First Real Flight - Flying the Raptor Prototype
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- Опубліковано 7 лют 2025
- Well, I finally got everything sorted out so it was time for a flight around the pattern. It was cut a little short as I opted to stay conservative on the temps and decided it was better to get it back down on the ground with a ton of valuable data rather than risk an unfavorable outcome.
- Авто та транспорт
I have witnessed several first flights. This was the scariest that did not end in disaster.
Hi Peter!
I am a fan of the Raptor project and big respect for you that you pulled it through up to this point! Please let me help with a single quick fix advice which will help your temperature problem by a lot.
As said before in another comment, I was developer for BMW/Audi/VW/Renault Diesel engines.
In your setup, the turbos are staged for boost pressure (at altitude). This means, that the first turbo (low pressure) needs to be the bigger one than the second one, MUCH bigger. Why? While mass flow is constant, the volume changes. The first stage squeezes the air to a smaller volume, but you are interested in the mass. This means, that the second turbo has to be much smaller by the ratio of the pressure rise of the first turbo. The way it is set up in the Raptor, you are experiencing a surging second stage.
OK, this explains why your boost pressure is not much better than for a single turbo setup, but your problem is on the opposite side: the exhaust.
The exhaust gases expand in the high pressure (second stage turbo) and expect a much larger turbo as the second (low pressure). Now, your turbos are almost equal sized, but the second smaller than the first. So you create a lot of backpressure, which rises the EGT to values that I don't consider safe in an aircraft anymore. Why the high EGT? Because the heat cannot leave the engine over the exhaust. Normally, the turbos would let the air expand, recovering the energy that way. But here, due to the backpressure it stays in the cylinders and the turbos are not doing what you want them to.
What is the quick fix? Get rid of the low pressure turbo and only use the high pressure turbo. You will notice that power goes up to 300hp instead of 230hp you currently have and in addition that temperature will go down A LOT! You won't need the twin turbo setup with your current hull (no pressurization and high empty weight).
Hope I could help you and that you take this advice serious. Keep up the good work and wish you much energy to continue your dream!
BR, Andreas
Andreas Schönwälder great advice. Everything you said makes perfect sense, simple fix take one turbo off 😀😎
Great advice, I hope Peter heeds it.
This times 1000. I am NOT a diesel engine developer, but I am a diesel nerd, having driven tuned VW Tdi's and a tuned compounded twin-turbo BMW 335d. I highly recommend and agree whole heartedly with Andreas...one turbo is much simpler.
As fun as the compound-turbo 335d was when both turbos were working properly (for that one week out of 3 years of ownership!), all the headaches of failed vaccum actuators (really? No feedback controls Andreas? Why? You made my life hard and have to constantly troubleshoot :( ), ....long story short: 1 turbo is better than 2 in mission-critical applications. Much more robust and simple to control and tune
I thought twin turbos were just for reducing lag, what´s the point of having twin turbos on this plane in the first place?
@@droneguts5122 In this case, the second adds additional pressure for higher altitude.
That oscillating was terrifying to watch, nice job keeping your wits about you and getting it back down in one piece.
Peter, congratulations on the first flight, been following your project from the start, well done, truly incredible achievement.
It’s worrisome he doesn’t seem to know why. I hope he gets some more experienced help. This is dangerous.
@@coloradocruzer I thought for sure the Wasabi guys would take the first test flight.
Agreed 100%
Over at the homebuilt aircraft forums we tried to warn that it would be unstable in pitch. The moderator Bill keeps removing warnings and banning members who tried to discuss this. It’s sad to see the forum get taken over by such arrogant deranged people. Used to be good
I'm relieved you survived. And somewhat surprised.
This is the only channel that the comments are just as interesting as the video itself....Congrat Pete,
We have been following you for a long time. After all the hard work and worry you put into Raptor it was quit thrilling to watch you make the first flight, congratulations.
You corrected and worked through problems on the ground, no doubt you’ll correct the flying problems. After reading a few of the comments it sounds like you have plenty of expert advice to gitter fixed.
It’s most enjoyable watching you build Raptor, good luck, we look forward to watching your progress.
Jack in Missouri
Congrats on the first flight!
I spoke to the gentleman who built Vari EZE # 20, And he mentioned that the early Vari Eze aircraft had a similar pitch oscillation problem. Burt Rutans fix was to increase the cord of the Elevator from 3 inches to 4 1/2 inches. After builders implemented that fix, there were no more pitch oscillation problems.
The problem is his elevator hinge design. The chord and angle of incidence changes when the elevators are moved.
HighMXHubby < you are correct! Entirely different elevator/canard geometry.
CONGRATULATIONS!!!!! Onward and upward...been following your progress for years. Your tenacity and ingenuity were rewarded today.
First off, congratulations, Peter!
Now a few comments, since they were solicited. To begin, I'm a long-time aviator, aircraft owner since the 70's, and have owned and flown many aircraft. I am an engineer as well. Though not an aero engineer, control systems have constituted a major portion of my career. The engine cooling business is solvable. More air, larger, perhaps repositioned ducting, rads, all that is straightforward stuff as you are aware. The big issue is the pitch instability.
I very much doubt this was a result of local thermals or other air mass instability. I say this for two reasons. First, after watching all of the ground-effect testing, I have noticed the same thing. Next, the instability was present and consistent throughout the flight - even during the flare. This pretty much rules out thermal bumps as a cause. As the amplitude was fairly substantial, some coupling to the roll axis is to be expected as well. So - what next?
I very strongly suggest not attempting flight, absent some concrete resolution of the issue, with the wheels up. In addition to changing the center of drag forces, the gear will have the effect of "spoiling the 'Q' of the system". In other words, it provides damping. This is, at this phase of testing, a very good thing. In any case, the aircraft has to be stable in pitch with the gear down anyway. please don't attempt flight with the gear up just yet.
Being mostly an old steam gauge guy, I have no good idea that sort of data logging your EFIS provides, and specifically the resolution of any logging it may have regarding pitch, roll, and also time. While you might be able to infer some of this from the video, that is clearly suboptimal. Next, is any logging of the control surface and/or controls position. Insofar as the stick position is concerned, this can be added temporarily with some LVDTs, and a portable data logger. The control surface position is more difficult.
Oscillation is always a result of some nonlinearity. PIO is of course, caused by a phase reversal between the control inputs and the roll or pitch rate and sign. There are simple ways to rule this out, (above), as well as determining the source of the nonlinearity - be it some sort of slop or flex in the control linkages, surfaces, hysteresis, or otherwise in the aerodynamic system.
Were this my monkey, I'd spend my time addressing the cooling issue, and enlist some more help with the controls problem. Again, congratulations, good luck, and by all means, stay safe my friend!
Perhaps instead of bringing the gear up as a potential solution for the oscillation, he could blank off the gear wheel wells with some flat carbon or fiberglass plates and some speed tape. That would potentially confirm/eliminate the wheel well theory without removing the potential damping provided by the gear.
@@OkammakO Well - maybe. First, that's a fair amount of work. Second, remember that the Raptor is a pusher. Big whopping hunks of material flying into the prop would be a bad thing in the event of the failure of the 100 MPH tape. Third, if it turns out to be this, the solution is pretty dang onerous, necessitating another set of doors, and all that entails. My opinion is that it's better to get a handle on the fundamentals of the problem first. Now you could be correct - but I hope not - for Raptor's sake.
Please take some advice from a 30 year aerospace engineer and test flight engineer. First, you have a power problem that Andreas Schönwälder has volunteered info to help you correct. He seems to be an expert on your system, you should listen to him.
Your takeoff run was way too long. It looks like you both had less power than needed and apparently did not have the expected pitch authority to rotate at the desired time. These are both reasons not to proceed with takeoff and go back and solve those problems before flying again. You have exposed problems. That is what test flying is for. Now you need to stay on the ground and fix these problems before going up again. Period. That is how professionals do it.
Bad idea - flying again and retracting the gear. This airplane ought to be completely comfortable flying gear down, slow speed, in the pattern. Finding out that it cools OK at higher speed answers nothing about the future of this plane.
Am I wrong in saying that a pilot who has any doubt on the takeoff should not take off, but if they must, to use all of the runway?
@@grinchyface All pilots reserve some of the runway for rejected take-off. If not, you have to calculate V1 as the speed where take-off can not be aborted anymore. Above this speed you have an area of uncertainty and danger in case of engine failure. All pilots try to avoid that.
@@ShortApproach It's semantics but V1 as you describe it applies to aircraft with more than one engine. Any failure after V1 you continue. That won't get you far in a single engine. VToss is what you're looking for.
@@grinchyface Yes, it is better to be down here wishing you were up there, than up there wishing you were down here. As for the runway length, it should not get to a point that they use all of the runway. For a test, an engineer should calculate the ground roll. That would then be confirmed by test "hops" before going flying. If the plane does not show it is ready to fly at the calculated speed and location, you go back and figure out why.
That's the crux of the problem, he obviously has made his mind up NOT to listen. The fact that he outright admitted that he was rushing to put the aircraft in the air, knowing there was already an indication of problems, tells the story. Get-there-itis has claimed many a pilot, seasoned and amateur, in many an aircraft, perfectly maintained and functionally certified. Peter needs to step back and get the humility in check before he ends up nothing more than the PIC name on an accident report. Just the comments here alone, many many many people with varying years of experience and disciplines in aircraft design and testing are practically pleading with him to listen. Such a shame to come all of this way, through so much sacrifice, to turn your back to the offers of experienced professional guidance. That said, much in the case of stupidity, there is no cure for stubbornness either. My best to him, but this is heading down a very catastrophic path. He was never in full control of the Raptor, the Raptor was in control of him...look no further than the amount of yoke input needed just to make the circuit. I'm not sure I'd even let an R/C plane leave the ground with that much oscillation. Truth hurts, but it can also save your life.
It looks to me like the plane is nibbling at a canard stall at least in the pitch oscillations. Could be gap related or just that it needs a little more speed to come out of it. I remember when some Long Ezes as well as the Velocity had a premature very light pitch buck at about 80 to 85 knots that actually went away at a slower speed. In bumpy air, you wouldn't even notice it. Danny added a leading edge cuff on the elevator to help the situation and keep it from happening. Because of differences in builder installation of these, rotation speeds where all over the place so I removed them. With slight changes in elevator gap, this situation was fixed. I am sure if you had your temps in check you could have increased speed by 10 knots or so to see if goes away. Still would have to be addressed but at least you would know. So, before the next flight, I would tuft the canard and let them overlap the elevators so you can see what the air is doing over them. If you see them move sideways when the oscillation occurs then you can be pretty sure it will go away with a little more speed. You might be able to fix it in the short term with some VGs but if you use them, start with a few sets first with tufts behind them and on each side so you can see what the results are. Also, you would want to add some to the main wing as well so you don't change your center of lift too much and get yourself in trouble. Since you have blended winglets, I doubt you have any intersection problems and in Yaw, it looks very good with that ball hardly moving, even with a short flight. Not sure if you had any inputs with the rudders but I would guess not. I noticed that the left aileron was always up somewhat and did move with the roll oscillations. I would make sure that your leverage on the roll push rods with relation to the bell-crank on the aileron is such that you don't have some flexing going on that allows unintended movements especially during the pitch oscillations. As the loading changes on the canard and wings, the loading on the control surfaces does as well and could make the situation worse. I could say much more in trying to help and will if you want. Having done many first flights, I know how crazy that first flight can be and I have never test flown a new design so hats off to you. You were very calm and that is exactly how you need to be. Congratulation and be as safe as you can be when doing these things. As I said, I am here if you need me, even for a quick call. Always happy to help. Scott
I believe you are correct. The oscillations in pitch do look like canard stalls and subsequent recoveries. On re-review of the flight, I noted little or no pitch inputs during the course of the oscillations. While your tufting idea is sound, it would mean at least one, perhaps more test flights which leaves me wondering how much scale model/wind tunnel work was done prior to finalizing the design. I congratulate the gentleman for realizing his dream and the fortitude to fly it, but I really believe he needs those wind tunnel tests with smoke before he tries flying it again.
I assume you're THE Velocity UA-cam channel. Hopefully this guy calls you. He needs some aero engineers involved or a company that has lots of experience designing canard aircraft... Unrelated comment, pressurize the XL5 or V-Twin.
Scott, I had the opportunity for a brief flight in an XL5-RG and it opened my eyes - great aircraft!
No one is more qualified to provide observations on this flight. Your willingness to share insight is a testament to you and the Experimental community.
@@L123Alpha Thank you for the insight; I didn't know of this individual's connection to the experimental a/c community, but his reasoning here appears correct.
@@rcktpilot Completely agree. His traffic pattern was flown at a relatively low altitude and entry into a deep stall could have left him with no room for recovery. A consult with a aerodynamicist at a minimum is certainly called for. As I've said earlier in this thread, I'd love to visualize the airflow over that canard and the rest of the a/c in a wind tunnel with smoke while demonstrating changes in pitch attitude. If a pole-mounted model in a wind tunnel with allowance for vertical movement shows a similar oscillation, I'd seriously reconsider the design of the canard. That assumes the angle of incidence of the fixed portion of the canard is correct and the CG is not too far aft. That said, I'd really hate to read an accident account involving this a/c.
Congratulations Peter! You have now designed, built AND flown your own plane! Not many people can say that. Hope you have a few cold ones and celebrate before getting back to work.
@Chet Carson ....Mr. Sharptongue is still at his snarky remarks....I bet you are a real piece of work.
You are really good at finding excuses, not so good at admitting faults.
This plane should be grounded before it kills you. (and/or someone on the ground)
Nothing in this build is done professionally,
"if you are going to say something negative in the comments, just don't, it's not helpful" is a great approach, you don't want to hear that you have problems, you just wants people to boost your ego and say that everything looks fine, so OK:
This looks like a stable, safe and nice flying plane, keep flying it just like it is, there are motion sickness tablets for the oscillation problem and it might get cooler outside so it won't overheat.
GREAT JOB PETER!!!! CONGRATULATIONS!!! Time to celebrate... You have acomplished BIG challenge.
I've been watching this project in the UK from the start and I'm thrilled to see this fly! Gonna grab a beer and celebrate with you Peter. Tremendous accomplishment.
Just having a glass of wine here!
Cheers! 😄🍷
Congratulations Peter!! I (along with.many others!!) have been watching/following for some time now! It is great that you finally got to 'break the surly bonds' of the earth and fly in an aircraft that you basically created!! Awesome job!! I like the small changes that you make.....baby steps!! You'll do great!!!
Congratulations on the flight. I admire your drive and tenacity. That being said, watching this scared the shit out of me. As a decently experienced pilot, I feel these flights are a ticking time bomb until something tragic happens. It scares me that the excuses continue, but this time you're truly playing with your life. I support you and everything that Raptor Aircraft is doing, but every fiber in my being feels that a professional needs to evaluate the specific causes of the oscillations and help you address them before further flight. Good luck in all your endeavors.
What excuses ?
@@PaulAnthonyDuttonUk In this case, suggesting that turbulence played a large role in the dynamic instability. In many other cases, finding something to blame the aircraft's issues on instead of owning the fact that certain things are messed up and need to be addressed. If you haven't already, watch Wasabi's videos on their flight testing. They reveal the other side of the coin.
The amount of PIO and aircraft movement relative to stick position is terrifying.
building, designing and flying your own airplane is always going to be a high risk activity.
Congrats Peter
You are a man amongst men
Your determination is unwavering .
The only disappointment I have is that you weren’t more excited about what you just accomplished .
Hold your head up high and be very proud of yourself .
“ I am “
Congratulations on surviving! That machine was very close to departing controlled flight at a couple of points.
You got there. What a milestone. As always, with your signature understatement. An idea to RC models. Carbon moulds in hot tin sheds. Audi engines and onboard aircon. Diagnosis delerium as always solving. Relentless. Always progressing. Week after week you would start the slow climb up the dune acutely aware of the desert ahead of you - while loyally sharing the climb with total strangers every week...............….The raptor flies.................................In that, there can be, no understatement.
Congrats Peter! It took me back to 2001 when I did my first solo with 6.8 hours under my belt. Keep going!!!!! Congrats again!!!
Show off!!! 😂😂😂
Still celebrating!!! Thanks brother!
Big one for Peter!!! All behind him!!!!
"Congratulations!" great to see you finally able to fly it. Now comes the tweaking and testing. Good job and thanks for keeping us inside this adventure!
Peter, this was pretty amazing to watch. You didn't have to take us with you on this trip, but you did, and we all got to experience something very cool (and very nerve-wracking!). Thanks! Looking forward to the next ...
I'm not an engineer, just a fan of aviation and fabrication that's been following your channel for more than 3 years now. I can't offer anything to help with the technical challenges but do want to say CONGRATULATIONS ON YOUR FIRST FLIGHT! Truly amazing progress, you should be very proud. Continued best of luck on the Raptor!
How many people on the planet, in history, have designed, built, and now flown their own aircraft? and even fewer living to tell about the last part?! Congrats! Yeah yeah, plenty of continuous improvement to come, but wow, what a milestone.
The Wright Brothers 🙂
Might want to give Mike Patsy a call...
Now they get to start over with either major aerodynamic modifications or a total redesign, because this airframe is trash. The fun never ends. Life is a journey.... YAY!
Ummm.....hundreds?
Hi there, I'm still alive and well, so is my plane. Nobody else on earth has a plane like mine, and it was created entirely by my own hand, minus the engine of course. Designing and building a plane from scratch is relatively simple, and plenty of people have done just that. Complexity goes up exponentially if you're trying to achieve new milestones, however.
Hats off to you, Peter. Thanks for taking us along for the first ride. It'll only get better from here. Nice job, man.
How many hurdles haven't you had to overcome during this years Peter! A few more is nothing.. Listen to advice given, sort, assess and heads down to get on with it. There is NOTHING you will not fix in time. You have shown that so many times over the years. All the best and stay safe! This show now got so much better :-).
Could not agree more! :-)
Congrat!! Susccesful first flight. Nothing broken. No injuries. Major achivement! Now to solve the issues and going on. My sincere congratulations!
Technally speaking, my impresaion is that you’ve got an aerodinamic neutral dynamic stability. That’s is close to negative so I will not try to gear up flight before you improve the dinamic stability. May be you can try to stop oscillations by picth inputs but been very prudent to do not induce pilot induced oscillation. It is a triky situation. Review your stability analisys look for why you have ended up with neutral dynamic stability
I almost had a heart attack as if I was flying it! Congrats Peter! Well done!
Followed probably 4 or 5 years and have never commented but, ... congratulations Peter! Well done !
That's not caused by gear, that's just plain old dynamic instability.
@@rafiqsaid4297 Indubitably
New name. Raptor out, dolphin in.
I tried to warn about this on the forum but Bill the moderator kept removing the posts. It’s sad to see him actively trying to get people killed because of his ego. This was fully expected.
You and the team should be very proud of yourselves Peter. This is a great achievement!
Congratulations Peter!
As a former Fighter pilot, experienced GA flyer and Long Range Biz Jet pilot, I've been following you since the beginning. My CONSTRUCTIVE FEEDBACK has ONLY 3 recommendations BEFORE next flight attempt:
1) ENGINE: It is developing plenty of heat, but not power for that heat. Please pay close attention to Engine expert @UCo6xJwOJMlD2kD5dOQ8L68g's comments. His experience will SAVE you LOTS of time and $$$.
2) PITCH OSCILLATIONS: (not related to Landing Gear at all) needs to be addressed by speaking to Canard Experts.
3) RIGHT ROLL TENDENCY: Requiring Consistent LEFT aileron input/trim is not normal and must be addressed.
@@ryanthomas2472 When you said "that person", was is the name? Do you mean my comment?
Congratulations, Peter! You deserve an enormous amount of credit for your hard work and stick-to-itiveness!
Peter, I’m sure everyone who has been following you from the start was holding their breath, you are amazing and I and all are so proud of what you’ve accomplished. Regarding the “bucking” perhaps think about corresponding reactions associated with the aileron counterweights. Perhaps a slight redesign of the affixed weight to make it lift and drag neutral. Once again GREAT JOB. I hope you can get out with a friend and have a celebratory cold beer and burger. PS: actually keeping your door in a closed but not latched is a good thing in case you go down, you’re not locked in if anything gets bent....
Congratulations on the first flight! Lots of jitters with the first. Now the real fun begins.
Always remember to take baby steps to expand the envelope. Always perform a deepening risk review with mitigation plan for the surprises. GREAT JOB!!
I'm excited to see this take flight, I'm also scared about how it flew, I don't think that was due to 'wheels down' - Please be safe and don't be afraid to look for bigger problems, best to find them before they find you. Take care and best wishes - this has been a long hard battle for you and I want to see you get there, in one piece!
Congratulations on this successful first flight. I have been waiting years to witness this !!!! Great job !
Congratulations!! What an amazing accomplishment! The entire aviation community is very proud of you. Thanks for taking us along for the ride!
Man! What a day. Celebrations are in order. I know it wasn’t perfect but rarely are first tries at anything. You have endured a lot to get to this point so don’t let anyone take that away from you. The amount of courage and willpower it takes to get this far is more than anyone but you can understand. As everyone else is offering input on what could be causing the oscillations, I just wanted to send you the big congratulations you deserve and let you know that I will be one of many in line to buy a kit from you, assuming that is still the plan. Way to go man!
Huge accomplishment now the real work begins to iron out that oscillation and temperatures. Congrats! This thing flies like a seasick angel!
You are doing awesome. We appreciate you more than you think. Keep doing what you are doing and god bless you.
Congratulations on the first flight but man that looked scary.
Congratulations Peter. I am impressed with your accomplishment.
Congratulations on the first trip around the pattern. If you have to deal with thermals again, arrange to go up in another airplane immediately after your next flight. If it is the conditions, that will be apparent in both planes. If it is something with the Raptor, you will see that as well. Keep it up, Peter.
This is where a chase plane would help. I'd send it around before you go up and then have it with you as you make your flight. Then you will have a baseline to compare to.
+ 🚁
Congratulations!!!! You did an Amazing job!!! You have alot a support here and lots of things to think about! Im 100% certain you will figure this out! Cant wait to see what's in store!! Love this aircraft and hope to be able to own one one day!
Hi Peter!
First, congratulations for the successful first flight!
I have worked as one of the developers for the diesel engine that you are using and also for BMW diesel engine development. I noticed that you have an error in your turbo setup (wrong mass flow calculation), which is restricting your power to something around 230hp, turning the rest of fuel into wasteheat. The car setup can not be applied here, it works completely different for your use-case.
There is a quick fix possible to gain 30% improvement in heat reduction or power output in case you would like the advice.
BR, Andreas
For the curious among us, what is the fix?
@@sl66ggehrubt
No, Peter did not do a proper test and he did not consult with any diesel injection or turbocharger experts.
If you look at the videos from about 2 years ago, Peter did test the engine on a dynamometer, and it produced about 200 HP, when the dyno died. He never bothered to take it back to check the power.
Peter did do static thrust tests, with the engine and prop installed in the airframe, and it struggled to make much more than 1,000 lbs of thrust. An IO360 can produce 800 lbs thrust. That thrust was equal to 200 to 250 HP range.
Peter timed a Cirrus SR20 (that has only 200 HP) accelerating up the Cherokee runway and the Raptor could match it up to 60 Kts and then the Cirrus walked away. It was noted in those videos that the Cirrus pilot opened his throttle very gradually and only firewalled it from 40 Kts. The Raptor is heavier, however, the acceleration suggests about 230 HP.
The engine does not have the original high pressure fuel pump which was replaced by an aftermarket pump.
At a very late stage, Peter found out that the high pressure fuel pump was operating at half pressure and he did increase that to about 90% of what it should have been.
If the high pressure fuel pump is operating at reduced pressure, the only way to deliver more fuel to the engine, is by leaving the injectors open for a longer period of time ie long after TDC. This results in burning fuel being expelled into the exhaust instead of doing work to push down the piston and produce power. The fuel expelled burning in the exhaust causes high EGT.
The engine is only producing about 230 HP and not 400 HP.
That is obvious from the take off with the aircraft barely able to climb and needing 85% power just to maintain level flight at about 120 Kts. It would need to fly at 200 KIAS, at sea level, on cruise power, to cruise at 300 KTAS at FL250. Did the Raptor look close to 200 KIAS ???
Half of the fuel is just producing heat instead of power and that is why it is running so hot.
Peter needs to listen to Andreas' advice.
The engine needs to be attached to a dynamometer and the high pressure fuel injection pump set up properly and the turbochargers changed until the engine makes at least 350 HP.
In any event, it probably needs 500 HP to make it perform.
I would start with the latest VW/Audi V8 which has the cylinder heads reversed and exhaust within the V - compact exhaust and less heat dissipation. It is not much heavier and it will easily make 500 HP.
Hi Andreas
Please give Peter the advice here because he will not ask you for it.
Best of luck!
Regards
Philip
Wow, I hope Peter sees this proposal. My aircraft happens to have a 350 HP engine too. Its initial climb performance is much better , despite being heavier and having a very draggy landing gear. From what the video shows, I think the Raptor was making much less than 350 HP. Andreas’ generous offer to help with the engine is a big deal,
@@N807DS Hi Antoine! From my flying experience in DA42, the landing gear equals to about 15%.
Awesome! I'm happy for you. I'm a member of the cozy mark iv user group. I render ready about in member who used a Subaru engine that fixed cooling issues. Might be worth reading.
I'll eat my hat if that's anything to do with thermals, and not likely to be landing gear related either. Whatever it is, probably should be sorted before the next flight or you might find yourself buying a new prop. But overall, huge congratulations are in order, for getting here after so much hard work, well done!!
I think it's most likely a control damping issue. It seemed like either the vortices coming off of the canards were upsetting the roll or it was some other aerodynamic factor doing it. In both cases you could solve it by putting a spring damper (kind of like a specialized version of a car's shock absorber) somewhere between the structure and a moving point on the ailerons. The equation to solve is a relatively simple ordinary differential equation (I think it's something like F_control = (d^2x/dt^2)m + b(dx/dt) + kx, evaluated over a step function, although the m is dubious because the control surface is rotating around a hinge, so you'd have to use I*alpha and set the equation around that, same thing though) that I'm sure is well within Peter's ability to do. Once the constants for the damping coefficient and spring constant are optimized then it's just a matter of installing the dampers and the oscillation should be much less severe.
@@cheapycheapy4689 A good theory as well. It definitely could be this. Either way a damping system for the ailerons would do well.
@@georgeingram9157 Yeah I agree with you on the aeroelasticity stuff, the wings are far too stiff and strong for that to happen at such low speeds I think.
@@CockatooDude I don't think it is damping per se, I think the aileron controls are way too soft, allowing BOTH ailerons to deflect upwards when loaded. They then act as elevators that automatically pitch the aircraft up under air loads. It's positive feedback.
@@bobmackey5758 Most of the issue seemed to be in the roll department, although I will agree that the pitching at takeoff was a little oscillatory.
Simply, amazing! We have a complete take off! Congrats from Brazil.
It's been a long time coming, but you're finally there! Congratulations, my good sir - you are an inspiration to all of us aviation enthusiasts out there!
That's cool Peter, congrats :) Huge milestone, great to be able to get heaps more Data now to fix any of the underlying issues. Going to repeat watching it a fair few times haha
Congratulations Peter with Raptor clearing the fence for the first time! Laminar flow wings inherently have a pitch bucking tendency at low speeds. Feels like a boat with aft following waves picking the aft up and dropping back down on the pitch axis. I'm thinking the roll axis will improve with with the gear up. My first thought is to add STOL VGs (Vortex Generators) wing kit to improve the airfoil and lift. This is a $100.00 parts solution... There are soft plastic ones available that are easy to clean around. Getting the airflow up for cooling shouldn't be much of a problem. I would first consider a suction dam as an easy cooling fix. I think you were catching strong thermals. I would look for a late evening test to verify in calmer air scenario... Best wishes test pilot! Welcome to the club!
Will Hibbard II +1 on adding Vortex Generators
Congratulations Peter! I Love seeing Simon say he wasn’t past the ads ... excited to view it but still supportive.
Awesome - Congratulations Sir, I am so happy and excited for you - had to pause the clip after landing to comment.
Back to the clip😊
Im glad you flew it yourself. You built it, You flew it! What an accomplishment!
Peter, I have been following you since the beginning and have to say CONGRATS on an excellent first flight. Yeah some things still need to be fine tuned but like any landing you can walk away from any first flight on a new design has to be the same way. Personally I would suggest keeping as much air as possible flowing (like opening the intake scoop) for cooling. If I had to bet on the oscillations I would bet on the canard stalling and recovering. Any way you got REAL BIG ONES to do the first flight yourself and not with a test pilot. Good for you!
Fantastic achievement Peter, do not let anyone take that away from you. I am sure you will figure out these issues like you have in the past.
Peter:
In watching the video, I do not see the stick moving with the pitch oscillations, and I don't see the elevators on the canard moving. But the spades hanging from the ailerons are all over the place, and in phase with the pitch oscillations. It looks to me like the aileron control mechanism is soft, and allowing the ailerons to deflect under aerodynamic loads. When the loads are high, both ailerons can deflect upwards, is if they were elevators. They are at the aft part of the wing and the aft part of the aircraft, so the wing loses lift and pitches up. That increases the AoA until the wing slows and approaches stall. Then the ailerons straighten out and the wing flies for a second before starting to pitch up again. The stated plan is to accelerate to higher speeds. That does not look like a good idea to me.
I know you asked for only positive feedback. Unfortunately the "positive feedback" is in this pitch control system.
My recommendation would be stay on the ground until the control stiffness is improved to prevent the ailerons from deflecting together at the maximum intended flight loads.
I think you are probably on to something there Bob. I had the same thoughts watching the video. I so wanted to see some shots of the other aileron....
Congratulations on a long awaited first flight. You certainly should be recognized for your determination and tenacity. Designing, building and flying a complex aircraft is quite a spectacular achievement!
However as my Dad used to tell me, “You’re 90% there with 90% to go.” There are many of us rooting for you to succeed but you’re obviously not there yet despite this milestone event. Please don’t fly it again until you have a much better handle on the stability and power issues and have implemented fixes. There are some very experienced canard folks that have offered experienced advice and some power system people who have some good ideas borne of direct involvement with that motor. You have engendered bountiful support and thoughtful input from your supporters. Please take their council to heart.
Take all the time necessary to digest the data, consider and implement fixes.
Lastly, and in my humble opinion, don’t raise the gear yet and consider hiring a test pilot well versed and experienced in flying canards.
Best of luck and be safe!
You are emblematic of what is good in aviation and in life. We want you around for a long time!
Congratulations on the first of many flights. You have turned just a thought into an aircraft that took flight. Lurch - crawl - walk - run, Raptor will get there.
Watched your progess since your first video Peter. It's been quite a journey. A remarkable achievement. Congratulations. I'm sure your dogged determination will see your ambitions for the Raptor realised.
I hope that post it note was approved for aviation by the relevant authorities!
Well done Peter, great to see someone with the conviction to follow their dreams instead of just posting negative comments in you tube 👍😁
You made my day, can’t imagine how you feel. Congrats Peter!
Huge success. You built something that took you for a flight! Baby steps, I'd start with cooling it down more so you can concentrate on smoothing the flight out. Congrats on a successful flight.
Wow! I can’t imagine what you are feeling right now. Amazing accomplishment. I have been watching this channel for a long time, and cheering you on. I admire your courage to push on. Each milestone sets the bar a bit higher. Agree that there is a lot of data to pour over. Take your time before the next flight. Enjoy a well earned victory!
Congratulations on your first flight with the Raptor. We’ve been looking forward to this.
Friend with that fancy accent, you need to do two things urgently :
1) stop playing test pilot, you need to hire a professional test pilot who does that for a living. You cannot be both builder and test pilot, it is never the right combo. You'd rather fly a chase plane and analyze things from outside.
2) talk to us, "US cowboys", who are fairly well versed in debugging canards, you are going apparently through the usual debugging phase, that has frustrated many of us, we'll be happy to bounce ideas with a fellow builder. We spent decades debugging this kind of planform, got bitten pretty bad too. Pitch stab and Dutch roll issues are common, as you are experiencing.
fellow builders who sympathize ....
PS: I can see some good feedback already below (Craig W), we all want you to survive + succeed obviously....
He did have a professional test pilot. Look up Elliot Seguin on UA-cam. There’s a couple videos of Elliot (a true professional) URGING Peter to not take this airplane flying until a long list of problems is fixed. Looks like the bug bit Peter a bit too hard and he wanted to fly.. shame
¡¡Bravo piloto!! ¡¡Bravo constructor!! ¡¡Bravo diseñador!!! Todo en UNA SOLA PERSONA!! Blessings and cheers for a successful first flight!!!
Your post-flight analysis is perhaps what is even scarier than watching this video and makes it alarmingly clear you actually have no idea what you're doing. I hope you take the advice given very seriously and wish you the best of luck on the program.
Fight to fly
This is scary gezz I want to see this guy succeed but I would agree there are some serious issues that need resolved before any further flights any ways how have you been it’s been along time since I have seen you Around?
Absolutely wonderful to see it fly!!!! No need to have someone else fly it. You'll fix any bugs and I'll be watching all the way. Great job!
I am from Russia, I was watch you first fly and I felt excitement and joy for you. Good luck in the future! You are really cool!
Well done, Tuatapere, it is so good to get the beast in the air. Good decision to land early, plenty of time to get thing correct.
First congratulations on flying it, great achievement. For cooling, adding an oil cooler makes sense but would not put it on the turbo return lines but normally via take plate. Working in motorsport, I would speak to a specialist radiator core maker like PWR who can advise on the most efficient one for your application. Makes a massive difference in cooling without increasing drag
www.pwr.com.au/
HUGE step forward. Very exciting progress. Agree oil cooling adjustment is needed. Great day for you! I know that this first flight is risky, and you managed it brilliantly. 👍👍👍
Phew. Congratulations!!! I am so glad you made it down safely!
You made the right choice to abort to 04.
I believe the cooling issue was a result of having the scoop closed. Seeing how quickly the temps went up, I would recommend opening the scoop fully for the next flight-there will be more drag, of course; but with the gear coming up, you will have a marked drag reduction.
Speaking of gear, the wheelwells certainly cause a huge amount of drag. Of course, without looking at the airflow, it is impossible to say if they are causing the oscillations.
BEWARE: When you retract and extend the gear, be ready for a HUGE yaw moment. With one wheel extending/retracting before the other, you are going to have a significant yaw differential.
I am personally praying for your safety and success.
-David S.
Congrats on the first flight. Now the fine tuning starts. So wonderful to see her in the air .
Short period oscillations likely NOT caused by airflow from the landing gear wells. The first uncommanded pitch motion began as you broke ground and your angle of attack increased. The aircraft continued to show oscillations through the brief pattern you flew and they appeared to be independent of speed and power setting. You had another set of large oscillations as you came into ground effect. Still a lot of aerodynamic work to do. Also, you have very little prop clearance in the flare...
Also, you have very little prop clearance in the flare...
Yeah...that freaked me out too...If you do it frame by frame, when the prop is right above the centerline it looks like maybe an inch...
ua-cam.com/video/_H9a2tGDaHE/v-deo.html
@@Brianckramer and no way to limit it like a mechanical interference or an air data pitch command envelope protection. But I immediately got queasy watching those oscillations, but we cannot see what is going on with the stick or controls. I just assumed they were PIO's. But the period made it look like a lack of longitudinal static stability. Idunno, but it gave me the creeps and some serious data reduction needs to happen before further flight. You know by Flight Test DERs.... I don't think the frequency of unsteady air at this speed would be from the wheel wells or doors, and also at 3,600 rpm is what % power for this thing? I heard a hint of 85% but didn't get an rpm for that. And a concept that will work is that constructive criticism is positive if it's directed at the key issues of safety and performance.
But these are the same oscillations we witnessed in the ground effect tests and it was declared "stable in all three axis" with much slapping of backs :\ I've never been so relieved to see a landing! Peter, you seem to almost be over analysing the minutia. Even if it was a gear issue, there's no way I'd want to fly something that behaves like this in the takeoff or landing phase of flight. I absolutely think it's time to hand over to test pilot(s) with experiencing assessing flight behavior. The fact that you stated feeling more comfortable after flying with an instructor points to a lack of experience and currency required of a test pilot. It's admirable that you sought out an instructor for safety and it's a credit that you've turned out such a gorgeous aircraft. Part of being a good project manager involves recognising limitations (in your skill set) where they exist and bringing in expertise when required.
Didn't the scale models first flight have pitch instability that was fixed for its second flight? The roll movement looked to be well within stable control response, fuel load and that wing tip weight will easily fix balance it.
The Rutan canard elevators seem to be down a bit more for nose up movement at slower speed and then move toward neutral as speed comes up. I used to use elevator neutral or even slightly down on ground roll since it seemed to accelerate faster due to less drag. Higher tire pressure really helps to gain speed on the ground. You might try some nose ballast to see of it helps reduce any sensitivity.
Congratulations on the air baptism and blue sky! You gave me shortness of breath on the take off. Looking forward to the next episode.
Big congrats Peter! This has been a long time coming!
Well done mate on inaugural flight. Definitely cowl open as you need all the air to cool during take off. Looking forward to more test flights with gear up and cowl open. Keep the faith!
First off, huge congrats on the first flight and to everything you've accomplished up to this point...but that looked pretty sketchy. I've been watching the progress of the Raptor since the beginning and I breathed a huge sigh of relief when you got it back on the ground. I know there were hurt feelings with Wasabi and all but I feel like it would be much safer for you and the program to have professionals do the test flights from here on out. You need knowledgeable and objective feedback from people who know what they're talking about, not internet "experts." I'm not an aerospace engineer but I do have an ATP, and I would agree that there is some serious aerodynamic instability going on. I do not think that will change by bringing your gear up, in fact it might make it worse since the gear are providing a keel effect when extended. You should be able to take off and climb to at least 1,000' AGL (pattern altitude) with the gear extended.
Excellent comments. Gear down/up isn't what ails that airplane. Hope Peter can sort it out.
@@sl66ggehrubt It sounded to me like he specifically asked for input, but not so much for personal attacks.
@@theralfinator I´ve read a lot of the comments here, since quite some time. Personal attacks are very rare. Or what i would see as personal attacks.
And you said it so nice, I wish I could do that
I didn't know an old guy my age could hold his breath so long. Nice job. Anyday the bird flies and the pilot survives it is a great day. 100% congratulations.
I know everyone's got an opinion, so I might as well throw mine in too! Firstly, congrats Peter, onwards and upwards! As far as the landing gear, might I suggest before trying the landing gear retracted. Maybe taking off without the gear doors and finding something to make the flow cover up the big wheel well area. Less things to go wrong (ie;problems with gear going up uneven causing a possibile problem). Also, I agree with an oil cooler. Eliminating problems and/or variables to concentrate on flying is a must and I know this is your way of thinking. Again, congratulations Peter, well deserved!
+ 1 for simply adding gear well covers... Good idea Keith Bauer!
Keith Bauer ... I think Peter mentions his consideration of this idea during this amazing video... go well. Stay well. Pretty exciting, I know I for one was holding my breath during this first flight.
Congratulations on your achievement. Would fly to a close location maybe a tower fly by with a prearranged camera to get another perspective.
Very impressive as a personal journey. Your are a master technocrat! Do not raise gear till all cooling issues totally resolved. When you raise the gear, you must have lots of time to deal with any gear problems. God Bless. Doug
This is it! The moment we've all been waiting for! Congratulations, Peter, for such a monumental milestone!!!
Looks a little heavy but I'm sure she'll be one majestic bird when the issues are sorted out.
excellent result, a big congratulations Peter !!
Congrats Peter! That was awesome. Thanks for taking us along for the ride.
Good thing you wore the brown pants. 😮
Glad to see you're alive, and the plane not being broken is a definite plus. I'd tend to agree with the other comments saying that the gear aren't the only problem, and you need to get the instability sorted out before swinging the gear.
Best of luck and be safe!
That was awesome to see the shadow of the aircraft on the ground
Peter, CONGRATULATIONS mate, bloody well done. After following your project for so many years, I almost don't believe I just watched the first flight. I had to wonder if you'll look back one day, and work out if you enjoyed that one. Nerve wracking doesn't even come close I bet. Probably someone has said it already, but I'd suggest smelling the oil and coolant at least, but even though you said 155, you should find most fully synthetic oils will be totally fine between 250~300F. Burning or sour smelling isn't a good sign though. Stay well.
Congrats Peter! I believe you will certainly resolve the cooling issues. Regarding the pitch and roll instability, put fluff on topside of the canard during next flight to see if canard stall is the cause (it looks similar to canard stall). Like others have mentioned, covering the wheel well might be best approach at this time to see if wheel well turbulence is the cause for roll instability, without adding additional tasks like operating the landing gear.
Edit: Peter, after carefully reviewing your first flight, I came to the following conclusions;
1. Approach and descent to runway 04 was very stable (likely due to reduced angle of attack of the canard) unlike departure.
2. 'Bucking' motion or pitch instability restarted again during flare to land (again due to increasing AoA due to reduced airspeed).
3. Moving the CG more forward will like worsen the pitch instability issue because more back pressure will be required to maintain lift which will ultimately cause even more canard stall.
Possible fixes or troubleshooting are as follows;
1. Increasing takeoff speed by additional 20% (this will ensure canard does not stall but may not be an option due to runway length and engine performance).
2. Increase the total surface area of the canard (probably for the production units).
3. Vortex generator will improve canard lift efficiency but may not be enough.
4. Add fixed slats to the canard. (Most likely the better option for this prototype).
WOW! I'm speechless! I expected anything but you in first person to do the very first flying! Congratulations!
I already seen you addressing apparently impossible problems with a strong determination, I'm pretty confident you're gonna solve everything. After all this is the purpose of a prototype.
Hi Peter, firstly congratulations on your first circuit with your craft! Great achievement after all the hours put in. I fly a Velocity 173RG in South Africa (last 17 years). When I fly solo I need to put in at least 20kg of ballast (on copilot side) otherwise my plane also goes into oscillation. I don't think the RG (retracted) will stop the oscillation. Good luck!👍😊
Congratulations, this is the moment we've been waiting for, sorry i didn't follow up last couple of videos , as i had tough time , but I'm good to see the achievement you've done , all the coming modification to sort the issues that arise, will be the fine tuning to the plane , my opinion the bucking motion could be because of both the gear down, and the weather , this is a great experience , and I'm sure next flight will be better when you evaluate all the collected data , every move you make is an add to build the Raptor , and you're doing very well , I'm very curious to see the coming update from the sky... all the best.
I don’t know much about aerodynamics, but I just wanted to say congratulations on a critical milestone reached and overcome! You did a really nice job handling those oscillations in the air. There’s still much to be done, but keep up the excellent work! You should be really proud of yourself. I know a lot of us sure are!
Congratulations my friend. I have enjoyed watching your videos of the buildup to this date. I look froward to your videos of your plane going forward. Should be exciting sir.
Need 2x airflow over the radiator cooling Induction.
Turbos need an independent oil cooling system and routed cooling.
Need to dial in trim settings on both axis in ground effect.
Diagnosis of the pitch and yaw dynamics. I'm sure it's related to the flex in the control system, the springs aren't cutting it. This is causing a inconsistency in the air flow over the main wing.
Nice flight however and congrats on this milestone.
Granted this setup runs two turbos vs the one stock however, this engine already had an oil cooler. It is a coolant to oil heat exchanger. The stock oil cooler may well be able handle the extra thermal load as long as the coolant temps are able to be maintained.
I'm sure the returns from the turbos are well over 600 degrees F. Seeing as they are peaking 1650F during minimal operation. The stand alone oil cooler from the engine was not designed to pull the BTU's from 2 turbos plus an engine.
Even on a cold day at altitude he'll struggle to keep temps down simply due to the flow issue.
An isolated system would eliminate any issues with the main drive component. I could do a thermal analysis on the system but peter would have to pay me for that.
I would work on the induction cooling and increasing the spring load tension in the flap-ailerons 1st if I were him.
@@triedproven9908 From what I remember, he's using two Garrett GTX ball bearing turbochargers. Those turbo's don't pass much oil through the center section, they actually have a restrictor in place in the center section to limit it. You don't need much oil flow in a BB center section compared to a journal bearing one, from my experience I doubt the turbochargers are contributing significantly to oil temps I'd be more worried about the coolant temps, they kept going up and up and seemed pretty high.
Congratulations, Peter! Fantastic achievement!
This is history in the making. Congrats.
Demon Got Me Pretty Amazing - A true First.
Congrats Peter! Keep pushing forward.