On Wed, 13 Apr 2005 17:11:40 -0500 "Mark Langford" <n5...@hiwaay.net> writes: > Al Friesen wrote: > > > Has there ever been a firewall separation issue with any KR out > there? Al > > That was my point. If it's worked for 20 or 30 other guys, then > it'll work > for others. I was just looking for verification from some of the 20 > or 30 > guys who've done this before. > > Larry, the engineer you mentioned was Bob Marcy (RR's structural > guy), but > he was talking about the KR2S firewall, not the KR2 firewall, at > least when > I heard him say that at Oshkosh one year.
I've never heard of an in flight failure, but have seen a tri-gear KR-2 tear the firewall out of the airframe on a hard landing. Definately not 21 gs, but then the nose gear can put a lot of torque on the firewall and is literally trying to pull the bottom out of the firewall on landing, as opposed to the engine pulling forward and down on the firewall. Also, if you look at the photos of Gene Byrd's crash http://www.jackandsandycooper.com/byrdcrash.html, you'll note that the engine and firewall are laying on the ground out in front of the airframe. Of course after a similar incident with a Bonanza, the engine was laying about 25 feet out in front of it, although it didn't take the firewall with it. FWIW, I have an aluminum angle cross brace behind the firewall attached to the shelf and a small amount of extra shear webbing added into the firewall support truss, but it is fairly minimal. -Jeff