk away while he can still walk. Designs fail all the time. It's the ability to learn why and improve that lets those people live. His issues run deeper than the landing gear simply being down or the engine on he brink of melting. The thing is damn near uncontrollable. Is it an aerodynamic issue or is it simply his build quality being sub par?
 
Shepherd said:
Ladies and gentlemen instead of snarking at the bears dance style, you should be amazed that the bear can dance at all.
A lot of people, with a lot more resources, have done far worse than this guy.
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That's one way of looking at it. I look at it as he enlarged the Velocity, stuck a poorly conceived auto conversion on the back, and wobbled it around the pattern while spouting performance claims that didn't pass any sniff test. He apparently spent millions in the process. No participation awards for that from me.

He was offered very good advice by experts in the field on how to improve his creation and at least make it safe and flyable. He's been dismissive to advice and has blocked a number of people from his youtube commentary because they were offering helpful advice, not acting as sycophants and fan-boys. Excessive ego and the inability to listen to experts are very bad traits in aircraft designers. He's demonstrated both in spades.

I'm just hoping the bear doesn't hurt anyone.
 
Can we discuss how he might attack the apparent longitudinal instability the Raptor is evidencing?

I already mentioned moving the cg forward, though that may be difficult at this stage.

How about...

Removing play from the elevator to stick cable run?

Add rigidity to the elevator in case flexing is the culprit?

Adding a friction dampener somewhere in the elevator control system?

Adding springs and/or counterweights somewhere in the elevator control system?

Modifying the elevator trim tabs to be servo or anti-servo?

I can’t see why he immediately jumps to the landing gear wells as a possible cause - that seems pretty farfetched to me. But he really needs to address this now, before being tempted to test it at higher speeds.
 
FastEddieB said:
Can we discuss how he might attack the apparent longitudinal instability the Raptor is evidencing?

I already mentioned moving the cg forward, though that may be difficult at this stage.

How about...

Removing play from the elevator to stick cable run?

Add rigidity to the elevator in case flexing is the culprit?

Adding a friction dampener somewhere in the elevator control system?

Adding springs and/or counterweights somewhere in the elevator control system?

Modifying the elevator trim tabs to be servo or anti-servo?

I can’t see why he immediately jumps to the landing gear wells as a possible cause - that seems pretty farfetched to me. But he really needs to address this now, before being tempted to test it at higher speeds.
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And if that longitudinal instability is the canard repeatedly stalling?
 
Racerx said:
And if that longitudinal instability is the canard repeatedly stalling?
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It isn't or he would have lawn darted in as the airplane decelerated from 105-110 knots to his landing speed of <95 knots and the canard fully stalled.
 
kyleb said:
It isn't or he would have lawn darted in as the airplane decelerated from 105-110 knots to his landing speed of <95 knots and the canard fully stalled.
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Velocity has a video about canard stall and bucking. Seemed similar to what Peter experienced. But I know nothing of canard aerodynamics and I doubt Peter does either.
 
Racerx said:
And if that longitudinal instability is the canard repeatedly stalling?
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Vortex generators?

I’m just throwing stuff out there. I have zero experience designing an aircraft, and just trying to think of how other aircraft design tweaks may have been utilized to enhance longitudinal stability.
 
FastEddieB said:
Can we discuss how he might attack the apparent longitudinal instability the Raptor is evidencing?
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He already has trim springs in the system. My guess is he's chasing pitch oscillations because there is so much slop in his elevator control system. The airplane does something, he applies corrective action, but it takes 1/10th of a second (or whatever) for that sloppy (push pull cable, IIRC) control system to move the elevator, so he's always 1/10th of a second out of phase. OTOH, his CG may be too far aft, but I think he's been given paramaters by Marc Zeitlin (sp) one of the guys he brought in last year about where to locate the CG for initial flights. Hopefully, he took that advice. The other thing is that maybe he's got some weird interaction because of the wide nose acting as an aero surface.

You're right about his landing gear theory being a red herring, as is his claim about turbulence. My guess is that he's found the same dutch roll tendency the model he built exhibited. Rutan used leading edge vortilons and rudders with surface below the wing to fix the roll issues inherent in swept wings.
 
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Racerx said:
Velocity has a video about canard stall and bucking. Seemed similar to what Peter experienced. But I know nothing of canard aerodynamics and I doubt Peter does either.
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Yeah, but think about it. The airplane will rotate at about 90 knots, meaning the canard can "fly" at that speed or less. Shouldn't pitch buck <corrected> at 1 G above that speed.
 
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Correct. When the canard is stalling, it's pretty noticeable. The nose drops until enough speed is regained for it to fly again.

This doesn't look like a canard "pitch buck".

I have no idea what's causing this. Maybe his CG is too far aft. Maybe the angle of incidence difference between the canard and main wing are too close so they're both near stall at the same time. That would be a pretty scary ride.

I used to have vortilons on my Velocity until I painted it. Figured I would try a flight without them. I couldn't tell any difference in flight behavior so I left them off.
 
midwestpa24 said:
From watching all of his videos, and how popular this topic is on multiple pilot boards on the interwebs, I'm really surprised someone from the FAA hasn't intervened at some point. His methodology for development and testing is non-existent, and downright dangerous not just to himself but others. During the flight video all I could think of was the innocent people on the ground under him that had no idea what was flying just hundreds of feet over their heads.
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I'd rather the FAA stay out of it unless he violates a reg. Having the FAA start getting their hands into clean sheet experimental aircraft testing is a recipe for disaster. Sure, this guy is an accident waiting to happen, but that's his right. The FAA wouldn't sign off on this thing being ready for flights away from the home airport at this point, so the only person he'll likely injure/kill is himself, statistically. I doubt there will be any more flights for quite awhile anyway, as he probably soiled himself on the test flight.
 
Pretty funny how far out of "spec" this plane has become. Granted numbers are always optimistic... But he thought stall speed would be 65 knots. Cruise of 220 knots at 7gph. The thing is roughly 1000lbs heavier than anticipated and could got to what 115knots at 20 gph?
 
Racerx said:
Pretty funny how far out of "spec" this plane has become. Granted numbers are always optimistic... But he thought stall speed would be 65 knots. Cruise of 220 knots at 7gph. The thing is roughly 1000lbs heavier than anticipated and could got to what 115knots at 20 gph?
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Smart people who have run the math on the Raptor's demonstrated acceleration think the engine is putting out ~225 hp. Peter blew them off and continued to claim 400+ HP. The aircraft's acceleration climb performance shows that it is substantially underpowered. At first, I wasn't sure it was gonna clear the trees on the test flight.

Other smart people have pointed out what a cluster the twin turbo setup is, with poorly matched turbos working against each other, creating more heat than power. Again, the response was denial or crickets chirping.
 
Is it time to trot out the Teddy Roosevelt "not the critic who counts" quote again? :p:rolleyes:
 
If the CG is too far aft now, what about with 3 rear passengers?

How do you change the static angles of attack on the canard and wing on something composite? I guess you don’t, other than rebuilding the entire canard and wing.

Is the canard perfectly interrupting the airflow to the wing at a certain AOA? Maybe raise or lower the canard?

I fly a 182 with a canard, but...
 
Racerx said:
Pretty funny how far out of "spec" this plane has become. Granted numbers are always optimistic... But he thought stall speed would be 65 knots. Cruise of 220 knots at 7gph. The thing is roughly 1000lbs heavier than anticipated and could got to what 115knots at 20 gph?
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Dude, relax. It's just because the gear was down. His next flight will have some GoPros mounted in the gear wheel
 
kyleb said:
Other smart people have pointed out what a cluster the twin turbo setup is, with poorly matched turbos working against each other, creating more heat than power. Again, the response was denial or crickets chirping.
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That turbo arrangement is a serious enigma.. automakers will do clever things with turbos to account for lag and all the various power demands and RPM ranges a car will run at, something like this needs to have more of a marine setup; a turbo-tuned to a constant setting

someone else mentioned this up thread but I think it has serious merit, Peter either should have focused on engine development or the aircraft and put a standard Continental or Lyco on the plane and perfected that. Trying to do two at once is like solving for two variables with a very dubious "known" value

PS.. I was tempted to write rotax but judging by that first flight video and the acceleration we've seen on the ground this thing clearly requires at least 300 horsepower
 
Tantalum said:
put a standard Continental or Lyco on the plane and perfected that. Trying to do two at once is like solving for two variables with a very dubious "known" value
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Tantalum suggesting the use of the 1950s technology that are Lycoming and continental engines? Wow.

I will add that it's not just the engine but also the redrive system. How many test hours are on that?
 
SoonerAviator said:
I doubt there will be any more flights for quite awhile anyway, as he probably soiled himself on the test flight.
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I really, really hope you're right about that, though to me this was the second-worst outcome imaginable behind crashing in flames. He forced it into the air (and almost halfway around the pattern, at less than half the pattern altitude) and then somehow managed to successfully get it back on the ground. Based on prior behavior, I doubt he's very scared; he's going to feel empowered.
 
flightwriter said:
Based on prior behavior, I doubt he's very scared; he's going to feel empowered.
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I think he is concerned for his mortality. In a couple of the in-cockpit videos of his ground runs, I noticed his hands shaking.

My guess is he's sitting in an extended stay hotel near the airport right now, contemplating how to fix the mess he's created. He's forcefully contradicted so many experts over the years "You need to fix this by doing X" "No I don't, I've done math and...", he's gonna have to eat a lot of crow to make the real changes he needs to make.

And I bet he has a huge case of project fatigue in that he's been "ready to fly" since about last August and the goal line seems to be further away today than it was a year ago.
 
iamtheari said:
In fairness, people with zero aerodynamic knowledge see all small planes as obscenely dangerous. But this is one of the times when the proverbial broken clock is dead-on accurate.
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In most cases I would agree with you, but the wife has spent hundreds of hours in small planes and wants to spend all of our extra time flying. I am probably a lucky husband in that regard.


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455 Bravo Uniform said:
If the CG is too far aft now, what about with 3 rear passengers?

How do you change the static angles of attack on the canard and wing on something composite? I guess you don’t, other than rebuilding the entire canard and wing.

Is the canard perfectly interrupting the airflow to the wing at a certain AOA? Maybe raise or lower the canard?

I fly a 182 with a canard, but...
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It's not hard to change in angle of incidence on the main wings. We use shims. The canard is a bit more work but not that difficult. It's one of the reasons why Velocity recommends not painting until you've flown off the Phase I hours. I was lucky (or maybe good) in that I required no changes in either the canard or main wings.

The main wing of the raptor is a bit higher than the canard. On the Velocity it's at about the same level. I will feel some buffeting at high AOA's so I would think that the raptor would be less prone to that.

Edit: But... He's got those obscene spades hanging down to balance the ailerons. That is a definite possibility.
 
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donjohnston said:
But... He's got those obscene spades hanging down to balance the ailerons. That is a definite possibility.
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When he put the weights on, they were formed from a couple of chunks of lead he just happened to have. They weighed four pounds each after shaping them to fix the spades.

He assured viewers he 'proved' they were the correct weight, and he didn't choose them just because he had a few pounds of lead laying around.

I found it quite astounding that an airplane 'designer' would just arbitrarily install eight pounds of lead on the ailerons so casually.

But PM is 'good with that'.
 
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3393RP said:
When he put the weights on, they were formed from a couple of chunks of lead he just happened to have. They weighed four pounds each after shaping them to fix the spades.

He assured viewers he had 'proved' they were the correct weight, and he didn't choose them just because he had a few pounds of lead laying around.

I found it quite astounding that an airplane 'designer' would just arbitrarily install eight pounds of lead on the ailerons so casually.

But PM is 'good with that'.
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And this is only one example of his "clever" engineering.

I think the redrive is the most telling example.
 
kyleb said:
And this is only one example of his "clever" engineering.

I think the redrive is the most telling example.
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I also recall him finalizing the aileron cable tension at 125 lbs. With the pulley mounts being constructed from .090 carbon fiber sheet bonded directly to the wing skins along with the four lb lead weights, it's no wonder the roll control of the aircraft is completely screwed up.

I suspect the rudder controls are similarly compromised, and that and possible assymetric wing and winglet incidence is contributing to control issues.
 
Reading through all of these engineering comments makes me wish Mike Patey would catch wind of this and sort this venture out. He'd rummage through his "Scrappy" spare parts box and the plane would be flying like a dream by next week.
 
drummer4468 said:
Reading through all of these engineering comments makes me wish Mike Patey would catch wind of this and sort this venture out. He'd rummage through his "Scrappy" spare parts box and the plane would be flying like a dream by next week.
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Patey would be well served to start with a gas can and a match. Nothing on the Raptor appears worth saving. The drivetrain is a mess, the aero is a mess, the weight is crazy high, the gear is too short, the pressure vessel didn’t work. What’s left?
 
kyleb said:
Patey would be well served to start with a gas can and a match. Nothing on the Raptor appears worth saving. The drivetrain is a mess, the aero is a mess, the weight is crazy high, the gear is too short, the pressure vessel didn’t work. What’s left?
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The engine might be worth saving. It just needs an overhaul and then it will be a really good fit for an A6.
 
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