I always heard the tooling and production line was destroyed when the Lock Haven plant was flooded back in '72. Maybe just a convenient excuse? The Cherokee line wasn't exactly a bomb.
The flood caused by Hurricane Agnes on 23 June 1972 was neither the first nor the last flood to hit Piper's Lock Haven plant, but it was the most damaging. Over 250 aircraft, finished or in various stages of construction, were damaged or destroyed, including twenty-one Comanches and twenty-five Twin Comanches. Among the airframes destroyed were N9300P, the prototype PA-24-300 Comanche that was first flown in 1967, and N8300Y, the prototype of a Twin Comanche 200 that had begun flight test shortly before the flood.
Though the factory was substantially damaged, production of Aztecs and Navajos resumed later in 1972, and Super Cubs and Pawnees in 1973. Production of the Cherokee and its derivatives, all in Vero Beach, Florida, was not affected. Navajo production moved from Lock Haven to Lakeland, Florida, after the flood.
At the time of the flood, Piper was already working on an improved version of the Twin Comanche, dubbed PA-40 Arapaho. Development continued after the flood with construction of one experimental prototype (lost during spin testing in 1973) and two pre-production prototypes. Changes from the PA-30/39 Twin Comanches included lengthened main landing gear, larger cabin windows and a much larger dorsal fin and a large ventral fin, to improve OEI handling, if not appearance. The Arapaho received FAA certification in 1974, and was planned for a 1975 model year debut. There were already preliminary plans for a 180 hp version and a T-tail, but those were never built. According to Piper historian Roger Peperell, Piper determined "there was not a big enough market for it and Piper management wished to use the Cherokee as the basis for its new models," so the PA-40 program was terminated.
Piper also planned an updated 260 hp single-engine Comanche, with airframe modifications similar to those of the twin-engine PA-40, to be introduced in 1974. But no prototype was ever constructed. Again, per Peperell, "[t]his updated Comanche would have been prohibitively expensive in relation to the Cherokee Arrow, hence a very restricted market which resulted in little justification to proceed with certification. The project was cancelled."
