RVbySDI
Well Known Member
The photos are very high quality but the sequence has too many gaps in it to adequately make determinations on cause. The video posted on YouTube is indeed more revealing in terms of sequence but the poor quality does not lend itself for examining much detail.koda2 said:As the builder of '96 (older) -6A, the photographs of the 7A tipping over are distressing. I could not find the video but here is what I see from the 4 photos.
The a/c is a later RV-7A which should have the upgraded nose gear leg and looks like it has the later nose fork.
A number of factors show that it was traveling at a very low groundspeed, i.e. multiple reference points in the photos, the way the props are bent, the proximity of the initial prop strike in the sod and final resting point, the fact that at the second photo both occupants have already braced themselves for impact, and that the impact vectors are almost completely vertical, being absorbed mostly by the dome of the canopy, which appears to have broken, and the roll bar, which did not fail, and which forced the longerons and fuselage skin to crumple. Furthermore, there is no apparent subsequent disturbed ground and the rudder position has not changed, which it should have, after impacting if the plane had slid. Also the primary point of failure appears to be the nose gear leg at a point just above the fork since it is bent a full 90 degrees aft, but the rest is not visible. So, my best guess is, the aircraft was taxiing at a relatively slow speed, was arrested by the sudden stoppage of the nose gear, and flipped over.
In looking at both the photos and the video I would say that contrary to koda2's postulation, the video shows the aircraft to be traveling at a very high rate of speed at the moment of flip over. My estimate is approximately 40 mph. The video does not reveal whether it was landing or taking off but it was at the arrival/departure end of the runway moving at this high rate of speed. Because of this I would speculate from watching the video that it was landing and on roll out.
If one looks closely at the video there is a point just before the flip over when the nose dips downward drastically. I believe this was the point of the nose gear contacting the ground and the start of the failure. The quality of the video is too poor to see any detail at that point but the sequence does suggest that there was an instantaneous contact of the nose gear to the ground and an instant later the flip over occurs. It would be very helpful to have a higher quality video to examine and to have eyewitnesses report on this. Ultimately, it would be beneficial to have the pilot report but until any of these occur we are just speculating a great deal on limited information.
I am glad the occupants are safe. I hope they can recover from this incident and can continue to enjoy flying again in the future.
Live long and prosper!