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ASN Wikibase Occurrence # 200706
Last updated: 24 January 2020
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Date:15-OCT-2017
Time:14:42 LT
Type:Silhouette image of generic F2TH model; specific model in this crash may look slightly different
Dassault Falcon 2000EX
Owner/operator:Netjets Europe
Registration: CS-DLB
C/n / msn: 80
Fatalities:Fatalities: 0 / Occupants: 2
Other fatalities:0
Aircraft damage: None
Location:Amriswil, TG -   Switzerland
Phase: En route
Nature:Executive
Departure airport:MŁnchen-Franz Josef Strauss Airport (MUC/EDDM)
Destination airport:St. Gallen-Altenrhein Airport (ACH/LSZR)
Investigating agency: STSB Switzerland
Narrative:
A Schempp-Hirth Arcus glider (HB-3442), was gliding back to Amlikon Airfield, Switzerland. The gliderís Flarm collision warning device was switched on; however, its Mode S transponder was not. At approximately the same time, a Falcon 2000EX corporate jet aircraft (CS-DLB), was flying from Munich Airport in Germany to St. Gallen-Altenrhein, Switzerland. CS-DLB was equipped with a Traffic Alert and Collision Avoidance System (TCAS).
Under supervision of the Zurich ARFA approach control unit, CS-DLB was approaching the Instrument Landing System (ILS) of runway 10 at St. Gallen-Altenrhein. Flying the base leg at an altitude of 5,000 ft AMSL and in Class E airspace, the flight paths of CS-DLB and HB-3442 crossed in opposite directions. The closest horizontal and vertical distances between the two aircraft were approximately 660 m and 40 m respectively. Both crews only noticed the other aircraft shortly before the point of closest proximity. The air traffic controllers, who the crew of CS-DLB were in contact with, were unaware of the glider.

Causes:
The serious incident was an airprox between a twin-jet business aircraft and a glider, which can be attributed to the fact that the two flight crews did not visually identify each otherís aircraft in a timely manner.
The following factors were identified as contributing factors:
- The instrument approach of the business aircraft led through Class E airspace, in which air traffic control does not provide separation between IFR and VFR traffic.
- The transponder of the glider was not switched on, which was not mandatory. The fact that the glider pilot did not have radio contact with the relevant air traffic control unit, which is not mandatory either, favoured the development of the serious incident.

Sources:

https://www.sust.admin.ch/inhalte/AV-berichte/CS-DLB_HB-3442.pdf

Accident investigation:
cover
  
Investigating agency: STSB Switzerland
Status: Investigation completed
Duration: 1 year and 10 months
Download report: Final report


Images:

Photo of CS-DLB courtesy AirHistory.net


Helsinki - Vantaa (EFHK / HEL)
25 October 2008; (c) Pertti Sipilš


Source: STSB

Revision history:

Date/timeContributorUpdates
30-Oct-2017 10:10 harro Added
08-Sep-2019 16:38 harro Updated [Narrative, Photo, Accident report, ]

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