Spanish Airport and Air Traffic Control authority AENA has ordered a number of external investigations into last Saturday's embarrassing power cut at Palma airport which left over 40'000 tourists trapped in the dark for six hours and cost airlines millions of pounds. The director of Son San Joan airport, Mariano Menor, said yesterday that technicians have located the fault and know what the damage is, although as yet the exact cause of the power cut has yet to be confirmed. Yesterday Menor toured the airport sub station where the fault has been discovered and said that AENA, while carrying out its own investigation, has also contracted the services of a number of outside technicians. Until the results of all the inquiries are known, Menor is refusing to comment on what caused the fault which disabled all essential services. However, suggestions that foul play is to blame have been strongly rejected, but AENA is prepared to accept that the cause could have been a design fault. Apparently a 15'000 volt spark in the power distribution section to both arrivals and departures caused a short circuit at 6am last Saturday. But Menor explained that the short circuit sent temperatures in the sub station soaring, damaging the emergency generators. The fault was apparently repaired by 11am, but it took technicians over an hour to re-establish power connections with the main terminal because of the widespread damage in the sub-station.