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My Poor -6. Engine mount broken in 3 places...

Ben R

Well Known Member
I posted a similar thread in the classifieds explaining why I was looking for a mount...hope I'm not breaking the rules but I wanted to share with everyone else what happened to me yesterday.

I had just began taxiing from my hanger yesterday when my -6 came to an abrupt stop in the grass not 15 feet from the hanger apron. I got out to see what was going on and my left tire was stuck in a very small hole (just big enough for the tire to fit into). My landing gear was bent rearward. I removed the cowling to find that the engine mount was broken in 3 places at the gear attach fitting. I was taxiing at a walking speed since I had just left the hanger. The grass had been recently mowed and I never saw the hole. It was so shallow that the wheel pant wasn't even damaged. I would imagine that there were some hairline cracks in the mount and this was the straw that broke the camel's back, but I can't say for sure. I've never landed the plane hard but I am the third owner.

I've owned the plane for about a month now and it tears me up that its going to be grounded for a while. I'm hoping Van's still sells the mount as I don't think this one could be repaired. I've posted some pics (maybe I did it right).
RecentlyUpdated


The moral of the story...be sure and take a few extra minutes to inspect your mount anytime the cowling is off (a hard lesson learned for me). If this had happened on the runway while landing, the end result would have likely been very different.
 
Ben, I am curious if you had a pre buy inspection on the aircraft. Was it operated on a grass strip in a previous life?

George
 
George,

I'm sorry to say that I didn't have a thorough pre-buy done on the plane (yet another lesson).

It had been operated on a grass strip for several years but it was pretty smooth.
 
I posted a similar thread in the classifieds explaining why I was looking for a mount...hope I'm not breaking the rules but I wanted to share with everyone else what happened to me yesterday.

I had just began taxiing from my hanger yesterday when my -6 came to an abrupt stop in the grass not 15 feet from the hanger apron. I got out to see what was going on and my left tire was stuck in a very small hole (just big enough for the tire to fit into). My landing gear was bent rearward. I removed the cowling to find that the engine mount was broken in 3 places at the gear attach fitting. I was taxiing at a walking speed since I had just left the hanger. The grass had been recently mowed and I never saw the hole. It was so shallow that the wheel pant wasn't even damaged. I would imagine that there were some hairline cracks in the mount and this was the straw that broke the camel's back, but I can't say for sure. I've never landed the plane hard but I am the third owner.

I've owned the plane for about a month now and it tears me up that its going to be grounded for a while. I'm hoping Van's still sells the mount as I don't think this one could be repaired. I've posted some pics (maybe I did it right).
RecentlyUpdated


The moral of the story...be sure and take a few extra minutes to inspect your mount anytime the cowling is off (a hard lesson learned for me). If this had happened on the runway while landing, the end result would have likely been very different.

Ben

Sorry about the misfortune with your "new" plane. Yes, it is likely cracks had been present in the mount for some time, and I suspect that mount had seen some hard days.

Vans should still have the mount in their inventory since they still offer finish kits for the -6. Your mount can probably be repaired by either a good craftsman or Vans' mount vendor. Give Vans a call and they will point you in the right direction.
 
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Thanks Sam. I'm going to give Vans a call in the morning and see what I can come up with.
 
Hi Ben

Sorry to hear about your problems, hopefully you can get a new engine mount soon.

Here in the UK we operate from 'rough grass' a lot. This has caused a few cracked engine mounts. So a modification has been developed where a metal filler is welded into the engine mount to add strength. My -6 had it done over 10 years ago, i know lots of -6 & -7's with the modification. if you search here, and on google for 'Netherhorpe mod' you will find details and pics. It my be worth considering for your next engine mount.

Good luck

Mark Turner
 
Ben, as much as that does suck, I would look at it on the bright side. It could have happened at worse time. Like during a landing!
 
Experimental Aircraft Metal Fabrication. Van's will send you directly to them if you want to ask about repair or if you need to have your new mount match-drilled to your existing gear legs.I dealt with them when I folded my nose gear last year; they were great. It took a few weeks to get the mount (my sense is that they do a steady business with Van's and slide you into their schedule) but it was perfect. I was lucky because my original mount was one of theirs, so the new mount bolted right in. It's my understanding that earlier mounts came from a supplier that did not jig them for welding and so there is some slight variation. AZTAILWIND encountered this a few years ago when replacing his mount; the bolt holes were slightly off. But when I raised the question, they said they could help since I was sending them my old mount to be assessed anyway. It turned out moot for me; they found their mark under the powdercoat immediately.
 
Ouch!!

When you catch your breath, can you post a photo of the lower gear attach point, that is the welded section around the lower firewall attach. This would have been the pivot during the failure.

Also, do you have wooden gear leg stiffeners bonded to the gear legs? These are designed to reduce the springiness of the legs and should be visible under the gear leg fairings.

Doug Gray
 
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Doug,

I'll try and post a picture of the lower gear attach point. It does not seem to be damaged at all.

I do have the wooden gear leg stiffeners which are also wrapped in carbon fiber.

Ben
 
Doug,

I'll try and post a picture of the lower gear attach point. It does not seem to be damaged at all.

I do have the wooden gear leg stiffeners which are also wrapped in carbon fiber.

Ben

Carbon fiber, eh?

In other words, your spring steel gear.....didn't. Very likely the loads that should have been absorbed by the gear got transferred to the mount.

Ditch the stiffeners and especially the carbon fiber so the gear can perform as designed.
 
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Thanks Jim, he already contacted me but we don't and never have built the -6 mounts so I sent him to Van's and recommended he replace it based on the way the side broke out of the landing gear receiver tube, it would be better to replace the receiver tube and you know what that will get into, that’s up to him though, it could be done, just a lot more work.
 
UPDATE

First of all, thanks to everyone for all of your replies and help! This is certainly a great community!

I've called every mount repair shop that was recommended plus a few others and it looks like I'm going to need a replacement mount as I've been told mine is beyond repair. (A few have offered to repair it but the cost would be almost as much as a new one). I called Vans today and they told me that the engine mount was the same for a -6, -7, and -9 and should match up. This is contrary to what I've been told by others. I'd hate to order a new mount and gear legs only to find that it didn't fit. While I'm not the builder, I do have the original plans so I'm planning to take a look at them tomorrow and take some measurements as well to hopefully see exactly what I need.
 
Ben,
As an earlier poster mentioned one risk you face with the new mount is how the firewall holes align. The second is the drilling for the gear legs. I don't know an acceptable method to re-drill the firewall holes if they don't align.

Consider trying a new mount, ship it back to vans if it doesn't work.

Having your existing mount re-manufactured may be a final option.

Doug Gray
 
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