The Ugliest, or is it the Strangest Aircraft Ever Built?

Garth Calitz
Sep 2
3 min read

By Rob Russell

We have often read about how beautiful and good-looking an aircraft is. We all have our own opinions, often shared by others too and others not. Of course, how do we define beautiful and good-looking? To some, a 747 is an amazing aircraft and good looking, but to others it is plain big and ugly. Some think the C-130 Hercules is a terrible-looking aircraft, but to many, it is one of the best of the best.

So we're never going to achieve a perfect answer. But one thing no one talks about is the ugliest aircraft ever built! We all have our own opinions, but there really were some ugly aircraft built. Luckily, most of them never made it past the test flying stage, or were only produced in limited numbers and then flown in areas where most of us will never see them flying (the Australian Outback comes to mind here!)

So let's look at some of these ugly-looking aircraft.

The Transavia PL-12 Airtruk is one of the quirkiest, most distinctive aircraft ever built — and often makes “ugliest aircraft” lists, though many pilots and enthusiasts find it charming. And many pilots had many happy hours flying them around the skies.

The Transavia PL-12 Airtruk is a single-engine agricultural aircraft designed and built by the Transavia Corporation in Australia. It's a shoulder-wing strut-braced sesquiplane (that is a Latin-derived word, meaning one and a half wings), the majority of which is all-metal construction, with the cockpit mounted above a tractor-location opposed-cylinder air-cooled engine and short pod fuselage with a rear door. The engine cowling, rear fuselage and top decking are of fibreglass. It has a tricycle undercarriage. It has twin tail booms with two unconnected tails.

Its first flight was on 22 April 1965, and it was certified on 10 February 1966. Designed purely for function over form, which explains its oddball looks. It was designed by Luigi Pellarini (Italian-born)

Let's look at some of its features:

Double-deck cockpit: Pilot sat on the top deck for clear downward visibility; the lower deck could carry 1–2 passengers or light cargo.
Twin-boom tail: This left the rear fuselage clear, making for ease of access to load chemicals or cargo.
Snub-nosed fuselage: Its short and stubby appearance, which gave it its boxy, “ungainly” look.
Fixed landing gear: Rugged and simple for farm or rough, unprepared strip usage.

Performance

Engine: Lycoming IO-540 piston engine (295–300 hp)
Max Speed: 215 km/h (134 mph)
Range: 800 km (500 miles)
Payload: 1,000 kg of chemicals/cargo.
Including the various test aircraft, only 138 were produced.

July 1978 saw the first flight of an improved model, the T-300 Skyfarmer, which was powered by a Textron Lycoming IO-540 engine. This was followed in 1981 by the T-300A with improved aerodynamics. Transavia finally ceased production of the T-300 in 1985.

In 1982, certification was undertaken to enable sales in the North American market. Assistance was provided by the Aeronautical Research Laboratories of the Defence Science and Technology Organisation (DSTO). Certification was held up because of excessive flutter and much time and effort were put into addressing this.

In 1985, an extended version was produced and released as the T-400. The engine was changed from a 6-cylinder to an 8-cylinder and the tail booms were extended by 750 millimetres (30 in). Other minor changes were made to the aerodynamics. Flutter clearance tests were again carried out by ARL and manufacturing proceeded.

An isolated flutter incident was reported in 1986 involving violent oscillations of the rudder and tail boom on the T-400 during a delivery flight. Investigations were carried out by ARL, and a split mass balance arm was fitted to each rudder. Before this, the aircraft had relied on frictional damping provided by the lengthy control cables. The modified aircraft was tested both on the ground and in flight trials in March 1988 over Port Philip, near Melbourne, Australia. All attempts to induce the oscillations showed that there was no indication of a mode of vibration becoming unstable. The maximum speed achieved was 160 knots (180 mph; 300 km/h), albeit in a steep dive. Oscillations were induced with an air-operated tool fitted with an out-of-balance rotating mass. This device had a rotational speed from 18 Hz down to zero for each charge of the compressed air cylinder.

The Airtruk found a niche in Australia, New Zealand, and the Pacific Islands and was very popular and well-liked there. Some of its detractors said, Well hidden from the rest of the world and far enough away that it did not scare anyone!