Adverse weather conditions had prevented Total from sending a helicopter to the leaking rig earlier this week, but the weather forecast for yesterday and today was more favourable.
" Total confirms that a helicopter took off from Aberdeen at 10:30 am (0930 GMT) today with the objective of landing on the Elgin PUQ (process, utilities, quarters) to allow a specialised team to perform a reconnaissance mission of the Elgin wellhead platform and the G4 well, if it is safe to do so," a spokesman said, adding that the crew would "proceed with extreme caution".
Aerial surveillance suggested that a sheen of light hydrocarbons resulting from the leak was evaporating naturally and would have a minimal environmental impact, the UK energy ministry said.
Successful relief operations will depend on weather conditions during the next few days.
The UK's MetOffice expected weather around Aberdeen to be "mainly dry and rather cloudy, with still a little light rain mainly towards the Moray Coast".
"It will be a milder night and winds will stay light," the MetOffice said.
For today it forecast conditions to be mainly dry, with light rains and maximum temperatures of 9 degrees Celsius.
Total said earlier this week that the team of engineers would assess conditions on the platform and find out whether a so-called "well kill" was feasible, by pumping mud into the well, and whether any other measures would be necessary.
Another, more expensive option being pursued in parallel is to dig two relief wells to the source of the gas at 4,000 metres depth, far below the sea bed.
Experts have said that option can take up to six months to complete, and Total has said it would push up daily costs to $3 million.
The gas leak was reported on March 25 and is spewing an estimated 200,000 cubic metres of natural gas from the evacuated platform into the air per day, forming a highly explosive gas cloud around the platform.
Total has said the leak is costing it $2.5 million a day so far.
