by Chris Kuyoth » Fri Mar 06, 2009 7:19 pm
Don,
I am familiar with the Cherokee rear seats as my dad flies a 235. To install cherokee seats in a Comanche, I would have to think that the services of a DER would be required in order to obtain FAA approval. The Cherokee seats mount in a piece of 5/8 plywood that is the rear floor. There is no structure in the correct location to hold the Cherokee seat nor a plywood floor in the Comanche.
The FSDO that approved my modification sent my proposal to the FAA Engineering office in Chicago prior to doing the work for a "pre-approval". I had to have drawings for the modification. Since I was simply installing B-model components, the Piper Comanche parts manual was deemed sufficient. I was advised by the FSDO to make sure I clearly stated in the 337 that I used only Piper PA24 parts and that the PA24 was certified with this configuration. Also, I had to include instructions for continued airworthiness. Since the owners & service manual for the 260 B & C addressed removal, installation and operation with & without the seats, I was covered with that verbiage. Long and short, I believe the path of least resistance is the B-model seats and supporting structure. Honestly, I doubt that my dad can get his rear seats out any faster than I can.
There is an old STC for "A" model Comanches that incorporated split rear seats and a 5th seat in the baggage compartment. A friend of mine has a Comanche with this mod. The front of the rear seats actually bolt to the spar.
Chris