What Does "flow" Mean?

corrigancr

Newcomer
Oct 12, 2017
1
0
1
Hi there, I'm a student pilot with about 35 hours flying out of CYGK (advisory-only airport). We have about 7 scheduled Air Canada flights to/from CYYZ per day here, and every time one lands the controller mentions "flow" back to Toronto-Pearson, which is either granted or cancelled, and I can't for the life of me figure out what it is... Does it just mean quick turnaround or something? This is Canada so we aren't under FAA rules but is anyone familiar with what that term means?
 

Stinger

Epic Member
May 24, 2009
1,559
21
38
Hi there, I'm a student pilot with about 35 hours flying out of CYGK (advisory-only airport). We have about 7 scheduled Air Canada flights to/from CYYZ per day here, and every time one lands the controller mentions "flow" back to Toronto-Pearson, which is either granted or cancelled, and I can't for the life of me figure out what it is... Does it just mean quick turnaround or something? This is Canada so we aren't under FAA rules but is anyone familiar with what that term means?
Delay programs. Either Call For Release, or Miles-In-Trail.
 

j_time41

Senior Analyst
Nov 17, 2008
1,015
8
38
34
Lakeville, MN
Other example of a flow program would be a time based metering delay flow program, where you take a delay (holding or vectors) of up to 40 mins for inbound pushes.
 

007hamster

Senior Member
Feb 25, 2009
205
0
16
NATCA Meeting
Delay program, or "metering" into an airport. An example is CFR "Call for Release". So we will tell the pilot "Flow into YYZ, advise 10 minutes prior to taxi". You say I'll be ready to depart at 0400z, we call YYZ flow control and say "Request Release C-FSDS Citation 750 wheels up 0400z" They ("Flow Control" for YYZ) will tell us "released" and a time, sometimes the time you want. Other times 15 or more minutes later. We tell you for example "C-FSDS Released at 0430z time now 0355 and one half"

It is important to give an accurate time because if you miss your slot, you will be cycled in behind everyone else. If you tell us you will be ready in 10 minutes and we get you that time, and you miss it by 3 minutes, we have to call and get a new time and that new time cold be 30+ minutes further out.

Also, at least in the US. The time issued is the time you will be "wheels-up" or tagged on the RADAR. There seem to be Allegiant pilots that think it is when they start taxi or when they are at the approach end of the runway. If your flow time is 0430 you should be at the runway at 0428 ready to go. I've asked MD80 pilots to expedite taxi to make a flow time, which I added a buffer to, and still miss it.

Example AAY100 calls up at 0400z we're ready to taxi in 10 minutes, I call flow and say "Request release AAY100 wheels up 0420z" giving them 20 minutes (the taxi time here is 5 minutes or less.) They call ready to taxi at 0417z, knowing darn well the wheels up time I issued of 0420z and I added an extra 10 minutes buffer because I assumed they would be slow. They get to the runway at 0421z, well now I have a guy on a one mile final, I have to launch them behind the C510 on a mile final, C510 has to exit, then launch AAY100, AAY100 won't tag up on the RADAR scope until 0425z... not okay. So I have to call flow again and they may say "AAY100 released at 0457z" a 30+ minute delay for an aircraft holding short of the runway just because they were 3 minutes late, missed their time, and now the sector is blowing up and 30 min is the best that flow can do to accommodate.

In short, flow time is essentially when you rotate (tag up on the RADAR display), not the time you pull up to the runway; And its better to add an extra 5 minutes, than to miss your time and have to be put back in the sequence potentially 30+ minutes later.

PS I know nothing about flow to YYZ, maybe someone with TMU experience can chime in with more info. I am just bored...
 

customcables067

Senior Member
Sep 1, 2010
199
1
18
It is important to give an accurate time because if you miss your slot, you will be cycled in behind everyone else. If you tell us you will be ready in 10 minutes and we get you that time, and you miss it by 3 minutes, we have to call and get a new time and that new time cold be 30+ minutes further out.

Also, at least in the US. The time issued is the time you will be "wheels-up" or tagged on the RADAR. There seem to be Allegiant pilots that think it is when they start taxi or when they are at the approach end of the runway. If your flow time is 0430 you should be at the runway at 0428 ready to go. I've asked MD80 pilots to expedite taxi to make a flow time, which I added a buffer to, and still miss it.
Someone can come along and roast me for not using correct phraseology ... but I solve this problem by specifically stating to the pilot after getting their release time from TMU, "AAY100 wheels up at 0430, plan to be rolling prior to that." Yeah, I know, not in the book. Sue me.

I'm sure after you ask them to expedite, they're grumbling at you about how you "gave them a delay and now want them to hurry up." I think the problem here is just bad communication and understanding of the system all around. We need like an index for pilots... EDCTs are +/-5, unless there's a CFR over the EDCT program... etc.... okay I'm done. :)
 

customcables067

Senior Member
Sep 1, 2010
199
1
18
And as we found out at our facility, CFRs are -2/+1.
I've read that too, but does your TMU Center give you "released at 2000" or "1958-2001?" If it's the latter, I suspect they are building the window for you, and expect the plane to tag up in that window, not 1956-2002. I could be wrong.
 

NovemberEcho

Epic Member
Dec 8, 2010
4,388
68
48
Long Island
Or at my facility, TMU is a group of individuals who sit and watch you go down the tubes with a 50/hr rate with 60kt tailwinds on the base and 40Kts to the face on final while twiddling their thumbs and drinking coffee. Then they get confused when you go into a hold.
 

j_time41

Senior Analyst
Nov 17, 2008
1,015
8
38
34
Lakeville, MN
Or at my facility, TMU is a group of individuals who sit and watch you go down the tubes with a 50/hr rate with 60kt tailwinds on the base and 40Kts to the face on final while twiddling their thumbs and drinking coffee. Then they get confused when you go into a hold.
I disagree....one of ours drinks hot chocolate