to slow, or not to slow...

wheelsup · August 21st, 2006, 12:04

Let's pretend you're flying along going into a hub city. ATC (center) gives you a vector up to 90 degrees from your course for spacing.

Would it mess up ATC's sequence to slow down on your own so you don't fly too far out of the way, but still get whatever seperation is needed, or continue at your current cruise speed on the vector?

The thought process here is that I don't want to go to far out of the way burning gas (takes more to go faster) and if you slow down from say 300 to 250 it'll save a little bit of $$. But I also don't want to throw a wrench in ATC's plans as that wouldn't be worth the gas savings IMO, and it might even screw it up even more down the road.

thx

Fox Xray · August 21st, 2006, 13:13

Things are so dynamic, especially vectoring to meet MIT requirements, it's hard to give a specific answer. You should not see a 90 degree vector, they happen, but not often, in that scenario I'm spinning you...

The way I would prefer is that you give me a heads up... like this:

ATC: N1234 turn 40 degrees right, vectors spacing.

N1234: 40 degrees right... and we're reducing to 250 kts.

If I need you to maintain present speed I'll either assign it or just tell you speed your discretion, or maybe just roger you. We develop a basic plan for situations, with ATC being dynamic the plan changes all the time, the more info we have, A/C is gonna slow down, speed up, etc. the better we can pre-plan our moves.

Hope that helps...

wheelsup · August 22nd, 2006, 00:11

thanks! makes sense. and I have been given 90 degree vectors before believe it or not!!! (don't get me wrong - I'm paid block or better so any extra time is cool with me...)

Merlin · August 22nd, 2006, 00:54

It seems to me that by the time we get the turn, we have usually already been slowed and that apparently didnt do enough, so the vector comes to finally meet the requirements--at least on an arrival.

I guess an exception may be that you are near the front of the line and are given, say 300 kts, behind someone doing 310 or better and you get the turn. But even then, I think they usually start slowing the line from the front and turning the guys in the back as things start to bunch up or they get too slow (isnt 250 the minimum assignable speed that Center can assign?)

Is that about right?

wheelsup · August 22nd, 2006, 02:41

i've gotten vectors quite often without having a speed assignment. obviously if there's a speed assignment, you must go that speed, you don't have the option of slowing down.

your example of slowing reminds me of one fine evening in TEB when the line to get in streched longer than PHL's final on a day with scattered clouds. I ended up 'having' to file a pop-up IFR with ny just to get in, there was a vfr baron holding for 45 minutes and I was hungry. "Flexjet XXX, slow to 180, 5-star XXX slow to 180, lear N##### slow to 180" the controller went on for about 5 minutes trying to open up a hole big enough for a 172 doing a buck twenty on final.

another funny time...I was ferrying a 172 alone in from upstate NY, and it was IMC. they were landing north @ TEB and the final was 20 miles south of EWR...for some reason I asked if they wanted me to slow down..."NO! Don't slow down! God please don't slow down!" in the most condescending/sarcastic tone I've ever heard. Good times.

casey · August 22nd, 2006, 21:19

Quote:

Originally Posted by Fox Xray

Things are so dynamic, especially vectoring to meet MIT requirements, it's hard to give a specific answer. You should not see a 90 degree vector, they happen, but not often, in that scenario I'm spinning you...

Hope that helps...

spend some time in with zhu, those guys give 70+ degree vectors "for spacing" all the time (at least to me) and they dont seem to talk to eachother when it comes to spacing and reroutes. I'll have a controller do something to satisfy the next sector for a handoff and have the next controller undo it, sometimes while im in the turn still from the last guy.

Merlin · August 23rd, 2006, 00:03

Quote:

Originally Posted by casey

spend some time in with zhu, those guys give 70+ degree vectors "for spacing" all the time (at least to me) and they dont seem to talk to eachother when it comes to spacing and reroutes. I'll have a controller do something to satisfy the next sector for a handoff and have the next controller undo it, sometimes while im in the turn still from the last guy.

Yeah, especially coming in from the north on a busy afternoon, we'll get a directive to slow to our slowest practical speed, then get a big turn. While in the turn, we'll get a handoff to the next center controller and it's direct RIICE and 310 or greater. Ive had this happen more than once or twice.

So what's going on? Do we just happen to achieve the correct spacing at the moment of the handoff or is there a lack of communication going on between controllers?

Jeremy

(BTW, I love this forum!)