Atlantic Airways Flight 670
| Atlantic Airways Flight 670 | |
|---|---|
 The affected aircraft in July 2004 |
|
| Accident summary | |
| Accident type | Rolling over the runway |
| place |
Stord Airport, Sørstokken , Norway
|
| date | October 10, 2006 |
| Fatalities | 4th |
| Survivors | 12 |
| Injured | 6th |
| Aircraft | |
| Aircraft type |
 BAe 146-200 A
|
| operator |
 Atlantic Airways
|
| Mark |
 OY-CRG
|
| Departure airport |
Stavanger Airport , Norway
|
| Stopover |
Stord Airport, Sørstokken , Norway
|
| Destination airport |
Molde-Arø Airport , Norway
|
| Passengers | 12 |
| crew | 4th |
| Lists of aviation accidents | |
The Atlantic Airways Flight 670 was a charter flight to the Faroese airline Atlantic Airways from airport Stavanger to Molde Airport with a stopover on Stord airport . On October 10, 2006, a serious incident occurred on this flight when a BAe 146-200 A rolled over the end of the runway in Stord and fell off a cliff. In the accident, 4 people were killed and 12 survived.
plane
The aircraft involved in the accident was a British-made BAe 146-200A . The machine was the work of British Aerospace at the factory airfield Woodford , Metropolitan Borough of Stockport , final assembly. The aircraft had the factory number E2075. The machine had completed its maiden flight on June 23, 1987 with the test number G-5-075 . In July 1987 the delivery to the Pacific Southwest Airlines followed. The machine received the aircraft registration N369PS . After the merger of this airline with USAir , the machine went to Atlantic Airways, where it went into operation with the registration number OY-CRG . For the airline, the machine was the first of this type to be flown in. The four-engine short - haul aircraft was equipped with four Lycoming ALF502R-5 engines. At the time of the accident, the machine had an operating performance of 39,828 operating hours with 21,726 take-offs and landings. The last technical maintenance was carried out on September 25, 2006.
The BAe 146 is a jet-propelled aircraft specially designed for operation at airports with short runways. With its four engines, it is designed for flat landings where the nose and main landing gear hit the runway at the same time. The machine has powerful wheel brakes and large spoilers to reduce lift and increase drag immediately after touchdown. The machines do not have a thrust reverser .
Airport
Stord Airport is a regional airport located on the Sørstokken peninsula on the island of Stord. The airport is 49 meters above sea level. The runway with the designation 15/33 can be approached from north-north-west and south-south-east. It is 1460 meters long and 30 meters wide.
The runway sleepers are 130 meters long at both ends of the runway, making the available runway length 1200 meters. There are steep cliffs along both ends of the runway. At the time the airport was built, the structural conditions at the airport met the statutory safety requirements, but these had been tightened before the accident. It was suspected that the runway was damp at the time of the accident and no such information was passed on to the pilots.
airline
Atlantic Airways is the national carrier of the Faroe Islands and was at the time owned by the Faroese government. At the time, OY-CRG was one of five BAe 146s that belonged to the Atlantic Airways fleet. The airline has signed a long-term charter flight contract with Aker Kværner as the heavy industry company was involved in the construction of the Ormen Lange natural gas spring near Molde. The charter flight contracts provided for regular scheduled flights between Stavanger Airport, Sola via Stord Airport, Sørstokken to Molde Airport, Årø in both directions five times a week. The company flew in connection with the construction of Snøhvit and the Alta Airport to Stavanger via Stord. In order to enable departures from Stord at full take-off weight, Atlantic Airways applied to the Norwegian Civil Aviation Authority on February 18, 2005 for permission to use a longer runway for the take-off run in Stord. The application was rejected on the grounds that the conditions in Stord were already below the internationally recommended safety minimums.
crew
There was a four-person crew on board, which consisted of a master, a first officer and two flight attendants. The pilot in charge was the 34-year-old captain Niklas Djurhuus, the first officer the 38-year-old Jakob Evald. The pilots had been flown in as passengers on an Atlantic Airways flight to Stavanger the previous evening. The flight captain had flown the route before and made a total of 21 landings at Stord Airport.
Flight history
The charter flight was operated by Atlantic Airways for Aker Kværner . On the flight, the company's workers were to be transferred from Stavanger Airport in Sola to Molde Airport via Sørstokken on Stord. Aker Kværner's shipyard was located on Stord. The machine had landed in Sola the previous evening at 11:30 p.m. and had undergone a maintenance inspection every 48 hours that night, which was completed at 5:00 a.m. In Stavanger 12 passengers had taken place in the plane. The flight started at 7:15 a.m. That morning it was raining lightly, the wind was blowing at a speed of 5.8 knots (3 meters per second), at an altitude of 750 meters there were some clouds in the sky. The visibility was very good with visibility of more than 10 kilometers. The virtual barometric pressure (QNH) was 1.021 hectopascals. The flight went smoothly up to the approach to Stord.
At 07:23 am, the pilots contacted Flesland's air traffic control and stated that they wanted to fly to runway 15 on visual flight. This would have corresponded to an approach from a north-northwest direction and a landing against the wind. Air traffic control in Flesland gave the pilots the clearance at 07:24 a.m. to descend to 1200 meters. The aircraft left the controlled airspace at 07:27. At the same time, the flight information service in Sørstokken had visual contact with the aircraft. The pilots decided to approach runway 33. In the corresponding landing with a slight tail wind, although a longer braking distance was to be expected, but thus would accelerate the arrival since the web was in flight direction and thus the approach is not only a traffic pattern to be flown had. The buoyancy aids were extended to 33 degrees at 7:31 a.m., which reduced the airspeed from 150 to 130 knots (approx. 280/240 km / h). The pilots had aimed at a landing speed of 112 knots (approx. 207 km / h) and were guided by the Precision Approach Path Indicator . The machine crossed the runway threshold at a slightly increased flight speed of 120 knots (approx. 220 km / h) and touched down softly on the runway at 7:32 a.m., a few meters behind the ideal landing point.
the accident
One second after touching down, the first officer called out the activation of the spoilers, which the captain activated half a second afterwards. Two seconds later the officer called: "No spoilers". He then glanced at the hydraulic pressure gauge, the switch set correctly. The braking force of the machine was reduced due to the failure of the spoiler system .
In the meantime, the master had switched the thrust levers from flight idle to ground idle and activated the brakes six seconds after touching down. For a period of 12.8 seconds after touching down, various screeching noises from the tires could be heard on the voice recorder. The braking continued halfway down the runway. Up to this point in time, the pilots did not see any significant speed reduction. The captain tried unsuccessfully to generate better braking force by pressing the brake pedals. He then pushed the brake lever from green to yellow. This activated the emergency brake and, as only became known in the course of the aircraft accident investigations, the anti-lock braking system was deactivated. Witnesses saw smoke and water spray rising from the landing gear.
From this point on, the point of no return was reached, at which the aircraft no longer had enough speed to make a missed approach . When the captain realized that the machine would most likely shoot past the end of the runway, he considered whether to steer the machine to the left, where it was going down steeply, or to the right, where there were rocks. As a last resort, the captain tried to reduce speed by first turning the machine abruptly to the right and then to the left before the end of the runway. At 07:32 a.m. local time, 22.8 seconds after touchdown, the machine fell at a low speed of around 30 km / h down the almost vertical slope behind the end of the runway at Stord. The machine rolled a few meters down the slope at an angle of about 45 degrees and plowed its way through the branches until it finally came to a stop. The wings broke off and the escaping kerosene caught fire.
Rescue and recovery operation
Three seconds after the plane fell off the cliff, the flight information service activated the distress alarm, which the rescue team confirmed four seconds later. Five seconds later, the flight information officer called the ambulance control center of the medical emergency service. Four minutes later, the police were notified, as was the Southern Norway Rescue Coordination Center, which dispatched its rescue helicopters. The police arrived at the scene of the accident at 7:44 a.m.
The machine had come to a halt on the slope about 46 meters from the end of the runway and 50 meters from the sea. When the machine stopped, the pilots switched off the kerosene supply and activated the engine extinguishing system. Nevertheless, a fire broke out 13 seconds after the machine fell off the cliff, initially focusing on the right wing and the central fuselage section, but quickly spreading.
The pilots could not announce the evacuation because the device was not working. The starboard and port front doors were blocked by the impact, as was the cockpit door. After the accident, the passengers climbed through the hull of the machine to the port-side rear door. Several passengers who had been sitting in the front part of the aircraft decided to leave the aircraft via the stern, as this part of the aircraft had remained largely intact.
The two pilots tried to open the cabin door to evacuate the passengers, but it was blocked. All further attempts to come to the aid of the passengers failed and had to be stopped because of the increasingly intense heat. Finally, seriously injured, the pilots climbed forward out of the cabin windows.
The injured were flown to hospitals in rescue helicopters. Three passengers and a Faroese flight attendant were unable to get out of the plane in time and perished in the flames.
45 seconds after the aircraft had rolled over the runway, the first fire engine from the airport fire department arrived at the scene of the accident, the second five seconds later. Within a minute and 45 seconds of the accident, a large part of the hull was on fire. The tail buckled 3 minutes and 30 seconds after the incident and 5 minutes and 45 seconds after the roll-over, engine number 3 switched off. Fighting the fire turned out to be difficult because the machine was in impassable terrain and the trucks could only drive up to the end of the runway. A fire engine left the scene of the fire after 8 minutes to be refueled with water and returned after another 5 minutes. The first fire engine of the local fire brigade arrived after 18 minutes. The firefighters initially saw no one near the wreck and assumed that all occupants were killed in the accident. They later realized that the people standing around were survivors. The fire was extinguished at 9:30 a.m.
A large part of the fuselage was destroyed by the fire, the aircraft nose and the underside of the fuselage in the cockpit area were preserved. The wing tips and ailerons were almost undamaged. The front wing spar was preserved so that the wings stayed together when lifted. The inner parts of the wings, including the spoilers, were destroyed, but two spoiler actuators were recovered. The stern remained largely intact. Most of the light metal components of the engines were destroyed. The compressor blades remained intact and showed no evidence of damage prior to impact. Three assemblies - the left main landing gear, an engine cover and engine number 4 - were found between the runway and the main wreckage and were not affected by the fire.
Accident investigation
The accident investigation was conducted by the Accident Investigation Board Norway (AIBN) . The flight accident investigators were flown to the scene of the accident by helicopter at 13:08.
The accident was filmed by three people. The recordings of one of the witnesses turned out to be particularly useful: the recording began 13 seconds after the machine rolled over the runway and lasted 21 minutes. The witness was across from Stokksundet at a distance of 1.5 kilometers from the scene of the accident. The witness sold his video tape to TV 2 , which handed the video over to the accident investigation authority. Investigators found that the runway was damp when they arrived, but could not determine whether it was wet during the accident.
Due to the massive destruction caused by the fire, it was almost impossible to conduct a meaningful accident investigation. The torn off left main landing gear was examined.
The commission of inquiry marked all tire tracks along the runway. The first tire tracks that they could assign to OY-CRG were 945 meters behind the threshold of runway 33. Tire abrasion was found. While initially following the center line, it could be determined that the machine was steered to the right after 1,140 meters and to the left 1206 meters. At 1274 meters, the machine slid to the left at an angle increasing gradually to 25 degrees and rolled over the runway after 1465 meters.
The flight data recorder was recovered, but was severely damaged by the fire. The magnetic tape-based device of the type Plessey Avionics PV1584J sent to the investigation center for aviation accidents. There, only three sections could be reconstructed using the remains of the tape. On the first one hour of the flight from the Faroe Islands to Stavanger was recorded, on the second 12 seconds of the approach to Sørstokken, which ended 43 seconds before the last three-second segment, on which the seconds 6 to 3 before the end of the recording were recorded .
The cockpit voice recorder of the type Fairchild A100S used a more permanent storage medium. It was sent to the same laboratory for examination, but no data could be read there due to fire damage to the circuit board . When the device was sent to the manufacturer, they were able to perform repairs that allowed the data to be successfully restored. The audio files were sent to the accident investigation center, where a chronological sequence of the processes in the cockpit could be reconstructed. It could also be determined that the spoiler lever had been brought into the correct position at the time of the accident.
The behavior of the pilots in the cockpit was professional - all communication in the cockpit was closely related to the flight. Correct crew resource management was carried out. The captain estimated that the machine would have come to a standstill on the runway had it been 50 to 100 meters longer. The first officer estimated the speed when taxiing over the slope at 5 to 10 km / h and was of the opinion that the machine would have come to a stop with a further 10 to 15 meters of runway length.
The six spoiler actuators were sent to a Norwegian Air Force facility for further investigation . Radiographic examinations confirmed that the valves were all in a retracted position. Flight simulator tests were carried out with the landing flaps retracted, but the machine could also be stopped under the prevailing circumstances within the runway area. From the investigations it was concluded that a landing with retracted landing flaps may be possible on a dry runway, but not when it is wet.
It was not possible to determine why the spoilers did not deploy on landing. Three hypotheses were considered - a mechanical failure in the gear lever, a failure of two microswitches in the gear lever, or two open switch-disconnectors in the spoiler lifting system.
It was found that at the time the master activated the emergency brake , the anti-lock braking system was deactivated because the emergency brake was not linked to the ABS. This selection blocked the brakes and resulted in a special form of aquaplaning in which the friction forces made the tires so hot that they slide over a layer of vapor on the runway, which greatly reduces the braking effect. This fact was made worse by the short safety zone behind the runway end and the lack of drainage channels on the runway surface. This sequence of events was able to be reconstructed in particular on the basis of a chassis tire that had a brake plate . This suggested that the friction generated during braking was concentrated on the point on the tire where the brake plate developed. This only allowed the conclusion that the tire stood still during braking and the brakes were therefore locked. According to the investigators, the blocking of the brakes had increased the braking distance of the machine by around 60 percent. The speed of the machine while rolling over the runway was estimated at 28 to 37 km / h.
The damage to the machine was not caused by taxiing over the runway, but rather by the terrain of the steep mountain slope. The fire started due to a fuel leak after the accident in connection with a short circuit in the electrical system. The fire then spread to the tanks, which ultimately led to the extent of the fire. Oxygen was added to the fire by an engine that was still active after the collision. Although the fire department arrived quickly at the scene of the accident, the rough terrain prevented them from efficiently containing the fire during the crucial period of the evacuation.
Before the accident, the aircraft was airworthy and certified, the pilots also had all the necessary authorizations and were in good physical and mental condition. The pilots had not undergone any training to prepare them for a failure of the landing flaps. The location of the airport and the lack of adequate safety standards played a decisive role in the outcome of the accident.
consequences
Flight 670 is the only Atlantic Airways incident resulting in death or aircraft loss. The airline stopped its flights to Stord in autumn 2007.
swell
- "Report on aircraft accident on October 10, 2006 at Stord Airport, Sørstokken (ENSO) Norway involving a BAE 146-200, OY-CRG, operated by Atlantic Airways", Accident Investigation Board Norway
- Accident report in the Aviation Safety Network
- Operating history BAe 146-200, CC-CET on planespotters.net
Individual evidence
- ↑ Atlantic Airways Aircraft Accidents , Aviation Safety Network , accessed April 21, 2019.
Coordinates: 59 ° 47 ′ 34 " N , 5 ° 20 ′ 23" E