Instrument Approaches with failures
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Jim,......
Once you are cleared for the "ILS Approach" and that approach contains "GS out" minima (ie LOC Appr.) you are also cleared if required to execute that approach as it is published .... the GS out part IS part of the published approach and is thus legal.
Cheers
Once you are cleared for the "ILS Approach" and that approach contains "GS out" minima (ie LOC Appr.) you are also cleared if required to execute that approach as it is published .... the GS out part IS part of the published approach and is thus legal.
Cheers
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Not sure which country we are talking about here but in the US,
If while doing an ILS approach you lose the glide slope, you can REQUEST the Localizer approach. You may not get permission from approach in time so you must execute a go-around and set up for the Localizer approach.
If while doing an ILS approach you lose the glide slope, you can REQUEST the Localizer approach. You may not get permission from approach in time so you must execute a go-around and set up for the Localizer approach.
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Fred is right - read the plate. For example:
EGCC
EGPA
I don't have time to elaborate, but I know you guys are smart enough to know that Gomer is also right. He shouldnt be, but he is.
Bottom line?
The people in your aircraft.
Zeb
EGCC
EGPA
I don't have time to elaborate, but I know you guys are smart enough to know that Gomer is also right. He shouldnt be, but he is.
Bottom line?
The people in your aircraft.
Zeb
The One Your Mother Warned You About
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SASless;
Right as usual. Most of us stroll down the approach expecting the lights to be there to greet us. However, suppose the fixed wing ahead bursts a couple of tyres (it's happened to me), a runway incursion happens or an approach ban comes in due to a rapid deterioration. To not know, and properly brief on the go-around and alternative approaches is highly irresponsible (LOC only procedures are usually on the charts). I fly fixed wing as well as rotary and it seems that the fixed wing mindset is very different to rotary. I flew on a line check recently and the chap checking me seemed surprised that not only were all the plates for our destination out of the book, but so were those for our diversion, in my fixed wing role that is SOP, in a helicopter it seems that many pilots only bother with the plate for the approach they are about to fly.
Once saw a fantastic catch out in the simulator. No flight director approach. The glide slope off flag on the HSI was hidden behind the needle when it was central. The crew thought that they had flown a perfect ILS until the heights didn't quite add up, they flew into the ground on the go round.
Right as usual. Most of us stroll down the approach expecting the lights to be there to greet us. However, suppose the fixed wing ahead bursts a couple of tyres (it's happened to me), a runway incursion happens or an approach ban comes in due to a rapid deterioration. To not know, and properly brief on the go-around and alternative approaches is highly irresponsible (LOC only procedures are usually on the charts). I fly fixed wing as well as rotary and it seems that the fixed wing mindset is very different to rotary. I flew on a line check recently and the chap checking me seemed surprised that not only were all the plates for our destination out of the book, but so were those for our diversion, in my fixed wing role that is SOP, in a helicopter it seems that many pilots only bother with the plate for the approach they are about to fly.
Once saw a fantastic catch out in the simulator. No flight director approach. The glide slope off flag on the HSI was hidden behind the needle when it was central. The crew thought that they had flown a perfect ILS until the heights didn't quite add up, they flew into the ground on the go round.
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What about approach briefings?
They should be clear, concise and to the point covering : Effective date, approach procedure, frequency/radio set up as required, , courses , altitudes, procedure turn [if required] MDA/DH, where to find the runway if its not alligned with the IB track, any special notes and missed approach procedure. I like to do a quick review of the Missed approach procedure while IB to the FAF.
Some guys do briefings that go on and on and on and on..., to the point that it becomes meaninglessly mind numbing
They should be clear, concise and to the point covering : Effective date, approach procedure, frequency/radio set up as required, , courses , altitudes, procedure turn [if required] MDA/DH, where to find the runway if its not alligned with the IB track, any special notes and missed approach procedure. I like to do a quick review of the Missed approach procedure while IB to the FAF.
Some guys do briefings that go on and on and on and on..., to the point that it becomes meaninglessly mind numbing
"If while doing an ILS approach you lose the glide slope, you can REQUEST the Localizer approach. You may not get permission from approach in time so you must execute a go-around and set up for the Localizer approach"
Not true. If the LOC minima are on the ILS plate, the approach is still technically an "ILS" approach even if you don't use the GS. If there are no LOC minima on the plate you need to request a different approach or go-around.
Not true. If the LOC minima are on the ILS plate, the approach is still technically an "ILS" approach even if you don't use the GS. If there are no LOC minima on the plate you need to request a different approach or go-around.
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Agree with MarcK and others! Bottom line is:
You have been cleared for all the procedures on the plate in front of you (and any NOTAM'd amendments). You don't need to request to change to localiser minimums. You can just do it. However, there may be 100 other reasons why you wouldn't.
The main reason touches on the stabilised approach concept with respect to 'workload'. If switching requires a deviation from approach brief, major level changes or aircraft configuration changes (climbs, flaps, power, attitude, speed), navaid switching, chart and plate checking, or any other procedure which increases workload significantly, then I would go-around.
By that statement then, it depends on so many factors. One pilot might elect to go around, another might elect to switch. No correct answer.
Below are a number of observations on this thread so far.
Paco said:
In an airline, the commercial department will love you if you keep overshooting and unnecessarily wasting fuel.
Yes this might be the case in some airlines. In others though, you would be definitely not allowed to continue (depending on where you are in the approach). This relates to the 'stabilised approach' concept, where, with loss of glideslope beyond a certain altitude (or FAF) renders you un-stabilised. Not so much an issue with helos, but definitely in the FW world.
SASless: I don't understand how GS-failure caused the crash you describe in post #5. You do bring up a point though. In US if you inform that you are going to be doing a coupled approach, the controller should put you 2 miles outside the approach gate.
BigKahuna said:
There is no correct single answer to your question, it depends where you are on the approach.
I perfectly agree. It also depends on the complexity of the LOC-only approach and how well you know it off by heart. At the point of GS loss, you MUST be sure that you are above the non-precision minimums. If there is any doubt, I would go-around immediately. This could happen where the non-precision approach (LOC-only) is a complex step down approach.
800 said:
This indicates that you have already established the approach and the aid (either on the ground or in the aircraft) has become unserviceable OR is out of tolerance. This then requires a missed approach.
Nope, because by going Loc-only, you are flying a procedure which does not require any of the 'unserviceable parts'. Remember the GS is on a totally separate receiving unit to the VOR / Loc system.
Hedski said:
I would be very surprised if an examiner could fail a candidate for choosing the apparent safe option,
Sometimes going around is not the safe option. This might be your last chance to get in, before the weather is forecasted to close in. You might be fuel critical. Again, a good examiner will discuss things here. He might fail a candidate for going around, thus not showing knowledge of all the options and regulations. (See Spinwing's last paragraph.)
Particularly in helicopters, sometimes the safer option (if available) is to simply couple everything up and bring the speed back and deal with the weather. With our range and endurance, go-arounds and alternates might not look so rosey.
Therefore if either failed half-way down the approach I would treat this in the same manner.
If you are half scale above the glideslope, you must discontinue using the GS for vertical navigation, due to the possibility of false glideslopes. However, this does not mean you cannot change to loc-only minimums.
If you are half scale below glideslope, then I would go around for sure.
ATCO2 asks:
When executing ILS/DME approach, DME because there are no markers, what do you pilots intend to do in case of DME failure. Will you go around immediately or you will continue ILS approach till DA/H?
I agree with Gomer here. The DME is not required for execution of the ILS approach. It is for identification of the FAF (intercept point) as an altimeter check height. It is also for the non-precision portion. So continue.
IHL said:
but the majority do have an NDB as the Final Approach Fix (FAF)-usually about 4.5 to 5 nm from the threshold.
Nope, just depends where you are! REMEMBER, the presence of NDB or some other marker at the FAF is purely for a non-precision approach procedure (LOC-only or some other NP approach). The FAF for an ILS is the point of intercept at the particular altitude. The FAF is not part of the ILS system. This is seen by the different types of ILSs which don’t have any marker at the FAF. (e.g. Radar vectored, ILS/DME)
A decent to localizer ONLY minimums (in the event of GS failure) would be done on timing from the FAF, i.e.cross the beacon start the time
This is not on every approach. In fact, timing is only used when the FAF is marked by station passage over a beacon. If there is a beacon at the MAP or MAP is defined by DME, then of course you won't be timing.
SASless:
How many of us brief the missed approach procedures prior to the start of the approach as a standard procedure?
Every time. Or at least the first part of it, then NFP will guide through rest!
IHL said:
Some guys do briefings that go on and on and on and on...,
SOPs help here greatly. Can cut a great deal out.
Well, that passed the time.
Comments welcome.
cl12pv2s
You have been cleared for all the procedures on the plate in front of you (and any NOTAM'd amendments). You don't need to request to change to localiser minimums. You can just do it. However, there may be 100 other reasons why you wouldn't.
The main reason touches on the stabilised approach concept with respect to 'workload'. If switching requires a deviation from approach brief, major level changes or aircraft configuration changes (climbs, flaps, power, attitude, speed), navaid switching, chart and plate checking, or any other procedure which increases workload significantly, then I would go-around.
By that statement then, it depends on so many factors. One pilot might elect to go around, another might elect to switch. No correct answer.
Below are a number of observations on this thread so far.
Paco said:
In an airline, the commercial department will love you if you keep overshooting and unnecessarily wasting fuel.
Yes this might be the case in some airlines. In others though, you would be definitely not allowed to continue (depending on where you are in the approach). This relates to the 'stabilised approach' concept, where, with loss of glideslope beyond a certain altitude (or FAF) renders you un-stabilised. Not so much an issue with helos, but definitely in the FW world.
SASless: I don't understand how GS-failure caused the crash you describe in post #5. You do bring up a point though. In US if you inform that you are going to be doing a coupled approach, the controller should put you 2 miles outside the approach gate.
BigKahuna said:
There is no correct single answer to your question, it depends where you are on the approach.
I perfectly agree. It also depends on the complexity of the LOC-only approach and how well you know it off by heart. At the point of GS loss, you MUST be sure that you are above the non-precision minimums. If there is any doubt, I would go-around immediately. This could happen where the non-precision approach (LOC-only) is a complex step down approach.
800 said:
This indicates that you have already established the approach and the aid (either on the ground or in the aircraft) has become unserviceable OR is out of tolerance. This then requires a missed approach.
Nope, because by going Loc-only, you are flying a procedure which does not require any of the 'unserviceable parts'. Remember the GS is on a totally separate receiving unit to the VOR / Loc system.
Hedski said:
I would be very surprised if an examiner could fail a candidate for choosing the apparent safe option,
Sometimes going around is not the safe option. This might be your last chance to get in, before the weather is forecasted to close in. You might be fuel critical. Again, a good examiner will discuss things here. He might fail a candidate for going around, thus not showing knowledge of all the options and regulations. (See Spinwing's last paragraph.)
Particularly in helicopters, sometimes the safer option (if available) is to simply couple everything up and bring the speed back and deal with the weather. With our range and endurance, go-arounds and alternates might not look so rosey.
Therefore if either failed half-way down the approach I would treat this in the same manner.
If you are half scale above the glideslope, you must discontinue using the GS for vertical navigation, due to the possibility of false glideslopes. However, this does not mean you cannot change to loc-only minimums.
If you are half scale below glideslope, then I would go around for sure.
ATCO2 asks:
When executing ILS/DME approach, DME because there are no markers, what do you pilots intend to do in case of DME failure. Will you go around immediately or you will continue ILS approach till DA/H?
I agree with Gomer here. The DME is not required for execution of the ILS approach. It is for identification of the FAF (intercept point) as an altimeter check height. It is also for the non-precision portion. So continue.
IHL said:
but the majority do have an NDB as the Final Approach Fix (FAF)-usually about 4.5 to 5 nm from the threshold.
Nope, just depends where you are! REMEMBER, the presence of NDB or some other marker at the FAF is purely for a non-precision approach procedure (LOC-only or some other NP approach). The FAF for an ILS is the point of intercept at the particular altitude. The FAF is not part of the ILS system. This is seen by the different types of ILSs which don’t have any marker at the FAF. (e.g. Radar vectored, ILS/DME)
A decent to localizer ONLY minimums (in the event of GS failure) would be done on timing from the FAF, i.e.cross the beacon start the time
This is not on every approach. In fact, timing is only used when the FAF is marked by station passage over a beacon. If there is a beacon at the MAP or MAP is defined by DME, then of course you won't be timing.
SASless:
How many of us brief the missed approach procedures prior to the start of the approach as a standard procedure?
Every time. Or at least the first part of it, then NFP will guide through rest!
IHL said:
Some guys do briefings that go on and on and on and on...,
SOPs help here greatly. Can cut a great deal out.
Well, that passed the time.
Comments welcome.
cl12pv2s
Last edited by cl12pv2s; 28th Mar 2007 at 23:15.
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cl12pv2s
I don't quite agree. You are describing the final approach segment not the FAF.
This is taken from Transport Canada's TP308, design criteria, I'm sure it conforms-in some way -to ICAO.
SECTION 3. ILS CATEGORY 1 FINAL APPROACH
930. FINAL APPROACH SEGMENT
The final approach segment shall begin at the point where the glide slope is intercepted and descent to the authorized decision height (DH) begins. This point should be coincidental with a designated FAFassociated with the non-precision portion of the approach. At locations where it is not possible for the point of glide slope intercept to coincide with a designated FAF, the point of glide slope interception shall be located prior to the FAF.
The FAF for an ILS is the point of intercept at the particular altitude. The FAF is not part of the ILS system.
This is taken from Transport Canada's TP308, design criteria, I'm sure it conforms-in some way -to ICAO.
SECTION 3. ILS CATEGORY 1 FINAL APPROACH
930. FINAL APPROACH SEGMENT
The final approach segment shall begin at the point where the glide slope is intercepted and descent to the authorized decision height (DH) begins. This point should be coincidental with a designated FAFassociated with the non-precision portion of the approach. At locations where it is not possible for the point of glide slope intercept to coincide with a designated FAF, the point of glide slope interception shall be located prior to the FAF.
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IHL / Gomer,
Thanks for the reference.
My point was from a pratical navigational point of view, rather than a regulatory on.
The FAP is indeed a position where the Final Approach Segment starts. This final approach segment is more for a regulatory standpoint, in so far as it provides a point for RVR minimums, company SOPs etc..etc..
For an ILS, it is not required in order to determine MAP as an marker beacon (as IHL was talking about) does for a LOC-only approach.
As in the TC requirement states, "This point should be coincidental with a designated FAF associated with the non-precision portion of the approach." I presume these points are conicidental to reduce confusion. Not sure.
cl12pv2s
Thanks for the reference.
My point was from a pratical navigational point of view, rather than a regulatory on.
The FAP is indeed a position where the Final Approach Segment starts. This final approach segment is more for a regulatory standpoint, in so far as it provides a point for RVR minimums, company SOPs etc..etc..
For an ILS, it is not required in order to determine MAP as an marker beacon (as IHL was talking about) does for a LOC-only approach.
As in the TC requirement states, "This point should be coincidental with a designated FAF associated with the non-precision portion of the approach." I presume these points are conicidental to reduce confusion. Not sure.
cl12pv2s
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If the FAP and the FAF are coincident, you can start your time at the FAF and revert to a nonprecision approach if the GS subsequently fails. Personally, I don't like to do that, and would do it only if I were forced to by circumstances, but it's legal. I've had check pilots ask me why I didn't start the timer at the OM, and my reply is that it does me no good, it's just something else to distract me, because I'm not going to continue the approach if the GS fails. Losing the GS means something has failed, and I don't have time to do the troubleshooting while flying the approach. I prefer to climb, call approach, and then figure out what happened and what I have left, before starting another approach. But that's just my personal attitude, not a regulation. I haven't been failed on a checkride for this, I just think they wanted to know what I was doing and why.
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cv12pv2s -
Just to make things clear to all - my comments were not meant to imply that you should take note of the commercial department rather than the FSO, but even the authorities when I did my very first IR (FW) recognised that the flight should be regarded as a public transport flight and therefore to be conducted "expeditiously". The examiner is therefore looking at you as if you were in a commercial company, and expects you to make big boys' decisions, including whether the flight should take place or not in the prevailing weather (it's not just an instrument rating!). Naturally, safety comes first, but someone who was unnecessarily taking the safe approach and prolonging events (reading between the lines) would be looked at with some concern when it comes to being let loose on the public.
I would still be inclined to carry on if I my situational awareness was good, I was in control, there was no reason to expect an untoward event, the workload was light, etc. Anything that distracts you from the job in hand - well, go around!
As for briefings - I must say that I prefer to keep them as minimal and brief as possible. To my mind, two pilots with similar training, company culture, etc should be pretty near on the same page anyway and take similar action in similar circumstances. A good one in the slack time before an approach, to ensure that all the plates are out and of the same revision, what the weather allows you to do and what to do if the ILS goes out are all fair game, but after that I think anything more verges on being a flight safety hazard when the workload is high.
Phil
Just to make things clear to all - my comments were not meant to imply that you should take note of the commercial department rather than the FSO, but even the authorities when I did my very first IR (FW) recognised that the flight should be regarded as a public transport flight and therefore to be conducted "expeditiously". The examiner is therefore looking at you as if you were in a commercial company, and expects you to make big boys' decisions, including whether the flight should take place or not in the prevailing weather (it's not just an instrument rating!). Naturally, safety comes first, but someone who was unnecessarily taking the safe approach and prolonging events (reading between the lines) would be looked at with some concern when it comes to being let loose on the public.
I would still be inclined to carry on if I my situational awareness was good, I was in control, there was no reason to expect an untoward event, the workload was light, etc. Anything that distracts you from the job in hand - well, go around!
As for briefings - I must say that I prefer to keep them as minimal and brief as possible. To my mind, two pilots with similar training, company culture, etc should be pretty near on the same page anyway and take similar action in similar circumstances. A good one in the slack time before an approach, to ensure that all the plates are out and of the same revision, what the weather allows you to do and what to do if the ILS goes out are all fair game, but after that I think anything more verges on being a flight safety hazard when the workload is high.
Phil
"the flight should be regarded as a public transport flight and therefore to be conducted 'expeditiously'".
Quite: it's the standard TRE brief to OPC/LPC candidates.
I've been following the thread with curiosity and am surprised by the comments to the effect that a go around must be carried out. If pre-briefed and above step down altitude (which you will be on a glideslope) and you have started your clock etc (if required at the point of G/S failure), convert to LLZ aproach. If no clue what the LLZ aproach MDA and MAPt are, or where you are, go around. Simple. CDF.
If there is no LLZ only approach, go around. Simple. CDF.
It's not rocket science! Remember; these procedures were designed for fixed wing pilots, so they can't be that difficult
PS. If anyone can find a UK AIP, ICAO annex 6, Pans Ops 8168, JAR OPS-3 reference etc etc, please quote it: buggered if I can find one!
PPS. AuxHyd, that is a well known incident which highlights the importance of General SA and you will find several videos on line about it. Here's a question (general): "how do you conduct your OM check height check?" Do you:
a) wait for the check altitude and say "yes xxxx ft and passing 4d, OM etc"
b) wait for the check altitude range and say "OM, 4d etc, and our passing altitude is xxxx ft"
Think about it, and determine which is the optimal method! (answer a
)
Quite: it's the standard TRE brief to OPC/LPC candidates.
I've been following the thread with curiosity and am surprised by the comments to the effect that a go around must be carried out. If pre-briefed and above step down altitude (which you will be on a glideslope) and you have started your clock etc (if required at the point of G/S failure), convert to LLZ aproach. If no clue what the LLZ aproach MDA and MAPt are, or where you are, go around. Simple. CDF.
If there is no LLZ only approach, go around. Simple. CDF.
It's not rocket science! Remember; these procedures were designed for fixed wing pilots, so they can't be that difficult
PS. If anyone can find a UK AIP, ICAO annex 6, Pans Ops 8168, JAR OPS-3 reference etc etc, please quote it: buggered if I can find one!
PPS. AuxHyd, that is a well known incident which highlights the importance of General SA and you will find several videos on line about it. Here's a question (general): "how do you conduct your OM check height check?" Do you:
a) wait for the check altitude and say "yes xxxx ft and passing 4d, OM etc"
b) wait for the check altitude range and say "OM, 4d etc, and our passing altitude is xxxx ft"
Think about it, and determine which is the optimal method! (answer a
)
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CAPT :
I agree with you about keeping approach briefings brief. The majority-I'll guess 99.9% - of pilots in 2 crew operations have the same training and the same expectations when doing approaches.
I fly both fixed and rotary. In the Fixed wing we do the approach briefing prior to decent approximately 75-80 NM miles back, in RW world its done usually at about 30 NM when in the terminal area.
It often happens in the FW world that when we're swithced over from Centre to Terminal they change the runway and then we have to rush the briefing and set up for the new runway. That always ticks me off.
212 Man: When over the OM/beacon. I call beacon crossing, beacon crossing altitude xxxx feet on glide slope or (ABV-BLO), check the flags on the HSI and report no flags.
It is also prudent to verify the localizer with the NDB track to preclude false loc capture. When using AP FD I don't arm the approach until within 8 degrees of the LOC track as displayed on the ADF.
I agree with you about keeping approach briefings brief. The majority-I'll guess 99.9% - of pilots in 2 crew operations have the same training and the same expectations when doing approaches.
I fly both fixed and rotary. In the Fixed wing we do the approach briefing prior to decent approximately 75-80 NM miles back, in RW world its done usually at about 30 NM when in the terminal area.
It often happens in the FW world that when we're swithced over from Centre to Terminal they change the runway and then we have to rush the briefing and set up for the new runway. That always ticks me off.
212 Man: When over the OM/beacon. I call beacon crossing, beacon crossing altitude xxxx feet on glide slope or (ABV-BLO), check the flags on the HSI and report no flags.
It is also prudent to verify the localizer with the NDB track to preclude false loc capture. When using AP FD I don't arm the approach until within 8 degrees of the LOC track as displayed on the ADF.
IHL, that's my point entirely: surely you should announce what range you are when you get to beacon/dme crossing height, not what height you are when you get to the range? 
One of the primary purposes of the check is to confirm serviceability of the glideslope (and to a lesser extent, the correct lobe) and the safest way to do this is as I describe.
The NZ and Guam incident/accident would tend to support this.
One of the primary purposes of the check is to confirm serviceability of the glideslope (and to a lesser extent, the correct lobe) and the safest way to do this is as I describe. The NZ and Guam incident/accident would tend to support this.
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Another question regarding an ILS approach:
On an ILS when can you descent on the glide path ?
So meaning when you are on base leg, with how much deviation can I start the descent? I know for a VOR approach it is 5 degree either side of the final track..
How is this on the ILS? Full scale deflection is 2,5 degree isn't it? I heard somebody saying 5 degrees as well but think that is incorrect but I can't find it anywhere.. Then there is this protection area of 10 degree each side but that's only for localizer, not for descent.. so if anybody knows the answer to the question...
Thanks in advance!!
Best regards,
Interpol
On an ILS when can you descent on the glide path ?
So meaning when you are on base leg, with how much deviation can I start the descent? I know for a VOR approach it is 5 degree either side of the final track..
How is this on the ILS? Full scale deflection is 2,5 degree isn't it? I heard somebody saying 5 degrees as well but think that is incorrect but I can't find it anywhere.. Then there is this protection area of 10 degree each side but that's only for localizer, not for descent.. so if anybody knows the answer to the question...
Thanks in advance!!
Best regards,
Interpol
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AFAIK, you can descend when 'established' on the localizer. I haven't seen an exact definition of established, but I think you have to at least have the localizer needle off the peg and moving toward the center. I like to have it within a dot of center, but I'm not religious about that, depending on the approach conditions. If ATC is turning me in on a short approach, very near the OM, (or the copilot has drifted more than a dot off 
) I may start the descent sooner, but never without having course guidance from the localizer needle.
) I may start the descent sooner, but never without having course guidance from the localizer needle.