My recollection of a suggested procedure (after high recon and at a safe altitude) as taught by Dave Denham:. .. . Establish hover;. . Check ng (compute limit with estimates prior to departure and adjust for actual) & tq;. . 1 per cent ng equals 7 per cent tq equals 200 lbs lifting power.. .. .Confined area departure-add for apparent wind:. . 1 per cent ng if 0-7 knots wind (holding hover well outside ETL);. . 2 per cent ng if 8-15 knots (buffeting at hover). . 3 per cent ng if hovering without decelerating through etl.. .. .My rule of thumb to compute NG mentally-1 degree C equals 0.25 per cent ng.