Around the Airport

Saturday, July 10, 2010

Displaced Threshold Part Two - Beware the Corn

Previously in NORDO News, we discussed the meaning of the two sets of three cones at each end of the runway and how they pertained to runway lengths and displaced thresholds.  What we noted was that many people seem to believe that these sets of cones indicate the end of the runway and thus they take off with runway behind them.  This time we'd like to discuss the other side of the coin, visibility. 

The displaced thresholds at Lee Bottom are there due to trees to the South and seasonal crops to the North.  If you taxi to the very end of each runway during certain times of the year, you could be blind to approaching aircraft and approaching aircraft may not be able to see you.  Therefore, in order to help you use the recommended full length of the runway  please read the following best practices.


When taking off on runway 18, you should stop at the set of three cones to do your run-up.  Doing so will do two things for you: 
1)  If you watch people taking off of any runway at any airport, you will often see people focusing on their run-up and then immediately taking off.  This is not always wise as the pilot's attention has been drawn away from the act of flying and thus also away from what is going on around them.  Therefore, you should do your run-up and then give yourself a window of time to get back in the game and look for aircraft on approach.  
2)  Stopping at the displaced threshold will also do one other critically important thing for you; allow you to see any approaching aircraft on base and final.  If you pull onto the very end of runway 18 during a season where corn is being grown in the field next door, there is a good chance you will not be seen by approaching aircraft and that you will not be able to see the same.  

Therefore, we strongly recommend that you stop at the displaced threshold (the set of 3 cones), do your run-up, get back in the game, look for approaching aircraft and THEN taxi out and take off with no extended period of holding on the runway.

When it comes to runway 36, there are a few other things to keep in mind.  During the summer months when the leaves are on the trees, even if you stop at the displaced threshold, you will not be able to see aircraft on a wide base.  Yet with that said, you should still stop here and do your run-up, then look for traffic and back taxi to take off with no extended holding on the runway.  Aircraft on final and turning from base to final will be able to be seen by following this procedure and aircraft turning to final will be able to see you.

And don't forget, these procedures also work at most other airports.

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