What happened
On 27 August 2023, a Boeing 737-800, registration G-DRTW, operated by Jet2.com, arrived at Palma de Mallorca Airport following a flight from Glasgow. The flight was initially delayed due to adverse weather conditions affecting the Balearic Islands. As the aircraft progressed through French and Spanish airspace, severe weather led to the activation of a Mass Diversion Plan (PDM) and a 'rate 0' restriction at Palma, meaning no aircraft were being accepted at the airport.
During the flight, the aircraft entered a series of holding patterns over the Pyrenees. During this period, the crew decided to change their destination to their alternate airport, Menorca. However, as Palma de Mallorca began to reopen, the crew decided to return to their original destination. During the descent, the aircraft' and low fuel warnings were triggered. Approximately 25 nautical miles from the runway, the crew declared a MAYDAY due to fuel, as the remaining fuel was projected to be 44 kg below the required final reserve. The aircraft landed safely at 11:20 UTC.
The investigation
The CIAIAC investigation examined the flight planning, meteorological conditions, and the management of air traffic control (ATC) services. The investigation focused on the high volume of traffic and the coordination between the Barcelona ACC and the Bordeaux ACC. The investigators reviewed the flight recorders, communications, and the efficiency of the tactical Air Traffic Flow Management (ATFM) measures implemented during the weather event. The inquiry also looked into the specific errors made during the flight plan updates and the communication challenges faced by the crew when attempting to contact the CCC sector.
Findings
- The crew had planned for extra fuel due to the anticipated adverse weather in the destination area.
- Severe meteorological conditions simultaneously affected all three major airports in the Balearic archipelago, leading to widespread airport closures.
- The investigation established that excessive workload in the CCC sector of Barcelona ACC and the collateral sectors of Bordeaux ACC was a primary cause, driven by the need to manage numerous diversions and complex coordination.
- An error occurred when a controller in the Bordeaux ACC entered the incorrect airport code (LEML instead of LEMH) into the flight plan system while the aircraft was in French airspace.
- The crew did not declare a 'MINIMUM FUEL' status prior to the emergency declaration.
- The tactical ATFM measures implemented were found to be inefficient due to the complexity of managing large-scale deviations across multiple ATC jurisdictions.
- Air traffic controllers were overloaded by the high volume of coordination required for diversions, congestion on frequencies, and aircraft entering adjacent sectors.