Three Ryanair flights approaching Valencia airport in Spain had to call mayday emergencies because of low fuel -- two of them within three minutes of each other, it has emerged.

All three Ryanair aircraft had been diverted from Madrid, about an hour's flight time from Valencia, because the Spanish capital was beset by serious thunderstorms two weeks ago.

It meant that other aircraft which were flying into Valencia, some of them also diverted from Madrid, had to remain in a holding pattern and give priority to the Ryanair flights to land.

Ryanair's Stephen McNamara confirmed the low-fuel emergencies to the Sunday Independent on Friday. He said: "Due to thunderstorms over Madrid on Thursday (July 26), Spanish ATC (air traffic control) instructed Ryanair aircraft to divert to Valencia where they were placed in a hold pattern. Sometime later the aircraft advised ATC that they would not have sufficient fuel reserves to return to Madrid and were permitted to land in Valencia. All aircraft landed normally. Ryanair sincerely apologises to the passengers affected by these diversions, which were due to adverse weather."

According to voice recordings of the conversation between a Ryanair pilot and ATC in Valencia, the flight commander clearly calls "mayday" because of low fuel. Less than three minutes later another Ryanair pilot also issued a mayday to Valencia ATC for the same reason.

A Ryanair spokesman confirmed that a third aircraft was also given landing priority on the same day because of low fuel.

The issue of how much fuel flight commanders on Ryanair aircraft are allowed to carry has been part of an efficiency drive at the budget airline.

At least two memorandums were sent to Ryanair pilots detailing the company's concern about what was described as "excess fuel explanations" -- a description of the reasons flight commanders have to give if they take on extra fuel over the recommended minimum fuel load.

A memorandum signed by Shane McKeon, deputy chief pilot and base captain at Stansted, and dated December 19, 2011, reiterates that pilots should only take on board the minimum as per the "plog" (planning log/flight plan).

"All of you are aware of our ongoing efficiency drive, particularly regarding fuel. The 'plog+300kgs' issue in particular has highlighted how further efficiencies are achievable and the number of 'excess fuel carried with no explanation' letters issued has fallen. There remain a small number of commanders who appear to have difficulty with operating with 'plog+300' or less."

The memorandum then outlines some of the explanations that have been offered by flight commanders for taking on extra fuel which Captain McKeon says are not acceptable.

"The most unreasonable excuse is: 'I like to land with three tonnes so I take the trip plus three tonnes.' This is not Ryanair policy, this is completely unacceptable, and is not what you are remunerated to do."

The memorandum ends: "Thank you. US senator Daniel Moynihan said: 'You are entitled to your own opinion, but you are not entitled to your own facts.' I trust this memo will be helpful in establishing facts. Thank you for reading this memo and thank you for your continued awareness of the efficiency element of the equation 'operate safely, efficiently and punctually'."

In a further statement of clarification issued on Tuesday, August 14th Ryanair’s Stephen McNamara said: “Due to severe thunderstorms over Madrid on Thursday (26 July) Spanish ATC instructed a number of inbound aircraft (including three Ryanair aircraft) to divert to and hold over Valencia Airport.

‘‘Having held over Valencia for 50mins, 68 mins and 69 mins respectively Ryanair’s 3 aircraft (following standard industry safety procedures) requested ATC permission to land immediately as they reached reserve fuel minimums, which allow each aircraft to operate for an additional 30 minutes (some 300 miles) of flying.

‘‘All aircraft landed normally with minimum fuel levels (approx 30 mins of flying) remaining.”

Sunday Independent