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Originally Posted by relayerdave
Hi, woxof...on youtube, there are many atc videos, a large proportion of which are from JFK controllers. A couple of questions:
1. In many of the videos, the ground controller taxis the aircraft to, for example "22R, shortened", or "31L at KK." I assume these are clearances for less than full-length departures, yes? If so, why do they use less than full length, and do the crews know in advance (and, therefore, plan in advance for) "shortened" departures?
Good question Dave. I don't think we've discussed intersection takeoffs in this thread. The first case you mentioned is actually a full length takeoff, using all of the runway that's available. The northeast portion of runway 22R has been closed for some time now and I'm not exactly sure what they're doing with it. It's maybe a couple of thousand feet of runway that's been torn up. When using this runway for takeoff, we taxi onto the runway at taxiway Yankee, but for some reason they refer to it as "22 Right, shortened" which is not a usage I've ever encountered before and I don't know why they don't just say "22 Right, intersection Yankee." In any case, this is all of the runway that is available.
The other example you mention, "31 Left at Kilo Kilo" is a common intersection departure issued by JFK. This still leaves over 10,000 feet of runway available for takeoff. The advantage of this clearance is that it eliminates the need to taxi across runway 22R/4L, which you would have to do to use the full length of 31L.
Yes, we know in advance if intersection departures are in use; the ATIS will have a remark to this effect. We get performance data for every runway and intersection in use, so we'll have takeoff speeds and power settings for both 31L, full length, and 31L/KK takeoffs.
If we set the plane up for the intersection departure and then we get sent out for a full length takeoff, we can use the same performance data. After all, if the speeds and power setting are good enough for 10,000 feet of runway, it will certainly work for 13,000 feet. But if it's the other way around (i.e. we're taxiing out for a full length takeoff and now the tower offers us the shorter taxi for the intersection departure), we have to set up the plane with the new data. This is all to ensure adequate performance in case of an engine failure at V1.
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2. There is a particular ground controller who appears very often in these clips who I find extremely funny. One thing he says a lot when a crew requests "taxi, with victor", he replies "you and victor go right Alpha, hold short (whatever)". Do you know who this guy is?
A lot of the JFK controllers have a New York attitude, and I mean that in a good way. They can have a little humor and most of them are really good at their job. They don't suffer fools gladly, and they expect you to able to understand and read back clearances concisely, but they will show patience with foreign pilots.
I've never heard the joke you mention but I like it and I'm sure I've talked to the guy you're talking about.