A pilot who crashed into a house after running out of fuel would probably have reached the runway had he not blundered converting gallons to litres - but only just.

Brain surgeon Donald Campbell's Piper Seneca plummeted into a semi-detached home in West Street, Shoreham, after he allegedly made an error while refuelling, a court heard.

The consultant neurosurgeon is accused of putting six gallons too little fuel into the twin-engine US-made plane when setting out for a round trip to visit patients in Sheffield.

Campbell, 54, allegedly intended taking on 30 US gallons but in an "unforgivable" maths error he only put in 90 litres, the equivalent of just over 23 gallons.

A Civil Aviation Authority expert told a jury at Chichester Crown Court that Campbell would have landed safely at Shoreham airport on the return leg of the flight in April 2001 with the extra six gallons on board.

Flight standards officer Ian Ramsay said: "Litres is the common standard measurement and, therefore, it is a common procedure to convert from gallons to litres.

"There are many methods. You can either have a calculator. You can have flip cards that give conversions for fuel."

Philip Shepherd QC, prosecuting, asked him what difference it would have made to the flight to have taken in six gallons too little.

Mr Ramsay replied: "That is very significant because it is eating into your planned fuel reserve. It could be quite critical if you had to use your reserve fuel."

Mr Shepherd then asked if Campbell would have made it the short distance to the airfield if he had had the extra gallons.

Mr Ramsay said: "It is highly likely the aircraft would have made a successful landing."

However, he added that if it had landed at Shoreham airport "there would have been very little fuel" left in the aircraft.

The crash occurred just five minutes after homeowner Helen Monahan had left to pick up her two young sons from school.

Campbell, from Battle, denies endangering an aircraft and endangering people and property. The case continues.