Our planned landing distance must be within 60% of landing distance available, does this planned landing distance include only the AFM distance or the 1.67 distance?

AFM Landing Distance - 2500'
EX: 6000' x .60 = 3600' (60% of 6000 is 3600')
Our AFM distance of 2500' is less than 3600' (60% rule) we are legal to land.

OR

AFM Landing Distance - 2500'
EX: 6000' x .60 = 3600' (60% of 6000 is 3600')
The difference this time is I take 2500' x 1.67 = 4175'
The 4175 exceeds the 60% rule and we cannot land on that runway.

So, my question is, does the 60% rule use the AFM distance OR the 1.67 distance?

I think you are getting wrapped around the axle. The 1.67 is based on the AFM distance, so your 4175 number would be correct. Keep in mind this is for flight planning. Your actual distance may vary and require inflight recalculation dependent on variables such as tailwind, braking action, possible wet runway Calc, Etc.

That's not the answer to my question.

Yes it is. The 1.67 is a multiplication factor to get the 60% distance. If your AFM landing distance is 2500' then 2500 x 1.67 = 4,125 your minimum runway length. The AFM number is still your actual stopping distance, so if you stop in 2500 ft, you're only using 60% of a 4,125 ft runway. That's the whole idea of using the factor for planning.

Your AFM distance should be "actual landing distance" which is calculated from crossing the 50' screen height at the threshold (displaced threshold, if applicable), throttles to idle, touchdown after about a 1600' to 1800' flare distance (50' screen to touchdown) and MAXIMUM braking with spoilers, if applicable deployed. Test pilots proved this could be done in that distance. "Legal Field Length", aka factored distance, aka 60% rule is supposed to give some allowance for pilot technique, etc.

GF

Will using the AFM landing distance satisfy the 60% requirement? Or, is the AFM x1.67 distance needed to satisfy the 60 % requirement?

To the OP - in the example you gave, 6000ft runway available, the required (AFM plus 1.67) is 4175. Since 4175 is less than 6000' that runway meets the requirement for planning purposes under 135.

Boeing aircraft are certified with a demonstrated landing distance. The test flight is accomplished at Vref, touchdown at 1000', max manual braking and no reverse thrust. This is the distance in the AFM.

From the demonstrated landing distance the required FAR Dry Landing Field length is calculated by the following method:

Demonstrated landing distance = .6 x (Available Runway Length). Or rewritten: 1.67 x (Demonstrated landing distance)=available runway.

For example, if the AFM distance for a given weight is 2500', then the required FAR Dry Landing Field Length for dispatch is 2500' x 1.67 = 4175'.

FAR Wet Landing Field Length is the Dry distance increased by 15%, or Dry x 1.15 = FAR Wet Field length

In the above example, the required Wet Landing Field Length would be 4175' x 1.15 = 4801'.

The AFM landing data is the certified landing distance provided by the OEM that is required by FAR Part 25 and 121.

Manufacturers will also provide Advisory Landing distances that include auto brake settings, non-normal configurations and contaminated runway conditions.

The Advisory distances are now factored to account for a longer flare distance and a 15% additive in accordance with the SAFO 06012 and TALPA ARC recommendations.

Don't Factor the Factor!

AFM landing distance is 2500ft

2500ft x 1.67 = 4175ft

you can land on any runway greater than 4175ft and be legal for the 60% rule.

Multiply the AFM Landing Distance by these numbers depending on the conditions and operation to see the minimum runway length required.

1.25 80% if DAAP approved
1.43 80% + 15% for Wet Runway
1.67 60% Rule
1.92 60% Rule + 15% for Wet Runway

Threegreens,

You need to be able to land within 60% of the runway. There are two ways to get to this number.

1. Get the runway length, take 60% percent of that and compare with AFM landing distance.
2 get AFM landing distance and multiply by 1.67 to get minimum runway length.

Example: runway is 10.000 max AFM landing distance is 6.000. On the other hand if you check the AFM and calculate that landing distance is 6000,multiply that by 1.67 and you get 10.000

Same calculation just from different sides. To calculate what 60% is multiply by .6 if you have a landing distance that is 60% multiply by 1.67 to find out what 100% is!!

1 divided by .6=1.67

Multiplying runway length by .6 will give you max landing distance, multiplying AFM Landing distance by 1,67 will give you minimum runway length