Swissair Flight 306

Swissair Flight 306

Swissair Caravelle similar to Flight 306
Accident summary
Date	September 4, 1963
Type	In-flight fire leading to hydraulic failure and loss of control
Site	near Dürrenäsch, Switzerland
Passengers	74
Crew	6
Injuries	0
Fatalities	80 (all)
Survivors	0
Aircraft type	Sud Aviation SE-210 Caravelle III
Aircraft name	Schaffhausen
Operator	Swissair
Tail number	HB-ICV
Flight origin	Zurich Airport
Stopover	Geneva International Airport
Destination	Leonardo da Vinci-Fiumicino Airport

Swissair Flight SR306, a Sud Aviation SE-210 Caravelle III, HB-ICV Schaffhausen, was a scheduled international flight from Zürich to Rome, via Geneva. It crashed near Dürrenäsch, Aargau, on September 4, 1963, shortly after take-off, killing all 80 people on board.

Take off and flight

Zurich International Airport (in Kloten, Switzerland) was in dense fog when the plane was due to take off at 06:00 UTC. At 06:04 the flight was allowed to taxi to runway 34 behind an escorting vehicle. At 06:05 the crew reported that they would taxi half way down runway 34 to inspect the fog and then return to take off point. This was done, using at times high engine power in order to disperse the fog. Around 06:12 the aircraft was back to the threshold of runway 34 and was allowed to set off. The flight took off at 06:13 hours and started to climb to flight level 150, its cruising height.

Four minutes later people on the ground noticed a whitish trail of smoke on the left side of the aircraft. Shortly after, a long flame from the left wing-root was seen. Around 06:20 the aircraft reached a height of around 2700 m. It then began to descend, entered a gentle left turn losing height more quickly. It then went into a final, steep dive.

Parts of the aircraft fell off and at 06:21 a "MAYDAY" message was heard. At 06:22 the aircraft crashed into the ground on the outskirts of Dürrenäsch. The crash site was 559 m above sea level, almost 35 km from Zürich/Kloten Airport.

Probable cause

The brakes became too hot during taxiing. This caused the aluminium wheels to burst, one of them on the runway prior to departure. Upon retraction of the landing gear hydraulic lines in the gear bay were damaged, either by the burst wheels, or the bursting of an additional wheel rims during the climb. The plane then spilt hydraulic fluid, which ignited on the scalding hot rims of the landing gear. The fire damaged the gear bay, then the wing underside. Finally losing its hydraulic pressure, the aircraft was rendered without hydraulic controls. These included the flying control surfaces of the aircraft. Smoke developed within the cabin and the cockpit, adding to the predicament of the crew. At around 06:18 it can be reasonably assumed, that control of the aircraft was lost totally. The final dive and impact destroyed the aircraft devastatingly.

Casualties

This crash had some severe effects for a small village in the Canton of Zürich. 43 people from Humlikon boarded the plane to visit a farm test site near Geneva. Among these were:

• 19 married couples (who had a total of 39 children aged between 3½ and 19 years that were orphaned).
• 1 mother of 3 minors
• 1 father of 2 minors
• 1 father of 2 adults
• 2 single men.

The village lost one fifth of its 217 people in the crash. The entire local council, the people who took care of the schools and the post office clerk all died.

Most orphans were looked after at home by relatives. Six children had to move, all but one of whom went to live with relatives nearby.

Just over a month after the crash, a new council was elected by the remaining 52 people entitled to vote. Due to the great loss of people it wasn't easy to fill all places.

A further problem was the upkeep of the farms, but here people from the nearby villages helped. Apprentices came from local firms, students, firemen, soldiers, boy scouts, railroad workers, policemen, school children etc.. People came from abroad to help.

Each day 40 to 70 people helped, a total of almost 2000 hours. The harvest of 600 tonnes of potatoes was lifted by hand. Corn was threshed and the new crop seeds were sown in time.

Today Humlikon has beaten this tragic event. It remains still a small village, the smallest in the Canton of Zürich.

External links

• Der Flugzeugabsturz in Dürrenäsch 1963 (German)
• Civil Aviation Disasters - Swissair 306 - Pilotfriend