Jeff Ryndak:
I need to find the part number of some parts. I have a 78 Sundowner, SN M-2061. I need a ground vent blower motor, and the 2 duct tubes that attach to it. I took it apart today and know why it failed. All the steel wire in the duct tubing is rusted, and left a pile of rust that came out when I took the tube off.
Editor:
There have been many warnings posted on MML and BAC, concerning the original CEET duct (basically lined CAT duct) used in these planes (and most others). It contained plain piano wire (not stainless steel), and the old neoprene-impregnated fabric duct hardens and absorbs moisture as it ages (the neoprene dries out and is no longer waterproof). If your under-floor air ducts have not been replaced, they are probably in the same condition… and they are up against your spar, your brake lines, your airframe skin, formers, etc. Rusty wire will cause severe corrosion anywhere that it touches aluminum.
With regard to the 14V blower motor, the original published part number was 1523-202-4. I believe that it has been superseded by PN 1523218-2 ($197 at RAPID); you should verify that with RAPID before ordering. RAPID shows 28 of them for $197 each. On the later 14V planes Beech switched to PN 169-380096-1 for the assembly (motor and blower wheel), which is no longer a valid RAPID number. PN 169-380096-3 is the 28V assembly, and is still a good number ($423 at RAPID). You can also try PN 1523218-4, cabin air blower motor, from Aero Space Controls Corp., Wichita, KS (in the BAC Links page): http://www.aerospace-controls.com/
The ducts and clamps are standard hardware, and can be ordered from Aircraft Spruce. I highly recommend the SCEET duct (lined SCAT duct), despite the higher price. It has stainless steel reinforcement wire, and the silicone construction material will never absorb or hold moisture. If you want more professional ducts (no cut ends), you can measure the needed length and order cuffed ducts from Custom Ducts (link on BAC). These are especially useful on ducts that must be regularly removed and reinstalled, as the molded cuff won’t unravel like a cut end. The recurring removal isn’t a factor on the blower ducts, though.