But seriously, why low fly at 400 feet during the RETURN from a job? We were always urged not to do so for good neighbourliness reasons. It's a well documented fact that the chance of a bird strike is far greater at low level. At my unit (and the company I worked for) used to encourage operating between 1200 and 1500 feet, whenever possible, above the main low level risks (wires, LL fast jets and most birds) and below most light aircraft, whilst being a bit less noisy for the anti-police helicopter lobby on the ground near the unit.