HEATHROW locals please be warned that a Beech King Air BE200 turboprop will check the calibration of the ILS (instrument landing systems) on all four runways during the nights of 18, 19, 20 and 21 September (Thursday to Sunday) between 2300 and 0500. This will involve the aeroplane over-flying the runways around 20 times each night and using minimum engine power on most occasions. If and when you hear the aircraft (and the small 6/8 seat pressurised aircraft is one of the quietest around) don”t get alarmed. There is no national emergency. http://www.baa.com