Displaced Threshold

[n3437d]

why is it OK to take off from a displaced runway but not land on one even though you are permitted to enter the Displaced runway once landed?

Just curious.

Joel
N3437D

[flyguy]

I WUZNT GOINTU MAKE A FUNNY CAUSE I LAN ED ON A "DISPLACE " PLACE A TIMER 2 - - DOANT GIT CONRFUSE WITH DISPLACE RUNWAYS CUZ THEIR ROUN SOMEWHERE BUT NOT ALWYAS JES AXE ARE MEMER WHO GET TO NOT FLY CAUSE THEYSA MOVE THE HOLE DURN ARIPORT

SO NO MORE SPEAK OF DISPLACE "RUNAWAY" BUT ONLY THRASHOLES


A displaced threshold is a runway threshold located at a point other than the physical beginning or end of the runway. The portion of the runway so displaced may be used for takeoff but not for landing. Landing aircraft may use the displaced area on the opposite end for roll out.

Most often the offset threshold is in place to give arriving aircraft clearance over an obstruction while still allowing departing aircraft the maximum amount of runway available for takeoff. A displaced threshold may also be introduced if a beginning section of the runway is no longer able to sustain the continuous impact from landing aircraft. In such a case, aircraft are expected to land beyond the displaced threshold. Departing aircraft are permitted to use the displaced section of the runway for takeoffs or landing rollouts because those aircraft are not impacting the runway with the force of a landing aircraft. This condition is usually encountered at airports with lots of heavy aircraft operations.

Displaced thresholds have arrows as the center line of the runway. A thick white line with usually four arrows pointing in the direction of the runway denotes the end of the threshold and the beginning of the runway.

Thresholds are counted as part of the runway, and are included in the runway size. When viewing a runway's size with displaced thresholds, one must find out how long the displaced thresholds are in order to calculate the maximum take-off and landing distance.

Note: This is mostly FAA verbiage but came from the Wikipedia.

[canav8]

Most important thing to include in that wiki def is that the pavement is not stressed for landing pressures, take off is only the weight of the aircraft rolling on it. Doug

[Brad Brady]

At Dwight the threshold is displaced because when landing ,someone caught a car going south when they were landing west. I guess that is enough for a displaced threshold!!!!

[n3437d]

Best answer goes to canav8 A few follow-up questions. What happens if (for anyone of a number of reasons) the errant pilot lands prematurely (but safely) upon the Displaced Runway? Will said pilot recieve a call from the tower? When a pilot flying a small single engine plane into a large ( > 7,000' runway) airport and is told to "report midfield" Does midfield take into account the 1000' (more or less) displaced runway?



Joel
N3437D

[canav8]

Best answer goes to canav8 A few follow-up questions. What happens if (for anyone of a number of reasons) the errant pilot lands prematurely (but safely) upon the Displaced Runway? Will said pilot recieve a call from the tower? When a pilot flying a small single engine plane into a large ( > 7,000' runway) airport and is told to "report midfield" Does midfield take into account the 1000' (more or less) displaced runway?



Joel
N3437D

Joel, AIM states that the threshold is not for landing at all, because of my previous said fact. Only time you can use it is in an emergency situation. Tower may not call you but if FAA is notified of your usage, you are guaranteed an LOI (Letter Of Investigation). For said reason above. Midfield is reference to geographic center of airport and not a runway of specific. Hope that helps. Doug

[canav8]

Joel, If your trying to start a game of Stump the Chump, I will be glad to keep quite. I have allowed many students the opportunity to win lunch on a bet if they could stump the old man. "They don't realize I am 3 potato chips shy of 250lb for a reason." LOL "I sure eat good in the neighborhood."

[Bruce Fenstermacher]

Joel, If your trying to start a game of Stump the Chump, ....."

Stump the Chump? Oh boy, know let me think....

[n3437d]

Nope, I am not one of the Click and Clack Brothers of NPR fame - Seriously - Shamed to admit this but I had opportunity to fly into a rather large airport this past friday and I was weak on my "huge field" knowledge. OK George, I should have brushed up before hand but this was a spur of the moment thing.

I am serious about my questions even though they may appear stupid to some of you vets.

Joel
N3437D

[canav8]

No worries, I tried to provide accurate info to you with references. I do not claim to all knowing but lunch is good when a bet is involved. I am also selective on the bet I take. Remember I live near Las Vegas. Joel, there is never a stupid question, especially if I can protect someones certificate from Elvis. LOL DOug

[GAHorn]

Perhaps the "tang-in-jowl" language of Ol'Gar made it too difficult to continue reading his response.... but if one will take the time to read the more-serious portion of his response, it contains most answers to your question...including the explanation regarding landing/touchdown forces and obstacle-clearance.

Short answer: Runway thresholds are the beginning of the runway. Displaced landing thresholds are not to be used for landing. What part of "displaced landing threshold" do you not understand?

[Brad Brady]

Best answer goes to canav8 A few follow-up questions. What happens if (for anyone of a number of reasons) the errant pilot lands prematurely (but safely) upon the Displaced Runway? Will said pilot recieve a call from the tower? When a pilot flying a small single engine plane into a large ( > 7,000' runway) airport and is told to "report midfield" Does midfield take into account the 1000' (more or less) displaced runway?



Joel
N3437D

If I'm heavy, and I know the airport........judgment makes my decisions....right or wrong....The insurance company will make the final decisions....if that becomes an option....hopefully not....Brad