Pitcairn Mailwing

The Pitcairn Mailwing family was a series of American mail carrier and three-seat sport utility biplane aircraft produced from 1927 to 1931.

Mailwing
PA-8 Mailwing in flight
Role Mail Carrier and Sport
National origin USA
Manufacturer Pitcairn Aircraft Company
Designer Agnew E. Larson
First flight 1927
Introduction 1927
Primary user U.S. Postal Service
Number built 106
Developed from Pitcairn PA-4 Fleetwing II
PA-6 Super Mailwing NC15307 at Old Rhinebeck Aerodrome

Design and development

The Pitcairn Mailwings were developed to carry air mail for the U.S. Postal Service. Of simple and robust construction, they had relatively benign flying characteristics.[1]

They were constructed using chrome-moly steel tube and square-section spruce spars with spruce and plywood built-up ribs. The fuselage was faired using wooden formers and covered with fabric. The tail sections were built up from steel tube and fabric-covered. The Pitcairn Mailwing had a ground-adjustable fin and in-flight adjustable tailplane.[1]

The undercarriage was of outrigger type with Oleo-Spring shock absorbers and disc brakes on the mainwheels. All versions looked very similar and changes were minor, with several fuselage extensions being the most obvious.[1]

The mail was carried in a fireproof metal-lined compartment forward of the pilot's cockpit. The Mailwings were flown extensively by the U.S. Air Mail service from 1927 until the end of dedicated Air-Mail routes.[1]

Pitcairn also built the same aircraft in sport versions for private use. These aircraft had the mail compartment removed, and a side-by-side two-seat cockpit was fitted.[1]

Variants
Pitcairn Mailwing PA-5, at the National Air and Space Museum
PA-7S Super Sport Mailwing

Data from: Aerofiles : Pitcairn[2]

  • PA-5 - original production version of 1927 with Wright J-5-9 engine; ATC 18 (32 built)
    • PA-5 Mailwing - mail carrier version
    • PA-5 Sport Mailwing - sport version with seats for two passengers
  • PA-6 - 1928 production version with Wright J-5-9 engine; ATC 2-22 (early), 92 (late) (53 built)
    • PA-6 Super Mailwing - mail carrier version
      • PA-6B Super Mailwing - (1 converted from PA-6)
    • PA-6 Sport Mailwing - sport version with seats for two passengers
  • PA-7 - 1929 production version with Wright J-6 engine; ATC 196
    • PA-7A Sport Mailwing
    • PA-7M Super Mailwing - mail carrier version (12 built)
    • PA-7S Super Sport Mailwing (15 built)
  • PA-8 - 1930 production version with Wright J-6 engine; ATC 364
    • PA-8M Super Mailwing - mail carrier version (6 built)

Operators
 United States

Survivors and aircraft on display

Specifications (PA-7M Super Mailwing)
Pitcairn PA-7 Sport Mailwing 3-view from Aero Digest April, 1930

Data from Jane's all the World's Aircraft 1931,[4] Aerofiles: Pitcairn[2]

General characteristics

  • Crew: 1
  • Capacity: mail compartment 40 cu ft (1.1 m3) / 550 lb (250 kg) payload
  • Length: 23 ft 9 in (7.24 m)
  • Upper wingspan: 33 ft (10 m)
  • Lower wingspan: 30 ft (9.1 m)
  • Height: 9 ft 6.5 in (2.908 m)
  • Wing area: 243.5 sq ft (22.62 m2)
  • Airfoil: Pitcairn No.1
  • Empty weight: 1,820 lb (826 kg)
  • Gross weight: 3,050 lb (1,383 kg)
  • Fuel capacity: 60 US gal (50 imp gal; 230 l)
  • Powerplant: 1 × Wright J-6 Whirlwind 9-cylinder air-cooled radial piston engine, 220 hp (160 kW)
  • Propellers: 2-bladed Standard steel propeller

Performance

  • Maximum speed: 150 mph (240 km/h, 130 kn)
  • Landing speed: 57 mph (50 kn; 92 km/h)
  • Cruise speed: 112 mph (180 km/h, 97 kn) (PA-5)[2]
  • Stall speed: 45 mph (72 km/h, 39 kn) (PA-5)[2]
  • Range: 520 mi (840 km, 450 nmi)
  • Service ceiling: 18,000 ft (5,500 m) (PA-5)[2]
  • Rate of climb: 1,100 ft/min (5.6 m/s) (PA-5)[2]
  • Wing loading: 12.1 lb/sq ft (59 kg/m2)
  • Power/mass: 13.8 lb/hp (8.4 kg/kW)

See also

Aircraft of comparable role, configuration and era

(Partial listing, only covers most numerous types)

References

Citations
  1. Juptner, Joseph P. (1963). U.S. Civil Aircraft Vol.2. Los Angeles: Aero Publishers. pp. 279–81.
  2. Eckland, K.O. "Pitcairn". aerofiles.com. Retrieved 27 December 2018.
  3. "Pitcairn". Retrieved 23 January 2011.
  4. Grey, C.G., ed. (1931). Jane's all the World's Aircraft 1931. London: Sampson Low, Marston & company, ltd. p. 307c.

Bibliography
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