507. Balance Computer Type Slide Rule


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I A Wallstenius: 507. Balance Computer Type Slide Rule. In: 24th Annual Conference, Denver, Colorado, May 17-19, pp. 20, Society of Allied Weight Engineers, Inc., Denver, Colorado, 1965.



In, 1963 a common SAS/SWISSAIR working group for standardization of aircraft weight and balance system and procedures was established. The aim of the group was to work out for the two airlines standardized basic principles for A/C weight and balance calculations and based on these principles propose proper aids for the practical execution of such calculations.
Three members from each airline representing engineering, ground handling and flight operation were delegated in order to cover all aspects that would come into the picture.
The main reason for the standardization was the risk for miscalculations that could occur when handling aircraft belonging to the counter partner.
It is evident that with same ground staff handling several operators' aircraft, there is a great danger involved in having different procedures for the balance calculation.
Several cases have occurred where the pilot has applied balance corrections, which had already been made once by the ground staff or the ground staff has omitted balance corrections which they thought should be applied by the pilot.
To minimize the possibility that the pilots misinterpret the balance information received from the ground staff, a standard was established with regard to the variables to be included in the balance calculation performed by the ground staff.
In October 1964 the working group finalized its work by a proposal to introduce balance computers type straight slide rule for use by the ground staff in their calculation and for checking purpose used by the pilots.
The purpose of this paper is to present this new type of balance computer for manual balance calculations common for SAS and SWISSAIR.
By use of these computers the ground staff is responsible for calculating the balance of the aircraft to be within approved limits up to zero fuel weight including the load distribution in the cargo holds and including the balance influence of the passengers.
Naturally, the ground staff in their weight calculation must secure that allowed take-off and landing weights are not exceeded.
Until further the new system applies only for A/C DC-8, Coronado and Caravelle, but we believe the same system can be used for all present.
Due to the fact that the balance calculation performed by the ground staff does not include balance influence of the fuel, additional calculations must be performed by the cockpit crew, especially on aircraft with adjustable horizontal stabilizer.
The working group tried to reach a common solution even on this subject but in spite of all efforts mad, different cockpit procedures make it impossible to standardize the mean to be used by the cockpit crew for calculation of C.G. and/or stabilizer setting for take-off.
In this paper, however, the SAS procedure for calculation of C.G. and stabilizer setting will be described as a computer of type straight slide rule also for this purpose is to be used for aircraft DC-8 and Caravelle.


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