Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 23; Flight Crew Total 20000; Flight Crew Type 13
Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Procedure; Human Factors; Company Policy; Aircraft
I went flying with a fellow pilot in our club airplane.  During the preflight inspection we observed that the stall warning was not working.  We consulted both FAR 91.213 and 91.205. There is no minimum equipment list for this airplane.  We determined that the stall warning was not required equipment.  We continued our flight and we made an entry in the club's squawk reporting system.  Later; another club member informed us that we should have grounded the airplane. He pointed out that indeed the stall warning is required equipment according to the POH.  It is not listed under any section labeled 'required equipment'.  It was listed in Section 6 weight and balance. In this weight and balance section there are coded letters next to equipment that have particular meanings.  The stall warning is listed with the letter code that indicates it is required equipment.Well; I learn or re-learn something new every day. This indeed is a learning experience. Doing research I learned a few other sources - in addition to the POH W&B section - that need to be consulted for required equipment.  Type certificate data sheet at www.rgl.faa.gov; and any STC's for the aircraft.
PA-28 pilot reported operating the aircraft with the stall warning inoperative contrary to the required equipment list.