An AAIB (UK) investigation revealed strong magnetic anomalies in the holding area for Runway 28 at London-City Airport.
In October 2006 a Raytheon Hawker 800XP experienced significant navigation problems after taking off from London City Airport (LCY) and was unable to comply with the Standard Instrument Departure (SID). The crew were able to recover heading information after approximately 10 minutes and landed back at LCY without incident. It transpired that several similar incidents had previously occurred with other aircraft and there have been similar incidents subsequent to this one.
The magnetic anomalies were caused by the 68 piled beam structures situated under Runway 28 Holding Area, remains of flame cut bollards spaced a regular intervals under Runway 28 Holding Area, reinforced concrete in Runway 28 Holding Area, and the railway lines below Runway 28 Holding Area. LCY was built on the site of a disused ship