Image: TJDarmstadt / CC BY via Wikimedia
A Lufthansa Cargo Boeing 777F, registered D-ALFG, returned to Frankfurt Airport shortly after take-off as a safety measure after an emergency on board due to inconsistencies in the instrument displays.
According to information from The Aviation Herald, the aircraft was flying from the German terminal to Shanghai Pudong International Airport, China, on flight GEC8402 when pilots told Mayday about uncertainty about actual altitude and airspeed.
The incident occurred on October 10th. Shortly after take-off, the commander checked the altitude display with the Frankfurt air control. The controller replied that the altitude displayed on his radar was 60 meters (200 feet), which was completely incorrect, while the crew reported that his altimeter read 1,800 meters (6,100 feet). The aircraft’s GPS indicated an altitude of 6,200 feet, creating uncertainty among the team about the reliability of the information. At the same time, the speed data also seemed unreliable.
As a result, the crew decided to take emergency action, the AvHerald reported. The commander pointed out the need for a landing priority to the air traffic controller and announced the triple “Mayday” on the phone, which indicated a risk to the safety of the flight.
He then said he would dump some of the fuel before returning to Frankfurt as the plane was being refueled for a long journey that had not taken place and had to reduce its weight so as not to affect landing performance.
After 65 minutes of take-off, the Triple-7 landed safely in Frankfurt. Interestingly, ADS-B (radio signals) data transmitted by the freighter and captured by flight tracking applications like FlightRadar24 showed that the aircraft did not climb more than 70 meters for the entire flight, which is an indication in particular that is incorrect.
The pilot’s preventive return action was found to be correct to highlight the problem of the reliability of basic flight information. According to FlightRadar24, the plane returned to flight on October 14, operating the original route to China.
The aircraft concerned is D-ALFG registered and very new. Lufthansa Cargo received it directly from the factory in March 2019.