135 Turbine Landing Limitations Question
 

I have a question regarding the following FAR 135.385


Large transport category airplanes: Turbine engine powered: Landing limitations: Destination airports.

(a) No person operating a turbine engine powered large transport category airplane may take off that airplane at a weight that (allowing for normal consumption of fuel and oil in flight to the destination or alternate airport) the weight of the airplane on arrival would exceed the landing weight in the Airplane Flight Manual for the elevation of the destination or alternate airport and the ambient temperature anticipated at the time of landing.

[(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:]

(1) The airplane is landed on the most favorable runway and in the most favorable direction, in still air.
(2) The airplane is landed on the most suitable runway considering the probable wind velocity and direction and the ground handling characteristics of the airplane, and considering other conditions such as landing aids and terrain.
(c) A turbopropeller powered airplane that would be prohibited from being taken off because it could not meet paragraph (b)(2) of this section, may be taken off if an alternate airport is selected that meets all of this section except that the airplane can accomplish a full stop landing within 70 percent of the effective length of the runway.
(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.

(e) A turbojet airplane that would be prohibited from being taken off because it could not meet paragraph (b)(2) of this section may be taken off if an alternate airport is selected that meets all of paragraph (b) of this section.

[(f) An eligible on-demand operator may take off a turbine engine powered large transport category airplane on an on-demand flight if all of the following conditions exist:
(1) The operation is permitted by an approved Destination Airport Analysis in that person's operations manual.
(2) The airplane's 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 80 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:
(i) The airplane is landed on the most favorable runway and in the most favorable direction, in still air.
(ii) The airplane is landed on the most suitable runway considering the probable wind velocity and direction and the ground handling characteristics of the airplane, and considering other conditions such as landing aids and terrain.
(3) The operation is authorized by operations specifications. ]


It was and has always been my understanding that you can not legally depart for your destination unless you know that you can stop within 60% of the usable runway that you plan to use. Recently I have been told that per paragraph E (highlighted in bold) you can legally depart for your destination airport even if at the time of departure your numbers show that you can not come to a full stop within 60 % of the effective runway at your destination as long as your alternate airport's intended runway of use allows the 60% rule. My question is- How is it legal to then land at your intend destination if the landing distance numbers show that you can not land within 60 percent of the effective rwy as it is stated in paragraph B above?

Was paragraph E inserted in this regulation for situations such as allowing a departure to an airport with say a contaminated rwy that the pilot was told will be sanded, swept, etc to permit better landing numbers upon his arrival that would then allow for a landing within 60% of the runway?? I just don't see how it is legal to attempt a landing knowing you can not stop within 60% of the effective rwy just because one listed an alternate airport that says you can. Seems to defeat the point of the 60 % rule. I appreciate any clarification!

B2 says you will plan to use the most suitable runway based on forecast winds and considering landing aids and terrain. I'd read that to say if the runway that is into the wind is too short to meet the 60% but there is another longer runway there and you can stop in 60% of your alternate runway, you can go. Or if there is no approach to a longer runway but there is to a shorter one. There's an Op Spec for it that talks about crew experience and a bunch of other factors.

So essentially anytime you land under 135 you have to be sure that you can land within 60% of the runway correct? I am being told that because of paragraph E, if one can not make the 60 % rule at his or her destination all one would have to do is list an alternate that you could land within 60% percent of the runway. Because of listing the alternate you are now legally able to land at your destination even though you may require every inch of the runway. To me that defeats the point of the 60 percent rule and doesn't make sense. Any other thoughts?

I could be completely wrong, but it seems if you can not make the 60% at your destination you may still depart for your destination provided you have an alternate planned that meets all the requirements for the paragraph.

I don't think that defeats the 60% rule, I kind of see this as a back up lets say you lose a system ex. some of your hydraulics and this might prevent you from landing with your Flaps extended requiring more runway.

If the 60% rule wasn't there you are in the middle of nowhere with no reserve fuel and you do not have enough runway to make a safe landing. (e) allows you to go to the airport of choice if all your systems are working. But if something were to fail you still have the alternate fuel required to get to an airport that would allow for a safe landing.

Just my take I've never had to deal with 135 stuff though, I'll be watching this topic to see other opinions.

No. An Eligible On Demand operator may "DAAP" a destination airport and depart if they comply with the 80% rule.

Yes, that's how it works.

[QUOTE=IFLY22;934144]So essentially anytime you land under 135 you have to be sure that you can land within 60% of the runway correct? QUOTE]

Remember this is preflight planning, when you get there if the nose wheel is still on the runway you're Ok.

There is an Ops Spec (A057?) that sets up a DAAP program (thanks AKASHA.) You just can't say we're going to Podunk today but the runway is too short to stop within 60 percent so we'll list Ginormous International as the alternate.

Ops specs will say generally say if you cant land within 60 percent at the destination then add an alternate that you can land within 70 percent and then you cna use 80 percent at the destination. 60 70 80 easy as pie.

80% of available distance Ops Spec requires FAA approval in Ops Specs though along with specific situation approval from the DO or CP depending on how the Ops Specs are written though correct?

Yes, it must be approved and certain limitations apply (i.e. zero tailwind on landing).

I think 135.385 is for planning purposes only, just like planning for an alternate. Once you take off, if for some reason you can't land within 60% or 80% it doesn't really matter, AS LONG AS YOU DON'T VIOLATE YOUR AFM and you remain safe.

It says "No airplane may take off". It doesn't say "no airplane may land". It is just for planning purposes. Once you are airborne the 60% or 80% rule have no affect any more. If the wind changes slightly or that runway because closed, you can land on any runway that your AFM says is legal and safe.

To further see how it's for planning it states "the following is assumed, bla, bla." For planning you have to assume certain criteria. Why wouldn't they just say use the actual. But once you get there if the wind changes by 1 kt, or even that runway becomes closed and there is another runway that is 10 feet shorter but that puts you 1% under the 60% or 80% you can still legally land.

It's all planning purposes only. Read the reg "no airplane shall take off". It didn't say no airplane shall land. And if you still have ambiguity it even says if you don't have your 60% planned, go ahead and take off anyway.

Quote from the 8900 manual "A flight may be dispatched which cannot meet the 60 percent runway requirement at the destination if an alternate airport is designated where the flight can land within the distance specified for an alternate airport." See how it uses the word "dispatched" and not "land". Just planning.

If you take off planning to land within 60% or 80% and factors change and now its 59% or 79%, you are still legal to land if it is in accordance with your AFM. It's legal but it may not be safe though!