Flight altitude arranged too low

The reporting of the past few days on the F/A-18 crash in the Susten region has prompted the military justice system to issue a clarification. The preliminary taking of evidence by the military examining magistrate has so far revealed the following:

On Monday, August 29, 2016, shortly after 4:00 p.m., a patrol with two single-seat F/A-18 fighter jets took off in an easterly direction at an interval of approximately 15 seconds from Meiringen military airfield. The target of the patrol was an air force training area in the Sustenhorn-Dammastock region, where an air combat exercise with an F-5 fighter jet was to have taken place. The Susten region was overcast at the time, which is why the patrol did not take off in visual flight mode but in instrument flight mode. The second pilot (trailer) follows the pilot in front (leader) with the help of his on-board radar. There was no direct line of sight between the two aircraft.

Aircraft handed over to air traffic control in Dübendorf

A few minutes after the start, the second pilot lost radar contact with the leader. The cause of this loss of contact is the subject of investigation. At that time, the second pilot was still in the take-off phase of the flight, which is monitored by the air traffic control of Meiringen airfield. This is operated by Skyguide on behalf of the Swiss Air Force. The pilot then requested clearance from the air traffic controller at Meiringen for an altitude at which he could continue flying. This behavior complies with the applicable regulations in the event of an abort of radar contact. The air traffic controller then ordered a flight altitude of 10,000 feet (approx. 3,050 m above sea level). Immediately thereafter, he handed the aircraft over to air traffic control in Dübendorf. The pilot then switched the frequency of his radio to that of the air traffic control in Dübendorf.

Shortly thereafter, radio contact with the second pilot broke off. As it turned out, the aircraft crashed at Hinter Tierberg at an altitude of about 3,300 m above sea level, killing the 27-year-old pilot. There is no evidence that the pilot's ejection seat was activated.

Specified flight altitude too low

As the investigation revealed, the altitude ordered by the air traffic controller was lower than the safe minimum altitude, which for this take-off sector is 14,300 feet (approx. 4,360 m above sea level). Why the air traffic controller ordered this too low altitude and what influence this order had on the further course of the flight is the subject of the investigation. It will also be investigated how the pilot's reaction to this order is related to the crash.

To date, there are no indications of a technical failure or of a connection with the radar installation at the Meiringen military airbase.

The current investigation is a preliminary taking of evidence. It serves to establish the facts of the case and is not directed against specific individuals. At the present time, the investigation is not focusing on individual elements of the facts, but is still proceeding in all directions. It is still too early to commit to specific variants of the course of the accident and the cause of the accident. The fact that no usable data from the flight data recorder will probably be available will make additional clarifications necessary. It is therefore unlikely that the investigations will be completed before the end of the year.

Source: Military justice