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ASN Wikibase Occurrence # 235534
Last updated: 27 April 2020
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Date:19-AUG-2018
Time:11:41
Type:Silhouette image of generic AS50 model; specific model in this crash may look slightly different
Eurocopter AS 350B3 Ecureuil
Owner/operator:Heli Bernina
Registration: HB-ZMI
C/n / msn: 7697
Fatalities:Fatalities: 0 / Occupants: 4
Other fatalities:0
Aircraft damage: None
Category:Serious incident
Location:Samedan (LSZS) -   Switzerland
Phase: Take off
Nature:Domestic Non Scheduled Passenger
Departure airport:St. Moritz-Samedan Airport (SMV/LSZS)
Destination airport:St. Moritz-Samedan Airport (SMV/LSZS)
Investigating agency: STSB Switzerland
Narrative:
The crew of the single-engine, two-seater Tecnam P2002-JF, registered as HB-KOU, was on a flight for the pilot for briefing at Samedan airfield (LSZS), Switzerland. Shortly before noon the pilot and instructor got ready for the return flight to Biel-Kappelen (LSZP). At 11:39:21 the pilot, sitting in the left seat, reported on the frequency of the Aerodrome Flight Information Service (AFIS) that they were at the holding point of runway 21 and ready for take-off. The AFIS (Flight Information Service Officer - FISO) staff member on duty then reported the current wind and added that the crew on runway 21 could take off at their own discretion ("[...] runway 21 take off your discretion."). The pilot confirmed this and rolled onto runway 21. Shortly afterwards, at 11:39:38, the pilot of the single-engine, six-seat turbine helicopter Airbus Helicopter AS 350 B3, registered as HB-ZMI, reported for the first time on the AFIS frequency and announced that he was on the ground at the base of Heli Bernina and ready for take-off towards the reporting point Sierra, crossing the runway via the Final Approach and Take-off Area (FATO) markings. This flight was a commercial sightseeing flight with three passengers. The FISO immediately replied that a single-engine aircraft would roll into take-off position on runway 21 and that HB-ZMI could take off at its discretion via the FATO and Sierra flight path: "[...] traffic a single engine lining up runway 21 for departure, [...], take off your discretion FATO Sierra.". The pilot confirmed this and stated that he was looking for traffic. A few seconds later, at 11:40:09, the FISO again contacted HB-ZMI with the proposal to proceed via threshold 03: "[...] suggest to proceed via threshold 03" As the FISO later indicated, due to a delay that occurred during the taxiing of HB-KOU on runway 21, it had the impression that HB-ZMI was better off via threshold 03 than via FATO. According to the pilot, the HB-ZMI was hovering above the landing field of Heli Bernina, which is located west of the airport buildings and from which the runway is not visible. The pilot confirmed receipt of this radio message, turned the helicopter around its vertical axis in the desired take-off direction and initiated take-off towards runway threshold 03. A little less than half a minute later, at 11:40:38, the FISO radioed HB-ZMI that a departure via FATO was now better, as the aircraft was already halfway down the runway: "[...] now is z'spot, better via FATO, the aircraft is mid runway." As the FISO later stated, he had sent this message because he had noticed that the HB-KOU was already at take-off and that the HB-ZMI was still unexpectedly and unusually on the ground for him. He had assumed that the pilot of the HB-ZMI would see the HB-KOU and cross behind her. The pilot of the HB-ZMI immediately replied that he would fly via FATO. He subsequently changed his take-off direction by 180, first flying parallel to the runway and then in a right turn towards FATO (see Figures 1 and 2). As the pilot later stated, he concentrated on his right side, as he expected the aircraft to be on that side. HB-ZMI then crossed the runway in the FATO area without the pilot ever noticing HB-KOU, which in reality was still to his left.
The flight instructor on board the HB-KOU stated that during the take-off run on runway 21 he had the HB-ZMI constantly in sight from the time of take-off. He had assumed that the helicopter pilot would also see their aircraft, continue flying parallel to the runway and only cross behind them. He was therefore very surprised when HB-ZMI turned in ahead of them and crossed the runway immediately before HB-KOU. The instructor immediately took over the control the pilot had until then and at an altitude of about 250 ft above the runway, he turned left to avoid the HB-ZMI. The pilot stated that due to his position in the left seat he had no visual contact with the HB-ZMI at first. Only when the HB-ZMI crossed in front of them at an estimated distance of about 150 m did he see the helicopter. The flight instructor then flew a slightly rising full circle to the left and immediately reported this on the radio with the remark that the helicopter had come very close to them. Afterwards the HB-KOU continued its departure as planned.

STSB Conclusions
The serious incident in which a dangerous approach between a starting light aircraft and a starting helicopter occurred is due to the fact that the helicopter pilot crossed the runway axis immediately before the starting aircraft without having visually checked its position beforehand.
The following facts contributed to the incident:
- Both the FISO and the crew on board the aircraft assumed that the helicopter pilot would see the aircraft and cross behind it without having confirmed these assumptions by the helicopter pilot.
- The FISO intervened several times by radio regarding the helicopter's departure route, which may have led to a certain confusion and an incomplete picture of the traffic situation on the part of the helicopter pilot.
A systemic contribution to the incident was that the landing sites of the local helicopter companies and the special approach and departure routes to these landing sites contained risks due to the location of these landing sites behind the FISO building and the resulting restricted visibility conditions, and in addition were not published either in the Aeronautical Information Publication or in the airfield briefing.

Sources:

STSB

Accident investigation:
cover
  
Investigating agency: STSB Switzerland
Status: Investigation completed
Duration: 1 year and 8 months
Download report: Final report


Revision history:

Date/timeContributorUpdates
27-Apr-2020 09:57 harro Updated [Aircraft type, Cn, Operator, Nature, Destination airport, Accident report, ]

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