Book Description

An extension and revision of the HARD-1 (Handy Approximate Radius Determination) combat radius calculation procedure described in RM-5280 for aircraft carrying external stores. HARD-3 calculates the radius capability for a particular aircraft having known climb and cruise performance, fuel consumption, drag, etc. The method is somewhat more complex than HARD-1 but it provides greater flexibility and improved accuracy: a wider choice in cruise conditions is now available, and the effect on radius of non-distance-gaining fuel allowances is computed more accurately. The computer program allows for variation in the disposition of empty fuel tanks and for target-bound refueling. Although designed specifically for a ground-attack mission, the procedure may be adapted for other missions. The results compare favorably with estimates made by following the mission-planning procedures described in military flight manuals. The JOSS program is included, along with a sample set of calculations and an explanation of the equations used. (Author).