Is it legal to land before the threshold?

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Johann

Pre-takeoff checklist
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Johann
I was just wondering this.
Is there a difference between non-towered vs towered? (I would think non-towered no one will care, while the tower might give you crap for doing it, but I mean from a legal/regulation point of view more than a practical one).
 
When coming in toward the displaced threshold, you are required to land AFTER the threshold marker. The runway before the threshold can be used for takeoffs (and for runout if coming from the opposite runway). Doesnt matter if it is towered or not.

The runway isn't strong enough for heavy landings before the threshold. At least thats the way I think of it. Landing is gonna dent it, takeoffs wont.
 
evapilotaz said:
I wouldn't do it non tower or tower. There may be a safety reason for that threshold to be placed there.
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If it's displaced, the usual reason is an obstruction.

Sometimes, the "pavement" prior to the threshold is an arresting system, and you'll be really unhappy if you end up on it for any reason. It's marked differently from a displaced threshold, however. Chevrons, rather than arrows.

See the AIM.
 
I think it has a lot to do with your familiarity with the airport and why the threshold is displaced.

There are a couple of airports I've regularly flown into over the years that have displaced thresholds due to a perpendicular powerline on short final. My 182 will drop like a rock when needed and at one particular airport I could clear the power lines by 50' and still land well short of the threshold.

YMMV.
 
The pavement short of the marked landing threshold may also not be stressed for landing forces, or even for the weight of the airplane at rest (with markings as appropriate per the AIM section on runway markings).

In any event, while I'm unaware of any specific regulation on this, depending on circumstances, if something bad happened as a result, the FAA would probably find a way to make a 91.13 careless/reckless charge stick.
 
Why would you want to land short? The displaced threshold is there for a reason.
 
If it is a displaced threshold, 9 times out of 10 it is because of an obstruction on the approach path. It interferes with the approach slope but they still want to give you the max available runway for take-off. More than likely it is stressed to handle the landing just like the rest of the runway, especially for a small single engine plane. Would I be willing to bank on that?...no.

A overrun is a different beast. Some have raised runway lights. If you landed on that you would soon meet a wall or runway lights that can do some serious damage. At commercial airports they usually have EMAS which will definitely shorten your ground roll:rofl: Plus since that section is never used by an aircraft, it is usually covered in loose gravel, shrubs, and such.


mrkbbd said:
Sometimes you need the whole runway...
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If thats the case then someone obviously did something wrong in the planning phase or made some poor choices before the wheels touched the ground.
 
Ron Levy said:
The pavement short of the marked landing threshold may also not be stressed for landing forces, or even for the weight of the airplane at rest (with markings as appropriate per the AIM section on runway markings).

In any event, while I'm unaware of any specific regulation on this, depending on circumstances, if something bad happened as a result, the FAA would probably find a way to make a 91.13 careless/reckless charge stick.
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Ron is correct. Landing on a dispaced threshold falls under the category of landing on grass next to the runway, or on taxiways--i.e. if you don't have permission and an operational reason to do it, you're likely to be hit with 91.13 should something happen. If nothing happens, its more likely to be the airport that goes after you rather than the FAA. Controllers will more than likely not say anything unless you land so short so as to create a runway incursion with another aircraft.

As others said, runways are displaced for a reason. Your distance calculations shouldn't use them for landing. If you need more length, change the conditions (cooler weather, lighter weight) or find another runway.
 
Gucci Pilot said:
If it is a displaced threshold, 9 times out of 10 it is because of an obstruction on the approach path. It interferes with the approach slope but they still want to give you the max available runway for take-off. More than likely it is stressed to handle the landing just like the rest of the runway, especially for a small single engine plane. Would I be willing to bank on that?...no.

A overrun is a different beast. Some have raised runway lights. If you landed on that you would soon meet a wall or runway lights that can do some serious damage. At commercial airports they usually have EMAS which will definitely shorten your ground roll:rofl: Plus since that section is never used by an aircraft, it is usually covered in loose gravel, shrubs, and such.




If thats the case then someone obviously did something wrong in the planning phase or made some poor choices before the wheels touched the ground.
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Also, if you really need all of that runway, you most likely haven't planned for the following takeoff. :wink2:
 
Jon63F said:
Also, if you really need all of that runway, you most likely haven't planned for the following takeoff. :wink2:
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That was my thought, but you might have lots of extra room for takeoff due to the displaced threshold.
 
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Jon63F said:
Also, if you really need all of that runway, you most likely haven't planned for the following takeoff. :wink2:
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Takeoff are optional; landings, mandatory. :D
 
Ron Levy said:
The pavement short of the marked landing threshold may also not be stressed for landing forces, or even for the weight of the airplane at rest (with markings as appropriate per the AIM section on runway markings).

In any event, while I'm unaware of any specific regulation on this, depending on circumstances, if something bad happened as a result, the FAA would probably find a way to make a 91.13 careless/reckless charge stick.
Click to expand...

In my airport planning career I've yet to run into a displaced threshold that wasn't full strength pavement like the rest of the runway. They're designed to full strength in order to support departing aircraft utilizing the runway/displaced threshold (in both directions), along with aircraft rollouts on landing in the opposite direction.

We use maximum takeoff weight of aircraft for pavement design. It's not the landing loads that tend to stress runways, it's the loads at maximum gross takeoff weight. FAARFIELD (FAA pavement design program we use) bases pavement strength on MGTOW.

That's not to say there's some airport out there somewhere that isn't that way, but I can say with confidence that most, if not damn near all, runway thresholds are displaced due to obstacles or RSA concerns.

That being said, it's generally not a good idea to land short of a displaced threshold...it's displaced for your safety.

Relocated thresholds, blast pads and overruns on the other hand may not be safe to land on due to pavement strength concerns.
 
Displaced thresholds near here are because of trees, trucks on roads, and other obstructions outside the fence. A STOL aircraft could clear those obstacles easily while landing short of the displaced threshold, but a small jet could not.
 
No plane most of us fly(for pleasure) will be a weight issue. Yes, I'd go with obstruction protection. If you did O.K. On your last eye test, you should be able to avoid obstructions visually.
 
Not to mention one busy body shooting video on his phone, and you'll get to play the FAA game.

I won't land before the threshold.
 
The FAA does think it is a big deal though. Why else would there be multiple question about it on the written. :p
 
For a long time when I was based at Dulles there was a 6000' "displaced" threshold on 19L (now 19C). It was eerie flying over a mile of pavement before landing. The reason was they were digging trenches across the middle to accomodate the drainage for the new western runway.
 
If you do it at Northway Alaska you might have to go back with a pickup to collect your gear.

100_0834A.JPG
 
I haven't seen Northway since the earthquake damage. Man, lots of wasted space there now. Used to be a terrible little hamburger joint on the field. Always had a burger everytime I was there.
 
That looks like a little more than the average 'displaced threshold' markings on a runway. Not to inviting landing short there.

Looks like a great weather day in Northway. I landed there last in 1992, on an Al- Can Hwy trip, fun times.
 
Back in my day this was a question included in the bank for the written.
 
I've seen several videos on youtube where airliners land before the displaced threshold. Here's an example of a 747 landing before the displaced threshold. The runway is over 11,000 feet long, plenty long for a 747... And by looking at the skid marks, I'd say it has been done more than once at that airport.

http://youtu.be/A5ZLUP1Aroc?t=1m2s
 
JC150 said:
Here's an example of a 747 landing before the displaced threshold.
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This is rather a miscalculation on the part of the pilot, poor landing, not a deliberate action. Airliners aim at the touchdown zone which is another 1000 ft or so beyond the threshold.
 
Silvaire said:
If you do it at Northway Alaska you might have to go back with a pickup to collect your gear.

100_0834A.JPG
Click to expand...

The image above is a relocated threshold, not a displaced threshold.

Seems to be a few people confused on the differences in this thread.

A relocated threshold is unusable for aircraft landing or departing in any direction (with some rare exceptions such as clearways & stopways). They're marked with yellow chevrons or arrows. Not guaranteed to support the weight of an aircraft.

Relocated Threshold:
1483941.jpg


Below is a displaced threshold. It's usable for takeoff in both directions and landing in the opposite direction. Marked with white arrows leading to the threshold. Generally displaced due to obstructions but they're full strength pavement like the rest of the runway.

Displaced Threshold:
AirportSonomaCalifornia.PNG
 
Just complementing
There are 4 runway measures (in lenght)

TORA - Takeoff Runway Available
This is the runway lenght, including displaced threshold but not replaced threshold.

TODA - Takeoff Distance Available
This is the TORA, plus the opposite clearway, witch includes the stopway. (It's the runway plus clearway of obstacles to get height)

ASDA - Accele-stop Distance Available
TORA + stopway, is the runway plus the stopway, which is used in case of an runway excursion.

LDA - Landing Distance Available
The runway used for normal landings, excluding displaced and replaced threshold and clearway/stopway as well.

Normally these measures are shown on Approach Chart (IAC) of the aerodrome.

Nice landings.
 
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