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wantobe
07-17-2012, 08:10 AM
I am reading "Appendix A to Part 23 - Simplified Design Load Criteria". My objective is to figure out the loading on control surfaces. Clearly it is not the best bedtime reading material.:(

A23.11 Control surface loads.
(c) Surface loading conditions. Each surface loading condition must be investigated as follows:
(1) Simplified limit surface loadings for the horizontal tail, vertical tail, aileron, wing flaps, and trim tabs are specified in figures 5 and 6 of this appendix.
(i) The distribution of load along the span of the surface, irrespective of the chordwise load distribution, must be assumed proportional to the total chord, except on horn balance surfaces.
(ii) The load on the stabilizer and elevator, and the load on fin and rudder, must be distributed chordwise as shown in figure 7 of this appendix.

On my vertical tail I have a horn balance. This gives me trouble. From (1) and figure 5 I can obtain the average loading on vertical tail as some lb/sf (pounds per sqaure feet). From (i) I can calculate the loading at each span location by multiplying the local chord except the span location where the horn balance locates. (ii) does not help because the formula in figure 7 would have a divide-by-zero singularity for horn balance locations.

So how can I obtain the loading on the horn balance? I know it is a very specific question, just in case someone out there....