A helicopter pilot who flew to a Sydney McDonald's to pick up some lunch has insisted he had permission for the landing.

Locals were left stunned when the helicopter landed at a park next to the fast food restaurant in Rouse Hill about 4.20pm yesterday.

The pilot was seen exiting the aircraft and collecting his order from the nearby McDonald's, before getting back into the chopper and flying away.

Speaking with KIIS 106.5'S Kyle and Jackie O this morning the pilot, who identified himself as "Dan", said he got permission to land at premises.

"Every now and then we do that sort of stuff," he said.

"Kyle if you ever need a cheeseburger give us your coordinates of where you live and we'll drop in with it."

Dan called into the show after Kyle and Jackie O promised the pilot of the helicopter US$1000 if they got in touch.

He asked for the money to be donated to Ronald McDonald House.

9NEWS has been told by the Civil Aviation Safety Authority (CASA) the landing was not technically illegal if the pilot had permission from the owner of the land.

CASA said investigations into the safety of the chopper's landing and take-off were ongoing.