[Dave Wallace]

The Night Raid Report for Duisburg says:
"Route Briefed: - All Groups: BASE - PETTEN - ENKHUISEN - DUISBURG - turn left - NOORDWIJK - BASE.
Yes - 109 Squadron (and also 105 Squadron beginning in the summer of 1943 when they began to use Oboe) always flew their own route and it was secret. They first went to "the waiting point" which was 10 minutes flying time (about 60 miles) from the target and was where they picked up the Oboe beam. They would listen to their VHF radio for their two letter call sign in Morse code, my father's call sign was "FL". Once they heard their call sign the Navigator would switch on the Oboe set, the Pilot would hear either dashes or dots in his headset as he turned down the 17 yard wide beam and steered the Mosquito into the centre of the beam where he heard a continuous low note that resembled an oboe. The Navigator was listening a second ground station that gave him time to target and he calculated the speed to arrive on target at the exact time they were to drop. If they had a tailwind and were going to be early, the Navigator would have the Pilot do a one minute instrument turn and they would leave the beam, fly a perfect circle and rejoin the beam in the same spot they left. Each Oboe run was tracked by two ground stations, each with about a dozen people, who plotted their position during the bombing run. The Pilot would hear dots if he was too close to the tracking station, dashes if he was too far away, & a continuous note while inside the beam. The controllers knew exactly how far off the release point (to a few yards) the drop occurred and the crews were given their results as soon as they landed. It made them quite competitive with each other.