Some clarity required on Decision Altitudes
As a military pilot (UK), I had always been told to make the decision at DH and that a subsequent dip during the go around was acceptable (and indeed expected, due to momentum). Looking at the ANO, Section 1 Part 5, para 47, it states that:
An aircraft to which this article applies, when making a descent to an aerodrome, shall not:
(a) continue an approach to landing at any aerodrome by flying below the relevant specified decision height; or
(b) descend below the relevant specified minimum descent height;
unless in either case from such height the specified visual reference for landing is established and is maintained.
(a) could be interpreted by some as you must not descend below DH period.
Personally, I think the part "continue the approach" means that as long as you have applied power for the missed approach at or before DH then you're OK.
However, its a bit of a shocker to find your understanding of a rule differs from the IRE's during a test (particularly if its a self-funded initial IR!!) - I feel for you.
An aircraft to which this article applies, when making a descent to an aerodrome, shall not:
(a) continue an approach to landing at any aerodrome by flying below the relevant specified decision height; or
(b) descend below the relevant specified minimum descent height;
unless in either case from such height the specified visual reference for landing is established and is maintained.
(a) could be interpreted by some as you must not descend below DH period.
Personally, I think the part "continue the approach" means that as long as you have applied power for the missed approach at or before DH then you're OK.
However, its a bit of a shocker to find your understanding of a rule differs from the IRE's during a test (particularly if its a self-funded initial IR!!) - I feel for you.
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Paul Chocks says:
Personally, I think the part "continue the approach" means that as long as you have applied power for the missed approach at or before DH then you're OK.
Agreed, that's what you need to do to pass the test. Of course if you do this right at the DA, then you will dip below. This is permissible and would not result in a test fail.
InTgreen writes:
Anyone else here nervous with the attitude of "if I were doing it for real, then I'd do it differently"?
Why are you nervous? We're not talking about 'practicing' here, we're talking about passing a test. In real life, if the weather is such that I have to fly down to DA, of course I'll do it. But on a test why not use the tolerance that you are given to your advantage? You can then practice flying to DA as much as you like. It'll be cheaper than 'practicing' with an examiner on board.
I'd be more concerned with Non-pc Plod's revelation that some examiners will allow pilots to keep practicing their approaches until they get one right!
Flight tolerances during a test are something that are standardised for the general guidance of the examiner. The important point to note is that it refers (in this case) to 'Starting go-around at DA/DH'. Not to 'making the decision whilst continuing the approach'.
The ANO states (thanks Paul Chocks):
An aircraft to which this article applies, when making a descent to an aerodrome, shall not:
(a) continue an approach to landing at any aerodrome by flying below the relevant specified decision height.
A decision as to whether to pass or fail a candidate isn't based on a show of hands on an internet forum, it's based on an examiner assessing as to whether the candidate flew within the tolerances laid down, with an allowance made for weather and other relevant factors.
The candidate in this instance has been told clearly the reason for their fail. They could take a copy of this thread to show the examiner (please Sir, Crab says) before doing it exactly the same.
And failing.
Again.
Or do something radical.
Use the tolerances to their advantage.
And pass.
Come on, Windy, what's it gonna be?
Personally, I think the part "continue the approach" means that as long as you have applied power for the missed approach at or before DH then you're OK.
Agreed, that's what you need to do to pass the test. Of course if you do this right at the DA, then you will dip below. This is permissible and would not result in a test fail.
InTgreen writes:
Anyone else here nervous with the attitude of "if I were doing it for real, then I'd do it differently"?
Why are you nervous? We're not talking about 'practicing' here, we're talking about passing a test. In real life, if the weather is such that I have to fly down to DA, of course I'll do it. But on a test why not use the tolerance that you are given to your advantage? You can then practice flying to DA as much as you like. It'll be cheaper than 'practicing' with an examiner on board.
I'd be more concerned with Non-pc Plod's revelation that some examiners will allow pilots to keep practicing their approaches until they get one right!
Flight tolerances during a test are something that are standardised for the general guidance of the examiner. The important point to note is that it refers (in this case) to 'Starting go-around at DA/DH'. Not to 'making the decision whilst continuing the approach'.
The ANO states (thanks Paul Chocks):
An aircraft to which this article applies, when making a descent to an aerodrome, shall not:
(a) continue an approach to landing at any aerodrome by flying below the relevant specified decision height.
A decision as to whether to pass or fail a candidate isn't based on a show of hands on an internet forum, it's based on an examiner assessing as to whether the candidate flew within the tolerances laid down, with an allowance made for weather and other relevant factors.
The candidate in this instance has been told clearly the reason for their fail. They could take a copy of this thread to show the examiner (please Sir, Crab says) before doing it exactly the same.
And failing.
Again.
Or do something radical.
Use the tolerances to their advantage.
And pass.
Come on, Windy, what's it gonna be?
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Hey beater, why the uncalled for reply to Windy?
"The candidate in this instance has been told clearly the reason for their fail. They could take a copy of this thread to show the examiner (please Sir, Crab says) before doing it exactly the same.
And failing.
Again.
Or do something radical.
Use the tolerances to their advantage.
And pass.
Come on, Windy, what's it gonna be?"
Windy stated at the start of this thread that he was failed for going below his DA.
A pilot can quite correctly fly to DA, make the decision to go around, after which the aircraft goes below the selected DA.
It's not a case of "please Sir, Crab says", it's a case of what is laid down, in particular Standards Doc 28.
As others have said, you are allowed to descend below DA / DH.
Just because someone is an IRE or IRRE it doesn't make them correct in all cases, and if what Windy says in his original post occurred then the reason to fail the candidate is wrong and/or a misunderstanding on the part of the examiner.
"The candidate in this instance has been told clearly the reason for their fail. They could take a copy of this thread to show the examiner (please Sir, Crab says) before doing it exactly the same.
And failing.
Again.
Or do something radical.
Use the tolerances to their advantage.
And pass.
Come on, Windy, what's it gonna be?"
Windy stated at the start of this thread that he was failed for going below his DA.
A pilot can quite correctly fly to DA, make the decision to go around, after which the aircraft goes below the selected DA.
It's not a case of "please Sir, Crab says", it's a case of what is laid down, in particular Standards Doc 28.
As others have said, you are allowed to descend below DA / DH.
Just because someone is an IRE or IRRE it doesn't make them correct in all cases, and if what Windy says in his original post occurred then the reason to fail the candidate is wrong and/or a misunderstanding on the part of the examiner.
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Clearcut case
Windy:: " So it goes like this "600ft, 590ft, 580ft, DA, looking up, nothing seen, going around" "
DA was (for him) 580ft - in his own words his Decision was AFTER DA - not allowed - not correct - therefore fail - no argument!
"DA," - 1 second
"looking up," - 1 second
"nothing seen," - 1 second
"going around" - decision made (just prior to statement) 3 seconds late!
3 seconds at 8 feet per second = 24 feet late!
..... good educational post though - thank you to Windy - sorry
DA was (for him) 580ft - in his own words his Decision was AFTER DA - not allowed - not correct - therefore fail - no argument!
"DA," - 1 second
"looking up," - 1 second
"nothing seen," - 1 second
"going around" - decision made (just prior to statement) 3 seconds late!
3 seconds at 8 feet per second = 24 feet late!
..... good educational post though - thank you to Windy - sorry
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Much as I sympathise with the idea that you must train and test to do exactly what you would do in real life, it is not possible, especially in SPIFR helicopters.
In testing (for the IRT or OPC/LPC) you have to have a point against which you can assess the candidate, but that point has to have a tolerance, hence the DA +50', -0' Standards Document 28 is not a training document, it is essentially a list of markers against which to assess a candidates proficiency.
In testing the candidate is in a FSTD, in which case he "knows" he will never see the ground unless the examiner has set the WX incorrectly! Or, he is in a helicopter with some form of artificial "blind flying" system, screens or glasses/hood etc. As an examiner you must see that he can fly an approach and knows the limits to which he can operate the helicopter, theoretically and practically.
In real life you are going to have the aircraft setup to fly the approach and be able to take in peripheral cues as they arrive, a flash of the surface in the chin bubble etc and when you see these cues you are going to be flicking your eyes back and fore between the instruments and the outside world until as you arrive at DA you more or less already know what is likely to happen. If you have seen only grey, soft cloud type stuff, you will be going around. If the flashes of surface have become longer and more distinct, you are looking to get those required visual references at DA that will allow you to continue the approach. Remember this is SPIFR, the pilot has to do everything and that includes looking out! So unless the chin bubble is clear of cloud but the cabin still in it, you are likely to be in a good position to make a sensible decision.
A word on what to do and say at DA when being tested, dont bother with "Decision, looking up, nothing seen, going around" - JUST DO IT! If you initiate the go-around at (or within +50') the examiner will pass you. If you initiate the go-around below DA (-0') because you talked for 3 seconds, he will fail you. You only have to tell ATC when you are going around, because they cannot tell when you pull pitch, the examiner can!
In testing (for the IRT or OPC/LPC) you have to have a point against which you can assess the candidate, but that point has to have a tolerance, hence the DA +50', -0' Standards Document 28 is not a training document, it is essentially a list of markers against which to assess a candidates proficiency.
In testing the candidate is in a FSTD, in which case he "knows" he will never see the ground unless the examiner has set the WX incorrectly! Or, he is in a helicopter with some form of artificial "blind flying" system, screens or glasses/hood etc. As an examiner you must see that he can fly an approach and knows the limits to which he can operate the helicopter, theoretically and practically.
In real life you are going to have the aircraft setup to fly the approach and be able to take in peripheral cues as they arrive, a flash of the surface in the chin bubble etc and when you see these cues you are going to be flicking your eyes back and fore between the instruments and the outside world until as you arrive at DA you more or less already know what is likely to happen. If you have seen only grey, soft cloud type stuff, you will be going around. If the flashes of surface have become longer and more distinct, you are looking to get those required visual references at DA that will allow you to continue the approach. Remember this is SPIFR, the pilot has to do everything and that includes looking out! So unless the chin bubble is clear of cloud but the cabin still in it, you are likely to be in a good position to make a sensible decision.
A word on what to do and say at DA when being tested, dont bother with "Decision, looking up, nothing seen, going around" - JUST DO IT! If you initiate the go-around at (or within +50') the examiner will pass you. If you initiate the go-around below DA (-0') because you talked for 3 seconds, he will fail you. You only have to tell ATC when you are going around, because they cannot tell when you pull pitch, the examiner can!
Hi JimL
The FAA document may be the most concise guidance and I have to say it sounds sensible, however it is not really applicable for passing a test with a UK examiner. As 135 driver rightly says, the guidance to examiners in the UK is found in 'Standards Document 28' which states:
Note, the requirement to initiate the go around is the CAA's bold, not mine. Doc 28 can be found here.
Regards
TeeS
Sorry JimL, I wasn't trying to teach you to suck eggs, the quote and link were for the benefit of Windy.
The FAA document may be the most concise guidance and I have to say it sounds sensible, however it is not really applicable for passing a test with a UK examiner. As 135 driver rightly says, the guidance to examiners in the UK is found in 'Standards Document 28' which states:
21.2 The candidate need not be failed if a height error of >100 feet occurs two or three times, but should be failed if any of the following occur:
Height error >200ft;
Height error >100ft sustained (& uncorrected) for an unreasonable time (normally about 15 secs);
At DH/DA, if the candidate fails to initiate the go around within 50ft of the DH/DA; or
If the candidate fails to maintain the helicopter within +50ft of the MDH/MDA at the MAPt.
Height error >200ft;
Height error >100ft sustained (& uncorrected) for an unreasonable time (normally about 15 secs);
At DH/DA, if the candidate fails to initiate the go around within 50ft of the DH/DA; or
If the candidate fails to maintain the helicopter within +50ft of the MDH/MDA at the MAPt.
Note, the requirement to initiate the go around is the CAA's bold, not mine. Doc 28 can be found here.
Regards
TeeS
Sorry JimL, I wasn't trying to teach you to suck eggs, the quote and link were for the benefit of Windy.
Last edited by TeeS; 14th Oct 2009 at 18:20.
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The Canadian POV
From the Transport Canada Flight Test Guide (Helicopters) TP 14728E (11/2007)
Precision Instrument Approach (3D) Performance Criteria
Base the assessment on the candidate’s ability to:
a. select and comply with the ILS instrument approach procedure to be performed;
b. establish two-way communications with ATC using the proper communications phraseology and
techniques, either personally, or, if appropriate, directs co-pilot/safety pilot to do so, as required for the phase of flight or approach segment;
c. comply in a timely manner, with all clearances, instructions, and procedures issued by ATC and
advise accordingly if unable to comply;
d. select, tune, identify and confirm the operational status of ground and aircraft navigation equipment to be used for the approach procedure;
e. establish the appropriate aircraft configuration and airspeed/V-speed considering turbulence, wind shear, microburst conditions, or other meteorological and operating conditions;
f. complete the aircraft check list items appropriate to the phase of flight or approach segment, including engine out approach and landing checklist, as appropriate;
g. apply altitude corrections to all minimum altitudes depicted on the approach chart used when aerodrome temperatures are 0 degrees Celsius or colder in accordance with the General Section of the Canada Air Pilot;
h. prior to final approach course, maintain declared or assigned altitudes within ±100 feet without descending below applicable minimum altitudes and maintain headings within ±10 degrees;
i. apply necessary adjustment to the published Decision Height (DH) and visibility criteria for the helicopter approach category when required, such as NOTAMS, inoperative helicopter and ground navigation equipment, inoperative visual aids associated with the landing environment;
j. on final approach course, allow no more than ½ scale deflection of the localizer and/or glideslope indications;
k. maintain declared approach airspeeds within +10/-5 knots;
l. maintain a stabilized descent to the Decision Height (DH) to permit completion of the visual portion of the approach and landing with minimal manoeuvring; and
m. initiate the missed approach procedure, upon reaching the DH, when the required visual references for the intended runway are not obtained.
Nice fuzzy language to allow the examiner some latitude in determining if the pilot was aware of what was going on with the approach.
W
Precision Instrument Approach (3D) Performance Criteria
Base the assessment on the candidate’s ability to:
a. select and comply with the ILS instrument approach procedure to be performed;
b. establish two-way communications with ATC using the proper communications phraseology and
techniques, either personally, or, if appropriate, directs co-pilot/safety pilot to do so, as required for the phase of flight or approach segment;
c. comply in a timely manner, with all clearances, instructions, and procedures issued by ATC and
advise accordingly if unable to comply;
d. select, tune, identify and confirm the operational status of ground and aircraft navigation equipment to be used for the approach procedure;
e. establish the appropriate aircraft configuration and airspeed/V-speed considering turbulence, wind shear, microburst conditions, or other meteorological and operating conditions;
f. complete the aircraft check list items appropriate to the phase of flight or approach segment, including engine out approach and landing checklist, as appropriate;
g. apply altitude corrections to all minimum altitudes depicted on the approach chart used when aerodrome temperatures are 0 degrees Celsius or colder in accordance with the General Section of the Canada Air Pilot;
h. prior to final approach course, maintain declared or assigned altitudes within ±100 feet without descending below applicable minimum altitudes and maintain headings within ±10 degrees;
i. apply necessary adjustment to the published Decision Height (DH) and visibility criteria for the helicopter approach category when required, such as NOTAMS, inoperative helicopter and ground navigation equipment, inoperative visual aids associated with the landing environment;
j. on final approach course, allow no more than ½ scale deflection of the localizer and/or glideslope indications;
k. maintain declared approach airspeeds within +10/-5 knots;
l. maintain a stabilized descent to the Decision Height (DH) to permit completion of the visual portion of the approach and landing with minimal manoeuvring; and
m. initiate the missed approach procedure, upon reaching the DH, when the required visual references for the intended runway are not obtained.
Nice fuzzy language to allow the examiner some latitude in determining if the pilot was aware of what was going on with the approach.
W
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Wizzard,
Could you elaborate, the only reference I can find shows that helicopters are typical of Cat A (ICAO). The reason I ask is that if you are doing 150kts on initial approach, the course reversal procedure for Cat A + B might be too tight in certain wind conditions. I accept that one can always be doing less than 100kts at the threshold making the last bit cat A, but my understanding is that your cat depends on your speeds at all points of the approach and go around.
Could you elaborate, the only reference I can find shows that helicopters are typical of Cat A (ICAO). The reason I ask is that if you are doing 150kts on initial approach, the course reversal procedure for Cat A + B might be too tight in certain wind conditions. I accept that one can always be doing less than 100kts at the threshold making the last bit cat A, but my understanding is that your cat depends on your speeds at all points of the approach and go around.
Doc 8168 Pt 1 explains the Category criteria well and they are purely a function of speed at the threshold, although the other segments will assume different speeds. The maximum speed for a course reversal for a Cat A procedure is 110 kts, however normally the procedure would be Cat A/B so the design would accommodate 140 kts - the Cat B speed. If you want to fly faster than that you'd need to follow the Cat C procedures (which are typically what you'll find in your FMS.)
Additionally, it states:
This clearly indicates that initiating the missed approach below the DA will run the risk of infringing the protection afforded in the procedure design.
Additionally, it states:
6.1.3 The missed approach should be initiated not lower than the decision altitude/height (DA/H) in precision approach procedures
