In May 1944 he returned to the Pathfinder Force to start a third tour of operations.
Rowland was posted to the Pathfinder Force that marked targets for other aircraft on strategic bombing missions over Europe.
Improvement in tactics like the development of the Pathfinder Force, created against Harris's wishes, also improved bombing accuracy.
Thus the tempo of development within the Pathfinder Force kept pace with the events of the times.
In 1943 he transferred to No. 35 Squadron of the Pathfinder Force but went back to his old squadron.
He was responsible for conceiving and forming the Pathfinder Force despite opposition from Arthur Harris.
In the end the decision was taken to install H2S units, starting with the Pathfinder Force.
No. 8 Group, also known as the Pathfinder Force, was activated on 15 August 1942.
Pathfinder Force was set up to lead the bomber stream to the target areas and drop markers for the remainder of the force to aim at.
No. 5 Group developed its own techniques separate to the Pathfinder Force and was using "sector bombing".