Air accident investigators have called for better air traffic control guidelines after a damaged plane flew over central London into Heathrow.
The cargo plane landed safely at Heathrow airport
The American cargo plane made sharp turns to lose height after one of four engines failed over Essex in 2004, said the Air Accidents Investigation Branch.
The Civil Aviation Authority (CAA) was asked to look at the way it deals with damaged planes flying over urban areas.
The CAA said it was considering the advice of the investigators.
The Air Accidents Investigation Branch, part of the Department for Transport, said in its report that the pilot's manoeuvres would not have been possible if the weather had been worse.
The plane, which took off from Germany and was bound for the US, eventually landed safely.
But the incident raised questions about whether aircraft in difficulty should be diverted over built-up areas, the report said.
The rules of the CAA, which is responsible for the safety of UK airspace, stated that it was "desirable" that damaged planes were not diverted over densely populated areas.
The investigators questioned whether those guidelines were sufficient for air traffic controllers.
"Where considered necessary, this guidance should be amended as soon as practicable," the report stated.
Chris Mason, of the CAA, said the authority would consider the investigators' recommendations.
The plane, registered to US firm Evergreen International Airlines, ran into trouble over the Thames Estuary when one of its four engines failed on 24 April 2004.
The pilot initially tried to return to Germany, but concerns about the three remaining engines prompted him to request an emergency landing in the UK.