Oddball, Experimental, or One-off

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The Supermarine Type 508 was a British experimental jet fighter prototype developed by Vickers-Supermarine in the early 1950s, serving as the primary ancestor to the Supermarine Scimitar.  It was designed to meet the Admiralty's Specification N.9/47 for a carrier-borne interceptor, featuring a straight-wing configuration, twin Rolls-Royce Avon RA.3 engines, and a distinctive "butterfly" V-tail designed to clear jet exhaust while maintaining stability. 

Key Development and Specifications

Maiden Flight: The first prototype, serial VX133, flew on 31 August 1951 at Boscombe Down, followed by a second prototype (VX136, later designated Type 529) on 29 August 1952. 
Design Origins: The Type 508 evolved from the Type 505, which was originally intended to land on flexible rubber decks without an undercarriage; the Type 508 incorporated a conventional tricycle undercarriage after the Admiralty abandoned the rubber deck concept. 
Performance: The aircraft achieved a maximum speed of approximately 607 mph (977 km/h), though this was considered modest, leading to the development of the swept-wing Type 525 variant. 
Operational History: The Type 508 (VX133) conducted carrier trials aboard HMS Eagle in 1952 and remained in service until 1956, while the Type 529 variant was destroyed in a crash landing on 19 December 1953.

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The DeKellis-Olson Air Truck, an experimental American light utility and agricultural triplane developed in the mid-1950s.

 

History & DesignDesigner:

 

It was designed by Tom DeKellis, a crop-dusting operator based in Oroville, California, who sought a more efficient alternative to the Stearman biplanes he was using.

 

Construction:

 

Built in 1957 by mechanic Alan Olson, the aircraft was a "chimera" constructed from surplus parts. It utilized three sets of wings from Piper PA-18 Super Cubs and components from a Vultee BT-13 Valiant.

 

Purpose:

 

DeKellis believed a triplane configuration would provide the additional wing area needed for better "low and slow" performance during crop-spraying operations. Its boxy fuselage was designed to house a large spray tank or dust hopper; some reports even claimed it could accommodate a Jeep.

 

Technical Details:

 

Engine: It was powered by a war-surplus 450 hp Pratt & Whitney R-985 radial engine.

 

Configuration:

 

The aircraft featured a unique four-wheel landing gear and a twin tail mounted on separate booms.

 

Flight History:

 

The Air Truck reportedly flew only once in 1955 (or 1957, depending on the source). The pilot, reportedly anxious to land, damaged the tail section during the circuit. The aircraft never flew again and was eventually abandoned.

 

Legacy

 

While this specific prototype was a failure, the "Air Truck" concept (a pod fuselage with twin tail booms for agricultural work) was later successfully refined by Italian designer Luigi Pellarini into the Bennett PL-11 and the more famous Transavia PL-12 Airtruk.

 

[facthunter]

Dusty Crop Hopper is scared of that.  Nev

[onetrack]

I'd imagine there was more than a little above the normal parasitic wing losses with that amazing setup? Going by that blokes style of thinking, I guess he was frightened of losing a wing, as well? So, the more the better?