Report on aviation accident at Oslo airport Gardermoen, Norway on 11 January 2017 with Cessna Aircraft Company 560 Encore, LN-IDB, operated by Hesnes Air AS
Luftfart rapport 2020/03 eng
The crew lost control of the aircraft shortly after taking off from Gardermoen. From a height of approx. 1,400 ft above the ground, the nose of the aircraft tipped down abruptly. In order to regain control and prevent the aircraft from colliding with the ground, the controls were forcefully pulled. The aircraft levelled off approx. 170 ft above the ground before the crew could continue climbing. Due to large G forces in connection with the incident, the aircraft was substantially damaged. AIBN has determined that a probable explanation for the aircraft's sudden dive is that the tailplane stalled as a result of icing caused by contamination from slush spray from the runway and/or from falling snow and sleet. The investigation has not revealed any technical malfunctions in the aircraft and its control systems.
There were icing conditions at, and in the airspace above Oslo Airport Gardermoen. After flying from Switzerland for more than two hours in approximately minus 50°C, the aircraft's structure (fuselage and wings) was chilled. The aircraft's ground stop lasted approximately 15 minutes at an air temperature of 0°C. The taxiways and runway were covered with 3-6 mm of slush and it was snowing when the aircraft took off without being de-iced.
The crew, which consisted of a Commander and a First Officer, had flown from Bern in Switzerland to Gardermoen with a passenger on board. After disembarking the passenger at Gardermoen, the aircraft was scheduled to be flown to its home base at Sandefjord Airport Torp without passengers on board. The crew had planned to make the ground stop as short as possible and if the weather conditions permitted, they would avoid de-icing. According to the crew, the snow did not accumulate on the wings before departure, they could only see melted water on the wing surfaces and therefore decided not to de-ice the aircraft.
The aircraft's anti and de-icing systems on the wings and tailplane were switched on, but AIBN's assessment is that the systems were not suitable to remove this relevant type of ice and snow. With the existing conditions at Gardermoen during the ground stop, AIBN is of the opinion that the aircraft should have been de-iced before take-off.
AIBN is issuing two safety recommendations based on this investigation. One goes to the aircraft manufacturer Textron Aviation / Cessna where the manufacturer is asked to inform the customers about the accident and the risk of tailplane stalling. The other goes to the Civil Aviation Authority Norway and deals with the Authority's routines when approving organisation of airlines.
Sikkerhetstilråding
Sikkerhetstilråding SL nr. 2020/01T
Onsdag 11. januar 2017 mistet besetningen kontrollen på en Cessna 560 Encore i lav høyde etter avgang. Den sannsynlige forklaringen på at flyet plutselig stupte ned, er at haleflaten steilet som følge av ising påført fra slush-spray fra rullebanen og fra fallende snø og sludd. Haleflatens gummi-avising «boots» var i automatisk modus og inaktiv under avgangen og den påfølgende steilingen. Textron/Cessna opplyser at de ikke tidligere har erfart tap av kontroll som følge av ising på haleflaten på sine flymodeller.
Statens havarikommisjon for transport tilrår at Textron/Cessna informerer alle sine kunder som opererer Cessna Citation om denne ulykken og om faren for forurensning på haleflaten i form av is eller annet med steiling som resultat.
Sikkerhetstilråding SL nr. 2020/02T
Onsdag 11. januar 2017 mistet besetningen kontrollen på en Cessna 560 Encore i lav høyde etter avgang. Undersøkelsen har vist at ansvarlig leder (AM) hadde flere vesentlige roller innen sikkerhet i selskapet. De forutsatte monitorerende og korrigerende roller, slik det synes å være tiltenkt gjennom EASA’s PART-ORO, var dermed fraværende.
Statens havarikommisjon for transport tilrår at Luftfartstilsynet endrer sine rutiner for godkjenning av organisasjoner i tråd med intensjonen i EASAs regelverk.
Fakta
| Sted | Oslo airport Gardermoen, Norway (ENGM) |
| Hendelsesdato | 11.01.2017 |
| ICAO flyplassindikator | ENGM |
| Luftfartøy | Cessna øvrige |
| Operatør | Hesnes Air |
| Reg. merke | LN-IDB |
| Flygeforhold | IMC |
| Fylke | Viken |
| Type hendelse | Luftfartsulykke |
| Type flyging | Ervervsmessig, ikke-regelbunden |
| Kategori luftfart | Middels, fly (5 700 - 10 000kg) |
| Flykategori | Landfly, Multi-engine, Turbofan/Turbojet |
| FIR/AOR | ENOS (Oslo ATCC) |