Guernsey Police are appealing for witnesses or anyone with information.
The laser attack occurred on 16 November at around 7.50pm.
It is believed to have come from the coastline in the Havelet Bay area.
'Incidents like this, whilst rare, are treated extremely seriously and can cause severe distraction to pilots in a critical time of flight,' Guernsey Police said.
'This not only endangers the aircraft and its passengers on board, but people on the ground below.'
Pointing a laser at an aircraft is an arrestable offence.
Police are appealing for anyone who was in the area at that time that may have any information to come forward.
Investigators are also keen to speak with any private or business owners that may have CCTV footage covering the incident location, which is around the La Vallette bathing pools area [a quarter mile south of Havelet Bay, St Peter Port].
Contact PC 177 Le Galloudec on 725111 or contact Crimestoppers, anonymously, on 0800 555 111.