The regulatory design and operating protocols permit V1 to be as low as Vmcg. Several problems arise which are not generally well known (which is why Mutt and I keep on talking about them)
(a) Vmcg is determined for nil wind in US practice. If there is much of a crosswind then the hazards start to increase dramatically in line with the increases in the real world Vmcg as compared to the certification value. It is, of course, not as simple as this as other factors are at play as well .... but the rapid onset of loss of control is very real and ought not to be downplayed
(b) be careful of rapid thrust changes as the dynamic handling characteristics might be different to what is expected ... this is more a concern with Vmca than Vmcg but could be a surprise factor in a flex thrust situation where the pilot elects to push up the levers aggressively .. far better to caress the levers ..
(c) the conventional runway width minima are based on geometry rather than handling problems. Under critical conditions, the pilot may well not be able to contain the aircraft within the normally accepted runway width .. ie one could end up in amongst the daisies on a width limited runway...
Sometimes the situation dictates a low V1 (eg short runway). A significant sucker bait problem can arise on a long runway at low weight (eg short ferry flight) where the uncritical pilot might well just accept the low speed weight-related schedule in circumstances (eg aft cg with a decent crosswind) where the intelligent selection of an available higher speed schedule would materially reduce handling risks during the takeoff ...
Last edited by john_tullamarine; 5th Jul 2002 at 03:28.