A report by air accident investigators in Spain has concluded that Ryanair operates flights with minimal fuel which “leaves none for contingencies below the legal minimums”.
The investigators noted that Ryanair’s practice of operating at the limit of fuel requirements means it saves money.
But they say this is leading other airlines to follow suit and putting airports at risk of facing “simultaneous emergency declarations for lack of fuel”.
The report recommends authorities across Europe revise guidelines on fuel reserves to take account of Ryanair’s policy.
The investigation by Spain’s air accident investigation agency CIAIAC into whether Ryanair operates flights with less than the recommended amount of reserve fuel concluded the carrier did not breach safety regulations.
CIAIAC examined incidents at Alicante in May 2010 and Valencia in July 2012 when Ryanair crew issued “Mayday” warnings and requested emergency landings because of low fuel reserves.
The report makes a series of recommendations, including that Ryanair modify its flight plans and operations manual and require its crews to “speak slowly and clearly enough so that they may be easily understood”.
It criticises the “inadequate decision-making” of a young flight crew in the 2010 incident and their failure to speak “slowly and distinctly” when communicating with air-traffic controllers.
The report concludes of Ryanair: “Though they comply with the minimum legal requirements, they tend to minimise the amount of fuel ... and leave none for contingencies.”
The report notes the carrier’s fuel policy “is based specifically on minimising the fuel load at the start of the flight ... As a result, Ryanair aircraft generally land with the minimum required fuel.
“This policy ... gives Ryanair a competitive advantage over other airlines that tend to fly with larger amounts of reserve fuel and therefore use more fuel.”
It notes: “Market competition is forcing other airlines to reduce their costs by adopting fuel policies similar to Ryanair’s.
“This could make it commonplace for airplanes to arrive at their destinations with the minimum required fuel and without reserves in the event of a delay.
“The arrival of several aircraft flying with minimum fuel at the same airport could give rise to several simultaneous emergency declarations for lack of fuel.
“In light of this, aviation authorities should establish expected typical average delay times at various airports ... to provide guidelines to airlines on the increased fuel reserves needed to fly safely.”
The incident in May 2010 saw a Ryanair Boeing 737 on a flight from Stansted to Alicante divert to Valencia after failing to land at Alicante in difficult wind conditions.
The crew declared an emergency before landing at Valencia where the aircraft was found to be below the final reserve-fuel level.
On July 26 last year thunderstorms over Madrid led to the serial diversion of flights to Valencia and three Ryanair aircraft were among four to request emergency landings because they had reached the limit of required fuel.
Spanish airports authority Aena demanded an investigation and the Irish Airline Pilots Association (IALPA) accused Ryanair of “making pilots uncomfortable about taking extra fuel” on flights.
That produced an angry response from Ryanair, which said it would “never put fuel before safety”.
Ryanair chief executive Michael O’Leary subsequently accused the Spanish authorities of orchestrating a campaign telling "half-truths” about the carrier.