# Why do some towers reference departures by compass direction, others by leg of pattern?

Got my Private about 6 months ago, and I've always wondered - let's say I request a VFR departure to the South, with the active runway being, say, 2. Some towers will give my departure clearance in reference to the requested compass direction, i.e. cleared for takeoff runway 2, right turn to heading 180 approved whereas other towers will reference it to a pattern leg, such as cleared for takeoff runway 2, right downwind departure approved. Similarly, I've noticed pilots based at airports that use the latter convention will follow that convention when making their departure requests. Is there any rhyme or reason behind which convention a tower follows?

• @SentryRaven Are we sure this is in relation to FAA regs? All indications seem to suggest it, but not seeing that definitively. Am I overlooking something? Chris, are you asking from the context of operations under the FAA? – J Walters Feb 12 '16 at 13:32
• @JonathanWalters Yes, as 7 out 5 EASA CAA / countries use mandatory reporting points to enter or exit a CTR. Departures via headings or downwind departures are not commonly used here. That sounds like FAA phraseology to me, but I can be wrong there... – SentryRaven Feb 12 '16 at 13:38
• @SentryRaven It's common shorhand at some airports (my home field included), but as far as I'm aware it's not officially recognized phraseology (at least the phrase downwind departure doesn't appear in the Pilot/Controller Glossary - I didn't look at the ATC Phraseology order though). – voretaq7 Feb 12 '16 at 19:19
• Maybe the OP will clarify... :) – SentryRaven Feb 12 '16 at 19:20
• Ah yes, apologies for not clarifying. Looking for an answer under FAA regs, or at least in the context of the US. I asked my old CFI and she said that sometimes a new controller will use a different phrasing than is common at the airport, so it may be as simple as "that's how it's always been done around here", but I'm curious to know if it's more formal than that – Chris Feb 13 '16 at 5:37

## 2 Answers

It depends on local custom.

Some airports have multiple runways, so controllers will use compass points instead of pattern legs, and this habit will carry over when they are assigned to a single-runway airport.

Other airports have noise abatement procedures which have specific names. Below are the departures for San Carlos airport, and pilots are expected to use a named departure, such as "Belmon Slough Departure" instead of "right-crosswind departure," and tower will readback the named departure.

From my experience, tower controllers are always being trained to use consistent phrases to make instructions clear at their airport, but in the end you are dealing with humans trying to communicate what they want you to do and what the limits of your clearance are.

To me, it is more relevant to your question that one controller is using a specific heading for you departure and the other referenced the local field downwind pattern. For your 1st example you are expect to turn to the specific heading of 180 and then proceed on our VFR departure. For your second example all you have to do is turn toward the downwind leg and then proceeded on your departure, giving you more leeway.

Keep in mind you are departing VFR so I wouldn't overthink it so long as you are complying with specific instructions.