Thread: Bent Engine Mount - 800-Hour Service

I was just notified by our mechanic that we have a bent engine mount in our 2006 CTsw, and that it wasn't this way during our last 100-hour inspection. I was told that this is most likely due to a very hard landing, but neither of us co-owners remembers such a landing or owns up to it. Further inspection will determine whether there is any damage to the firewall. Are you in agreement that such a condition is most likely due to a single event - or the result of a series of imperfect landings over time? In the early days, we new pilots bounced it around pretty good, but that was a few years ago. Anyone experience a repair like this? Repair time and cost? File against insurance or pay out-of-pocket?

wlfpckrs,
When you say that the engine mount is bent, exactly what does that mean? Are you talking about the small engine mount, engine side of rubber mounts, or the main mount on the firewall? and what exactly is the deformation? The reason I ask is because a lot of my landings are in fields with the occasional 'arrivals' rather than greasers and I've yet to see any impact on the either of the mounts, which to me, would suggest a single heavy landing event.
Mac

Our mechanic is getting into this inspection and mentioned that the rubber is cracked on the lord mounts on the firewall. Could that contribute significantly to the prop spinner sitting lower than normal?

Usually if the spinner is sitting to low on the cowling it is due to worn engine mounting/cage rubbers ..although i have seen a few bent engine/nose gear frame's but these were due to very heavy landings one's you would definitely remember ..is the droop the reason your mechanic is saying the mount is bent ?

Mike

I think that is what first caught his attention.

Then if it hasn't had any known hard landings it will probably turn out to be worn mounting rubbers a common fault on CT/CTSW i have seen some that the prop is almost touching the front spat ..changing the rubber's brings the spinner back in line with the cowling's

Mike

Pulling the engine to make this repair, would it make sense to go ahead and install the firewall insulation/blanket? I assume that, if we were ever planning to do it, now would be the best time to do it. Having said that, I understand that it is optional, not mandatory. Any thoughts from any of you CT owners about the firewall insulation? How much would my part of the cost amount to? I'm not looking to spend money unnecessarily, but if it's a good idea and money well spent, I'll consider it.

If it were my money and my airplane, I would do it. I think that the firewall blanket quiets down the cockpit a little and I think it is a very worthwhile safety addition.

wlfpckrs,
We just went through this with our 2004 CT2K. We knew our rubber engine mounts were cracked and had been watching them for years. We decided to change them out this year and add the firewall blanket at the same time.
I strongly recommend the blanket. It improves safety by slowing the progression of an engine fire into the cockpit. As video of the recent Colorado Cirrus midair graphically displayed (Boulder Plane Crash: Deadly Mid-Air Plane Collision (VIDEO)), it doesn't do much good to have a ballistic chute if your plane is on fire. In fact, in the event of a fire you probably should try to get down as quickly as possible and not deploy the chute unless you have lost control or until you are low over unlandable terrain.
The firewall blanket doesn't weigh much and the factory is currently covering most of the cost of retrofitting older aircraft that did not have the blanket installed at the factory.
With respect to your original question: In general a series of imperfect landings will not damage the engine mounting frame. The plane is designed for these landings. Stresses remain within the elastic range of the nose gear and engine supports. In other words, the parts bend and then bounce back without accumulating any significant damage.
Only a very hard landing will result in stresses which exceed the threshold of the elastic range, resulting in plastic deformation and permanent damage the forward frame.
Mike Koerner

Here's a stretch--Not sure what arrangement Cirrus has on the firewall and have heard FD puts a special coating of some space age heat/flame stuff on newer aircraft.....How about a coating that stuff for those still in need? Would it preclude after the fact electrical grounding and other issues?