The group was returning from a trip to southern France to test the new Hill GH2, one month after the end of the 1975 Formula One season.

On 28 November, the day before the accident, Hill had flown his Aztec to Le Castellet Airport, next to the Paul Ricard Circuit in southern France.

The group were at the Paul Ricard Circuit testing the team's new Hill GH2 racing car for the 1976 Formula One season.

Contact was made with London Air Traffic Control Centre at 20:45 and a weather report for Elstree was obtained, giving a visibility of 2,000 metres and a cloud base of 300 ft AGL.

At 21:21, having descended to 4,000 ft (1,200 m) passing south of Lambourne VOR, Hill was informed that visibility at Elstree had decreased to 800 metres.

It then descended further, colliding with more trees, rolling to the right, striking the ground with its wing tip and finally crashing into a copse.

[6][7] Elstree's runway was equipped with edge lights and a low-intensity visual slope indicator, but lacked any radio aid and there were no published instrument approach procedures for the airfield, making it unsuitable for low-visibility operations.

On all three attempts, descending to as low as 300 ft (90 m) AGL, the airfield lights either remained not visible or were spotted too late to proceed with the landing.

[8] It was sold by Melridge Aviation in April 1972 to Grand Prix (Bahamas) Ltd and a request was made to remove the aircraft from the FAA register.

The investigators offered three possible reasons for the pilot allowing the aircraft to descend into the ground:[6] The Times reported that Hill may have over-estimated his flying ability.