Emair MA-1

Paymaster / Diablo 1200
Emair MA-1B at Harlingen Texas in 1975
Role	Agricultural biplane
Manufacturer	Emair
First flight	1969
Number built	73

The Emair MA-1 Paymaster was a 1960s American agricultural biplane aircraft built by Emair, which was part of the Hawaiian Murray company. The prototype was constructed and flown in New Zealand, with production aircraft built in the United States at Harlingen, Texas.

Development

The prototype Murrayair MA-1 was built by Air New Zealand on behalf of Murrayair Limited of Hawaii, United States. Based on the Stearman 75 Kaydet, it had an increased wing area and modification to the forward fuselage to accommodate a pilot (in a raised cockpit for better visibility), a jump seat (used to carry an assistant or mechanic between stations), and a chemical hopper. The fixed tailwheel landing gear was strengthened and a more powerful Pratt & Whitney Wasp radial engine fitted. It first flew in New Zealand on 27 July 1969, then it was dismantled and shipped to Hawaii to obtain United States certification. After obtaining the type certificate (on 14 April 1970),^[1]

Production and development

Emair began production of the aircraft at Harlingen in Texas. The production aircraft were named Agronemair MA-1 Paymaster at first, then designated the Emair MA-1 Paymaster. Production ended in 1976 after 25 had been built.^[2]

In 1975 Emair developed an improved version, the Emair MA-1B Diablo 1200, which was essentially an MA-1 with a more powerful Wright R-1820 radial engine. The more powerful engine did not increase the maximum takeoff weight but allowed operations at higher altitudes, and its lower output speed helped reduce propeller noise.

At the end of the 1980s the company halted production after a further 23 Diablos had been built.^[3]

Variants

Murrayair MA-1

New Zealand-built prototype with a 600hp (447kW) Pratt & Whitney R-1340-AN1 Wasp radial engine.

Emair MA-1 Paymaster

Production aircraft, 25 built.

Emair MA-1B Diablo 1200

Improved version with a 900hp (671 kW) de-rated Wright R-1820 radial engine, 48 built.

Specifications (Diablo 1200)

Data from The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 1600

General characteristics

• Crew: One
• Length: 30 ft 0 in (9.14 m)
• Wingspan: 41 ft 8 in (12.70 m)
• Height: 11 ft 9 in (3.58 m)
• Wing area: 400 ft² (37.16 m²)
• Empty weight: 4250 lb (1928 kg)
• Gross weight: 8400 lb (3810 kg)
• Powerplant: 1 × de-rated Wright R-1820 radial piston engine, 900 hp (671 kW)

Performance

• Maximum speed: 117 mph (188 km/h)
• Rate of climb: 1700^[4] ft/min (8.6 m/s)

References

1. J W R Taylor 1971, p.360.
2. J W R Taylor 1980,p.333.
3. Simpson 1991, page 349
4. J W R Taylor 1980, p.334.

• The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 1600.
• Taylor, John W R (editor). Jane's All The World's Aircraft 1971-72. London:Sampson Low, 1971. ISBN 0-354-00094-2.
• Taylor, John W R (editor). Jane's All The World's Aircraft 1980-81. London:Jane's, 1980. ISBN 0-7106-0705-9.
• Simpson, R.W. (1991). Airlife's General Aviation. England: Airlife Publishing. ISBN 1-85310-194-X.