From day one as a controller, the toughest part of understanding this dynamic environment is when and how to issue speed control. Let me start off by saying, if you're an S3 you should already know the phraseology, and have somewhat and idea of what aircraft types will fly what speeds in all phases of flight; This includes departure, cruise, and primarily the final approach phase due to the concept of compression along the final approach course.
Recently, I have been flying on the network and have been given clearances that make no sense, are illegal, or need some general polishing.
I'll discuss a few examples of what speed control can and should look like, while also offering various techniques.
Let's say you have a Boeing 737 descending out of 12,000 for 10,000 and 250 @ 10K. If the aircraft is the only plane in your airspace, and you're giving the aircraft a descent to 3,000 there surely is no reason to slow the airplane down. The issue we run into is, misinterpretation of the aircraft's speed because we see 290 or 310 (ground speed in the data block). Note, the upcoming point I'm going to make is BASED off how far away the aircraft is from the final approach course, and typically it applies more so when the aircraft is already committed on a base leg or on a straight in. If you slow the airplane down for no particular reason, you're doing one of two things..
1. You think you're helping the pilot by telling him/her to slow when in fact you've just increased pilot workload and have put the airplane in a position where the rate of descent now DECREASES as the aircraft is now required to pitch up. This is why the 7110.65 states, SLOW first, THEN descend OR DESCEND and then SLOW.
2. You're inferring that you can essentially fly the airplane better than the pilot and in turn you have not done what you should do which is, GO get the flying miles you need to now put the aircraft in a comfortable position to fly the proper glidepath.
If you're confused, let me clear this up. Pilots know the rule, "No greater than 250 below 10K", but what you have to understand is that, there has to be a recognition of a pilot's altitude in reference to the final and you need to be proactive in this process. Being proactive doesn't mean slowing the #1 and only airplane in your airspace because you just feel like doing it, it means making decisions that are practical. If you realize the aircraft on a base leg is 2200 feet too high for the approach and hes 6 miles from the IAF, SLOWING doesn't help, YOU need to go get the additonal flying miles and issue a quick 20-30 degrees turn, and then possibly one turn to join the final.
My point so far is, don't slow to just slow. Slow when it's needed. Let the pilot fly the aircraft. If you don't tell him/her to slow, they will at some point, and that is what I would call, proper situational awareness on the part of the pilot.
Next...speed control while sequencing.
Let's say you have two aircraft on opposite downwind legs. When a sequencing is starting to develop it is essential you have recognition of the aircraft's speed, if you don't know what it is, ASSIGN it (DAL843 maintain 250 kts, DAL843 maintain 210 kts OR greater, DAL843 maintain 210 kts or DAL843, maintain present speed). I use those examples of phraseology because they are CLEAR cut. Typically a sequence can always be maintained far out from the airport (20-25 nm or so) at 210 knots. If you do not know what the aircraft's speed is but it's somewhere in the range of 210-240 groundspeed and you like it, keep your phraseology simple, maintain present speed. You'll notice, this is not the center environment, there is absolutely no reason to ever have to ask an airplane in the terminal area "Say airspeed". Jets are jets, and there is typically only four speeds we stick with 99% of the time.
1. 250
2. 210
3. 180
4. 170
5. Slowest practical is used 1% of the time and it's typically when YOU the radar controller has messed up. Yes, you jacked up the sequence. There is no reason to have to use slowest practical unless the pilot truly did not listen to any of your instructions.
In going back to the scenario I bring this up because every aircraft that follows DAL843 is at the mercy of this aircraft's performance. Having an aircraft slow down on you 20 miles away to 180, may be practical during an FNO, but when they do it for no reason, it hurts you as a controller and the concept of keeping an expeditious flow of traffic.
So, as DAL843 is assigned 210 kts and issued a base leg turn. My other aircraft at this point if abeam the other aircraft is also at 210 kts. Remember, the SOONER we can make speeds compatible, as long as we turn at the appropriate position, the spacing along the final approach course will remain the same, assuming the aircraft are LIKE types. As I'm ready to clear my first aircraft, DAL843, it is essential that when I issue the PTAC, I INCLUDE speed. DAL is number one, I have two examples of phraseology to use. DAL843, 8 miles from XXXXX, turn right heading 270, maintain 3,000 until established on the localizer, cleared ILS Runway 30 approach, maintain 180 knots til XXXXX or maintain 180 OR GREATER til XXXXX. It is important to understand we cannot assign more than 180 kts to the final approach fix, that is why we use the phraseology OR greater which gives the pilot the option. Now that our second aircraft is in position to follow DAL, we issue the PTAC. "AAL701, 14 miles from XXXXX, turn left heading 330 maintain 3,000 until established on the localizer, cleared ILS Runway 30 approach, maintain 180 kts, til XXXX or maintain 180 OR LESS until XXXXX. The phraseology OR LESS shall only be used when the trailing aircraft has no one else in the sequence to follow.
The above example is very easy to apply and it's typically what you'll see when aircraft are close to one another. But what if an aircraft is 20 miles away, and is in a position to PTAC with several aircraft in trail to follow; OR you're trying to close a gap between two airplanes and you want the trailing aircraft to catch up. Well, you have two options.
1. Assign a speed, 210 or greater for example/
2. Assign a heading to join the localizer. Yes, JOIN the localizer. When the aircraft is within reasonable distance 10 miles or less, CLEAR the aircraft with the following phraseology. "SWA633, 10 miles from XXXXX, cleared ILS Runway 30 approach, maintain 180 knots OR greater until XXXXX". Visualize this. SWA was already committed to 210 kts. You have to understand that a pilot will chirp if you don't clear them within reasonable distance from the FAF because most carriers and GA will NOT do 210 ALLL the way to the FAF, seeing that most of these fixes are placed on about a 5 mile final. Slowing the aircraft from 210 to 180 is VERY manageable. It provides the pilot to get into a dirty configuration very quick, then once at 180, and they hit the FAF, they will go into a full dirty configuration and fly the appropriate vREF speed.
3. Other option is to CLEAR the aircraft, (but note, when you clear an aircraft after issuing speed control, the pilot can slow down to whatever they like. Your TECHNIQUE to manage this is the following. "SWA633, 16 miles from XXXXX, turn right heading 270 maintain 3,000 until established on the localizer, cleared ILS Runway 30 approach, maintain present speed until further advised. Once the aircraft is several from the fix OR you have achieved the appropriate separation, issue the following ""SWA633 maintain 180 kts to XXXXX, contact tower 119.3".
Additionally, spacing is something we need to discuss as well. In air traffic, there is no guessing on when airplanes need to be turned to follow another airplane or when to PTAC. It is key to note two rules that you'll remember for the rest of your life.
1.For every 60kts, an aircraft will travel 1 mile
If an aircraft is showing 18 (180) on the datablock, that aircraft is flying at 3 miles a minute. Simple math...6, 12, 18 (6x3) add the zero.
2. The speed in the data block, is the distance aka miles, that the aircraft will travel in 6 minutes. So when you're setting up the sequence and you're trying to figure out who is number ONE, TWO, THREE...the speeds DON'T lie. If aircraft one is showing 26 in the data block and aircraft two is showing 20, aircraft one will fly 26 miles in 6 minutes and
aircraft two, 20 miles in 6 minutes. You're simply measuring from the position symbol to the final approach course. If it looks like a tie, slow one down, and keep the other fast. MANAGE your speeds.
Note, if the aircraft are already within 20 miles of the airport for example, and using the 6 minute rule isn't helping because the distance to fly to the threshold is shorter than their speed, cut the speed in half and use the 3 minute rule. If one is 15 miles away showing 20 in the data block, then we know that that aircraft will by 10 miles in 3 minutes.
Remember, stick to basic speeds. Never in the history of successful air traffic has someone issued 230 kts. Stick to the basics. 250, 210, 180. If your speed is not working DON'T tell the airplane to slow to 150, go get the flying miles and vector! You can easily close gaps by using 210 kts if the aircraft ahead is at 180. You can close gaps at 250 kts if the aircraft ahead is at 210. It is VERY difficult to close a gap when the lead is at 180 and the trailing is at 250 kts. Getting the aircraft from a clean config to a dirt config, ie...spoilers, flaps, gear etc is very difficult and does not instantly happen. Be smart, be decisive but do NOT overcontrol. If the aircraft is number one, with no one else to sequence stop controlling their speed and let the pilot fly the airplane.
In reference to a visual approach, keep it simple..
"ASQ4251 cleared visual approach, runway 30, maintain present speed (closing gap).
Then....."ASQ4251 maintain 180 kts to 5 DME or 5 mile final, contact tower xxxx".
If the aircraft is number one with a sequence to follow "ASQ4251, cleared visual approach runway 30, maintain 180 kts OR greater to 5 DME or 5 mile final, contact tower 119.1".
If anyone want's to sit down and talk more about this, or run a sweatbox with a few aircraft to demonstrate this, give me a shout dvento27@gmail.com
Enjoy your weekend guys.
