This I posted on another forum:
Another document I have recently acquired is about trials of the Norden bomb sight in the Mosquito during July 1944.The conclusions were that the bomb sight was well made, was easy to learn how to use, but was more complicated in operation than the British Stabilized Automatic Bomb Sight (SABS).There were tactical limitations to the use of the Norden. A bank of 18° would topple the gyro - not an issue in a B-17 and the way they were used, but not good for a type such as the Mosquito. Furthermore, in the Mosquito installation a bank of 5° would make it impossible for the bomb aimer to sight through the telescope.It was noted that of 25 test bomb runs at 15,000ft in only 15 was it possible to aim and drop bombs due to the weather. The Norden required a long straight run up to target with little or no cloud in that time.During the tests it was found that it was difficult to level the gyro in flight due to fluctations of the bubbles in the level gauges. It was thought that this was due to slight instability of the Mosquito, no issues having been experienced in the similarly sized P-38. The experience was that the sight would often need to be releavelled, after which the crosshairs would invariably be off target.The Mosquito used was a B.XX, whose CoG was further aft than normal, which may have contributed to the instability experienced.Bombing results were poor, with an average distance from target of around 500 yards.