Service Bulletins 19-08-26 and 16-05-23 Published - Nose gear leg and fork

[gblwy]

I know I'm late to the party, but I now have a broken noseleg, and subsequently a broken aeroplane.

My flying partner had a bounced landing, and the noseleg broke right off near the midpoint. There's no obvious indication that fairing screwholes in the leg had anything to do with it.

However, looking at the break it appears there may have been a pre-existing crack running in an arc around the circumference. I'm no expert, and the UK Air Accident Investigation Branch have requested material from either side of the break to undertake their own investigation. I cut off a slice either side of the break which they now have. I'll be interested in the outcome, bearing in mind the discussions above.

This was the original noseleg with 600 hours. I'm not aware of any previous hard landing which may have initiated a crack. At the annual inspection three months previous to the accident I removed the noseleg fairing to examine the leg, but didn't notice anything untoward.

Treat the noseleg with respect, especially if you are still awaiting an updated one! Everything forward of the step bulkhead is now scrap - including the step bulkhead itself unfortunately - so wiring, brake lines, rudder cables, and static line all have to come out prior to installing new parts.

[Piper J3]

Originally Posted by gblwy

Treat the noseleg with respect, especially if you are still awaiting an updated one! Everything forward of the step bulkhead is now scrap - including the step bulkhead itself unfortunately - so wiring, brake lines, rudder cables, and static line all have to come out prior to installing new parts.

Can you share a photo of the broken part?

[gblwy]

Try this, I forget how to post pics. I suspect the brown patch (see top half of the first pic) may illustrate the extent of a possible crack. I think this was the bit that remained with the wheel. The lower part of the first pic is the bit attached to the firewall. It happened on a grass strip, so this lower shot may just be mud.

https://www.dropbox.com/s/ovo6t5p0so...seleg.jpg?dl=0


https://www.dropbox.com/s/w88li8rfed...rward.jpg?dl=0

[PilotBrent]

Bottom skin is damaged which I think is one large piece. Maybe rebuilding the entire fuselage section is more straightforward way to go. Might be easier than trying to match some of the new with existing parts. Either way, very sorry you are facing this.

[gblwy]

I've ordered all the forward fuselage parts, cowling parts, step bulkhead and both side skins - and numerous other smaller parts. All three firewall sections are bent as is the floor, the instrument panel base and tunnel. The tunnel walls pushed back and damaged the step bulkhead. Aft of that looks OK. Parts availability is the issue, I reckon I can "just" replace all bent bits.

[Piper J3]

I wonder if this is first RV-12 nose gear to break in that location. The new revised strut has a secondary tube welded inside at the radius bend leading into the lower mounting flange. Wouldn't help in this instance.

Maybe Van's will chime in. Hoping not another SB...

[rvbuilder2002]

Any part of any airplane can be broken if the loads the part was designed for are exceeded.
The damage in these photos looks very similar to other RV-12’s whose nose gear has made an uncontrolled abnormal contact with the ground.
If the leg is stabbed into the ground a sufficient amount, the inertial mass of the airplane causes the hollow leg to fold because of the overload. Sharply folding the tube causes it fracture at the fold.
The damage visible on the fwd fuselage is also similar to others I have seen though maybe a bit worse.
Unfortunate, but very repairable.
Like you said, just replace any parts that are bent, and fortunately, with the way the RV-12 is constructed, that is a much simpler process than i would be on many other aircraft..

[RFSchaller]

Bummer, Keith. I hope you’re back in the air soon.

[NinerBikes]

Originally Posted by rvbuilder2002

Any part of any airplane can be broken if the loads the part was designed for are exceeded.
The damage in these photos looks very similar to other RV-12’s whose nose gear has made an uncontrolled abnormal contact with the ground.
If the leg is stabbed into the ground a sufficient amount, the inertial mass of the airplane causes the hollow leg to fold because of the overload. Sharply folding the tube causes it fracture at the fold.
The damage visible on the fwd fuselage is also similar to others I have seen though maybe a bit worse.
Unfortunate, but very repairable.
Like you said, just replace any parts that are bent, and fortunately, with the way the RV-12 is constructed, that is a much simpler process than i would be on many other aircraft..

To the extent of the damage observed, would the newer reinforced landing leg have made any difference in the resultant damage, in your expert opinion, Scott? Or was this just a really hard landing or a possible nose first landing, instead of main gear.

[rvbuilder2002]

Originally Posted by NinerBikes

would the newer reinforced landing leg have made any difference in the resultant damage

Probably not.

The re-enforcement and other changes to the leg are quite a distance away from where the leg folded and broke.