RV-7a Nose-Gear Collapse Part 2...

[AlexPeterson]

Originally Posted by bret

I also went the taper pin method, does anyone know if this pin has the same strength as the AN hardware it replaced, it is a larger diameter so maybe stronger?

Bret, if you have an extra taper pin, take a file to it and to an AN bolt. The harder one has a higher tensile strength (not accounting for diameter differences, if they exist). Also important in the taper pin design is that the holes are tapered equally (matching) to the pin, and are complete. One wants both ends of the pin to see the shear equally.

[bret]

I bought all the taper pin hardware from Aircraft Spruce, so I hope it is of the correct grade.......

[BJohnson]

Originally Posted by plehrke

...this gear failure looks different then others as it looks like it failed due to more side loads then the others. The gear is bent to the side as apposed to others are straight aft.

If the bolt sheared, the leg can rotate causing the sideways loading.

As to the gear's durability, doesn't Vlad fly the stock nose gear without any aftermarket bits? If so, given where he has gone with his -9a, that is an huge endorsement for the durability, simplicity and functionality of the stock design when flown right.

[gasman]

In the video it also looks like the old Matco wheel with the bearing spacers that have been known to pinch the bearings during heavy load conditions and cause the nose wheel bind and pull the nose leg under till the front of the fork snagged on the surface of the runway. This, along with a failing bolt due to an improper installation of the stop, could have caused this.

I don't think this situation is entirely pilot error. On the RV6 plans, you had to look really hard to find the one and only sketch of how the stop was to be installed. So I can see how there are many installed wrong...... It just looked right.

The other problem that came along with the RV6 was a change from a Cleveland wheel to a Matco wheel some time before 1998. The problem with that wheel and axle is well documented............. It just proved to be a bad combination.

[Walt]

Just an FYI, I use NAS6605-28 bolts to replace the standard AN5 when I have them out, the NAS is a good deal stronger than the AN counterpart
(160K vs 120K I believe) and it's a few thousands larger which helps make it a tighter fit.

[snopercod]

Originally Posted by snopercod

I'm not getting any audio on your videos. Other YouTube videos work.

I fixed my computer problem. My sound card was set to 5.1 surround and I only have two speakers. I set it to "stereo" and now I can hear the audio along with your video. Previously I could only hear YouTube videos that were encoded in 5.1, but not stereo. Who knew?

[boandrv7a]

Right on... Now you can hear me in all my goofyness...

[339A]

It just so happens that I was cleared to land #2 behind the incident airplane. I've been debating whether or not to give my very brief view of what I witnessed that day...

Let's start with the day before. We attempted to go to Greeley for breakfast, but it was so bad we wound up turning around and headed back to FTG. LLWS was all around us and we saw 40 - 50 kts winds a thousand feet off the ground.

The day of the incident the winds were out of the ENE. (we were using runway 080) I don't recall exactly what they were, but it was starting to get gusty and the winds were picking up (certainly above 15Kts) I headed out to do a few TNG's, I don't have the exact time, but it was somewhere after 10:00 AM.

I had taken off of runway 8 and was in left traffic for a TNG. The tower cleared me #2 after the RV ahead of me. I spotted him on final as I turned base, as I was making my base to final turn he seemed to be about to touch down. Wasn't paying too much attention as I was flying my plane....

The next thing I notice, is the incident aircraft is in a sharp left (90 degree) turn and headed for the grass. At that point, it APPEARED to me that it was still on all three legs. It didn't look like it nosed over till it hit the edge of the runway/grass. By that time I was on the radio to the tower, telling them the RV went off the runway and I was going around. FWIW that's all I saw.

A Photo of the plane being towed.

FTG Bent Gear by Scott Mills, on Flickr

[boandrv7a]

Scott - Thanks for posting that!!! The day before the incident, I was out in the RV doing TnG's (actually did a video on it - https://youtu.be/X3X-ieGvcmk). Was a nice day for that kind of thing! Ugh!

Jim