How Did A Wasp Nest Cause A Boeing 757 To Crash In 1996?

February 1996 saw the Dominican Republic’s deadliest aviation accident, when Birgenair flight KT301 crashed after departing Puerto Plata. The crash is also the joint-deadliest involving the Boeing 757, along with American Airlines flight 77 on September 11th, 2001. The accident’s unlikely cause was a wasp nest, but how did this bring the plane down?

Birgenair Boeing 757
The aircraft involved was one of two 757s operated by Birgenair. Photo: Aero Icarus via Flickr

What was Birgenair flight 301?

Birgenair was an Istanbul-based Turkish charter carrier that commenced operations in 1988. Its first aircraft was a Douglas DC-8, although it later added aircraft from various Boeing and McDonnell Douglas families. Among these were two Boeing 757-200s. The airline had close relationships with tour operators in Germany and the Dominican Republic.

The former of these stems from the fact that its initial flights served Turkish Gastarbeiter (‘guest workers’), many of whom had moved to Germany for employment. As far as its services to and from the Dominican Republic were concerned, Birgenair flew these in co-operation with German tour operator Öger Tours and Dominican company Alas Nacionales.

Alas Nacionales had an air operator’s certificate (AOC), but no aircraft, hence it partnered with Birgenair to serve Europe. One such flight was operated by Boeing 757s from Puerto Plata to Frankfurt via Gander and Berlin. In 1996, this was the subject of a tragic accident.

Birgenair Douglas DC-8
Birgenair’s first aircraft was a Douglas DC-8. Photo: Felix Goetting via Wikimedia Commons

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A deadly wasp nest

On February 6th, 1996, Birgenair flight KT301 was well loaded with 176 passengers, of which 167 were German, and nine were Polish. Of its 13 crew members, 11 were Turkish, with the remaining two being Dominican. The aircraft operating the flight bore the registration TC-GEN, and was 11 years old at the time. It previously flew for Eastern Air Lines and Nationair.

This particular flight was the aircraft’s first in 20 days. For nearly three weeks, it had been sitting unused at Puerto Plata’s Gregorio Luperón International Airport (POP). In the two days immediately before the accident, its pitot tubes had been left uncovered. These devices measure operational factors like the plane’s airspeed and altitude.

Birgenair Boeing 757
Birgenair’s other 757, TC-GUL. Photo: Simon Butler via Flickr

Owing to the lack of cover, a wasp nest was found to have been built inside one of these tubes before the flight. This blocked the tube’s ability to correctly register airspeed, which had fatal consequences. Having departed Puerto Plata, the captain’s airspeed indicator (ASI) was overreading due to the blockage, showing a speed of 350 knots (650 km/h).

Crash and impact

This prompted the autopilot to reduce the aircraft’s speed and pitch its nose upward, despite the first officer’s ASI correctly showing a speed of 200 knots (370 km/h). The autopilot then disengaged, and the pilots themselves reduced thrust. This caused the aircraft to stall, as well as a flameout of the left-hand engine due to inadequate airflow.

Birgenair Boeing 757
Birgenair ceased operations just over a month after the crash. Photo: JetPix via Wikimedia Commons

With the pilots having now increased the thrust in an attempt to fight the stall, the fact that only the right-hand engine was running threw the plane into a spin. The aircraft inverted, and, with the crew unable to recover the situation, it then crashed into the Atlantic Ocean.

Tragically, all 189 occupants of Birgenair flight 301 died on impact. According to a memorial in Frankfurt, only 73 bodies could be recovered, with 116 lost to the sea.

The accident severely impacted Birgenair’s international reputation. Extensive negative publicity, particularly in Germany, caused a sharp drop in bookings at the airline. It suspended operations on March 8th, 1996, with plans to resume in 1997. However, it ultimately ended up filing for bankruptcy shortly afterward, bringing Birgenair’s story to an end.

Were you aware of the crash of Birgenair flight 301 in 1996? Do you know of any other incidents where wildlife has inadvertently caused safety issues? Let us know your thoughts in the comments.