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Turd Ferguson

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Just out of curiosity, I searched the NTSB aviation database from Jan 1, 2020 until today. Search parameters were Rutan, LongEz, Varieze, etc. Only one accident and that was a forced landing due to fuel starvation/exhaustion. I guess they decided to discontinue 'unexplained loss of control crashes' this yr......

So I searched back to Jan 1, 2000, ~21 yrs. Same results. Not sure where these Rutans are that keep having unexplained loss of control crashes.
 

Marc Zeitlin

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You mean like the Rutans which keep having unexplained loss of control crashes?
When you don't know what you're talking about, you really should keep your mouth shut (but DK will prevent that, I'm sure). I've asked before and had zero response from you - to what "unexplained loss of control crashes" are you referring? Point me to some, please, preferably NTSB reports, or even just a web description of a "unexplained" crash. VE, LE, COZY, Berkut, E-Racer, Velocity - don't care. Point me to the crashes to which you continue to refer.

You also continue to conflate multiple factors. There is no "instability" or "divergence" in Rutan canard configuration aircraft _IF_ the CG is in the right place (within the approved range). All the above listed Rutan derivative canard aircraft are stable in pitch with appropriate CG's.

_IF_ Peter is finding that he needs to push after the pull on takeoff, that's a completely consistent behavior with canard aircraft - it's just that PM has no clue how to FLY canard aircraft, as he's had no training. I've transitioned 15 - 20 people into canards, and one of the two main things that I need to beat into them is that they will need to pull to get the nose off the ground, then they need to RELAX back pressure (NOT push, as that will induce PIO's) to maintain the appropriate AOA. Generally, it takes 3 - 5 takeoffs before people get the feel for it. My son, who is not a pilot, was able to get the feel last week after doing two or three takeoffs.

Someone training themselves, particularly when they don't even know what they're looking for or what to expect, should be expected to do poorly at this and misinterpret what's going on. THIS is not a fault of the airplane.
 

BBerson

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I think he is now pulling it off and relaxing back pressure much like any tricycle gear airplane.
I watched the canard last flight, he popped it off then relaxed and held it a few feet above the runway.
 

Wanttaja

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You mean like the Rutans which keep having unexplained loss of control crashes?
Funny, my ears were burning.

I took a look at my 1998-2018 database of homebuilt aircraft accidents. Out of 4,230 accidents, I show 61 cases of unknown loss of control, as well as 57 cases where the NTSB was unable to determine the reason for the accident.

Looking at just Rutan Long-Ez, I've got 51 total accidents. None of those fell into my "Unknown Loss of Control" category. Only one of the accidents fell into the "Cause Undetermined" category:

"The pilot/builder of the experimental amateur-built airplane was flying in the number two position in a flight of three airplanes. Radar data identified the airplane flying about 1.5 nautical miles (nm) behind the lead airplane and about 4 nm ahead of the number three airplane. As they approached their destination, the pilot of the lead airplane asked for a radio frequency change to the destination airport’s common traffic advisory frequency. The accident pilot and the pilot of the number three airplane acknowledged this request. However, the accident pilot never checked in on the new frequency. Radar data at this point identified the airplane in a straight cruise ground track at an altitude of about 500 feet over flat desert terrain. The wreckage was located almost directly beneath the last radar data point. Vegetation and soil disturbance at the initial impact point suggested that the airplane was in a 25-to-30-degree right bank and 15-to-25-degree nose-low pitch attitude at impact. Autopsy and toxicological testing of the pilot revealed no evidence of impairment or incapacitation. Postaccident examination of the engine and airframe revealed no evidence of mechanical malfunction or failure that would have precluded normal operation. The investigation was unable to determine why the pilot failed to maintain control of the airplane." (WPR11FA429)

The pilot was the original builder of the airplane, and he'd been flying it for about ten years.

Ron Wanttaja
 

Marc Zeitlin

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Looking at just Rutan Long-Ez, I've got 51 total accidents. None of those fell into my "Unknown Loss of Control" category. Only one of the accidents fell into the "Cause Undetermined" category:
The accident you reference occurred during the Kanab, UT fly-in for canards a few years back - I was there, but did not participate in the fly-out to Bryce Canyon that day.

The plane did not have an "unexplained loss of control", as you point out that the airplane contacted the ground in a manner that is consistent with the pilot letting go of the controls and allowing the laterally unstable aircraft (as most high performance aircraft are) start a slow roll and descent into the ground. While the autopsy/tox report didn't show anything, the belief in the community was that it was a medical impairment of some sort that prevented the pilot from continuing to control the plane, as there was nothing known to be wrong with the plane, and the pilot had been flying it safely for 10 years. Occam's Razor, and all that.

There's another "loss of control" accident with Jack Morrison's heavily modified 2nd E-Racer on (I believe) his first flight. The plane had engine issues and Jack told the tower he was coming back in to land. The plane then started a slow roll/dive into the ground and Jack was killed. Folks that knew him stated that he had serious medical difficulties, as well as arm trouble and should not have been in the plane, so the belief is (again) that the crash was caused by medical issues that prevented the pilot from controlling the plane.

There was one Long-EZ breakup in Mexico many years back when a pilot without O2 attempted to climb to over 18K ft. to get over some convective weather (the others in the flight turned back). The plane broke up in a dive and the pieces were found in the Gulf of California - the assumption was hypoxia and LOC, followed by an uncontrolled dive and unplanned disassembly in the air.

None of the three were in any way caused by pitch instability, divergence (whatever DZ means by that), deep stall, or any other aerodynamic quality of the airplane other than the inability to land itself when the pilot isn't flying the plane.

None of this, of course, says diddly about the Raptor, which is a new design with unknown characteristics, but which should be reasonably similar in flying qualities to Velocities.
 

rbarnes

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Just watched the latest vid. Pretty well established now that the plane flies reasonable straight and is controllable, and requires a 3,000' !!!! ground roll with 1 person and 12 gallons of gas on board. That might be a problem...
 

Marc Zeitlin

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Just watched the latest vid. Pretty well established now that the plane flies reasonable straight and is controllable...
Not unexpected. It seemed to require a fair amount of aileron deflection to maintain wings level, so it's probable that the left wing is at a slightly higher angle of incidence than the right wing (left aileron up when level). This is not unknown with canards - a fair percentage require shimming of a wing after the first few flights to get into trim, and then fairing in the strake to match. My COZY MKIV did, by about 0.4 degrees, and I've advised numerous others on how to fix an out of trim issue. Gurney flaps can work reasonably well outboard of the ailerons as well. The pitch oscillations will decrease as PM becomes more familiar with the plane.

This is in no way an endorsement of PM being the primary test pilot, or of the plane as a whole.

and requires a 3,000' !!!! ground roll with 1 person and 12 gallons of gas on board. That might be a problem...
How many people and how much gas it's got on board is not germane - what's important is how close the plane is to MGW. Given the empty weight, with Peter (at, I'm guessing, about 160 lb) and 72 lb. of gas, he's at somewhere around 93 - 95% of MGW. That's AWFULLY high to be starting testing - there's no margin.

My plane (COZY MKIV), at sea level, MGW, full forward CG, and DA of about 1000 ft. (Fitchburg, MA in early August) required about 3000 ft. of runway to break ground at about 80 KIAS. At 75% of POH MGW (70% of MY MGW), DA of 1000 ft, almost aft CG limit, my takeoff roll is about 1500 ft. at about 75 KIAS. Lots of factors affect takeoff in canards, not the least of which is CG position - somewhat less so, GW. I have no clue at what % CG Raptor is being flown (nor do we yet know what the CG range should be).

And as a reference, at aft CG, 95% of MGW, DA of 10,000 ft. (yes, that's 10K ft DA - Durango, CO, lunchtime, middle of August) we took about 4500 - 5K ft. to rotate - no freaking power, and no freaking lift :). But the runway is 10K ft long, so it was fine. On the other hand, at SL on a standard day, lightweight (65% MGW), I'm off the ground in 1000 ft at 70 - 75 KIAS. Gotta know your plane.
 

BBerson

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I was looking at the Cozy MKIV on wiki. Was about 2000 gross weight and 180hp and 83 sq.ft. wing area.
So a future Raptor could be gross weight 4000 and 360hp and 166 sq.ft for a crude comparison?
 

Doggzilla

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Just off the top of my head there have been two different unexplained fatalities since this thread began. One with a loss of control crash in the pattern, and another where an experienced canard pilot crashed taking an aircraft home after a purchase. And one of the pilots who flew the same model confirmed that controls were very touchy in the vertical compared to other canards.

You will know if you’ve found the first case because it was supposed to be an airbrake test and Burt Rutan himself was brought in to investigate but was unable to determine the cause.
 

Wanttaja

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I checked my 1998-2018 NTSB accident database for accidents attributed to ANY Rutan aircraft for Loss of Control for Unknown Reasons. Didn't find any. If my process is bad, I want to correct it. Please post the NTSB numbers or provide dates.

I did find two associated with canard designs other than those produced by Rutan.

MIA08LA152 involved a Velocity 173RG. "According to witnesses, after becoming airborne and reaching approximately 50 feet above ground level the airplane's engine began to surge. The airplane then entered a bank to the left and impacted a marshy area, producing a debris path approximately 100 feet long. The main wreckage came to rest with the engine partially submerged. All major structural components and flight control surfaces were accounted for at the scene; however, flight control continuity could not be confirmed because of impact damage. Postaccident examination of the airframe and engine identified no anomalies that would produce engine surges or a loss of control. "

However, this involves an aircraft with obvious mechanical issues (engine surging). It also was a sales flight for a potential buyer; not far-fetched that the pilot may have responded to the problems incorrectly.

LAX06LA141 was a Velocity XL. However, it was under flight test and was being operated with the CG aft of the recommended limit. Again, though, we're looking at problems that apparently began with engine issues. "One witness, who was also a pilot, stated that when he initially spotted the airplane it was fairly high. As the airplane approached his location, he began to hear the engine sputter; it would momentarily stop for several seconds and then start again. The engine continued the sputtering pattern and the airplane began a clockwise spiral. As the engine continued to sputter, the airplane completed two full 360-degree revolutions (spirals) while descending. During the third revolution, the airplane maneuvered into a wings level configuration and descended toward terrain. The airplane disappeared from the witness's line of sight but he subsequently observed black smoke; he could no longer hear engine noise. "

This case had an experienced pilot (4500 hours) but he only had six hours in type. Was being operated by Raytheon. Velocity Aircraft confirmed the CG was out of the recommended range, but said the plane should have still been controllable.

Ron Wanttaja
 
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wsimpso1

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Just off the top of my head there have been two different unexplained fatalities since this thread began. One with a loss of control crash in the pattern, and another where an experienced canard pilot crashed taking an aircraft home after a purchase. And one of the pilots who flew the same model confirmed that controls were very touchy in the vertical compared to other canards.

You will know if you’ve found the first case because it was supposed to be an airbrake test and Burt Rutan himself was brought in to investigate but was unable to determine the cause.
Citation needed. You know which incidents you are talking about: please cite verifiable N-numbers, dates and locations, NTSB reports, etc.
 

Marc Zeitlin

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I was looking at the Cozy MKIV on wiki. Was about 2000 gross weight and 180hp and 83 sq.ft. wing area.
So a future Raptor could be gross weight 4000 and 360hp and 166 sq.ft for a crude comparison?
The MAIN wing area is somewhere around 85 sq-ft, but the total wing area (with canard and strakes) is generally considered to be about 101 sq-ft. See:


If you want to scale power to weight and wing loading, then yeah - your #'s are in the right ballpark, with the correction for total wing area.

_MY_ plane's MGW is 2175 lb, but I've only ever flown there a couple of times. I'm 99% of the time below 2100 lb.
 

pictsidhe

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Empty weight, gross weight, wing area, ho, cruise speed. All numbers from Wikipedia, even the fantasy performance numbers for the Raptor.
Long EZ 710 1325 115 144
Cozy IV 1050 2050 88 180 220
Velocity XL 1700 2700 102 310 240
Raptor 3144 3800 167 300 350

Hmm, the Raptor will leave a Velocity in the dust.
I wonder if in this world, it would be able to keep up with a long EZ? It has a very similar payload.
 
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BBerson

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If you want to scale power to weight and wing loading, then yeah - your #'s are in the right ballpark, with the correction for total wing area.
So your gross wing loading is 20.2 pounds per sq. ft.
If Raptor was similar it should have similar takeoff. I never had more than 13 pounds wing loading in my Cherokee, so it seems high to me, but normal for these types.
Regarding the excess weight consider the Raptor prototype apparently has all the options, so fully equipped. Some four seaters are two seaters with all the options. It's common to advertise in specs and flight manuals empty weights far below what owners choose. As you said, gross weight is what counts. So he has an optional total aircraft parachute. I couldn't find a weight for the Cirrus chute system, perhaps 100 pounds?? Some interesting and tragic reading about the Cirrus chute: Scott D. Anderson - Wikipedia
Raptor could be significantly closer to competition weight without the chute and A/C and a few other options.
 
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