A radio frequency mix-up was to blame for a near miss at Birmingham Airport, according to an air accident report.
The pilot of a six-seater private aircraft lost contact with air traffic controllers and passed "over the top" of a stationary passenger plane.
The Socata TBM 850 landed safely after avoiding the Flybe-operated Q400 bound for Guernsey.
The Air Accidents Investigation Branch (AAIB) described the events of 12 January as a "serious incident".
In its report, the AAIB said the pilot of the TBM thought he had selected 118.300 megahertz (MHz) on his radio standby position, but in fact the active frequency was 118.030 MHz.
'High workload'
There was no time for the Flybe plane, carrying about 50 passengers, to taxi clear of the runway before the TBM arrived.
The report said: "The controller's only option was to keep the Q400 obstructing the runway and rely on the TBM pilot either going around or seeing and avoiding the Q400."
It added that the tower controller had not read a recent safety notice which contained advice for dealing with this type of situation, but did alert the other controllers on duty, and the supervisor, of the problem.
The AAIB made four safety recommendations and said the pilot's decision-making process had been "degraded" by a "high workload".
There was no damage to either plane.
BBC News - Birmingham Airport near miss caused by radio mix-up