# When to turn base at towered airport?

When at a towered airport and instructed to make "left pattern for runway 3," am I supposed to wait for the base leg turn until tower clears me for landing? This seems to be the norm, but I can't find anything in the FAR/AIM to indicate what is acceptable.

Related: I often get confused when in the downwind pattern and I hear something like this: "123X, tower, you are #2 for runway 3, following a Cessna on final." Does this mean I should turn base and follow the Cessna?

I know the correct answer is to ask ATC to clarify, but it would be ideal if this were spelled out in the AIM.

• Added faa-regulations, as phraseology and terminology used indicates US based question. Phraseology and behavior would differ for easa-regulations. – SentryRaven May 21 '15 at 7:35
• – Farhan May 21 '15 at 13:25

You have a few questions here.

...downwind pattern and I hear something like this: "123X, tower, you are #2 for runway 3, following a Cessna on final."

In this case what you will do is continue your down wind leg while scanning for the Cessna traffic, some towers may ask you to "report traffic in sight" in which case you will say "traffic in sight" when you can see the Cessna. If he is on a long final you can begin turning your base (assuming you are in a similar small plane of a similar speed) when he is on your beam (right off your wing tip). This should provide adequate spacing for you to come in properly. Keep in mind that the tower may also instruct you to do things to keep separation like "123X Extend your down wind 1 mile" etc.

...instructed to make "left pattern for runway 3," am I supposed to wait for the base leg turn until tower clears me for landing?

This depends on where you are coming in from. I have flown into towered airports on the runway heading and simply come into the pattern on final and was cleared to land about a mile from the runway. Other wise I typically report my midfield downwind to the tower "Piper 12345 Reporting Left Midfield Downwind for RW24" then the tower will respond with my landing clearance or instructions to extend. While it is the towers responsibility to clear you for landing and what not, controllers are not perfect, you can continue on towards the runway in your pattern but if you have not been cleared you should go-around or ask for clearance.

The other situation I have been in is a case where the controller deliberately does not clear you but has you come into the pattern and approach. This occurred while they were waiting for an IRF plan to come through for one of the regional jets waiting for departure. Since they did not know when it would come in I was instructed to continue my pattern and would be cleared on final if they did not need to get the jet out. However I was explicitly told I would be cleared on final so I knew what to listen for.

• One minor nitpick: When you're given a traffic point-out by ATC it's good practice to report when you have the traffic in sight, even if they didn't specifically ask you to. Once you have visual contact with the traffic the tower can have you follow them and maintain visual separation - it helps with the controller's workload, and they won't keep calling the traffic for you which reduces frequency congestion. (Common Sense Exceptions Apply obviously: If the frequency is really busy & you can't get the call in it's usually not critically important.) – voretaq7 May 21 '15 at 17:30
• Very good point. I may be a little bit biased since the controllers at KPNE are very on top of that since there is a lot of jet traffic as well as GA. They will always request you call traffic in sight. Some times you will get a "You are #2 behind Piper on final now" and that they usually just want a "#2 behind piper on final" read back. But you are absolutely correct. – Dave May 21 '15 at 18:34
• @Dave: Thanks! Follow up: If the tower doesn't give me any other instructions except for the "make left pattern for runway 21," I can turn base whenever I like? Worst case, I'd have to go-around if not given landing clearance? – David May 23 '15 at 22:08
• @David, I would always go around if not given clearance just to be safe. And yes if you are in the pattern you can make your turns as you need at a towered airport. They wont call them out for you unless they say something like " Piper 123X extend your down wind ill call your base" even then I have been in the case where I have had to remind them they extended my downwind. They key is to be on speed so that your extended legs are shorter than if you came in to fast. – Dave May 24 '15 at 3:10

I am Australian, but I can't see why these procedures would differ greatly between our countries.

The answer to your first question is no. In the absence of airport-specific published procedures, you do not need to wait for tower clearance to turn base, however you must tell them that you are commencing the turn. Usually once you tell them that you're turning base you are given a landing clearance. The exception is when you are specifically asked to report before turning base - it is not uncommon for tower to ask you to report when ready for the base leg, in which case you must not turn until cleared.

Regarding your second point, if I take it exactly as you have presented it here that is a traffic information message only, with no clearance. The same procedures as above apply. However if you are told that you're following traffic in the pattern, you must not turn base unless you have identified the other aircraft. Accidents have been caused by the trailing aircraft 'cutting in front of' the aircraft in front.

• it is not uncommon for tower to ask you to report when ready for the base leg, in which case you must not turn until cleared.- This is why I did not answer, being an EASA-kid. Unless the instruction extend downwind is used, I am free to turn base whenever I like. report downwind is an instruction to report, not to extend. – SentryRaven May 21 '15 at 7:57
• @SentryRaven That's the common usage in the US too: "Report" means "Tell me", though it's implied that you may be asked to change your plans when you report. (When the tower wants you to do something nonstandard they'll tell you: extend downwind or I'll call your base get used frequently if the tower wants you on the downwind longer than a "normal" pattern would dictate, otherwise you fly a standard traffic pattern just like you would at an untowered field). – voretaq7 May 21 '15 at 17:25