The Operational Cycle
The waiting station may be in any direction from the PHDA. The following analysis is based on the worst case assumption that it is upwind of the PHDA and the wind strength is 10 knots. This is the worst case because it requires two 180° turns neither of which would be required for a downwind waiting station.
The first action after take-off and establishing a safe height, is to initiate a turn downwind. Due the large span the radius of turn is, for practical purposes, a function of the relative airspeeds of the inner and outer wingtips rather than bank angle. Minimum safe airspeed (sufficient margin above the stall) for the inner tip is taken as 55 knots while maximum airspeed for the outer tip (power limited) is taken as 110 knots. This has the effect that the inner tip radius of turn is equal to (actually fractionally less) than the span and the required bank angle to keep the ball in the middle is approximately 1.5° i.e. the inner tip needs to be about 80m belowthe outer. Thus, as soon as a safe height is reached after take-off, the inner tip speed is adjusted to 55knots while maintaining altitude while the outer tip builds up speed and altitude to reach 110 knots and 80m above the inner tip. Once established a 180° turn (this is the worst case)will take 5.5 minutes. On reaching the PHDA a second 180° turn is required in order to turn into wind for landing. It is likely that the PHDA will be drifting downwind and that the optimum place to deploy the reflector sheet will in the downwind half of the PHDA on a downwind heading so that the sheet can be towed to maintain its station relative to the PHDA. Thus yet another (worst case) 180° turn will be required after landing i.e. in the buoyancy mode. Being carried out in this mode the turn is completely different from the airborne turn. It is executed by going ahead with the engines on one half of the wing and going astern (reverse thrust) on the otherhalf... In this mode the turn could well take as much as 15 minutes before deployment of the reflecting sheet can be started.
As soon as the desired heading is reached the terminal floats can be lowered and deployment started. On completion, and assuming all four members of the squadron are in place, action is complete other than any repositioning called for by central control. In due course it will become apparent whether the operation has been successful or the hurricane has matured to the point where there is no prospect of success. In either case the squadron will return to their waiting stations.