Ian Collins aimed the light at the aircraft and forced it to turn side on, resulting in it having to abandon its call to Wolverhampton for a burglary at commercial premises on July 21. The laser was shone into the cockpit for several seconds. The aircraft was moved round in a bid to shield the crew from the beam, and CCTV was used to capture the act.
Walsall Magistrates Court was told yesterday that 35-year-old Collins, who runs a car repairs business, had been with up to six others at a fishing pool near Jenner Road, Beechdale, when it happened.
He aimed the pen while crouching by a tent.
Collins admitted shining a light at an aircraft in flight so as to dazzle or distract the pilot.
Mr Nigel James, prosecuting, said Collins, of Rochester Croft, Reedswood, had been the "main offender".
Collins had been due to face trial but indicated a guilty plea ahead of yesterday's hearing.
Mr Sarbjit Singh Lalli, defending, said: "People who were fishing had the laser pens.
"He foolishly gets involved."
Collins was fined £400, and ordered to pay £200 costs and a £15 victim surcharge.
Sentencing him, presiding magistrate John Palmer said: "It is a stupid thing to do, as well as an extremely dangerous thing to do."
It is the second time someone has been brought before the courts for such an offence in Walsall in the last week.
Matthew Robinson, 24, of Bentley, was last week ordered to pay almost £350 after admitting shining a pen at a helicopter in Little Bloxwich.