Loss of Communications
Thread Starter
Joined: Oct 2006
Posts: 127
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From: Antigua, W.I.
Loss of Communications
I need a reference to cover the following situation:
Enroute to destination airport, an aircraft loses communications. On arrival, pilot adheres to loss of comm procedures and conducts an instrument approach to minimums - but has to go-around due weather and divert to alternate.
From this point I cannot find concrete guidance in the regs as to what altitude he is supposed to climb to when diverting to alternate. My interpretation of the regulations is that he is required to maintain the MSA for the route. This would present serious problems with respect to fuel burn at less than optimum altitude and seems ridiculous.
So, anyone able to point me to the appropriate documentation??
Thanks
Enroute to destination airport, an aircraft loses communications. On arrival, pilot adheres to loss of comm procedures and conducts an instrument approach to minimums - but has to go-around due weather and divert to alternate.
From this point I cannot find concrete guidance in the regs as to what altitude he is supposed to climb to when diverting to alternate. My interpretation of the regulations is that he is required to maintain the MSA for the route. This would present serious problems with respect to fuel burn at less than optimum altitude and seems ridiculous.
So, anyone able to point me to the appropriate documentation??
Thanks
Joined: Jun 2001
Posts: 2,627
Likes: 2
From: UTC +8
. . . but the airplane has four [4] generators, one battery, and three [3] VHF radios. Additionally, there's an APU with two [2] generators that could be used inflight in an emergency. Communication's failure in an airplane is remote, unless your battery is completely dead.
Joined: Aug 2001
Posts: 755
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From: Europe-the sunshine side
I had experienced loss of communication ,imediately after take-off, with all gen correctly functioning, on all 3 VHF radios. The stuck mike is out of the question , we checked and removed all mikes,use both cpt and fo buttons on different radios and freq , nothing.
The problem disapeared after around 5 min, and at home base the tech's couldn't find anything wrong.The problem did not reapeared on that plane.
So,Glueball,anything can and will happen, someday.
The problem disapeared after around 5 min, and at home base the tech's couldn't find anything wrong.The problem did not reapeared on that plane.
So,Glueball,anything can and will happen, someday.
Thread Starter
Joined: Oct 2006
Posts: 127
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From: Antigua, W.I.
All flight plans have that Glueball, as well as multiple redundancy on the aircraft (not to mention crew cell phones). But as Alexban says it could happen.
So back to my question - does your flight plan alternate route/altitude allow you to divert as per flight plan in that scenario? The routing is not the problem - the altitude is the grey area.
What I'm looking for is a reference in JARS, CAA or FAA that states so. I've been unable to find any guidance on this matter as all loss of comm procedures seem to assume that you will land at destination.
Maybe someone from ATC could jump in here.
So back to my question - does your flight plan alternate route/altitude allow you to divert as per flight plan in that scenario? The routing is not the problem - the altitude is the grey area.
What I'm looking for is a reference in JARS, CAA or FAA that states so. I've been unable to find any guidance on this matter as all loss of comm procedures seem to assume that you will land at destination.
Maybe someone from ATC could jump in here.
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Posts: n/a
An ATC (western Europe perspective) view.
It's true that modern transport aircraft have multiple redundancy but it's also a fact that aircraft do go comm fail. There are different reasons - there have been certain radios that go to sleep (I'm not sure whether the cause has been positively identified) and, hard to believe I know, but sometimes pilots switch the darn radios off in error (well, set the audio up in such a way that they don't tx or rx or both). But, admitedly, it is a rare event.
So there is a need for procedures to follow. A few years ago the radio comms fail procedures in Europe were revised and harmonised. The revised procedures reflect current reality in a high density traffic environment well served by radar. And that reality is that as soon as an aircraft squawks RT FAIL ATC will assume that the aircraft will continue according to the FPL and will try to move everything around it out of the way.
Now the likelihood of a comms failure happening - which is improbable - at the same time as finding the weather is below minimums - which is unlikely (given the proportion of flights that have to divert) - is very very small. Probably too small to write procedures that have any value (i.e. help the situation to be resolved in a specifically predictable manner). In practise, if an aircraft with a comms failure goes around the same thing is likely to happen as before the go around - ATC will watch what the aircraft does, move other traffic out of the way, and do anything and everything that it can to help. Add ACAS into the equation and it's hard to come up with a set of procedures that are sure to work better.
In different environments, however, the European solution will not be the best one.
It's true that modern transport aircraft have multiple redundancy but it's also a fact that aircraft do go comm fail. There are different reasons - there have been certain radios that go to sleep (I'm not sure whether the cause has been positively identified) and, hard to believe I know, but sometimes pilots switch the darn radios off in error (well, set the audio up in such a way that they don't tx or rx or both). But, admitedly, it is a rare event.
So there is a need for procedures to follow. A few years ago the radio comms fail procedures in Europe were revised and harmonised. The revised procedures reflect current reality in a high density traffic environment well served by radar. And that reality is that as soon as an aircraft squawks RT FAIL ATC will assume that the aircraft will continue according to the FPL and will try to move everything around it out of the way.
Now the likelihood of a comms failure happening - which is improbable - at the same time as finding the weather is below minimums - which is unlikely (given the proportion of flights that have to divert) - is very very small. Probably too small to write procedures that have any value (i.e. help the situation to be resolved in a specifically predictable manner). In practise, if an aircraft with a comms failure goes around the same thing is likely to happen as before the go around - ATC will watch what the aircraft does, move other traffic out of the way, and do anything and everything that it can to help. Add ACAS into the equation and it's hard to come up with a set of procedures that are sure to work better.
In different environments, however, the European solution will not be the best one.
Joined: Apr 2006
Posts: 970
Likes: 54
From: uk
Can anyone outline what the anti-terrorist response would be, in Europe at least, in the situation described?
Intercept? Watch? Ignore?
It would be helpful to know what to expect, and I don't see any need for secrecy about it.
Intercept? Watch? Ignore?
It would be helpful to know what to expect, and I don't see any need for secrecy about it.
Joined: Dec 2006
Posts: 2,486
Likes: 8
From: The No Transgression Zone
there's no guidance in the lost com procedures for the scenario you present---nor for en route diversions due to wx etc under part 91
but no law [even something as set in stone as the lost coms procedure] would ever force the pilot to endanger the aircraft in other words if you must break the 'law' you must to prevent disaster the law in the absence of 'law' is to do what you have to do to ensure a safe flight there is no guidance---also atc may expect [and hope] for such a move if you've lost com and the and there's a weather diversion common sense and judgement are the law now.
most likely in the US you'd be in radar contact so they would get every one out of your way and they'd probably obtain knowledge of what your most likely diversion would be---sometimes life just sucks.
but no law [even something as set in stone as the lost coms procedure] would ever force the pilot to endanger the aircraft in other words if you must break the 'law' you must to prevent disaster the law in the absence of 'law' is to do what you have to do to ensure a safe flight there is no guidance---also atc may expect [and hope] for such a move if you've lost com and the and there's a weather diversion common sense and judgement are the law now.
most likely in the US you'd be in radar contact so they would get every one out of your way and they'd probably obtain knowledge of what your most likely diversion would be---sometimes life just sucks.
Joined: Apr 2003
Posts: 186
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From: orbital
I think if you search FAR 91, you will find something to the effect that the PIC has the authority to do whatever is necessary to ensure the safe completion of the flight.
In reality, of course, you would squawk 7700, transmit blind, and just come back and land. TCAS might be of use also.
In reality, of course, you would squawk 7700, transmit blind, and just come back and land. TCAS might be of use also.
Joined: Dec 2006
Posts: 96
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From: Rome
I think if you search FAR 91, you will find something to the effect that the PIC has the authority to do whatever is necessary to ensure the safe completion of the flight.
In reality, of course, you would squawk 7700, transmit blind, and just come back and land. TCAS might be of use also.
In reality, of course, you would squawk 7700, transmit blind, and just come back and land. TCAS might be of use also.
