Lost Comm

[JEP]

Couple of questions for everyone on this topic:

Do you calculate your expected ETA based on filed departure time or on actual?

How often do you get to the approach fix at a substantially different time than you estimated?

Now my knowledge is a bit rusty, but I believe it would be on filed departure (at first). Now I also recall that if your actual time is going to be 'x' amount greater, then you need to update/inform atc....

(that's all I have early in the a.m. after my Sierra Nevada tour last evening.anic: )

 

[Ian_J]

Couple of questions for everyone on this topic:

Do you calculate your expected ETA based on filed departure time or on actual?

How often do you get to the approach fix at a substantially different time than you estimated?

When the clearance limit is a fix from which an approach begins, commence descent or descent and approach as close as possible to the expect further clearance time if one has been received, or if one has not been received, as close as possible to the Estimated Time of Arrival (ETA) as calculated from the filed or amended (with ATC) Estimated Time En Route (ETE).

 

[cool92092]

I've seen my fair share of ga radio stack and can't really conceive a situation where the comm side of the stack would stop working all together and the nav side function normally. I've had mic problems before where I couldn't transmit because of a loose wire in the PTT but I could still hear the transmission (wound up using the handheld mic).

For the pilots here: Has anyone ever experienced lost comms in IMC with fully functional nav radios and what did you do in that situation?

For the controller side of the board: How often do you deal with a nordo aircraft in your airspace (under IFR) ?

Thanks for your input guys.

 

[wjmiller3]

I've seen my fair share of ga radio stack and can't really conceive a situation where the comm side of the stack would stop working all together and the nav side function normally. I've had mic problems before where I couldn't transmit because of a loose wire in the PTT but I could still hear the transmission (wound up using the handheld mic).

For the pilots here: Has anyone ever experienced lost comms in IMC with fully functional nav radios and what did you do in that situation?

For the controller side of the board: How often do you deal with a nordo aircraft in your airspace (under IFR) ?

Thanks for your input guys.

Different antennas, lose one the other still works.

 

[///AMG]

Yeah I'm not really sure why folks think the comms are interconnected to the nav radios. TACAN, VOR, GPS all are separate units with individual antennas on all aircraft I have flown. There may be some sort of gucci combined displayif you fly a glass cockpit, but they are different radios behind the instrument panel / avionics bay door plain and simple.

And yes, I have had my UHF radio die on me and my TACAN, VOR and GPS all worked just fine. Luckily I haven't been in actual IMC when this has happened, but of course it doesn't make any difference to the aircraft....and we had a back-up VHF radio which did work.

Some interesting misconceptions have been highlighted and corrected here....good productive thread!

 

[fish314]

I've seen my fair share of ga radio stack and can't really conceive a situation where the comm side of the stack would stop working all together and the nav side function normally. I've had mic problems before where I couldn't transmit because of a loose wire in the PTT but I could still hear the transmission (wound up using the handheld mic).

For the pilots here: Has anyone ever experienced lost comms in IMC with fully functional nav radios and what did you do in that situation?

For the controller side of the board: How often do you deal with a nordo aircraft in your airspace (under IFR) ?

Thanks for your input guys.

In most of my flying I've been in Non-GA Airplanes, and usually each radio is separate, so it's more likely than not to lose 1 and not the other. There are quite a different ways to set up comm and nav equipment, and the regs are written broadly to anticipate a wide range of scenarios.

As for the second part, I haven't ever had a lost comms issue, but one of the guys in my squadron lost all the radios on a KC-135 (all FOUR of them- powered by different buses, but they all went through the same cannon plug!). They squawked 7600, and called up approach control on a cell phone. The received a vector over the cell phone for final and flew the ILS.

 

[fish314]

I agree with you Ian J. I think that you are supposed to use your Actual departure time, because it says, "based on your ESTIMATED TIME EN ROUTE". (Though, I admit that language is hardly as clear as it could be).

I think if they wanted you to use your filed or planned departue time, the language would read something like "filed arrival time" or "as calculated from your filed departure time AND estimated time en route."

 

[SteveC]

Seems strange to me to use filed departure time, mostly because our actual departure can vary by a large amount from what we filed, depending upon when our pax arrive and are ready. In all cases we get our clearance prior to entering IMC, and in almost all cases are talking to a controller before or very shortly after take-off. Since ATC now has a pretty good idea of our departure time, wouldn't it make more sense to use actual departure time and estimated time enroute to come up with an ETA? And if we use that data isn't it pretty well assured that we will actually arrive at the IAF pretty close to ETA?

I suppose that we could come up with a scenario where we get a clearance, take-off from an uncontrolled airport and lose comm before talking to ATC, in which case I suppose we'd have to use filed departure time to calculate ETA. But in real life I can't come up with a scenario in which we aren't in contact with ATC prior to take-off to get the clearance (always with a void time), or we can maintain VFR until getting the clearance airborne. Either way if we lose comm prior to talking to ATC in the air they will either know within a few minutes when we departed, or we will be staying VFR and returning to the departure airport.

I guess that what I'm taking the long road to say, is that I'm not coming up with a scenario in which I'd arrive at an IAF that varied from my ETA by any substantial amount of time.

 

[Ian_J]

Steve - the AIM doesn't say anything about "departure time." It only says filed or amended ETE. It doesn't matter when you departed - ATC knows when you did. So they will be expecting you to use your filed ETE in the case of lost comms, unless you've amended your ETE with them over the radio.

 

[SteveC]

I'm in agreement Ian. I guess I was skimming too quickly because I thought I saw a couple people above say that your ETA is based on filed departure time. I'll slow down and read closer next time...maybe.

 

[HeyEng]

As for the second part, I haven't ever had a lost comms issue, but one of the guys in my squadron lost all the radios on a KC-135 (all FOUR of them- powered by different buses, but they all went through the same cannon plug!). They squawked 7600, and called up approach control on a cell phone. The received a vector over the cell phone for final and flew the ILS.

When I was at LTS a few years back there was a -135 had total comm failure during an AR. It caused quite the havoc around the pattern when they got back, but they got in just fine. I wonder if it was the same guy?

And Train, I always knew you were a fraud. Glad someone called you out on it!

 

[fish314]

When I was at LTS a few years back there was a -135 had total comm failure during an AR. It caused quite the havoc around the pattern when they got back, but they got in just fine. I wonder if it was the same guy?

And Train, I always knew you were a fraud. Glad someone called you out on it!

This wasn't an Altus jet, it was over at Mickey D's (MacDill AFB, FL). I think the intended receivers were F-15's out in FLA A.

 

[n9088d]

So, clear something up for me boss.

Are you a controller, or are you training to be a controller? I don't know how to read all that stuff in your signature, but it looks like the AT-SAT is a test to GET INTO school to become a controller, meaning you're not moving any aircraft around just quite yet. Or did you go through school already, or I guess most accurately: what's your status?

I'm a CFII. I'm also going through the ATC application process. Thanks for your thoughtful question.

 

[n9088d]

My point was in an earlier post it was asked by n9088d "what gps is associatied with coms?" They are associated because they are in the same box.....so same power source. You lose power to your 430/530/1000 gps unit, you dont have nav/coms.

You missed my point. I've been flying with the 430 for many years. Learn more about how the systems work (not just what the screen looks like) and you'll understand my point.

 

[n9088d]

You're lack of understanding for what goes on outside the cockpit is even more frightening. What do you think you're the only one out there flying? I know what happens in the cockpit, like I've said three times now I'm a pilot as well.

I could keep debating this with you all night but in the end I can't have a rational debate with the irrational so before we get another thread locked let's just agree to disagree and I'll go on correcting all your erroneous information. And so the mod doesn't boot me I'll do it more benevolently next time.

This guy is my hero.

Okay, now I better extricate myself from this thread as there is a tremendous lack of intelligent conversation going on here.

I believe someone challenged my point that lost comm is often associated with electrical failure. It's simple statistics. Google it.

My other recommendation is for everyone to praise davolijj for contributing useful thoughts to this thread and shutting down the "172 cloud buster with lost comms in nonradar for 10 years who's seen a little." Jtrain, let me know if you ever need an IPC. I'll be glad to give it to you. Just plan on at least a few months worth of sessions.

 

[///AMG]

I believe someone challenged my point that lost comm is often associated with electrical failure. It's simple statistics. Google it.

Yes, if you lose electrical power you will lose your radios. On the other hand, there are quite a few reasons to lose your comms which don't involve an electrical failure. I can think of 10 different ways that I could go lost comms in my aircraft, just off the top of my head, and only one involves an electrical failure. Like I said before, I have had a number of lost comms episodes, but have only ever had one electrical failure.....interestingly enough, I still had comms for that one until the battery died a few miles from the field and I took ALDIS lights in for the recovery. Those are my personal "statistics" FWIW. My only point was that you shouldn't automatically assume that there is a more serious impending electrical failure just because you lost comms, and that you shouldn't do anything drastic or possibly dangerous because of it. Know what I mean?

 

[jtrain609]

I'm a CFII. I'm also going through the ATC application process. Thanks for your thoughtful question.

Good to know. I'm also a CFI/II/MEI/former part 135 company instructor/furloughed 121 guy, so I know where you're at now. Thanks for that, it makes this whole process a lot clearer ya know

 

[jtrain609]

This guy is my hero.

Okay, now I better extricate myself from this thread as there is a tremendous lack of intelligent conversation going on here.

I believe someone challenged my point that lost comm is often associated with electrical failure. It's simple statistics. Google it.

My other recommendation is for everyone to praise davolijj for contributing useful thoughts to this thread and shutting down the "172 cloud buster with lost comms in nonradar for 10 years who's seen a little." Jtrain, let me know if you ever need an IPC. I'll be glad to give it to you. Just plan on at least a few months worth of sessions.

It's good to know that somebody with less experience and ratings than me wants to give me a 3 month IPC. If I'm ever in your neck of the woods I'll buy you a beer, maybe we can talk more IFR procedures

 

[Ian_J]

I'm in agreement Ian. I guess I was skimming too quickly because I thought I saw a couple people above say that your ETA is based on filed departure time. I'll slow down and read closer next time...maybe.

Figured it was something like that. I myself have never been guilty of skimming.

In other news... it appears we have quite the tally-whacker measuring contest going on in this thread!

 

[fish314]

I don't see the reasoning behind holding at the fix.

(1) When the clearance limit is a fix from which an approach begins, commence descent or decent and approach as close as possible to the expect futher clearance time if one has been received, or if one has not been received, as close as possible to the Estimated Time of Arrival (ETA) as calculated from the filed or amended (with ATC) Estimated Time En Route (ETE).

(2) If the clearance limit is not a fix from which an approach begins, leave the clearance limit at the expect furhter clearance time if one has been received, or if none has been received, upon arrival over the clearance limit, and proceed to a fix from which an appraoch begins and commence descent or descnet and approach as close as posible to the estimated time of arrival as calculated from teh filed or amended (with ATC) estimated time en route.

First, the phrase "as close as possible" to me, means that there is some recognized leeway, or slop. How much time is "as close as possible?" It's going to take me 2 minutes to do a 360, which is the smallest maneuver that I can make IMC, so if I arrive less than 2 minutes early, doing a 360 will just move me from early to late. Does it really buy anything?

Secondly, the second paragraph has you travel from your clearance limit to a fix from which you can commence an approach, when your clearance limit is not an IAF. Since ATC has no way of knowing which particular fix you are going to pick before hand, and you have no way of communicating your intentions, how does ATC know when you will be commencing your approach or from which fix? They really don't, all they can do is watch you on the scope (if they have one), and try to clear folks out of your way. They certainly can't be counting on you arriving or departing at a particular time to sequence other folks in and out, when they don't even know what approach you'll be following.

Thirdly, the first paragraph of the section grants additional leeway by stating that pilots are expected "to use good judgment in whatever actions they elect to take" and that it "is virtually impossible to provide regulations and procedures applicable to all possible situations associated with two-way radio failure." The regulations acknowledge that the situation is unusual and fluid.

Fourthly, as several of us have been posting, your ETA as calculated from your ETE is based on your actual takeoff time, not your scheduled or filed takeoff time. How far off are you going to be, anyway?

Put all of that together, and I don't think it makes any sense to hold at the fix, once you get there. I think the idea is to fly your route to your clearance limit, and try the best you can to make your ETA. I don't think the regulation is trying to tell us to hold until some specific time (except when we are in receipt of an EFC time). What I think it is telling us is don't speed up or slow down merely because you have a radio failure. Just fly predictably at a speed to arrive at the IAF "as close as possible" to your ETA, then fly your approach and land. If you read the whole section, I think it leads more to that interpretation, rather than just focusing on the on sentence in question. That's how I read it, anyway.