Howard Aero 500
The business aviation community wanted a vehicle that was fast, far-reaching, pressurized and new. Dee Howard had the answer - the Howard 500.
By 1959, Howard was flying his prototype of the 500, a larger aircraft that was based upon the PV-1 but had a redesigned fuselage and a 25% larger wing area. Howard's 500 featured pressurization - 6.75-psi; maximum cruising speed of 338 knots; with its 2,500-hp P&W R-2800 CB-17 engines throttled back to 1,100 hp each, the 500 could cruise for more than 8.5 hours and cover about 2,400 nm. But most importantly, the Howard 500 was constructed from new metal. At least the fuselage and the wing centre sections were new; the outboard wing panels were from surplus PV-1's. The aircraft was granted a new aircraft certificate under the transport-category regulations that existed then, on February 20, 1963.
The 10- to 14-passenger 500, with its cabin high enough to accommodate a standing six- foot-two-inch man, had water injection (officially called ADI for anti detonation injection) and four-blade, 11- foot-diameter props; a 0.45-to-one propeller drive reduction gear reduced the prop revolutions to less than half the engine's speed. A two-speed supercharger enabled the 34,000-pound Howard to fly up to 35,000 feet, although the maximum certificated ceiling with passengers was 25,000ft. Hydraulically operated rudder boosts lowered the minimum control speed, with one engine inoperative, from nearly 200 knots on the original Navy versions of the PV-1 Ventura to 95 knots. A yaw-limiter system, which sensed the aircraft's yaw angle and provided an electrical signal to the rudder boost system, was necessary to produce the required positive rudder force gradient with increasing yaw angles. Auto feathering assured that any loss of power below a BMEP of 75 psi with the throttle advanced beyond the 45-inch mp position would streamline the blades and eliminate the performance and Vmc penalties. The aircraft's sole compressor for cabin pressurization was located on the left engine, and it would declutch itself automatically if the right engine failed, thus enabling the left engine to produce maximum power during single-engine operations.
Production continued through the mid-'60s with twenty-two 500s sold.
Howard 500HP Autumn 2012 – David D Koloc
Cabin height: 6ft 2in.
Pax cap: 14.
Cruise: 300 kt.