Marlman Flying Girder

Flying Girder
Front quarter view of the Marlman Flying Girder
Role	Agricultural airplane
National origin	United States
Manufacturer	William A. Marlman
Introduction	1957
Number built	1

The Marlman Flying Girder was a low-cost American cropduster developed in the 1950s.^[1]

The Flying Girder was the project of William A. Marlman, who was based in Las Animas, Colorado. A 1955 newspaper report detailed that Marlman had designed an agricultural aircraft, referred to the "Pack Air", and that it was currently under construction.^[2] If the aircraft proved successful, Marlman planned to establish a factory at Las Animas in order to produce them.

Two aluminum channels, 20 ft (6.1 m) in length, were bolted together to form a single box-section beam that formed the basis of the design.^[3] A 260 hp (190 kW) Lycoming engine, driving a tractor propeller, was fitted to the foremost point of the box beam. Positioned behind the engine was a simple slab-sided enclosed fuselage. The aircraft had a constant chord rectangular wing planform, with no dihedral. The wings featured full-span flaps, and endplates fitted to the wingtips.^[3] A conventional tailplane and tailfin were located at the aftmost point of the box beam. The Flying Girder was fitted with a fixed conventional undercarriage.

To cater to its intended function as an agricultural aircraft, it was designed to spread both dust and sprays. A 20 cu ft (0.57 m³) hopper was incorporated into the rear of the fuselage, and 50 US gal (190 L) tanks were built into the wings.^[3]

By early 1957 the aircraft had been approved by the CAA. Its operational history is not known.^[3]

Data from Popular Mechanics^[3]

General characteristics

• Crew: 1
• Powerplant: 1 × Lycoming piston engine, 260 hp (190 kW)

Performance

• Cruise speed: 120 mph (190 km/h, 100 kn)
  
• Landing speed: 70–90 mph (110–140 km/h; 61–78 kn)
• Stall speed: 40 mph (64 km/h, 35 kn)

Aircraft of comparable role, configuration, and era

• Grumman Ag Cat
• Larson D-1