135.385 Landing Distance

[LearDriver]

The correction factors are "not" cumulative as I understand it. While, of course, it is only being wise to consider the wet landing distance. It would not preclude you from taking off if the additional 15 percent is what puts you over the limit. The wet runway factor need only to be figured into the AFM landing distance.

Take Care,

 

[charter dog]

The correction factors are "not" cumulative as I understand it. While, of course, it is only being wise to consider the wet landing distance. It would not preclude you from taking off if the additional 15 percent is what puts you over the limit. The wet runway factor need only to be figured into the AFM landing distance.

I'm not quite sure I quite understand what you mean by that. The way I read it, 135.385(d) requires that 115% of the factored dry distance be available in order to take off a turbojet airplane for the planned destination with a wet/slippery runway unless the AFM has an approved procedure to shorten the wet landing distance. Eligible on demand operators are excepted in accordance with their OpSpecs. In any case, you may also take off if a suitable alternate airport meeting all requirements is selected and available.

(d) Unless, based on a showing of actual operating landing techniques on wet runways, a shorter landing distance (but never less than that required by paragraph (b) of this section) has been approved for a specific type and model airplane and included in the Airplane Flight Manual, no person may take off a turbojet airplane when the appropriate weather reports or forecasts, or any combination of them, indicate that the runways at the destination airport may be wet or slippery at the estimated time of arrival unless the effective runway length at the destination airport is at least 115 percent of the runway length required under paragraph (b) of this section.

(b) Except as provided in paragraph (c), (d), (e), or (f) of this section, no person operating a turbine engine powered large transport category airplane may take off that airplane unless its weight on arrival, allowing for normal consumption of fuel and oil in flight (in accordance with the landing distance in the Airplane Flight Manual for the elevation of the destination airport and the wind conditions expected there at the time of landing), would allow a full stop landing at the intended destination airport within 60 percent of the effective length of each runway described below from a point 50 feet above the intersection of the obstruction clearance plane and the runway. For the purpose of determining the allowable landing weight at the destination airport the following is assumed:

So assuming no AFM procedure allows a shorter distance to be used, it appears that you need to be able to land in 60% of the effective runway length as calculated by the above method for a dry runway and 115% of the factored dry distance if wet or slippery. If conditions change enroute, you may still land if the unfactored dry or wet/slippery (as applicable) AFM landing distance is available.

Best,

 

[LearDriver]

I do see your point. It does say for (taking off) that you must have 115 percent of the effective landing distance required by section (b), the 60 percent rule, when it is wet or slippery. They make it easy don't they.

I stand corrected - I think....

Thanks,

 

[charter dog]

They make it easy don't they.

They sure don't!

I don't expect that to change anytime soon either. Working through the questions that come up on here is a great exercise for all of us. Nobody can know or remember it all and then properly apply it in the real world. We'll keep trying though!

Best,

 

[CFIIer]

just to bring this dead horse back to life...

If I'm flying to a wet rwy, and the dry landing distance is 3000ft, I multiply that by 15%, giving me 3450.
I then divide 3450 by .6 which comes to 5750. That is the required distance of the runway for me to takeoff.... Is that the correct method of going through that senario?

Thanks

 

[B737Dvr]

Be careful.....

Effective landing length off of a visual approach and effective landing length (usuable landing length) off of an ILS approach are two very different things.

If you are flying 135 into say, Atlanta-Peachtree. An ILS on 20L will yield you a very much shorter usuable landing length than that off a visual approach. If you are flying an ILS you must apply that 60% rule or 80% if using some form of runway analysis to the shorter length landing off the ILS. The full runway is not available and this will bite heavier jet operators in the rear if you get ramped.

fyi....

 

[Corp Pilot]

60% Planning / AFM for Landing

135.385 provides "Flight Planning" requirements. Once airborne the AFM (91) numbers provide actual runway length requirements. This is the short, simple and accurate explanation.



AA Order 8400 – Air Transportation Operations Inspector’s Handbook has been replaced by Flight Standards Information Management System (FSIMS). The link is provided below.


http://fsims.faa.gov/

http://fsims.faa.gov/PICResults.aspx?mode=Search&q=aircraft+performance+and+computation+rules&kw=aircraft+performance+and+computation+rules&status=a&syn=1&sort=0&


[FONT=&quot]E.[/FONT] Application of Flight Handbook Performance Limits. Many of the requirements of Subparts I of part 121 and part 135 apply only until the aircraft takes off from the departure point. Other requirements from these subparts apply at all times as do the AFM limitations. For example,§§ 121.195 and 135.385 prohibit a large, turbine airplane from takeoff unless, allowing for en route fuel burn, the airplane will be capable of landing on 60 percent of the available runway at the planned destination. The regulations do not, however, prohibit the airplane from landing at the destination when, upon arrival, conditions have changed and more than 60 percent of the runway is required. In this case, the airplane must only be able to land on the effective runway length as shown in the flight manual performance data.

 

[TransMach]

FAR 135.385 + FAA Order 8900.1

Corp Pilot, your right. When I answered this thread in June 2006 (nearly 2 years ago) 8900.1 didn't exist.

The good news is that 8900.1 is a vast improvement over the 8400 Order for the FAA employee who is to apply the rules. I've used 8900.1 many times since it's publication to support exactly what we have been doing all along and my FAA POI goes right along with it (like he should).

Cheers!

TransMach

 

[osy007]

Took him 2 years to find the answer that someone else already answered...lol

 

[TransMach]

Took him 2 years to find the answer that someone else already answered...lol

My goodness! Aren't you "Spot On"!

TransMach