Peter Anderson
Pre-takeoff checklist
Seemed like it used a ton of runway to get an inch off the ground. I wish them the best! I hope it works out.
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Determining the nosewheel liftoff speed is a standard test. Getting airborne but remaining in ground effect is not. There are people that do it, and maybe even people that recommend it, but I doubt you'll find many, if any, trained and experienced test pilots (not just home-grown) who think it's a good idea.I would expect the real test pilot(s) to do the same thing more than once to get the feel for the plane.
Determining the nosewheel liftoff speed is a standard test. Getting airborne but remaining in ground effect is not. There are people that do it, and maybe even people that recommend it, but I doubt you'll find many, if any, trained and experienced test pilots (not just home-grown) who think it's a good idea.
Nauga,
practically
AC90-89B has some suggestions that are a good starting point. Hopefully you've got some estimate of stall speed in the configurations you plan to fly (weight, CG, flap settings, etc) - rotate at some multiple of stall speed (presumably above NWLO speed ), climb at some higher speed, also a multiple of stall speed, and get to an altitude where you've got time and options for sorting out the handling and issues without running out of runway. In early testing I have always added some margin above the expected operational speeds just in case stall speed and other performance predictions are off, then work down to operational numbers in testing.Whats the preferred method after you know nosewheel liftoff speed? Just rotate normally and fly it?
I didn't mean to get airborne and remain in ground effect, but rather to do just what was shown in this video: reach flying speed, throttle back, and lift the nose so the plane leaves the ground but can't stay off it for long. Vaughan Askue's "The New Flight Testing Homebuilt Aircraft" book is well-regarded and recommends this type of "landbacks" after taxi testing. I'm not a test pilot; at least not yet. Glad to have your perspective on the subject.Determining the nosewheel liftoff speed is a standard test. Getting airborne but remaining in ground effect is not. There are people that do it, and maybe even people that recommend it, but I doubt you'll find many, if any, trained and experienced test pilots (not just home-grown) who think it's a good idea.
I'm not the first one to suggest it, but I believe that after performing preliminary evaluations of the aircraft's flight characteristics, his test pilots will refuse to fly the airplane.
Except that to evaluate flight characteristics one must first achieve flight.I'm not the first one to suggest it, but I believe that after performing preliminary evaluations of the aircraft's flight characteristics, his test pilots will refuse to fly the airplane.
That’s been the case so far.
Except that to evaluate flight characteristics one must first achieve flight.
Yep. This will be the test pilots' third trip to evaluate and possibly test fly this project. Yesterday, I visited the field where the project is based. It is about 20 miles from my home field. It is a terrible location for the first flight of this airplane. It is on top of a hill (the over-runs on both ends are nasty drops), is just over 5,000', and this is a heavy airplane with a high takeoff and landing speed. Add to that the questionable engine/drivetrain and the fact that the whole area is covered in pine forests (there are very few suitable off-airport landing sites). Test flying this airplane will be a really sketchy proposition.
Yep, did my ME there. Nothing really suitable around there for off airport. I fly past on a regular basis for work but I’ve yet to see him out taxiing yet. He must keep it inside most of the time.
At least the pine trees are a bit softer than a field of oak trees, lol.The first flight (assuming it is successful) should be a climb over the airport to 10,000' then head direct Cartersville (or Calhoun), then direct Rome. Nice 6,000' field at Rome with great over-runs and lots of nearby pastureland. I'm betting this thing ends its flying time in a field or ditch somewhere. Not that I'm pulling against them, but I do not think the powertrain is properly conceived/implemented. So they need to relocate to a friendlier location for an off-airport landing.
I did my first night landing and takeoff there. On the takeoff, once the we lifted off, we were IMC. There was nothing but black outside the windshield.Yep, did my ME there. Nothing really suitable around there for off airport. I fly past on a regular basis for work but I’ve yet to see him out taxiing yet. He must keep it inside most of the time.
I go between loving and hating this guy. I love the desire to create something new and achieve his vision. I hate that he's doing it in the manner he is. Give people your drawings and wishlist and get some legit engineers and experts to help
Spot on. I both admire his tenacity and drive to make something despite the naysayers; but cringe at much of the approach he employs to engineering approach for problem solving.
The Raptor's interior fit & finish looks superb. I was recently in Van RV-10 factory demonstrator and Raptor's interior fit & finish looks nicer. Doesn't mean the plane will fly better or at all.
thats because van builds every airplane with a hard rule, build it strong, but build it light. fancy interiors look good but add wasted pounds.
as to test pilots walking, if elliot walks he will not find anybody crazy enough to test fly it. elliot has flown a lot of aircraft that others have said no way!
I have no argument with anything you stated above. 100% agree. The point was not fancy verses not-fancy interiors. The point was the one skill Peter the Raptor guy has is fit & finish. The Van's factory RV-10 Demo plane I was in, had a cosmetically malformed composite right side window pillar. I was told this was their very first RV-10 plane that flew. The fitment & craftsmanship as a first attempt showed, as one might expect from a factory prototype.
Peter from Raptor might be a very good builder or build supervisor, but not such good engineer?
Peter has missed the point. He's spent time on the beautiful interior, air conditioning, pressurization system, fancy panel, and probably a few other things which don't matter on a prototype. His focus needed to be on getting the airframe and engine right, and he's missed the mark there. The airframe is a thousand pounds overweight, the control systems are a mess, and there are some serious problems in his engine/PSRU combination. Basically, he seems to have built an airplane that looks good and has lots of bells and whistles, but isn't going to do the flying part very well.
I'm not as concerned about the prop clearance vs. gear flex and uneven surfaces. The gear is probably flexed to its limit already, given all the stuff piled into the plane's empty weight. And it won't ever reach Vr on an uneven surface, given that it apparently needs a few thousand feet of smooth pavement to reach Vr.There were a few videos that stood out to me
(A) his control cables have (had?) a lot of slack, that was the result of some pullies just appearing to be randomly bonded to the bottom of the "floor" somewhere, not affixed to any strengthend stringer or rib
(B) the plane nearly shook itself apart with an obscene flutter after taxiing a little faster than normal, resulting in gear damage.. his answer to fix was some awful aerodynamic guesswork and dubious control surfacing balancing methods
(C) his answer to some viewer questions about prop clearance was to just measure the distance from the prop to the ground, without any real apparent consideration for differences in loading, "flex" in the gear, uneven surfaces, grass, etc
It's funny because it's true.I'm not as concerned about the prop clearance vs. gear flex and uneven surfaces. The gear is probably flexed to its limit already, given all the stuff piled into the plane's empty weight. And it won't ever reach Vr on an uneven surface, given that it apparently needs a few thousand feet of smooth pavement to reach Vr.
The Raptor's interior fit & finish looks superb. I was recently in Van RV-10 factory demonstrator and Raptor's interior fit & finish looks nicer. Doesn't mean the plane will fly better or at all.
The first flight (assuming it is successful) should be a climb over the airport to 10,000' then head direct Cartersville (or Calhoun), then direct Rome. Nice 6,000' field at Rome with great over-runs and lots of nearby pastureland. I'm betting this thing ends its flying time in a field or ditch somewhere. Not that I'm pulling against them, but I do not think the powertrain is properly conceived/implemented. So they need to relocate to a friendlier location for an off-airport landing.
Looks like the test flight crew agrees with this sentiment. They have apparently headed back to California after rejecting Cherokee County as a suitable test flying location for this aircraft.
I have to say that I am not impressed with the professionalism of the flight crew. It seems they could have addressed that on day 1.
I have to say that I am not impressed with the professionalism of the flight crew. It seems they could have addressed that on day 1.
Just wondering if the test flight crew's risk profile perceptions have changed with a closer look, and determined the surrounding emergency landing terrain was no longer suitable. Another thought, their reason could be part of a professional courtesy to walk away from a dangerous situation, but condemn or trash the builder or design.
Just thinking about it, few would hire a given crew if they condemn a concerning situation on the way out the door. In my business, we walk away for an ancillary reason and not the core which would condemn the program not allowing a change of course. [...]
I can see how this could be a possibility, but then again they've already been playing this game for a while now. There have already been several items of which I thought were so obvious that they could have told him even before their first visit that they want them fixed.
I think that putting this Audi Diesel engine on it was a very poor choice and certainly would not want to fly an aircraft with such a high landing speed with it, independent of whether there are subtitle emergency landing areas nearby. Then again, neither the engine nor the airport location have been a surprise for the Wasabi guys.
I'm not impressed by Wasabi. In my opinion, it is an indication of poor character to play such games with this guy who most likely invested his entire life's savings plus some more into this business. Keep in mind, that all the down payments are in an escrow and not accessible to him!