Previous

Next 

Wrong opinion about bridle

Here's something you can often hear :

"The longer the bridle, the more accurate it is"

What do you think about it ? Here's, in chord percentage, the influence of the lengthening by 2cm of a A line (and consequently the shortening by 2 cm of the C line). In the first case, the bridle is 60% of the chord long, and in the second case 120%. The length of the B line is the same in both case. Initial position : 25%. Position of A,B,C (chord percentage) : 10%, 31% et 60%. Chord length : 1m

First case : bridle is 60% of the chord length. The new position of the meeting point of A,B,C lines is the intersection of the two circles. Result : a variation from 25% to 30% (+5%).

First case : bridle is 120% of the chord length. The new position of the meeting point of A,B,C lines is the intersection of the two circles. Result : a variation from 25% to 34.5% (+9.5%).

Conclusion : the longer the bridle, the more difficult to tune it is (a small variation of bridle length means a bigger variation in the profile angle of attack).

 Previous

Next