TC-HEZ
2017-MAR-10 · Büyükçekmece, Istanbul, Turkey

Swan Aviation — Flight TC-HEZ

A Sikorsky S-76C++ helicopter operated by Swan Aviation struck the Endem TV Tower in heavy fog shortly after departing Istanbul. The aircraft was carrying executives from Eczacibasi Holding to a meeting in Bozuyuk when it entered an area of severely restricted visibility. The crew failed to maintain adequate clearance from the tower, which was a known and charted obstacle. The collision caused the helicopter to crash onto the State Road D100 highway, killing all seven people on board.

Aircraft
Sikorsky S-76C++
Registration
TC-HEZ
Phase
Cruise
Cause
Controlled Flight Into Terrain (CFIT)
Souls on Board
7
Fatalities
7
Origin → Dest
Istanbul Atatürk Airport, Turkey → Bozüyük, Bilecik, Turkey
Report
Final

Investigation Summary

The flight was a private charter for Eczacibasi Holding, carrying a Turkish businessman and four Russian guests. Despite heavy fog and poor visibility at the time of departure from Istanbul Ataturk Airport, the flight proceeded under Visual Flight Rules (VFR). Approximately six minutes into the flight, the helicopter entered the vicinity of the Endem TV Tower, a 257-meter (843 ft) structure. While the tower was clearly marked on aviation charts as a significant obstacle, the investigation noted that the tower was located within a designated 'no-fly' zone. The crew failed to maintain vertical or lateral clearance while operating in Instrument Meteorological Conditions (IMC). The main rotor or fuselage struck the tower, leading to a total loss of control and a subsequent impact with the D100 highway in the Buyukcekmece district.

Final Conclusions

The primary cause of the accident was the pilots' decision to continue flight into deteriorating weather conditions (heavy fog) which resulted in a loss of visual reference. This led to an accidental collision with a known stationary obstacle (the Endem TV Tower) that was clearly marked on aviation charts. The investigation highlighted that the lack of visibility prevented the crew from seeing and avoiding the tower during the low-altitude transit, and they failed to adhere to the minimum safe altitudes required for the area.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Airframe Hours
1,008
Engines
Turbomeca Arriel 2S2

Crew Experience

Pilot in Command

Total hours
4,383
On type
383

Experienced pilot who failed to maintain clearance from a charted obstacle in IMC.

Co-pilot

Total hours
3,268
On type
268

Systems & Failure Modes

i

Visual Flight Rules (VFR)

The crew was operating in conditions that likely required Instrument Flight Rules (IFR) due to fog, but they were flying in a low-altitude environment where visual contact with obstacles is critical.

i

Obstacle Collision Avoidance

The aircraft struck a stationary, charted TV tower that the crew failed to avoid due to restricted visibility.

Interesting Facts

  • 01The helicopter was manufactured in 2008.
  • 02The aircraft's Manufacturer Serial Number (MSN) was 760717.
  • 03The Endem TV Tower is a 257-meter (843 ft) structure clearly marked on aviation charts as an obstacle.
  • 04Weather at the time of the accident was reported as heavy fog with very low visibility.
  • 05The crash site was located on a major highway (D100) in the Büyükçekmece district.
  • 06All seven occupants, including two pilots and five passengers, were killed instantly.

Safety Actions & Advisories

Visibility and Obstacle Awareness

The Turkish Directorate General of Civil Aviation emphasized the importance of pilots adhering to no-fly zones and maintaining strict weather minimums, especially in areas with known high-rise obstacles like the Endem TV Tower, which was located in a restricted area.

Location

Büyükçekmece, Istanbul, Turkey · 41.0261, 28.6208

Case File History

  1. CorrectionUpdated investigation summary and safety actions.
  2. New evidenceUpdated findings and sources.
  3. Final reportUpdated investigation summary, final conclusions and findings.

Related Cases

Case ID · swan-aviation-s76-2017Last updated · Filed

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