Cape Town - An aviation expert has said that the plane crash that claimed five lives in the Plattekloof area on Sunday may have been the result of a "procedural approach that went wrong".The aviation term 'procedural approach' refers to a pre-arranged flight path a plane takes, often while awaiting permission to land.Aviation expert Eon de Vos of Crew Resource Management on Sunday posted on Facebook possible reasons for the crash, based on the images released by Emergency Medical Services."Appears at this stage [unconfirmed] to be a procedural approach that went wrong. First responders reported very low visibility around the Tygerberg area," De Vos wrote in a post with an accompanying picture.De Vos also suggested that the plane appeared to have attempted to land, based on "three tracks made by the undercarriage" of the plane.But Arthur Bradshaw, former general manager of the Air Traffic and Navigation Services Company (ATNS), said it was unwise to speculate too much about the exact nature of the crash until all the facts were made available.Bradshaw did say, however, that the holding procedure involved when an aircraft’s landing is delayed was common and not complicated. "It’s a refined system based on radar operations. The holding stacks too are quite efficient. It’s a normal procedure."'Technical glitch'News24 reported on Sunday that a "technical glitch" with flight systems at Cape Town International Airport caused flight delays for most of Sunday morning.The glitch is understood to relate to flight slot coordination, which allocates an order for incoming and departing air traffic.ATNS spokesperson Percy Morokane said the technical failure "could have been experienced anywhere in the world".Morokane emphasised that the air crash involving an aero-medical fixed-wing aircraft from Namibia bound for Cape Town could not be linked to the system failure.He told News24 on Monday that ATNS’s report could take some time to compile before its release.