At the end of Vaughan-Fowler's tour with 161 Squadron he requested a transfer to another operational squadron, preferably one under command of Group Captain Pickard, whom he had flown under while at 161 Squadron.
He was assigned to 21 Squadron, which was part of Pickard's 140 Wing.
At the time Vaughan-Fowler's transfer 21 Squadron had converted to the de Havilland Mosquito and was flying intruder missions.
These missions were put on to suppress German night fighter activities against Bomber Command.
The Mosquitos would fly out at night to locate and orbit an airfield known to be in use by German night fighters.
Vaughan-Fowler's night flying and navigational skills were useful in this endeavor.
Just having the Mosquito in the air was a strong deterrent to German operations.
As his plane neared the field the airfield lights would suddenly be turned off, and they would not launch as long as he was overhead.
He was promoted to Flight Lieutenant in November 1943.

The usual practice was for pilots to rotate from an operational squadron to a training or administrative duty before they were rotated back to operations.
After 60 operational flights the pilot's obligation to fly was fulfilled.
However, Vaughan-Fowler loved to fly.
After each of his tours he scrambled to get assigned to another squadron in a flying role.
He was able to continue to fly operationally until the end of the war.

In January the group began training for a daylight raid against a French prison.
At the end of Vaughan-Fowler's tour with 161 Squadron he requested a transfer to another operational squadron, preferably one under command of Group Captain Pickard, whom he had flown under while at 161 Squadron. He was assigned to 21 Squadron, which was part of Pickard's 140 Wing. At the time Vaughan-Fowler's transfer 21 Squadron had converted to the de Havilland Mosquito and was flying intruder missions. These missions were put on to suppress German night fighter activities against Bomber Command. The Mosquitos would fly out at night to locate and orbit an airfield known to be in use by German night fighters. Vaughan-Fowler's night flying and navigational skills were useful in this endeavor. Just having the Mosquito in the air was a strong deterrent to German operations. As his plane neared the field the airfield lights would suddenly be turned off, and they would not launch as long as he was overhead. He was promoted to Flight Lieutenant in November 1943.
The usual practice was for pilots to rotate from an operational squadron to a training or administrative duty before they were rotated back to operations. After 60 operational flights the pilot's obligation to fly was fulfilled. However, Vaughan-Fowler loved to fly. After each of his tours he scrambled to get assigned to another squadron in a flying role. He was able to continue to fly operationally until the end of the war.
In January the group began training for a daylight raid against a French prison.
Peter Vaughan-Fowler