4 ms·
> The FAA says that for each percent of downhill slope, landing distance is increased by 10%. This is accurate as to their recommendation, but it was surprisin
by inaccuratebee 9mo ago
> The FAA says that for each percent of downhill slope, landing distance is increased by 10%.
This is accurate as to their recommendation, but it was surprising. I know it’s inaccurate, because at a perpendicular angle there would be no way to land. I know they don’t allow an angle that steep, but that means this is “gut feel” inexact math that seems unsafe.
- InitialLastName 9mo agoThe force required to stop on an inclined plane is proportional to the sine of the angle. At angles less than 10 degrees (~17% slope, far steeper than the FAA would allow for an airport), the small angle approximation of sine is within 0.5% of linear.
- dsvf 9mo agoI don't know if their math is incorrect, but your intuition of the limit case is - downhill slope is the ratio of height change per length. A perpendicular angle thus has "infinite percent" slope (since the denominator, length, is zero), which intuitively matches an infinite landing distance.