Wiggy,
so the INS was irrelevant to the bombrun,
AFAIK.
Was the IN stand-alone or integrated?
Just to clarify the importance of an accurate heading reference for radar bombing, whether using the HRS or IN, most radar attacks would be using an offset technique.
The radar is 'fixed' on a radar significant feature some distance from the real target. In the case of a target surrounded by water features a headland gives a well defined aiming point. The bombing computer is then offset back to the real target.
The accuracy of his technique is dependent on 3 things, the ease of identifcation of the aiming point, the accuracy of the calculation of the offset distance and most importantly the accuracy of the heading reference sysetm used by the computer.
As a ball park, a one degree heading error with an aiming point 10000 yards from the target would give an error on the ground of 174 yards.
For a runway target the usual close-in aiming pont would be a hangar. This is a cultural feature and susceptible to deception so the distance aiming point would ideally be a physical feature. Also, in the case of a runway, it may be possible to breakout the runway from the surrounding terrain. This is particularly true of an airfield with parallel runway/taxyway and well vut grass.