wrigley23 said:
Ok controllers (mainly center guys), quick question? Do vectors or speed reduction usually produce more seperation (especially when you have to maintain something retarded like 20 miles in-trail)? Ive watched reactions of guys I've flown with and it seems 10 left or 20 right is way less painful than, "maintain 250 knots for spacing".
Wrigly,
I'm not a Center type, but do work a sometimes busy approach control. Speaking about departures, vectors will get more separation faster than speed control will, but what I use depends on a number of factors. If you're departing out certain DP transitions, I know the receiving Center sector wants you ON the DP radial, not six miles either side and overtaking, so I'll use a combination to get 6-7 miles in trail. Going towards other sectors on a different DP, those sectors don't mind if we go direct first VOR, so we'll do more vectoring and less speed control. Most often, I'll try to use a speed 10 kts slower than the guy ahead just to
insure you don't overtake the preceeding departure, and the Center will take the speed off when they get lateral or vertical later.
At my present facility, our LOA states that we will give the Center at least 5 miles in trail. At other facilities, like my previous one, the LOAs say 3 miles, increasing to 5. Since the tower is sometimes only giving me
2 miles initially, and they may give me four aircraft in a row out the same DP, the vectors can get rather large, (30-40 deg) to achieve 6-7 in trail before they all leave my airspace. No big deal if they're going out different gates.
On arrivals, I
try not to use 190 or less until on downwind, and I also try not to assign greater than 170 to the FAF. The biggest problems on finals where I work are Cessnas in headwinds, and Boeing gliders. Some of the 757s are using target speeds 30 kts slower than the 737ngs, and if they get caught up high on the arrival, you practically have to shoot them down, or send them back out the departure gate to start the STAR all over again....
I swear, cuss 'em all you want, I LOVED working 727s on finals better than any other jet. They could do anything I asked. They could follow a C210, or lead a T-38. They could slow and descend like nothing else with a first class section.
