135 math dummy

[minimums]

What are some good formulas that are easy to remember in calculating the 60% or 80% (DAAP) rules? Plus the additional 15% for nasty runways.

Us math morons want to know

 

[leardawg]

Compute the ACTUAL landing distance, then DIVIDE that by .6 or .8, whichever is applicable.
Ex. If your computed actual landing distance is 3000 ft, 3000 divided by .6 = 5000. This means you need at least 5000 feet of runway available to be 135 legal. If the 80% rule applies, 3000 divided by .8 = 3750 as the minimum ruway length.

If the runway is wet, multiply the initial result x 1.15 . Ex. If you need 5000 feet minimum dry runway available, 5000 x 1.15 = 5750 feet minimum runway available. (3750 x 1.15 = 4313 minimum runway available for the 80% situation).

If you're like me, you will need a calculator handy (i.e. with you on the road) to figure it out.

Hope this helps. (Maybe someone else has a better or quicker way).

 

[Hawk Driver]

What are some good formulas that are easy to remember in calculating the 60% or 80% (DAAP) rules? Plus the additional 15% for nasty runways.

Us math morons want to know

Multiply your landing numbers from the AFM by 1.92 for contaminated runways. This gives you the new landing distance including the 60% required 135.

For non-contaminated runways either mulitply your numbers from the AFM by 1.67 or divide the number by .6, the 1.67 isn't exact but pretty close.

Example: 3000 required by AFM for landing
3000 x 1.67= 5010 Part 135 landing distance required dry.
3000/.6 = 5000 Part 135 landing distance required dry.
3000 x 1.92 = 5760 Part 135 landing distance required wet.

Hope this helps.

HD

 

[minimums]

Awesome

Thanks guys, I appreciate the help! Good examples.