After an uneventful flight from Rotterdam (RTM), the crew were cleared for an ILS approach to runway 27 at London-Heathrow (LHR). After the landing gear was selected down but the crew noticed that the left main landing gear showed an unsafe indication. The captain decided to carry out a go-around. Before initiating the go-around manoeuvre he asked the first officer to consult the ‘MAIN GEAR UNSAFE AFTER DOWN SELECTION’ check list to see whether he should raise the gear. The gear was then raised during the go-around. The aircraft was instructed to climb to 3000 feet and entered the Epsom NDB holding point at 12:01. Recycling the gear was also unsuccessful. The first officer then left the flight deck to check visually if the left main gear was down and locked. His inspection showed that the gear was not in a safe condition. The ‘Alternate Down Procedure’ was followed, but this was also unsuccessful. The captain then carried out a level ‘2g’ (60ø bank) turn at 170 kt. This manoeuvre, however, did not affect the left main gear unsafe indication. At 12:12 the crew decided to perform an emergency landing. After preparing the cabin for the emergency landing, the crew intercepted the ILS to runway 09R. The aircraft’s touchdown was normal, right mainwheel first. About 5 seconds after all the landing gear were in ground contact the left main landing gear collapsed and the aircraft left wing tip, left propeller and the rear left portion of the fuselage contacted the runway. The aircraft veered to the left coming to rest on the hard surface clear of the runway in Block 81. The AAIB bulletin did not contain a Probable Cause statement.