Displaced Runway Threshold

[Condorito]

Most people think you can't land on them, that's what I was taught at least.

Doing a bit of reading, the TC AIM says:

AGA 3.3 Displaced Runway Threshold

Occasionally, natural and human-made obstacles penetrate
the obstacle limitation surfaces of the take-off and approach
paths to runways.

To ensure that a safe clearance from these obstacles is
maintained, it is necessary to displace the runway thresholds.
In the case of runways for which instrument approach
procedures are published in the CAP, the usable runway
distances for landings and takeoffs are specified as declared
distances. The displacements are also depicted on the
aerodrome or airport diagram in both the CAP and the CFS.
For other runways not having published CAP approaches,
the requisite data is given in the CFS. Where a threshold is
displaced, it is marked as shown in AGA 5.4.1.

When the portion of the runway before the displaced
threshold is marked with displaced threshold arrows (see
AGA 5.4.1), it is permissible to use that portion of the runway
for taxiing, for takeoff and for the landing roll-out from the
opposite direction. In addition, this displaced portion of the
runway may be used for landing; however, it is the pilot’s
responsibility to ensure that the descent path can be safely
adjusted to clear all obstacles. When taking off from the end
opposite to the displaced threshold, pilots should recognize
the fact that there are obstacles present that penetrated above
the approach slope to the physical end of the runway, which
resulted in the threshold being displaced.

When a section of a runway is closed, either temporarily because
of construction or permanently because the full length is no
longer required, the closed portion of the runway is unavailable
for the surface movement of aircraft for taxiing, take-off or
landing purposes and is marked with an “X”, indicating that
the area is not suitable for aircraft use. A lighted “X” may also
be used to mark a temporarily closed runway.
The closed portion of the runway may be shown on the
aerodrome or airport diagram in the CFS and the CAP for
identification purposes; however, declared distances will only
include runway length starting at the new threshold position.

______________________________________________________________________________________________________________________________________________

Then onto the FAA AIM

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, as shown in FIG 2-3-4.

______________________________________________________________________________________________________________________________________________

It doesn't say you can land on them as we can in Canada. Am I missing something???

[PilotDAR]

Well, if you're flying a GA aircraft which needs the additional runway length afforded by landing into a displaced threshold area, something's wrong. I learned this lesson with a surprise pull up, but no damage, when at the last second I noticed arrestor cables in the displaced area. It could have been bad, and would have been my fault.

If displaced for approach path reasons, I suppose you can land in accordance with the CARs, just make sure that is the reason!

[Cat Driver]

Nanaimo's runway 34 is a typical example of a displaced threshold that can be landed on at the discrestion of the pilot.

[photofly]

Tillsonburg had a displaced threshold on 26 (I think it is) and now some trees on the approach have been cut down and the displacement markings painted out.

[ahramin]

Absolutely you can land on it. As DAR said though, why? It's like making your aiming point 200 feet before the runway so you can flare over the grass and land on the first foot of pavement.

Rather than incorrectly saying you can't land on a displaced threshold, instructors should use it as an exercise in PDM. "Yes you can land on a displaced threshold. Let's figure out some situations where it would be appropriate to land on it instead beyond it as I've taught you."

As Cat said, Nanaimo is a good example of this. In this case the displaced threshold is for a hill that need not be flown over. Offset your approach and you no longer need to ignore the first 1000' of the runway. But even landing beyond the displaced threshold, I can easily make the taxiway without braking, so what's the point?

[Cat Driver]

Well for me the point was my hangar was at the south end of the airport and traffic permitting I could land on the first thousand feet and backtrack with ease.

Why taxi a mile if you don't need to?

[ahramin]

Thanks Cat, there's your example Condorito.

Here is an example of when you would not land on the displaced threshold no matter what the circumstances: You don't know why it's displaced.

Edited for clarity.

[digits_]

Thanks Cat, there's your example Condorito. And here is an example of when you would not land on the displaced threshold no matter what the circumstances: You don't know why it's displaced.

If the quote/references from the first message is correct, then you do know the reason: obstacles in the approach path.

Quite peculiar reasoning though. As far as I know, under JAR, it isn't allowed.

[Colonel Sanders]

under JAR, it isn't allowed

That's really not very relevant. There's no GA
in Europe, where Airbuses are flown from one
overcrowded city to another.

99% of the time, a threshold of a certified runway
is displaced because during the annual inspection,
someone noticed some trees (or other obstacle)
poking up into the 3 degree glidepath.

So until they get around to trimming the trees,
they paint a displaced threshold.

If you're doing a day GA approach, the obstacles
probably aren't a factor - you can see and avoid
them.

If you're doing a night approach, you might want
to obey the displaced threshold.

If you're a transient pilot and haven't a clue why
the threshold is displaced, probably best to respect
it unless you have a very good reason not to.

If you're a local pilot, you know what's going on
and can use what you want.

A good example is runway 04 at CYOW, which
if you look at the CFS is displaced 251 feet. If
you've ever landed there, you can see why - the
fence and trees.

[pelmet]

Hugely long displaced thresholds at JFK. Some more than 3,000 feet and there are no obstacles on final.

[Colonel Sanders]

A displaced threshold is a runway marking that identifies the runway threshold for landing aircraft, at a location other than the physical end of the runway. Because a displaced landing threshold is farther down the runway than the actual runway end, aircraft on approach must maintain a higher altitude to reach the extended touchdown point, which results in a slight decrease in noise over residential areas located near the ends of runways. The Port Authority has incorporated displaced runway thresholds on runways at JFK, Newark Liberty, and Teterboro airports

[pelmet]

So typical. A "slight" decrease in noise which is probably barely perceptible and now we've got heavy jets at max landing weights on artificially short runways that are wet or contaminated such as 22R at JFK. I wonder how many people the NIMBY's have killed?

It make for some interesting approaches so that those who moved close to airports can get their beauty sleep.

http://www.youtube.com/watch?v=SfaMBO2k7RM

747's do it, I wonder if the A380 does as well. This runway is the easy one compared to the right side.

[CpnCrunch]

In the UK, you can have displaced thresholds due to the start of the runway not being strong enough to handle lots of planes landing on it. And CS should note that general aviation isn't doing any worse in the UK than it is in Canada. Before I moved from the UK to Canada I thought that Canada was the holy grail of aviation, but now I see that Canada is actually much more regulated than the UK, and these days it isn't really much cheaper.

[Colonel Sanders]

Canada is actually much more regulated than the UK

Holy sh1t. If the UK is slacker than the homebuilt
scene in Canada, it must be the wild f__king west.

these days it isn't really much cheaper

Really? What's the cost per litre for gas? Mogas
here is $1.22/liter, 100LL is $1.75/liter.

What about landing fees? What about wx? People
in the UK bitch endlessly about both.

I thought that Canada was the holy grail of aviation

How on earth did you get that idea? That's the USA.

[CpnCrunch]

Really? What's the cost per litre for gas? Mogas
here is $1.22/liter, 100LL is $1.75/liter.

What about landing fees? What about wx? People
in the UK bitch endlessly about both.

It does cost more, but then you don't have to travel as far. Crappy weather and landing (and other) fees seem to be a fact of life at certain places in Canada as well. I guess the point is that people like to bitch no matter where they live.

[Colonel Sanders]

Crappy weather and landing (and other) fees seem to be a fact of life at certain places in Canada as well

Sure, but consider living someplace with fewer
people than Toronto or Vancouver.

99.999% of Canada is a giant aviation playground
of uncontrolled airspace. You don't have to talk to
anybody, and rarely when I am flying, do I ever see
another airplane away from an airport. A great big
empty sky. I rather like that.

I have more than my fair share of bureaucrats that
personally despise me, but despite that I have a bit
of fun:

http://www.youtube.com/watch?v=Fcy4ZhGHHaE
http://i.imgur.com/FeqlX.jpg
http://www.youtube.com/watch?v=EIyIDJAc7f8

Are there a whole lot of people having more fun
than that, in the UK?

You could probably do better, if you were ambitious,
like your own MiG-21 or F-104 or SU-27.

Are there a lot of pilots privately flying mach 2
fighters in the UK? There are in the USA, and
there's nothing holding you back from doing it
in Canada, either.

[photofly]

In the UK, road fuel is north of $2 per litre, and avgas probably more like $3 per litre.

Anyone who thinks aviation regulation in the UK is "light touch" should try to get their head around European Regulations (EU) 1178/2011 (amended by Regulation No 290/2012) for flight crew licensing, CAP804 alone - which is the just the UK CAA's guide to interpreting the new European regulations - runs to more than 800 pages. And those are just the rules for licences.

[Beefitarian]

Are there a lot of pilots privately flying mach 2
fighters in the UK? There are in the USA, and
there's nothing but Transport Canada holding you back from doing it
in Canada, either.

Fixed that for you. You were not seriously suggesting they would let you import something that cool and register it to fly? They won't even let you have functional ejection seats. Even though they don't seem to mind BRSs. I guess they figure a Cirrus on a parachute is too light to do much harm. Didn't you see the hassle that guy had bringing a rather incomplete plane in on a trailer? "Restricted weapon"

[Shiny Side Up]

In the UK, you can have displaced thresholds due to the start of the runway not being strong enough to handle lots of planes landing on it.

This happens sometimes in Canada too. It was the case at CYRM for a while when the ends of the runway started sinking into the swamp before they did some repaving a while back. I think the one end was displaced 500' or so.