Say Again? #50: Lost Communications -- NORDO -- Part 1

  • E-Mail this Article
  • View Printable Article
  • Text size:

    • A
    • A
    • A

''Atlanta Center -- how do you read?'' ''Atlanta Center?'' ''Anybody?!'' Lost comm can be a minor event when your flight plan follows the rules. But when you're going Direct, how can ATC get all those other planes away from you? AVweb's Don Brown takes us on a flight when you don't talk to anybody.

Say Again?

I've been threatening to write this article for a while now and it's as good a time as any. If you want to start an argument among pilots you only have to ask one little question: "Yeah, but what happens if you go NORDO?" If you read any aviation forums on the Internet, you know that question will generate at least a dozen responses.

That's the reason I decided to finally write about the subject: All those responses the subject generates. Perhaps I have a twisted sense of humor but I find many of them funny. Of course, the only reason I can find any humor in them is because an aircraft going NORDO now is pretty rare. At least for any length of time it is. We have pilots get lost on the radio almost every day. But it usually only lasts for a few minutes. An aircraft losing communications for an entire flight is, thankfully, almost unheard of these days.

Rules of Old

You might be asking yourself why I would bother with the subject if it is so rare. I have a simple answer: It will help you understand the system better. One of my favorite responses this subject generates is that the NORDO procedures are "out of date." That's like saying that the signs on the interstate that read "Slower Traffic Keep Right" are out of date. Folks on the interstate in Atlanta might ignore that rule (and the speed limit) on a regular basis but that doesn't mean the rule is out of date. Let's look at the rules.

FAR 91.185 -- IFR Operations: Two-Way Radio Communications Failure

(a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio communications failure when operating under IFR shall comply with the rules of this section.

(b) VFR conditions. If the failure occurs in VFR conditions, or if VFR conditions are encountered after the failure, each pilot shall continue the flight under VFR and land as soon as practicable.

(c) IFR conditions. If the failure occurs in IFR conditions, or if paragraph (b) of this section cannot be complied with, each pilot shall continue the flight according to the following:

(1) Route (etc.)

(2) Altitude (etc.)

(3) Leave clearance limit (etc.)

The VFR part is easy: If you're in VFR conditions, or you encounter VFR conditions, land as soon as practicable. It's the IFR part that people think is hard, and hard to read, so we left it out for now. But let's not get ahead of ourselves. Let's start at the very beginning. Instead of playing around with the legal mumbo-jumbo in the FARs, let's get some practical advice: Let's go to the AIM.

First Things First

What to do in the event of a communications failure is contained in Chapter 6 of the AIM: Emergency Procedures. So I am (of course) going to start in Chapter 5: Air Traffic Procedures. You see, the first part of using the NORDO procedures is determining that you have, in fact, lost communications.

AIM Chapter 5, Section 5-3-1 (En Route Procedures)

c. ARTCC Radio Frequency Outage. ARTCCs normally have at least one back-up radio receiver and transmitter system for each frequency, which can usually be placed into service quickly with little or no disruption of ATC service. Occasionally, technical problems may cause a delay but switchover seldom takes more than 60 seconds. When it appears that the outage will not be quickly remedied, the ARTCC will usually request a nearby aircraft, if there is one, to switch to the affected frequency to broadcast communications instructions. It is important, therefore, that the pilot wait at least 1 minute before deciding that the ARTCC has actually experienced a radio frequency failure. When such an outage does occur, the pilot should, if workload and equipment capability permit, maintain a listening watch on the affected frequency while attempting to comply with the following recommended communications procedures ...

This part answers the first question you'll have: "How long should I wait before I try something else?" You should wait "at least one minute" before you start believing something is wrong. Please notice that one minute is the minimum. I've had coordination to accomplish on the landline that takes more than one minute. And remember the part above about what happens if it's the Center's radio that failed? If we really lose our radio (actually the main transmitter and two backups) we'll get another frequency assigned to the sector and send an airplane over to the old frequency to get everybody to the new frequency. I assure you that will take more than a minute. If it's been a minute (or more) and you begin to suspect something is wrong you can move on to the next part:

1. If two-way communications cannot be established with the ARTCC after changing frequencies, a pilot should attempt to recontact the transferring controller for the assignment of an alternative frequency or other instructions.

That's simple enough. I believe most pilots already know this and it's the most logical course of action so I won't dwell on it.

2. When an ARTCC radio frequency failure occurs after two-way communications have been established, the pilot should attempt to reestablish contact with the center on any other known ARTCC frequency, preferably that of the next responsible sector when practicable, and ask for instructions. However, when the next normal frequency change along the route is known to involve another ATC facility, the pilot should contact that facility, if feasible, for instructions. If communications cannot be reestablished by either method, the pilot is expected to request communications instructions from the FSS appropriate to the route of flight.

NOTE - The exchange of information between an aircraft and an ARTCC through an FSS is quicker than relay via company radio because the FSS has direct interphone lines to the responsible ARTCC sector. Accordingly, when circumstances dictate a choice between the two, during an ARTCC frequency outage, relay via FSS radio is recommended.

Let's review. Wait a minute or so, call again, then call the previous controller if you still can't get anybody. If that doesn't work, contact the next facility (if known) or Flight Service. There's one other frequency you can try that is listed in Chapter 6 of the AIM: 121.5. The emergency frequency, or as some people call it, Guard. If all else fails, try that one.

Be Prepared

Now before your mind goes skipping ahead, I want you to pause and think about all this. If you are an (overly?) careful and prudent pilot, when you're planning your flight, you'll have these frequencies written down before you ever get in the airplane. Where might you find these frequencies? Well, a good place to start is the approach plate for the airport of your departure. I know it sounds backwards, but approach plates are just a good source of information for departure. If you look at the Hickory, N.C., (HKY) approach plates you see that the Tower is 128.15, Atlanta Center is 125.15 and Atlanta Center clearance delivery (when the Tower is closed) is 124.25. That's three frequencies right there. Be sure to find out the Flight Service frequency for that area, too.

There's another bonus in looking at the approach plate for your departure airport. You might have to fly that approach. If you do, it will probably be in circumstances that aren't particularly pleasant. By the way, you can't hurt my feelings by calling me a Boy Scout. "Be Prepared" is a pretty good motto. It sure beats not being prepared.

There's another place you can look for information and it's germane to the subject at hand: The HICKORY ONE Departure Procedure. You might want to take a look at that. It will become important shortly.

Road Trip

Let's take a trip to see how the rest of the rules work. I don't know about you, but trying to plug rules into the real world is the only way I can really tell how they work. Reading the AIM (or any other publication) just puts me to sleep unless I have a specific scenario in mind.

Here's the flight plan we'll use:

110 kts.
Dep. KHKY (Hickory, N.C.)
6,000 feet
Arr. KTYS (Knoxville, Tenn.)

And here is a low-altitude en route chart of the route (click the graphic for a larger version):

280 Kb

Yes, I know that hardly anyone files a route like that anymore. That's one reason they don't think the rules are up to date -- they don't follow all of them. Bear with me and let's see how this works out.

Your radio lasts just long enough to get your clearance from Hickory Tower to take off. Use your imagination as to why it fails. Everything else in the airplane works fine.

You've been assigned runway heading (Runway 24) and you're cleared to 4,000 per the HICKORY ONE departure procedure. "Cleared for takeoff, Runway two four" is the last thing you hear. You break ground, trim the airplane up for climb and you hear ... nothing.

"Hickory Tower, Cessna one two three four five. How do you read?"


You're in the clouds now and that first twinge hits you. Now is a good time to remember the old saying, "Aviate, Navigate, Communicate." Well OK, let's see what we've got.

Aviate: Positive rate of climb and a thousand feet to go before you reach four thousand. All the instruments look good.

Navigate: You've got a good signal from BZM VOR and V20 is off to your right slightly. What's the MEA? 5,000 but the MOCA is 3,600 until VAESE. You're good for a few more minutes to VAESE (even though you aren't on the airway) so you level off at 4,000. ATC assigned it so it must be good for at least a few miles. It's something to keep your eye on though.

Communicate: Let's see what's wrong. The correct frequency for HKY Tower is dialed in and it looks like the radio is set up correctly.

"Hickory Tower, Cessna one two three four five. How do you read?"

Again, you get nothing. It's been over a minute already and logic would dictate that you should be on the Center by now, so you give Atlanta Center a call on 125.15:

"Atlanta Center, Cessna one two three four five. How do you read?"

No reply. Now you start to worry for sure. The chances of two separate facilities losing their radios at once are astronomical. It must be your radio. What are your options? Just like the book says, you've tried Hickory Tower and you've tried the "next responsible sector" -- Atlanta Center -- with no success. You can try them again -- and you will -- but let's not forget that nagging problem of being on a heading and terrain. You can try FSS later if you have the time also.

"Atlanta Center, Cessna one two three four five. How do you read?"

What Now, Ollie?

Still nothing. You double check everything but can't find a problem. It's time to prioritize. Aviate. You don't need ATC to fly. Navigate. I think it's time to concentrate on that. The "runway heading" is taking you further from the airway and you know the terrain is rising. What should you do?

Let's pick up where we left off in the AIM, Chapter 5, Section 5-3-1 (En Route Procedures):

3. IFR conditions. If the failure occurs in IFR conditions, or if subparagraph 2 above cannot be complied with, each pilot shall continue the flight according to the following:

(a) Route.

(1) By the route assigned in the last ATC clearance received;

(2) If being radar vectored, by the direct route from the point of radio failure to the fix, route, or airway specified in the vector clearance;

(3) In the absence of an assigned route, by the route that ATC has advised may be expected in a further clearance; or

(4) In the absence of an assigned route or a route that ATC has advised may be expected in a further clearance by the route filed in the flight plan.

All right. When the Tower assigned you "runway heading" they didn't tell you to "expect" anything. They did give you your "assigned route," which was the HICKORY ONE departure and then "as filed." If you take a look at the HICKORY ONE departure it says, "Expect radar vectors to join filed route. All aircraft maintain 4000 feet, or assigned altitude. Expect filed altitude/flight level ten minutes after departure." If you can't talk to ATC, you can't get a vector to "join your filed route" but that is what you are to expect. Option 1, 2, 3 and 4 all say get back on your route. You know the airway is to your right, so let's go to the right.

What about the altitude?

(b) Altitude. At the HIGHEST of the following altitudes or flight levels FOR THE ROUTE SEGMENT BEING FLOWN:

(1) The altitude or flight level assigned in the last ATC clearance received;

(2) The minimum altitude (converted, if appropriate, to minimum flight level as prescribed in 14 CFR Section 91.121(c)) for IFR operations; or

(3) The altitude or flight level ATC has advised may be expected in a further clearance.

Momma MEA

This presents a stickier problem. You're not really on a "route segment." You're already at the last assigned altitude and you know you can't stay here much longer. You might not be able to wait "10 minutes" to climb to your "filed altitude." You don't have the Combined Federal Regulations handy at the moment, and you don't have time to look up Section 91.121 (c) even if you did, much less convert the minimum altitude that you're not even sure of. Let's get rid of the uncertainty, get back on the airway and get to the Minimum En Route Altitude (MEA) shown on the chart.

If you ever find yourself in this situation, you probably won't have time to wonder what ATC is doing, so let's wonder about it now. First, they'll be trying to call you. If you don't check in with the Center, the Center controller will call the Tower and remind the Tower to switch you. That is, if the Tower doesn't call them first and say they couldn't get you to acknowledge the frequency change. Regardless, it shouldn't take but a few minutes before it dawns on them that you might be NORDO. Then they'll start wondering what you're going to do.

Deaf, Dumb or Blind

Fortunately, you've already decided what you're going to do: You're going to fly a heading to join V20 and you're going to climb. Is there anything else you should do? I'd recommend two things. One you'll find in this section of the AIM and one you won't.

AIM Chapter 6, Section 6-4-2: Transponder Operation During Two-Way Communications Failure

a. If an aircraft with a coded radar beacon transponder experiences a loss of two-way radio capability, the pilot should adjust the transponder to reply on Mode A/3, Code 7600.

If your transponder is working and you're in radar coverage, it won't take but a few seconds for the controller to notice it, say a few choice words and start moving other airplanes out of the way. Give him a minute to notice you're squawking 7600, key the microphone and say something like, "Atlanta Center, Cessna one two three four five transmitting in the blind, turning to join V20 and climbing to five thousand."

Pilot/Controller Glossary

TRANSMITTING IN THE BLIND -- A transmission from one station to other stations in circumstances where two-way communication cannot be established, but where it is believed that the called stations may be able to receive the transmission.

I will issue one warning about transmitting in the blind: Don't overdo it. Remember, I just said the controller will start moving other airplanes out of the way if he sees you squawking 7600. He needs the frequency to do that. Don't tie up the frequency with a bunch of transmissions. After all, it may just be your receiver that is broken and your transmitter might be working. Make an announcement saying what you're doing and then stop.

Keeping it Simple

Once you get back on the airway, life becomes a lot simpler. There are rules to guide your actions from here on out. You've got a route all the way to Knoxville (TYS), so all you have to worry about is altitude. There's not a thing you can do about other traffic, so let ATC worry about that. By being on the airways and having filed a good route, you've made their job a lot simpler, too.

Let's say you get back on the airway right around the VAESE intersection. You're level at 5,000, in the clouds, and you still haven't been able to contact Hickory Tower, Atlanta Center or Flight Service. Make double sure that you don't have a stuck microphone. That would be embarrassing if that was the problem wouldn't it? If you're crossing VAESE, it's time to climb to 6,000.

It's natural to think that you should climb to 6,000 prior to reaching the route segment where the MEA is 6,000. A careful reading of AIM 6-4-1(3)(b)(3) will tell you otherwise. Read "Example 3." Or it's a whole lot easier to look at the pictures in the FAA 7110.65 4-5-6 Minimum En Route Altitude. Look at Figures 4-5-1 and 4-5-2. The only time you want to climb early is to meet a Minimum Crossing Altitude (MCA). Insert lecture here about FAA publications agreeing with each other so that pilots and controllers are playing on the same page.

Hang In There

The rest of the trip is a breeze. Well, right until you wind up over Snowbird VOR (SOT) at 8,000. Then you have to start thinking about when -- and how -- you're going to get back down and land. Sorry to leave you hanging like this but I'm out of time.

I hope you can see that filing the airways makes a complicated NORDO situation a little less complicated. There are clear, unambiguous rules about when to climb and how high you should climb to stay out of the rocks. It also simplifies ATC's job of separating you from other aircraft. We'll see if the same holds true for the descent and approach phases next month.

Have a safe flight.

Don Brown
Facility Safety Representative
National Air Traffic Controllers Association
Atlanta ARTCC

Want to read more from air traffic controller Don Brown? Check out the rest of his columns.