On the 14th of February in 2010, a private jet disappeared from radar on a routine ferry flight from the Czech Republic to Sweden.

At 20:08, the twin-jet Cessna 550 B Citation Bravo departed Prague with a two-man crew. It was a ferry flight to Karlstad; there were no passengers nor cabin crew. The flight crew were well qualified and no previous issues with either pilot had been recorded. The night flight was planned for Karlstad in Sweden. The take-off was normal and there were no weather restrictions.

It should have been a routine flight. But eleven minutes later, the aircraft entered German airspace and then disappeared.

The Air Traffic Controller contacted the aircraft to state they were cleared to climb from FL260 to FL330 (26,000 feet to 33,000 feet). The flight crew never responded. Radar recordings showed that the Citation departed from its flight path with an abrupt 90° turn to the left. Then at 20:19, the radar signal disappeared.

The crash site was discovered that night near Reinhardtsdorf-Schöna, a small village in Saxony near the Czech border. The aircraft was completely destroyed. The mountainous terrain was densely covered with conifers and 30-40 cm (12-16 inches) of snow. The impact crater was 2 metres deep and covered an area of 16m by 16m (52 feet x 52 feet) with evidence of a post-impact fire. The debris from the crash was found spread as far as 120 m (400 feet). The snow at the crash site was covered in fuel.

The German Federal Bureau of Aircraft Accident Investigation (BFU) transported the wreckage to Brunswick for evaluation. They were able to recover the control and tail surfaces and determine that the important structural parts of the plane were complete. They also recovered the Cockpit Voice Recorder.

And that’s when the mystery was solved.

The recording from the cockpit was shocking: the flight crew discussed whether the other had ever done a barrel roll in the dark. They agreed to try one. They initiated the manoeuvre and swiftly lost control of the aircraft which plunged over 20,000 feet to crash into the forest.

Analysis of the Cockpit Voice Recorder showed evidence that shortly before the crash an aerobatics manoeuvre (barrel roll) was initiated.

The aircraft was neither designed nor approved for such manoeuvres.

The BFU issued the following Safety Recommendations:

Recommendation No.: 10/2010

The CAA-CZ responsible for air operators within the Czech Republic should arrange for an inspection of the involved air operator’s aircraft in regard to structural overload.

Recommendation No.: 11/2010

The CAA-CZ should determine actions for the improvement of the air operator’s Quality Management System and the Safety Culture

The investigation into the accident by the German Federal Bureau of Aircraft Accident Investigation (BFU) is still in progress.

The Citation may not be rated for barrel rolls but the Czech pilots certainly weren’t the first to try it:

The stresses on the aircraft during this kind of aerobatic maneouvres are considerable, which is why the first recommendation of the BFU was for the air operator to be forced to do an inspection of every aircraft to be sure that the they are still structurally sound.

The bizarre aspect for me is that both pilots felt this was a reasonable thing to do during an admittedly boring night flight to Sweden. That’s the point of the second recommendation: a hard look at the culture within which these pilots were employed.

I was suprised to recognise my personal bias about pilots when I read up on the flight crew. The Captain of the aircraft was a 27-year-old woman. Belly rolls in the dark seemed such a stupidly macho thing to do, I just presumed that the flight crew consisted of two young men.

You can read the special bulletin (in German only) on the BFU website: Bundesstelle für Flugunfalluntersuchung – Thema 1 – BFU Bulletin Februar 2010. The final report has not been released.