Oddgeir Uglum

54510163, Sep 19, 1995

Oct 6, 1993

8/132659

Richard E. Foy - Medford OR
Oddgeir Uglum - Lake Oswego OR

Erickson Air-Crane Co. - Central Point OR

B64D 116

244136

A fluid drop system for an aircraft for use in firefighting is described. The preferred embodiment uses electronic control circuitry coupled with a hydraulic controller that opens and closes the fluid tank's door panels to rate-control fluid drops based on fluid volume remaining in the tank. The circuitry produces a command generated drop rate profile based upon manual drop rate and drop fraction selector controls. It does so by constant comparison of the instantaneous volume of fluid remaining in the tank with a predetermined, desired instantaneous remnant volume in accordance with a defined, declining-volume profile, e. g. one defining a constant drop rate. A stabilized feedback control circuit ensures that, at any instant of time, the opening in the tank's door panels releases a volume of fluid that will maintain the remnant tank volume equal to the desired tank volume. Such variable forces on the fluid as inertia, acceleration, declining mass and splashing automatically are compensated for by the feedback-based fluid drop rate control circuitry. External variables such as aircraft groundspeed, heat intensity, etc.

53201850, Jun 14, 1994

Jun 15, 1992

7/898506

Richard E. Foy - Medford OR
Oddgeir Uglum - Lake Oswego OR

Erickson Air-Crane Co. - Central Point OR

A62C 3100
B64D 116

169 43

A fluid drop system for an aircraft for use in firefighting is described The preferred embodiment uses electronic control circuitry coupled with a hydraulic controller that opens and closes the fluid tank's door panels to rate-control fluid drops based on fluid volume remaining in the tank. The circuitry produces a command generated drop rate profile based upon manual drop rate and drop fraction selector controls. It does so by constant comparison of the instantaneous volume of fluid remaining in the tank with a predetermined, desired instantaneous remnant volume in accordance with a defined, declining-volume profile, e. g. one defining a constant drop rate. A stabilized feedback control circuit ensures that, at any instant of time, the opening in the tank's door panels releases a volume of fluid that will maintain the remnant tank volume equal to the desired tank volume. Such variable forces on the fluid as inertia, acceleration, declining mass and splashing automatically are compensated for by the feedback-based fluid drop rate control circuitry. External variables such as aircraft groundspeed, heat intensity, etc.