16 Jun 2016

Ten Years Ago: Mardna's 111km model seaplane world record

Ten years ago Toomas Mardna set a world record for aeromodelling that still stands today: a 111km out-and-return flight with a piston-motor seaplane, flying along the banks of Lake Maardu in Estonia.

If you want to bag a distance world record in aeromodelling it can help if you get up early, when the wind is calm and the sky is clear.

For Toomas Mardna exactly ten years ago on Friday 17 June 2006, 'early' meant a pre-dawn start. Together with co-pilot Juri Laidna the pair were aiming to set a world record out-and-return flight with a model Mardna had designed and built himself.

Mardna was well-known in Estonia and the international aeromodelling scene. A member of the Estonian Aerosports Federation his FAI Sporting Licence number was EST0002 – he was in at the very beginning.

For the record attempt he had designed and built a special radio-controlled piston-motor seaplane. Controlled with throttle, rudder and elevator the FAI 3 Open Seaplane had a wingspan of 3.38m and a fuselage length of 2.01m. The engine type was O.S FS-52S.

On their chosen day the team of two pilots and three official observers – Peep Vare, Lauri Laidna and Prii Laanesoo – arrived at their take-off spot on the banks of Lake Maardu, northern Estonia, at 4am.

There the model was assembled and checked. Empty of fuel it weighed 2.93kg, with fuel it weighed 4.832kg.

Floating the model on the still waters of the lake the pair tested its flotation. Then, using a GPS they noted their coordinates. It was a still mid-summer’s morning, with an air temperature of 9C, a clear sky and still wind.

Engine testing followed, and then at exactly 4.57am the record flight got underway. Mardna launched the model onto the water and prepared for flight. Within five seconds the seaplane model had completed its take-off run and was in the air, soaring gracefully into the sky.

After tagging the official start gate the model set off on course, flying at an altitude of 150-180m AGL. The pilots and official observers followed in two cars, chasing the plane as it travelled at about 70km/h.

The turnpoint was reached at 6am, before most people are even out of bed. But there was no stopping for coffee – instead, 100m past the turnpoint the model turned and the pilots switched. It was now Juri Laidna’s turn to take the controls.

Now heading back into wind the cruising speed dropped to 25km/h, but after increasing engine RPM to 6,500RPM that increased to 40km/h. Flying at 150m AGL and still with good visibility they made it back to their start point at 7.27am.

There, the motor was stopped and the model glided down through the air for two minutes until it landed softly in high grass on the edge of the lake, some 35m past where it had started from.

The flight had lasted 2h31min31sec and covered 111.01km.

The distance was calculated using official FAI software, and the record was officially ratified on 31 October 2006.

The record still stands today.

See the FAI Record File 

Photo Credit: Lauri Laidna