Greenlandair aircraft accident near Nuuk in 1962
| Greenlandair aircraft accident near Nuuk in 1962 | |
|---|---|
_AN1366152.jpg) A PBY Canso type machine |
|
| Accident summary | |
| Accident type | Demolition of the landing gear doors and sinking of the machine when landing in water |
| place | near Nuuk , Greenland
|
| date | May 12, 1962 |
| Fatalities | 15th |
| Survivors | 6th |
| Aircraft | |
| Aircraft type |
 .svg){kind=small} Canadian Vickers PBV-1A Canso (PBY-5A)
|
| operator |
Eastern Provincial Airways for Greenlandair
|
| Mark |
CF-IHA
|
| Departure airport |
Sondrestrom Air Base , Greenland
|
| Destination airport |
Nuuk , Greenland
|
| Passengers | 18th |
| crew | 3 |
| Lists of aviation accidents | |
The Greenlandair accident at Nuuk in 1962 occurred on May 12, 1962. On this day, a Canadian Vickers PBV-1A Canso (PBY-5A) of Eastern Provincial Airways (CF-IHA) operated on behalf of Greenlandair , with which a Greenlandic aircraft crashed lines domestic flight of the Sondrestrom Air Base in Kangerlussuaq to Nuuk was carried out on landing on the water. In the accident, 15 of the 21 people on board the machine were killed.
machine
The machine that crashed was a Canadian Vickers PBV-1A Canso (PBY-5A) with the serial number CV-365, built in 1944 by Canadian Vickers in Montréal for the Royal Canadian Air Force . The twin-engine amphibious aircraft had a retractable landing gear for landings on land and a buoyant fuselage for water landings. The machine had been approved by Eastern Provincial Airways with the aircraft registration CF-IHA . It was equipped with two radial engines of the type Pratt & Whitney R-1830-92 , each with an output of 882 kW (1200 hp).
Inmates
The flight from Kangerlussuaq to Nuuk had taken 17 Danish passengers and one Greenland passenger. The three-man crew were Canadian employees of Eastern Provincial Airways, there were a captain, a first officer and a flight engineer on board. No flight attendants were provided on the regional flight.
The captain had 4,000 hours of flight experience, 3,400 of which with the Royal Canadian Air Force and 600 with Provincial Airways. He had his type rating for the Canso since June 14, 1961. Since then he had flown 151 hours in the role of first officer and 20 hours in the position of captain with this type of aircraft.
The first officer had 1,300 hours of flight experience, 650 of which he had flown with the Canso. Of these, in turn, he had completed 600 hours in Greenland.
Weather
On the day of the accident, the flight and landing conditions were favorable. The visibility in Nuuk was eight to ten kilometers, the water was crystal clear and practically without waves.
Flight history
 
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Overview map of flight route |
The machine took off from Kangerlussuaq at 09:05. The flight was carried out under instrument flight rules at an altitude of 10,000 feet and proceeded without any special incidents up to the approach to Nuuk. The flight engineer went through the landing checklist and confirmed that everything was OK. At an altitude of 400 feet, the support floats were lowered. The flight speed was reduced to 100 miles per hour (approx. 161 km / h) and the engine speed was increased to 2300 revolutions per minute. The flight captain initiated the final approach near the island of Qeqertarsuaq (Hundø) . He reduced the airspeed to 95 miles per hour (about 153 km / h) and lowered the machine at a vertical speed of 100 to 150 feet per second while he monitored the descent on the instruments.
the accident
The plane landed at 10:55 a.m. When the Canso touched down on the water, the landing felt normal to the pilots. After a few seconds, however, the machine made an abrupt swerve to starboard , while the aircraft nose plunged deeper and deeper into the water. The machine was braked faster than usual. The master tried to counteract the starboard dangling by using the buoyancy aids and increasing the performance of the starboard engine, but his actions did not bring about the hoped-for success. When the machine finally deviated 90 degrees from the landing direction, the first officer pulled the two levers for the fuel supply. When the emergency exits in the roof could then be opened, the cockpit was already a meter under water. Both pilots exited the machine through these emergency exits and climbed onto the wings, from where they climbed to the hatches in the cargo compartment in the aft cabin area. The first officer tried to open the starboard hatch, but this was not possible, although the handle could be turned. With combined forces and support from occupants from inside the cabin, the pilots finally managed to open the port hatch. Two passengers were able to leave the machine through the opened emergency exit and climb onto the wings of the machine. The pilots discovered an infant and the unconscious flight engineer, both of whom were floating in the water that had entered the cargo compartment. The first officer pulled them both out of the sinking machine. There were no more passengers to be seen. The flight engineer stated that he had inspected the landing gear flaps before take-off and could not see that they were ajar. However, his method was not foolproof. Ultimately, the malfunction of the landing gear door trigger mechanism was assumed to be the most likely cause of the accident.
Victims and survivors
The 15 remaining passengers drowned in the machine. The captain and first officer were uninjured, the flight engineer had suffered minor facial injuries and was hospitalized for observation on suspicion of a concussion .
root cause
The rescued passengers later stated that it would have been impossible to open the rear cabin doors from the inside after landing because the luggage and luggage nets were placed in the plane in such a way that the handles of these doors were inaccessible. The patrol boat did not arrive until eight and a half to nine minutes after the accident, as the boat crew had expected that the machine would land in another area and had been looking for it there. Contrary to the flight safety regulations, the landing was carried out in an area in the water that was not monitored by air traffic control. Air traffic control monitored Nuuk Bay, as it was often floating debris that could pose a threat if an amphibious aircraft such as the Canso landed in water. Most of the debris was garbage from a nearby garbage facility that was blown into the bay by the wind.
As it was feared that the Canso could sink completely, the machine was towed to the island of Qeqertarsuaq. The machine ran aground there. It was then towed to the port of Nuuk, where it was further examined. It could be determined that the landing gear was retracted on landing. The nose landing gear flaps were missing, which is why the thesis was investigated very early on that the flaps had been torn off during the water landing and the machine was flooded via the front landing gear shaft. Three scenarios were considered as the cause of the landing gear flaps tearing off:
- A faulty landing technique
- A collision of the machine with objects or ice on the water during landing
- A malfunction in the mechanics of the landing gear flaps, as a result of which the flaps were not closed and locked on landing
The very little experience of the flight captain in his function and with the type of aircraft used spoke in favor of the first scenario. It was questioned whether the pilot was even experienced enough to be used in passenger operations in Greenland. There were also opinions that landings at speeds in excess of 80 miles per hour would generate such water pressure that the nose gear doors of a PBY Canso would be torn off. Experts from the Danish Air Force denied this. During the investigation into the accident, four test landings were carried out with a PBY Canso on loan from the Danish Air Force at speeds of 80 to 95 miles per hour. The investigation found that landings at speeds of 96 miles per hour with descent rates of 150 feet per second can be considered normal on a PBY Canso. The thesis of a faulty landing technique was thus rejected.
The option of a collision of the machine with objects on landing could not be completely discarded, as there was generally a lot of floating debris in the fjord and there could also have been ice floes in the water in some places. Investigators found, however, that a collision with an object would have produced an impact sound that could have been clearly heard inside the machine. None of the survivors could remember hearing such a sound. After a collision, the machine could possibly have been thrown back into the air. The pattern of damage in the landing gear well suggested that the structure here had been exposed to forces coming from below. The thesis of a collision with objects was thus also rejected.
Finally, the scenario of a malfunction in the mechanics of the nose landing gear doors was investigated. For this purpose, various hydraulic assemblies and locking mechanisms that were used to operate the nose landing gear and landing gear flaps were removed from the machine and taken to the Værløse military airfield in Denmark for further investigation . Upon inspection, it was found that the parts were in very poor condition. It was found that the hydraulic valve for operating the landing gear doors had leaked at times, which could have affected the opening and closing of the doors. Accordingly, the locking bolts could have triggered before the flaps were fully retracted. In such a case, the locking bolts would have prevented the flaps from closing completely and the doors would have been seven centimeters open. The warning light in the cockpit would have indicated that the flaps were locked, since the microswitch belonging to it is dependent on the reset mechanism of the locking bolts. The flight engineer stated that he had seen the flaps before departure and that he could not find that the flaps were ajar. The flight engineer's test procedure was not considered foolproof by the commission of inquiry. Ultimately, the investigation committee considered the defect in the locking mechanism of the landing gear flaps to be the most likely cause of the accident.
swell
- Accident report PBY, CF-IHA in ICAO Circular 71-AN / 63.
- Accident report PBY, CF-IHA in the Aviation Safety Network
- Crash of a Canadian Vickers PBV-1A Canso off Nuuk: 15 killed
- Årsagen til flyveulykken ved Godthåb endnu ikke fuldt clearly stated in the Atuagagdliutit of May 24, 1962