The disappearance of the MH370 from air traffic control displays was possibly deliberate, or perhaps just the unfortunate result of a series of failures. Time may reveal. Perhaps more worrying is the disappearance of many planes over the well monitored skies over Europe. Earlier this month, there were reports from air traffic control centres over Austria, Germany, Slovakia and the Czech republic, that a number of aircraft disappeared from radar displays, presumably arising from the failure of secondary surveillance radar. Classic symptoms of interference were in evidence, with these aircraft being lost intermittently over a few minutes. Given that multiple radars and multiple planes were subject to the same issue, it seems like a case of unintentional interference, with some rogue system blocking the transponders on the aircraft. Initially a NATO electronic warfare exercise was blamed in Hungary. The defence ministry in Hungary denied the issues citing that the electronic warfare devices only had a range of 4000 metres. Whilst it is credible that these devices are only used for intentional interference over ranges of 4 km, it is rather odd to think that the denial implies that radio waves stop their interference potential at 4 km! However, more convincing is the fact that these military exercises only coincided on one of the occasions where the interference was reported. The investigation continues to try and identify the source, but until then I wonder if we may see some more unscientific comment, including perhaps the odd conspiracy theory or two!