Tuesday, June 16, 2009

Jargon, chatter, and mayonnaise, er, I mean "CB" slang

Well, I promised I would finish up with this subject last month, but things have gotten in the way... I had hoped to write the last word on the subject today, but this has turned into a two day post.

So, to introduce the concept of proper radio terminology, I quote the Aeronautical Information Manual, "Good phraseology enhances safety and is the mark of a professional pilot. Jargon, chatter, and "CB" slang have no place in ATC communications."

Last month I posted about the phrase "with you" sometimes used when pilots checked in on a new frequency. It is an extraneous modifier, because the very fact that one is "checking in" means that they are "with" the Air Traffic Controller. My post generated this comment:

Another age-old radio debate! Really, "with you" isn't so bad. I used to use it because it sounded cool. Took a while to get rid of that habit! But now I say "xxx Center, *level* at eight thousand." The reason "with you" isn't so bad, in my book, is that if you say "with you at {altitude}" instead of "level at {altitude}" it's the same number of syllables and takes pretty much the exact same amount of frequency time. I don't really know why pilots debate this so much, it seems to be controllers that get annoyed at "with you". Annoying controllers tends to lead to longer vectors, fewer direct clearances, etc. so that's why I got rid of the "with you" but it really is a silly debate.
I would like to focus on the "annoyed" comment. Why would there be a perception that controllers get annoyed and then take it out on later clearances and instructions? Pilots and controllers are all professionals, right, trying to get a job done safely, efficiently, etc.? Certainly the mark of a professional is to not be vindictive. One might get frustrated if someone blatantly disregarded protocol, like calling the TCAS, or Traffic Collision Avoidance System (right), a fish finder. But just to be safe, what could pilots do to make sure they're making the most of their side of Pilot - Controller communication?

The first obvious answer is for pilots to know their way around the Pilot/Controller Glossary.

This Glossary was compiled to promote a common understanding of the terms used in the Air Traffic Control system. It includes those terms which are intended for pilot/controller communications. [...] Use of the Glossary will preclude any misunderstandings concerning the system’s design, function, and purpose.
Within this glossary there are pretty obvious definitions, because we use them in our normal conversation, like VERIFY− Request confirmation of information; e.g., “verify assigned altitude.”

But a word can have additional meanings when associated within the aviation context, like FIX− A geographical position determined by visual reference to the surface, by reference to one or more radio NAVAIDs, by celestial plotting, or by another navigational device.

And then there are the really confusing definitions, that even have to reference different publications, just in case there is any question, like VISIBILITY− The ability, as determined by atmospheric conditions and expressed in units of distance, to see and identify prominent unlighted objects by day and prominent lighted objects by night. Visibility is reported as statute miles, hundreds of feet or meters.
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
a. Flight Visibility− The average forward horizontal distance, from the cockpit of an aircraft in flight, at which prominent unlighted objects may be seen and identified by day and prominent lighted objects may be seen and identified by night.
b. Ground Visibility− Prevailing horizontal visibility near the earth’s surface as reported by the United States National Weather Service or an accredited observer.
c. Prevailing Visibility− The greatest horizontal visibility equaled or exceeded throughout at least half the horizon circle which need not necessarily be continuous.
d. Runway Visibility Value (RVV)− The visibility determined for a particular runway by a transmissometer. A meter provides a continuous indication of the visibility (reported in miles or fractions of miles) for the runway. RVV is used in lieu of prevailing visibility in determining minimums for a particular runway.
e. Runway Visual Range (RVR)− An instrumentally derived value, based on standard calibrations, that represents the horizontal distance a pilot will see down the runway from the approach end. It is based on the sighting of either high intensity runway lights or on the visual contrast of other targets whichever yields the greater visual range. RVR, in contrast to prevailing or runway visibility, is based on what a pilot in a moving aircraft should see looking down the runway. RVR is horizontal visual range, not slant visual range. It is based on the measurement of a transmissometer made near the touchdown point of the instrument runway and is reported in hundreds of feet. RVR is used in lieu of RVV and/or prevailing visibility in determining minimums for a particular runway. (See why you would need a glossary? The definition continues, but I'll let you read on in your own time if you'd like.)

Plus, there are some things a pilot has to pick up OJT (on the job training) when talking to ATC. You can tell a pilot who's unfamiliar at this if she modifies her call sign with the word, "student," because "The FAA desires to help student pilots in acquiring sufficient practical experience in the environment in which they will be required to operate. To receive additional assistance while operating in areas of concentrated air traffic, student pilots need only identify themselves as a student pilot during their initial call to an FAA radio facility."

Dayton tower, Fleetwing One Two Three Four, student pilot.

Sometimes it's not so obvious, and confident sounding pilots make mistakes (I am using this term generically to mean errors in judgement, technique, phraseology, etc). A lot of pilots fly only occasionally, so they get rusty, or are just nervous on the frequency of a busy, new airport when they do just fine at their home base (Read this post about me, a 16 year pilot on O'Hare's frequency). Or, we've just been doing this so long, we get a little lazy. For example, our VHF frequencies from 118 to 136 MHz are used for civil air/ground voice communications. So when we tune up a frequency it is, for example, 122.80, like the radio at left (121.50 is in the standby position). Occasionally, controllers and pilots will drop the one at the beginning (since the frequency is always going to start with one) and just say, "Twenty-two point eight." Additionally, most ground controllers transmit and receive on 121.7 or .8 or .9, etc., so a controller might just tell a landing aircraft on rollout to contact ground, on "Point 9," meaning 121.9. This could be confusing to a pilot unaware of this shorthand. You can listen live to some ATC facilities.

So even in that last paragraph, though it is often done, I used incorrect terminology, and I will tell you why it is. The relevant chapter in the Aeronautical Information Manual, which I refer to often here, states:

a. Radio communications are a critical link in the ATC system. The link can be a strong bond between pilot and controller or it can be broken with surprising speed and disastrous results. Discussion herein provides basic procedures for new pilots and also highlights safe operating concepts for all pilots.

For example: Saying "Twenty-two point eight" as I mentioned above is incorrect phraseology, and is often even shortened to "Twenty-two eight" (no point). This would be even more confusing had the frequency been 120.95. If I were to say, "Twenty ninety-five," as many of us do, I could be referring to 120.95 OR 129.5. That's where the link can get broken.

According to the AIM, proper phrasing of numbers:

4-2-8. Figures

a. Figures indicating hundreds and thousands in round number, as for ceiling heights, and upper wind levels up to 9,900 shall be spoken in accordance with the following.

1. 500 five hundred

2. 4,500 four thousand five hundred

b. Numbers above 9,900 shall be spoken by separating the digits preceding the word "thousand."

1. 10,000 one zero thousand

2. 13,500 one three thousand five hundred

e. When a radio frequency contains a decimal point, the decimal point is spoken as "POINT."

122.1 one two two point one

So what does it matter that I say "Twenty-two point eight" instead of "one two two point eight"? If there is any confusion about what a pilot or a controller has said, the other party has an obligation to clarify any transmission, in the interest of safety, as well as to not result in a FAA violation on their record. [That would be bad.] So the controller in this situation may query the pilot whether she was planning to switch to the frequency that she was in fact given. If not, the pilot could switch over to the wrong one and transmit, hear nothing, transmit again, and then finally decide to switch back to question the controller to verify the correct frequency. In this case, it was the pilot's fault resulting from the use of improper terminology.

If at altitude, this would probably not be a big problem, just a delay in handoff. However, if the pilot was in the landing phase and didn't switch over to tower to get say, the instructions to execute a missed approach in a timely manner, it may cause, you know, a problem with other airport traffic. On the other hand, though, it has happened that the controller will give the wrong frequency inadvertently, either because they misspoke or listed a frequency for the incorrect sector. When the pilot switches back, the controller reissues the correct frequency. Teamwork.

I have heard many errors over the years, on both the pilot side and the controller side. One that is common is for a controller to transpose the numbers in a call sign. Sometimes when I am flying, to not cause further congestion, I will answer a call for "ExecJet 904" even though my call sign is ExecJet 940, because I figure chances are it's for me. If I say, "Was that last call for ExecJet 940?" The controller will then have to repeat the whole clearance, further tying up the radios. If the controller didn't realize she misspoke, then she might respond to you with a tone of voice as if assuming you just weren't paying attention and missed your call. Sometimes it just easier to answer the call and pause, to see if the controller comes back and corrects you. 9 times out of ten, it IS for me. Unfortunately, on the recent day that this happened, there was an ExecJet 904 on the frequency. So, what did I hear? "No, ExecJet 940, you stay with me." Doh!

Where's the condiment mentioned in the title? Tomorrow you'll have mayo, I promise.

1 comment:

  1. Anonymous11:32 AM

    Loved your article - sharing with all my controllers here at Stockton ATCT.
    Thanks, Sandy Holcomb
    Air Traffic Manager