Displaced threshold question.

[Geko]

I learned @ YYJ. If you land before the displaced threshold markers on 02 or 13 while doing the short field landing on your PPL flight test, you'll be assessed a fail for that exercise. Now with an obvious lack of critical thinking aside I have no problem freely admitting that when I was a > 70 hour student I would probably do the same thing as the pilots in Naniamo.

[iflyforpie]

When I was taught to fly, it was to aim for the 1000 foot makers. Of course, this was on a 7300' runway.

Actually, now I remember this was only the case for landing on 15 (now 16) at YLW or for circuits on 33 (34). When we came in for a full stop, we would land by the second to last taxiway and exit at the end to save taxi time.

[Sidebar]

Runway 34 in Nanaimo has a 1000 foot displaced threshold.

Can you legally land before the 1000 foot marks?

I'd say yes. See below, emphasis added. I've never flown into Nanaimo, but looking at the CFS and Google maps, there's 2 items of note. First, the PAPI for 34 is offset 20 degrees to the right, and there's a hill just west of the extended rwy centreline. I expect the hill is the reason the threshold is displaced.

From TP 312 - Aerodromes Standards and Recommended Practices http://www.tc.gc.ca/civilaviation/publi ... r1/1-1.htm

Displaced threshold. A threshold not located at the extremity of a runway. Displaced thresholds are used when an obstacle in the final approach area intrudes into the specific obstruction clearance surfaces. Displacing the threshold provides the required obstacle free slope. The declared landing distance (LDA) which assumes a specified obstacle clearance plane is therefore measured from the displaced threshold; however there is no restriction to an aircraft actually landing on the usable runway prior to the displaced threshold. This portion of the runway is also available for take-off or rollout.

[Cat Driver]

Ask a simple question of pilots and you are sure to get a blizzard of different answers and opinions.


This was my question.

Runway 34 in Nanaimo has a 1000 foot displaced threshold.

Can you legally land before the 1000 foot marks?

Bottom line seems to be you can legally land on the displaced portion of runway 34 in Nanaimo.

[Geko]

Ask a simple question of pilots and you are sure to get a blizzard of different answers and opinions.


This was my question.

Runway 34 in Nanaimo has a 1000 foot displaced threshold.

Can you legally land before the 1000 foot marks?

Bottom line seems to be you can legally land on the displaced portion of runway 34 in Nanaimo.

Wouldn't that be more linked to message boards and everyone on the internet needing to be correct or share their experiences with others?

[atpl53]

Sorry Cat, but this what you asked...

Ask a simple question of pilots and you are sure to get a blizzard of different answers and opinions.


This was my question.

Runway 34 in Nanaimo has a 1000 foot displaced threshold.

Can you legally land before the 1000 foot marks?

Bottom line seems to be you can legally land on the displaced portion of runway 34 in Nanaimo.

Then...you went on to explain the reason for your question....

The reason I am asking is because the question came up today watching airplanes land and almost every airplane flew to the displaced threshold markers before touching down.

Someone who is a high time pilot said it is illegal to touch down before the displaced threshold and that is why most everyone including the flying schools fly to the displaced threshold.

I can not find anything in the flight supplement that mentions that.

I think that's why you got so many answers.

As for flight schools teaching to land beyond the displaced threshold....think of it this way. I'm teaching students who may one day be pilots and who may fly to airports with which they are unfamiliar. Rather than having established the habit of ignoring those markings, I have have established respect for them. If they then chose to check things out with the locals after the fact and find that landing before the displaced threshold would most likely NOT create a problem, they can then make their own decision.

Also, I wonder what the insurance liability might be if you happened to prang your airframe while landing within those markings.

Just my $.02

Dan

[Cat Driver]

I think that's why you got so many answers.

Yes, I agree.

As for flight schools teaching to land beyond the displaced threshold....think of it this way. I'm teaching students who may one day be pilots and who may fly to airports with which they are unfamiliar. Rather than having established the habit of ignoring those markings, I have have established respect for them.

Respect for them?

What possible lack of respect would one show for the markings by landing before them when it is perfectly legal to do so?

If they then chose to check things out with the locals after the fact and find that landing before the displaced threshold would most likely NOT create a problem, they can then make their own decision.

Am I to understand that the average person with good eyesight can not determine if a thousand feet of paved runway is not safe to land on without asking the locals?

Also, I wonder what the insurance liability might be if you happened to prang your airframe while landing within those markings.

If it is legal to land on a paved runway how could the insurance company refuse to pay should you have an accident?

It is either legal or illegal, unless of course we become so paranoid that we can no longer use common sense, then I would suggest we do have a problem.

[iflyforpie]

Considering that insurance will still pay--under certain circumstances--for an aircraft that is damaged hundreds of miles away from any airport; I am sure they will still pay out for an aircraft damaged landing before the displaced threshold for something like, say, a nose wheel collapse.


If we need the advice of the locals before landing an aircraft, why do we teach precautionary landings?

I think that refusing to do an approach to land on a Certified Aerodrome before the displaced threshold based on lack of local knowledge (but having read the CFS) is overkill.

[Brewguy]

If it is legal to land on a paved runway how could the insurance company refuse to pay should you have an accident?

Ah, come on Cat ... you know better than that now don't you? Do you really think insurance companies deal in anything as black & white as legal vs. illegal?

Example: Highway off ramps have a 'cautionary' speed posted. Its not illegal to go faster than that speed. However, if you do go faster than the cautionary speed, and lose control, I'd be willing to bet that a) the police would determine that you were careless or didn't exercise the necessary level of care, and b) an insurance company would weasel out of paying for any damages.

Wouldn't a displaced threshold be considered some form of 'safety' markings? Sure you can land on that area, at your own discretion; but for sure some insurance weenie would find some loophole or 'Freeman' type quasi-legal argument if you pranged something while exercising that discretion.

Better to follow the example of the other sheep and not over think it.

Just playing Devil's Advocate, personally, I'd land on it. After all, what good is runway behind you.

[FlaplessDork]

Whats the point of marking it as a displaced threshold at all if its legal to land on?

[Sidebar]

Whats the point of marking it as a displaced threshold at all if its legal to land on?

To quote TC, this is "management of risk to an acceptable level." Obstacles in the approach path are hazards, and the displaced threshold is the risk mitigation. See my previous post.

[Cat Driver]

The displaced threshold at Nanaimo on runway 34 was installed for night approaches and landings and includes a papi.

Day VFR landings are perfectly safe when landing on the displaced threshold.

[atpl53]

Cat.
I wasn't lookin' to pick a fight. My point is that as a transient pilot I MAY not be keenly aware of the reason for the displacement.

from the TC site http://www.tc.gc.ca/CivilAviation/publi ... GA/3-0.htm

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 will not be available 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.

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.

(Emphasis added)

I have landed at airports throughout New England where the obstacles come and go on a daily basis. In reduced visibility (NO, NOT IFR), they may not be as easy to see as the displaced threshold markings. I guess in my defense, I would rather teach that the markings are there for a reason and not that we get to pick and choose which ones we feel like abiding by.

Dan

[atpl53]

This is what I was referring to:

http://www.tc.gc.ca/publications/EN/TP1 ... 1_2006.pdf

Take, for example, the December 9, 2003, fatal crash of
a Piper PA-28-181 in Sugar Land, Texas. The 350-hour
non-instrument-rated private pilot was attempting a
night landing in good visual conditions. After the pilot
confirmed to the controller he saw the runway, the flight
was cleared to land. Instead, the airplane struck power lines
running perpendicular to the approach end of the runway,
which featured a displaced threshold of 1 964 ft. Both
aboard the Piper died in the crash. At the time, wind at the
airport was reported from 3 20°, at 16 kt gusting to 25 kt.
The NTSB [U.S. National Transportation Safety Board]
determined the probable cause was the pilot’s failure to
avoid power lines and noted the night-time conditions and
the high winds...
... Rarely are power lines marked for night operations, but displaced thresholds are.

[stef]

The difference from the American rules could be significant. I flew over a displaced threshold once somewhere in Alabama I think it was, thinking that I could touch down on it if I wanted, only to find it was marked with plywood and framing lumber painted white.

[Cat Driver]

I have landed at airports throughout New England where the obstacles come and go on a daily basis. In reduced visibility (NO, NOT IFR), they may not be as easy to see as the displaced threshold markings. I guess in my defense, I would rather teach that the markings are there for a reason and not that we get to pick and choose which ones we feel like abiding by.

Dan

Dan:

I was not looking for a fight with anyone here when I posted these questions.

My reason was to find out what most pilots and especially instructors think about the subject.

There was quite a difference in opinion at the airport between the pilots who were discussing this and one pilot who is fairly high time insisted that the instructors do not land on the displaced threshold because it is against the law and they can be charged, so I decided to ask the pilots here what they think.

Bearing in mind that I am only expressing my own opinion here I would like to explain how I see this question.

First the airport is a licensed airport for both VFR and IFR day night operations and it is evident in the flight supplement why the displaced threshold was put there one does have the choice of where you can land as long as the visibility is sufficient to clearly see the landing area you plan to touch down on.

Second is the question of obstructions on the approach end that could be a danger, obviously pilots familiar with this airport would know there are no obstructions that prevent you from using the displaced threshold.....if there were to be an obstruction raised it would be notamed.

So considering the above I still don't understand why so many feel it is poor airmanship to perform a legally approved landing?

[atpl53]

...poor airmanship to perform a legally approved landing?

Agreed. Guess I was just trying to be certain that I am not professing support for the Do-What-Ever-You-Feel-Like philosophy which is often apparent. If I have done due diligence and am 100% certain that I can land on a displaced threshold without endangering anything, then I am good to go.

Dan

[Charlie Papa Lima]

I have had this exact same discussion...

I fly into Nanaimo regularly and although we use runway 16 most of the time, I will land before the displaced threshold on runway 34. The reason for the displacement as I understand it is that it is to provide adequate terrain clearance for a straight in approach to 34, due to the rising terrain at that end of the runway. Hence the offset approach. We do then have to add power for the taxi off at bravo but I would rather do that than end up off the other end!!

Just another $0.02

CPL

[Big Pistons Forever]

At the new PPL level I expect the pilot to plan to touch down on the displaced threshold if it is the first landing at an airport he/she has never been to before. The reason for this is the displaced threshold will provide for a normal final approach descent path. However if on final they have a nice stabilised approach then I would see no problem with them slightly steepening the approach to touch down early.

At the CPL level I expect them to touch down at the most operationally practicable point. So for example at Nanaimo I would expect them to plan a touch down at the point where light braking will result in taxi speed just as they arrive at taxiway Bravo...which would be passed the runway 34 displaced threshold

BTW the last time I was at Nanaimo I was number 2 for 34. The (local) pilot landed right on the numbers braked hard and then started backtracking for the exit at the 34 threshold. I naively expected him to roll out and turn off and thus spaced myself accordingly. I was able to just make it work but I was massively unimpressed by the "airmanship" exhibited by this guy..... but hey he obviously got great instruction because he was stopped before he even reached the displaced hold line

[FlaplessDork]

Day VFR landings are perfectly safe when landing on the displaced threshold.

I agree, but people are getting more stupid.

I compare student landing past the displaced threshold to a helmet wearing narcoleptic. They need that extra protection.

[Cat Driver]

BTW the last time I was at Nanaimo I was number 2 for 34. The (local) pilot landed right on the numbers braked hard and then started backtracking for the exit at the 34 threshold.

If he/she touched down past the displaced threshold point on the numbers why would he/she want to backtrack?

Seems strange to fly a thousand feet down the runway land and then backtrack with someone behind them on final.

[Brewguy]

"Airmanship", eh? Do they still teach that?

Cat, out of curiosity (not being familiar with that airport, and how its taxiways are laid out)... these same locals that usually overfly perfectly good runway to land beyond the displaced threshold; How many back-track and use the whole runway for takeoffs?

[Cat Driver]

Cat, out of curiosity (not being familiar with that airport, and how its taxiways are laid out)... these same locals that usually overfly perfectly good runway to land beyond the displaced threshold; How many back-track and use the whole runway for takeoffs?

On runway 34 the taxiway is at the start of the runway, but runway 16 taxiway B is over a thousand feet from the start of the runway and a lot of pilots do not back track for take off.

By the way I am not suggesting that anyone touch down at the start of the runway and then have to taxi a couple of thousand feet to exit the taxiway, however doing touch and goes is a different issue.

If you use the start of the runway you have another thousand feet to land on if the engine should quit.

By the way I had an engine quit on a touch and go on that runway and the extra thousand feet made it easy to land straight ahead.

NOTE:

Please remember I am not one of the pilots who received the blessing from TC to be an instructor so take all my posts with that advisement.