RV7 Scary sequence of photos

TangoWhiskey

TangoWhiskey

Touchdown! Greaser!
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3Green
Yikes! The RV Hotline http://www.expercraft.com/hotline/current was in my
eMail box this morning. There is a story in it about a UK RV-7A that had photos taken WHILE it was NOSING OVER. There were no injuries reported in the story.

A link to the story.
http://www.pprune.org/forums/showthread.php?t=279412

Here are the photos taken while it was flipping.

http://www.airteamimages.com/49328.html

http://www.airteamimages.com/49329.html

http://www.airteamimages.com/49330.html

http://www.airteamimages.com/49331.html

Video of the same event.

http://www.youtube.com/watch?v=NfaCGc16jQ0

Somebody had a fast shutter on the still photo sequence.
 
Wow! Just glad everyone is OK.
 
bbchien said:
Yowse! Tiny wheels and turf!
Click to expand...

No an uncommon problem with the RV7A. Not a defect, but they can and do nose over. I dream of building one of those one day - I am leaning towards the 7 (tailwheel model) just because I want that kind of flying (landing actually LOL). I hope that roll bar hieght is adequate in that kind of situation, but those folks got out okay.
 
PeteJE said:
No an uncommon problem with the RV7A. Not a defect, but they can and do nose over. I dream of building one of those one day - I am leaning towards the 7 (tailwheel model) just because I want that kind of flying (landing actually LOL). I hope that roll bar hieght is adequate in that kind of situation, but those folks got out okay.
Click to expand...

Most nose-over's in the -xA's of the RV's are caused by poorly inflated nosewheel tire rubbing the side of the nosewheel pant, causing the tire to 'lock up', leading to a nose-over. The problem is that the hole in the bottom of the wheelpant where the tire comes through is actually cut to size by the builder. Some builders try to squeeze by with the smallest hole possible to decrease drag. Once stories of this problem starting coming out, we actually went back and made the hole a little bigger. So far, no problems.

I notice in the pictures that this plane actually had the nosewheel pant removed for some reason, so obviously this wasn't the problem here. I haven't watched the video yet, but if he was indeed taxiing too fast and if he has a IO-360 hanging on the front, that's a lot of weight to be bouncing on the spindly nose-gear leg that comes with the kit.
 
I've seen several -6A's and -7A's exhibit excessive nosewheel shimmy on paved runways...I guess they weren't holding the nose off long enough after touchdown...:dunno:
 
I think the speed at time of incident might be underestimated ...
 
10-15 mph my ass! Sorry...not trying to be confrontational but there is no freaking way 10 mph is going to flip a plane, not even an RV. The vid shows them going MUCH faster than that.
 
tdager said:
10-15 mph my ass! Sorry...not trying to be confrontational but there is no freaking way 10 mph is going to flip a plane, not even an RV. The vid shows them going MUCH faster than that.
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I don't think the speed really matters. The nosewheel collapsed. I could see 10 mph flipping an airplane if it bit into the grass just right. The prop is going to dig in hard and will have some torque to it.

It doesn't look like they did anything too terrible pilot wise other then have too weak of a nosewheel.

I wouldn't pay any attention to the speed on the video. It was recorded with a cell phone which is likely out of sync with realtime.
 
If you watch the video carefully, you can see the tail dip down (nose goes up) and then immediately snap back up (nose goes back down) about 20ft or so before the flip. It also appears that the nose gear folds up and the plane still moves forward a bit before actually flipping over.
 
Yet another possibility is that he got on the brakes too hard. RV's will nose-dip pretty good if you hit the brakes too hard on roll-out. That nose gear leg is fairly flimsy. In the video, he *looks* like he's fairly fast on roll-out, but this could be a visual miscue due to poor video. If he's rolling pretty fast and his the brakes hard enough, combined with inherent roughness of a grass runway, I could definitely see the front gear leg collapsing.

The pilot is the only one that really knows what control inputs caused this. Only time will tell as to whether or not he comes 'out' with info.

EDIT: Just read the later-posted link: Appears that 'braking' was mentioned by the pilot in the write-up. One 'good' thing about RV's is that the elevator maintains authority at very low speeds. If he's pulling back to keep weight off the nose too early, it could definitely pull the nose off the ground, followed by heavy "OH CRAP" braking, and wham.. there she goes.
 
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man i was looking today and they got a whole sub-forum at vansairforce about this subject. seems to me the best bet is to just go with the straight 7. seems the 7A is just as or more susceptible to nose overs.

Plus, Leah says that "taildraggers look cooler" :D
 
CJones said:
Most nose-over's in the -xA's of the RV's are caused by poorly inflated nosewheel tire rubbing the side of the nosewheel pant, causing the tire to 'lock up', leading to a nose-over. The problem is that the hole in the bottom of the wheelpant where the tire comes through is actually cut to size by the builder. Some builders try to squeeze by with the smallest hole possible to decrease drag. Once stories of this problem starting coming out, we actually went back and made the hole a little bigger. So far, no problems.

I notice in the pictures that this plane actually had the nosewheel pant removed for some reason, so obviously this wasn't the problem here. I haven't watched the video yet, but if he was indeed taxiing too fast and if he has a IO-360 hanging on the front, that's a lot of weight to be bouncing on the spindly nose-gear leg that comes with the kit.
Click to expand...

Was kind of hard to tell, but it looked like the gear collapsed at the caster, or the caster broke, and it dug in and pole vaulted. At least they got one nice picture of it before they wrecked it. At the speed it was going when it vaulted though, they should have still had the nose off the ground or at least light. My call, poor pilot technique has had a cumulative effect which finally caused the nose gear to fail, I could be wrong....
 
Henning said:
Was kind of hard to tell, but it looked like the gear collapsed at the caster, or the caster broke, and it dug in and pole vaulted. At least they got one nice picture of it before they wrecked it. At the speed it was going when it vaulted though, they should have still had the nose off the ground or at least light. My call, poor pilot technique has had a cumulative effect which finally caused the nose gear to fail, I could be wrong....
Click to expand...

That's what I was thinking, too. Seems like they were really screaming down the runway - especially in an RV. I can keep the nose off the ground in -7DL REALLY slow. There isn't an aerial shot of how far down the runway the actual flip took place. Could be possible they landed really hot, tried to save it with a combination of brakes and 'up' elevator. Too much speed would pull the nose off the ground for a bit, combined with heavy braking causing the nose to come back down hard and 'snap'.
 
Shame though. What a beautiful plane.
 
Wellp.. Looks as though the nose-wheel pant has both pros and cons on grass runways. It's come up in the RV 'circles' that, even though improper trimming around the wheel can cause problems, it can also act as a skid plate if the gear leg is bent backward far enough. It's obvious in the pre-flip pics that the wheel pant was removed for some reason.
 
so either way, the nosewheel is the problem :)
 
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