Investigators are recommending that Spanish authorities review fuel advice for Madrid-bound flights after three Ryanair weather diversions to Valencia each resulted in pilots declaring a fuel emergency. The 26 July diversion of the Boeing 737-800s sparked controversy because the budget airline appeared to be singled out for criticism in Spain.

Ryanair publicly denounced various Spanish-led claims over the nature of the Valencia event as false, and highlighted similar cases involving other carriers which had not attracted the same attention. Investigators found a LAN Airbus A340 had also declared an emergency at Valencia.

In a joint probe with Spanish air safety agency AESA, the Irish Aviation Authority says weather forecasts indicated a 40% chance of thunderstorms in Madrid when the three flights - inbound from Palma, London and Stockholm - were scheduled to arrive. All three flights departed for Madrid and diverted to Valencia with fuel "in excess" of requirements, the inquiry says.

On approach to Madrid, the Palma flight executed a go-around and was hit by lightning. The crew diverted when remaining fuel reached 2,900kg (6,400lb) but vectoring around weather added 40-50nm (75-90km) to the nominal 150nm route. The aircraft was too high on arrival and more vectors were needed - even after it had been cleared for immediate approach after its emergency call.

The London flight discontinued its approach to Madrid after seeing preceding aircraft go around, and diverted, with 2,900kg of fuel, after weather prevented it following vectors to a holding point. It similarly experienced a prolonged flight to Valencia, and the captain indicated to the inquiry that Valencia air traffic control seemed "overwhelmed" with the traffic - at one point confusing the Ryanair flight with a LAN aircraft, adding to the workload.

The Stockholm flight, after going around, initially asked to hold east of Madrid but this subsequently became impossible. It was instead directed west, and diverted when fuel reached 2,600kg, declaring an emergency after noting that air traffic control was advising flights of 35min delays.

All the Ryanair crews declared emergencies in accordance with European operational requirements, says the inquiry, once calculated usable fuel for landing dipped below final reserve. But it also points out that diverting with fuel "close to" the minimum diversion fuel, given the circumstances, was "likely to present challenges" to the crews - particularly given that holding points southwest of Madrid increased diversion time to Valencia. The latter's controllers, it adds, were "under significant pressure" from the number of diversions to the airport.

Investigators are recommending that AESA reviews delays at Madrid to see whether additional fuel ought to be required - particularly given that "extensive" vectoring and holding often occurs when Madrid's southerly runways are in use.

Source: Flight International