Landing on displaced threshold

[subpilot]

My airport has taxiway closures for the next few weeks and so the tower has requested our flight school to request full length landings which in there description means to land on the displaced threshold, thus allowing our aircraft to clear the runway before the construction area begins. I can't find the official or legal meaning of "full length landing" (besides requesting to use the full length on the landing roll) or any exceptions that would allow landing on the displaced threshold. Is this operating practice okay and would it most likely require a local waiver or could I request this anywhere I land at that has a displaced threshold?

[Rocketman99]

That doesn't sound kosher at all.

[29.92inHg]

I'm thinking the threshhold was displaced for a reason. If it wasn't good enough to land on before, why now. Having said that I really don't think its legal either. Landing full length would be to use the whole runway, and they are basically running LAHSO.

[Holocene]

I don't think it's actually illegal to land on a displaced threshold. And if ATC is condoning it, I probably wouldn't think twice about doing it in a light airplane.

[dasleben]

Originally Posted by Holocene

I don't think it's actually illegal to land on a displaced threshold. And if ATC is condoning it, I probably wouldn't think twice about doing it in a light airplane.

Thresholds are displaced for a reason (obstacles), which would mean to me that safe operating practices would normally dictate that one should not use it for landing.

[subpilot]

This threshold is displaced for convenience (so i've heard) as there are no obstacles and the displaced threshold is rated for landing on (again, so I have heard).

airport diagram if interested:
http://204.108.4.16/d-tpp/0908/00036AD.PDF

I did one today but just felt weird doing so as I have always been taught that this is not ok.

[29.92inHg]

Thats is a Looooong runway regardless of the displacement. Do you really need to land on the displaced part to begin with (where is the construction at). The whole thing is odd, however.

[Holocene]

Originally Posted by dasleben

Thresholds are displaced for a reason (obstacles), which would mean to me that safe operating practices would normally dictate that one should not use it for landing.

Obstacles aren't the only reason. I doubt ATC or the airport operator is going to allow landings prior to the displaced threshold if the original reason involved a safety hazard.

[dasleben]

Originally Posted by Holocene

Obstacles aren't the only reason. I doubt ATC or the airport operator is going to allow landings prior to the displaced threshold if the original reason involved a safety hazard.

You're right. I should have said "obstacles, mostly" instead of simply "obstacles."

But I wouldn't do something just because ATC says it's okay. I once had ATC tell me it was okay to go direct to a VOR when the route was painting Level 5 returns on the radar. I'd want to know for sure that the displaced threshold was suitable for landing first, and that the FAA approves of using it for landing during construction (and I don't mean ATC).

[JJink]

Originally Posted by subpilot

My airport has taxiway closures for the next few weeks and so the tower has requested our flight school to request full length landings which in there description means to land on the displaced threshold, thus allowing our aircraft to clear the runway before the construction area begins. I can't find the official or legal meaning of "full length landing" (besides requesting to use the full length on the landing roll) or any exceptions that would allow landing on the displaced threshold. Is this operating practice okay and would it most likely require a local waiver or could I request this anywhere I land at that has a displaced threshold?

Cool…………….I always try to skim the last arrow of a displaced threshold on purpose flying GA aircraft. The surface is always rated as good as the runway and if you cleared to do it, why not.
Good time to practice short field landings……….objective is to make the first taxi way.

Check these guys out.

[MikeD]

Originally Posted by dasleben

You're right. I should have said "obstacles, mostly" instead of simply "obstacles."

But I wouldn't do something just because ATC says it's okay. I once had ATC tell me it was okay to go direct to a VOR when the route was painting Level 5 returns on the radar. I'd want to know for sure that the displaced threshold was suitable for landing first, and that the FAA approves of using it for landing during construction (and I don't mean ATC).

Displaced thresholds can be for obstacles, or can even be for noise abatement, as a few airports have them.........how the logic works of a few 100 extra feet making a noise abatement difference works, is beyond me though.

[vikingair]

I was just down in BFL...the threshold is like 3000 feet down the runway!
Im pretty sure the Brasilla and F-18 that departed full length put more stress on the DT than I would have landing my 3800lb Seminole. Im sure the FAA grants temp waivers all the time for airport ops.

We're about to lose our runway at KMER for 7 weeks while they repaint and scrape rubber. I'm actually looking forward to using the taxiway for landings and seeing how they configure lights n such. We could actually land on the ramp..theres gotta be 3000 feet at least and as long as you dont clip the underground tank manholes you'd be allright.

[Sunburn]

2. Displaced Threshold. A displaced threshold is a threshold located at a point on the runway other than the designated beginning of the runway. Displacement of a threshold reduces the length of runway available for landings. The portion of runway behind a displaced threshold is available for takeoffs in either direction and landings from the opposite direction. A ten feet wide white threshold bar is located across the width of the runway at the displaced threshold. White arrows are located along the centerline in the area between the beginning of the runway and displaced threshold. White arrow heads are located across the width of the runway just prior to the threshold bar....

AIM 2-3-3 (h)

[subpilot]

Originally Posted by Sunburn

2. Displaced Threshold. A displaced threshold is a threshold located at a point on the runway other than the designated beginning of the runway. Displacement of a threshold reduces the length of runway available for landings. The portion of runway behind a displaced threshold is available for takeoffs in either direction and landings from the opposite direction. A ten feet wide white threshold bar is located across the width of the runway at the displaced threshold. White arrows are located along the centerline in the area between the beginning of the runway and displaced threshold. White arrow heads are located across the width of the runway just prior to the threshold bar....

AIM 2-3-3 (h)

Thank you Captain Obvious







(no disrespect )

[Sunburn]

Originally Posted by subpilot

Thank you Captain Obvious







(no disrespect )

None taken, I laughed as well, and I do not mean any disrespect to you, but it is clearly spelled in the AIM what a displaced threshold is, and what you are allowed to do with it. Now, I'm not saying that a controller will not try to bend that, but not all controllers know what a pilot can legally do.

[Barty]

Originally Posted by vikingair

I was just down in BFL...the threshold is like 3000 feet down the runway!
Im pretty sure the Brasilla and F-18 that departed full length put more stress on the DT than I would have landing my 3800lb Seminole. Im sure the FAA grants temp waivers all the time for airport ops.

We're about to lose our runway at KMER for 7 weeks while they repaint and scrape rubber. I'm actually looking forward to using the taxiway for landings and seeing how they configure lights n such. We could actually land on the ramp..theres gotta be 3000 feet at least and as long as you dont clip the underground tank manholes you'd be allright.

When they closed the runway at KRYY to resurface and widen it, the taxiway that was used as a runway was limited to day VMC use. They had some temporary markings on the taxiway, but made no changes to the lighting.

Interesting that is going to take that long there, they had the runway closed and re-opened in less than 4 weeks. However, the ILS had to be re-checked after the construction and the glide slope has not been able to be put back into service yet, and it is just a couple months shy of 1 year that it has been down.

[trafficinsight]

Originally Posted by vikingair

I was just down in BFL...the threshold is like 3000 feet down the runway!
Im pretty sure the Brasilla and F-18 that departed full length put more stress on the DT than I would have landing my 3800lb Seminole. Im sure the FAA grants temp waivers all the time for airport ops.

We're about to lose our runway at KMER for 7 weeks while they repaint and scrape rubber. I'm actually looking forward to using the taxiway for landings and seeing how they configure lights n such. We could actually land on the ramp..theres gotta be 3000 feet at least and as long as you dont clip the underground tank manholes you'd be allright.

I landed on the taxiway at MER on my solo cross country while they were paving the runway... Even the taxiway was the largest runway I'd ever landed on!

[TheresaPilot]

Originally Posted by Barty

When they closed the runway at KRYY to resurface and widen it, the taxiway that was used as a runway was limited to day VMC use. They had some temporary markings on the taxiway, but made no changes to the lighting.

That's how it was when I flew to one that was being worked on in Oklahoma (can't remember the exact airport). They really only painted numbers on either end of the taxiway.

[XcalibeR]

I could be wrong, but I think one of the reasons a displaced threshold is not allowed for landing is that that part wasn't built for the force of landing planes. Or rather, it's not officially rated to the same weight threshold as the runway it's associated with. That means for a training aircraft, there shouldn't be any issue. But, "officially," there isn't any guarantee that the threshold won't collapse the instant you touch down.

[Zondaracer]

http://www.youtube.com/watch?v=A5ZLUP1Aroc

This KLM pilot clearly lands prior to the threshold and claims that it was "ok" because it was displaced for an ILS approach. He claims landing short saves the company fuel and taxi time (which sounds right), but I can't justify that as a reason to land before the threshold.

[Barty]

Originally Posted by XcalibeR

I could be wrong, but I think one of the reasons a displaced threshold is not allowed for landing is that that part wasn't built for the force of landing planes. Or rather, it's not officially rated to the same weight threshold as the runway it's associated with. That means for a training aircraft, there shouldn't be any issue. But, "officially," there isn't any guarantee that the threshold won't collapse the instant you touch down.

Typically that's the case where an airport operator has decided to stop maintaining a certain length of the runway up to the standards required to support landing certain aircraft. When my home field was resurfaced to concrete, the entire length, including the displaced threshold on the rwy 9 end, was built to the same standard. There are some airports in south Georgia that have lengthy displaced thresholds where it is pretty apparent that the runway used to cover the full length, but the operator just stopped maintaining the last 1000' or so except to patch a pothole or seal cracks. I can't really see it saving them a ton of money in the long run, so I'm not sure why some airports end up like that.

[Holocene]

btw, "landing on displaced threshold" is exactly what you're supposed to do. The runway threshold is "displaced" by the appropriate markings, and normally you would land on it or a bit farther down.

I noticed I made this same semantic error in my first post, and wanted to clear it up, haha.

[granlistillo]

Just thinking outloud here, but some displaced threholds have the arrow for using it for T/Os but not landings. Could it be a differences in the bearing strength of the pavement? Not too sure that would be an issue with light aircraft.

[MikeD]

Originally Posted by granlistillo

Just thinking outloud here, but some displaced threholds have the arrow for using it for T/Os but not landings. Could it be a differences in the bearing strength of the pavement? Not too sure that would be an issue with light aircraft.

Some of those that I've seen have a displaced threshold for either an obstruction or even noise abatement for landing purposes. For takeoff, they're just like the rest of the runway, and for landing rollout from the opposite direction, they're fine for that too.

Take GYR in AZ for instance, RW 3-21 is 8500, but 21 has about a 2100' displaced threshold that used to be all part of the runway. It's in excellent condition with a concrete hammerhead / hold area and asphalt. In the early '90s, the displaced threshold was added to 21 for purely noise abatement purposes, since the area to the N through E of the airport is now "noise sensitive" Litchfield Park, so there's really only 6400' available for landing on 21, pending you touch down on brick-one. However, landing on rollout on runway 3, it's fine to roll to the end, and you have the full 8500 available as well as on takeoff on 21. What a waste of good runway surface for landing........

http://maps.google.com/maps?hl=en&sa...tab=il&start=0

[Photo credit, Mr. James Slater]

[Maurus]

Originally Posted by Zondaracer

http://www.youtube.com/watch?v=A5ZLUP1Aroc

This KLM pilot clearly lands prior to the threshold and claims that it was "ok" because it was displaced for an ILS approach. He claims landing short saves the company fuel and taxi time (which sounds right), but I can't justify that as a reason to land before the threshold.

Perhaps there are special procedures for the airport that allows for landing before the threshold? There were tons of tire marks before the threshold which would indicate that it happens a lot there.