Hi there,

I can't seem to find any real, definite answer to the question where exactly the touchdown zone on runways is, or how long it is.
Google spits out various definitions, as well as different runway marking examples.

So what's clear is, that the aiming point is 1000ft from the runway threshold.
After that, there markings every 500 ft., sometimes just 2, sometimes more.

But where exactly does the TDZ end? Some say 1000ft after the aiming point, some say 3000ft from the threshold, some say a third of the runway.

Has anybody a valid, official definition for me? 

Thx
Stu

 

@Stu Antonio

If I’m not completely mistaken and remember correctly the touchdown zone is from the first start of the markings to the last one of the last 500ft stripe. The big blocks as you say is the aiming point the other 3-2-1 markings on the side of the centerline indicates the whole zone. The amount of stripes I would say is based on the length of the runway and countries differences. 
Have a nice day! 
// Simon 

The TD Zone starts at the three stripes marking in your picture (normally 500 ft after threshold) and ends at the last one strip marking.

The runway markings are all defined in the icao annex 14 which is about aerodrome standards. What @Phil Tereny said is what I also remember.

Here you can see an example from Google Earth. The TD is between the red lines, and the distance between the bars (green lines) is 500 ft. Also remember, that the big white stripe (the so called aming point) isn't always 1000 ft. from threshold!

Thanks guys!!!