A major probe is underway after a Jet2 flight from Scotland landed in Spain ‘below its final fuel reserve’ with less than 30 minutes worth of fuel left. 

Flight LS-189 from Glasgow Airport, operating on a Boeing 737 aircraft, issued a 'fuel Mayday' before making an emergency priority landing at Palma de Mallorca Airport.

The incident occurred on Sunday, August 27, when severe thunderstorms with hurricane-force winds lashed Mallorca, causing widespread damage across the island as well as flight chaos, with over 50 flights cancelled and 18 flights redirected away from Palma de Mallorca airport.

The stormy weather also saw a P&O Britannia cruise ship crash into another vessel off the coast of Palma after its moorings snapped, resulting in a number of passengers suffering minor injuries.

Due to the severe storms, the flight, carrying 187 passengers and six crew on board, was forced to enter into a number of holding patterns at 35,000 ft over the Pyrenees, before eventually landing safely in Mallorca almost three-and-a-half hours after departing from Glasgow. 

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The seriousness of the event has promoted a full investigation by Spain’s Civil Aviation Accident and Incident Investigation Commission (CIAIAC), a division of the Ministry of Transport, Mobility and Urban Agenda (MITMA), Diario De Mallorca reports.

A preliminary report by the CIAIAC details that the Jet2 flight “received priority and, finally, after three hours and twenty-six minutes of flight, landed at eleven twenty" in Palma de Mallorca, "without incident, but with 39 kilograms less fuel than the final reserve fuel.”

The average flight time between Glasgow Airport and Palma de Mallorca Airport is two hours and 30 minutes, the report notes.

The distress call was also made due to the fact that “if they remained in flight, they would land with less than 1,159 kilos of fuel”, according to the report.

Raquel Sánchez Jiménez, Acting Minister of Transport, Mobility and Urban Agenda, concluded that “there were no injuries and the aircraft was undamaged.” 

The fuel carried by aircraft is highly regulated, with the fuel for a commercial flight divided into taxi fuel, trip fuel, contingency fuel, alternate fuel, final reserve fuel, additional fuel, and extra fuel.

Simply Flying describe final reserve fuel as “the absolute minimum fuel that is required for an aircraft to remain airborne safely”. 

30 minutes of fuel is required for a jet (such as the Jet2 plane) and 45 minutes for a turboprop, as jet aircraft can hold at higher altitudes in thinner air. 

As per procedure, when the calculated usable fuel predicted to be available upon landing at the nearest airport where a safe landing can be made is less than the planned final reserve fuel, the pilot-in-command shall declare a situation of fuel emergency “MAYDAY FUEL”.

Full-scale fuel emergencies such as was the case with the Jet2 flight from Glasgow are considered very rare.

READ MORE: 'Too heavy to fly' flight from Scotland makes emergency landing

In 2019, the pilot-in-command of Vistara flight UK 944 travelling from Mumbai to Delhi in India when poor weather conditions meant the plane was unable to land in Delhi and had to divert to Lucknow - around 260 miles away.

The pilot was forced to issue a ‘fuel Mayday’ call after the plane began running out of fuel and had started eating into emergency reserves, with the plane landing with just 200 kg of fuel remaining – enough for five to six minutes’ flying time.

News of the incident involving the Jet2 Glasgow to Mallorca flight comes after two planes travelling from London Heathrow to Los Angeles declared mid-air emergencies while in the skies above Scotland.

On Sunday, September 17, Virgin Atlantic flight Flight VS23, operating on a Boeing 787 aircraft, declared a 'Squawk 7700' while flying over the Hebrides.

Footage from FlightRadar24 showed the plane performing a U-turn over North Uist at 34,000 feet before diverting back to Heathrow. 

Virgin Atlantic later confirmed that the aircraft returned to Heathrow "as a precautionary measure" as a result of a "minor technical issue". 

Less than 24 hours later, Delta Air Lines flight DL187 made a U-turn over Glasgow after also declaring an emergency at 34,000 feet. 

A Delta Air Lines spokesperson told The Herald that the flight returned to Heathrow shortly after take-off "due to a medical emergency". 

Unconfirmed reports online suggested the reason for the diversion was because one of the flight deck crew felt unwell.

A Jet2 spokesperson said: “We can confirm that flight LS189 from Glasgow to Palma did not run out of fuel. At no point was anybody’s safety compromised and the aircraft landed as normal.

"Due to the severe weather conditions affecting the island of Majorca on Sunday 27th August, many aircraft due to land at Palma Airport were held for longer than usual at the request of air traffic control.

"Due to this, and as a precautionary measure, our highly-trained crew onboard the flight requested a priority landing, which is standard operating procedure when the flight crew believe that the aircraft may land with less than reserve fuel amounts.

"We are fully supporting the authorities with their investigation, as well as conducting our own investigation.”