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Smith XP 99 Prop Jet

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Wingspan
  
12 m

First flight
  
July 29, 1982

Length
  
9.32 m

Manufacturer
  
Mike Smith Aero Inc

The Smith X-99 Prop-Jet was a six seat turboprop powered business aircraft designed in the United States in the 1980s. Only one was built.

Contents

Design and development

The Prop-Jet was an attempt to produce a small, propeller driven business aircraft capable of cruising at speeds above 350 mph (560 km/h). It was powered by a 550 shp (410 kW) Pratt & Whitney Canada PT6 turboprop engine, mounted in a long nose and driving a four blade, constant speed propeller. The fuselage was a monocoque constructed from graphite and glass-fibre epoxy sandwich. The pressurised cabin accommodated pilot and five passengers in three rows of seats, with a baggage space behind. Access was by port side doors forward and another over the trailing edge on the other side. The tail unit was made from Kevlar/graphite/glass fibre epoxy sandwich. The fin was swept and the tailplane mounted, with anhedral, almost at the top of it. The elevator carried an electrically driven trim tab.

To speed the completion of the first prototype, the Prop-Jet used the wing and undercarriage of a Beechcraft Baron 58P, though a composite structure wing was envisaged for production aircraft. The Beech wing was a two spar aluminium box structure, without sweep and mounted between mid and low positions with dihedral of 6° and fitted with slotted Fowler flaps. The tricycle undercarriage was enclosed behind doors after retraction.

The Prop-Jet flew for the first time on 29 July 1982. By 1985 Mike Smith was reported as seeking financial backers but only the one prototype Prop-Jet was built.

Specifications

Data from Jane's All the World's Aircraft 1985–86 All performance figures at maximum take-off weight except where noted.

General characteristics

  • Crew: One
  • Capacity: Five passengers
  • Length: 30 ft 7 in (9.32 m)
  • Wingspan: 37 ft 10 in (11.53 m)
  • Height: 10 ft 6 in (3.2 m)
  • Wing area: 119.0 sq ft (11.06 m2)
  • Aspect ratio: 12.02
  • Airfoil: modified NACA 23016.5 at root, 23012 at tip
  • Empty weight: 3,153 lb (1,430 kg)
  • Max takeoff weight: 6,000 lb (2,722 kg)
  • Fuel capacity: 220 US gal (832.5 L; 183 Imp gal)
  • Powerplant: 1 × Pratt & Whitney Canada PT6A-41 turboprop, 550 hp (410 kW) derated from 634 kW (850 hp)
  • Propellers: 4-bladed Hartzell Propeller Type HC-B4TN-3AL/LT1073F-12-5, 7 ft 6 in (2.29 m) diameter constant speed

    • Performance

  • Cruise speed: 325 mph; 282 kn (523 km/h) economical, at 31,000 ft (9,450 m)
  • Stall speed: 86 mph; 75 kn (138 km/h) flaps down,power off
  • Range: 1,448 mi (1,258 nmi; 2,330 km) with maximum payload
  • Ferry range: 1,544 mi (1,342 nmi; 2,485 km) with maximum fuel
  • Service ceiling: 31,000 ft (9,400 m) service
  • Rate of climb: 3,500 ft/min (17.8 m/s) at sea level at weight of 5,182 lb (2,350 kg)
  • Wing loading: 50.0 lb/sq ft (244.1 kg/m2)
  • Power/mass: 0.093 shp/lb (0.150 kW/kg)
  • Take-off distance to clear 50 ft (15 m): 2,376 ft (724 m)
  • Landing distance from 50 ft (15 m): 2,498 ft (761 m)

    • Avionics

  • Collins nav/com, ADF, transponder
  • Texas Instruments TI-9100C LORAN
  • Full blind flying instrumentation

    • References

    Smith XP-99 Prop-Jet Wikipedia
    (Text) CC BY-SA