Singapore AAIB Report - B777-300ER Loss of Separation Incident (Houston)
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Everyone is focusing on the charts & the crew, ATC aren't blameless either. The controller should have checked the cleared level immediately after the crew failed to report it, especially with only 1'500ft to go with traffic descending on top. Nothing mentioned about Mode S, do the Houston radars show it? If not then this case must highlight how safety could be vastly improved with it.
Without seeing the actual chart, it is hard to see why this crew got it wrong.
However, in my opinion, something as important as the cleared altitude/level should be clearly and unambiguously shown. In the AAIB report, the box from the plate shown has the cleared altitude of the SID tucked away in the explanation of the routing - in the same font, and font size as the rest of the narrative. The box above is titled initial climb, the box below is titled routing. The departure is unusual in that the actual first cleared altitude is 600', and then the SID cleared altitude is written in a box titled routing. I think this is ambiguous, and as a pilot I think I would expect to find all reference to cleared altitudes in that box - in bold type - and not in the routing box.
Pilots in modern commercial flight operations need such important things to be very clear, and they should not expect to have to read every word of a chart to find something as basic and as safety critical as this. Some pilots prefer the visual representations, others prefer the text explanation. On all the Jepps and AERADS I have ever used, the first cleared altitude/level is either shown very clearly on the pictorial diagram of the routing at the appropriate point, or clearly written as a bold heading above the departure explanation box.
This is something that we make sure we brief for every departure - "what do you make the first cleared altitude?",and then we confirm that that altitude is set on the FCU and on the PFD.
So, on the face of it, two reasons for this loss of separation: Poor plate layout and design, and poor pilot briefing. This was then compounded by an incorrect TCAS RA reaction.
However, in my opinion, something as important as the cleared altitude/level should be clearly and unambiguously shown. In the AAIB report, the box from the plate shown has the cleared altitude of the SID tucked away in the explanation of the routing - in the same font, and font size as the rest of the narrative. The box above is titled initial climb, the box below is titled routing. The departure is unusual in that the actual first cleared altitude is 600', and then the SID cleared altitude is written in a box titled routing. I think this is ambiguous, and as a pilot I think I would expect to find all reference to cleared altitudes in that box - in bold type - and not in the routing box.
Pilots in modern commercial flight operations need such important things to be very clear, and they should not expect to have to read every word of a chart to find something as basic and as safety critical as this. Some pilots prefer the visual representations, others prefer the text explanation. On all the Jepps and AERADS I have ever used, the first cleared altitude/level is either shown very clearly on the pictorial diagram of the routing at the appropriate point, or clearly written as a bold heading above the departure explanation box.
This is something that we make sure we brief for every departure - "what do you make the first cleared altitude?",and then we confirm that that altitude is set on the FCU and on the PFD.
So, on the face of it, two reasons for this loss of separation: Poor plate layout and design, and poor pilot briefing. This was then compounded by an incorrect TCAS RA reaction.
Last edited by Uplinker; 28th Nov 2015 at 10:10.
However, in my opinion, something as important as the first cleared altitude/level should be clearly and unambiguously shown. In the AAIB report, the box from the plate shown has the first cleared altitude tucked away in the explanation of the routing - in the same font, and font size as the rest of the narrative.
Despite that I'd like to think that, as philbky has said, the thought of a straight climb to cruise level right off the ground in the States might have rung a few alarm bells with somebody, but then again I wasn't there.
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Capn Bloggs
The problem is even more diabolical than you suggest. As the crew obviously did NOT know the phraseology, the PM's R/T WAS incorrect as he should done as you suggested and stated that they were planning to climb to FL310 until told otherwise by ATC, which clearly would have sounded odd so he omitted this. ATC on the other hand heard what they expected to from a crew familiar with the procedure. That ATC did not query the lack of a planned altitude likely confirmed in the crew's minds that what they were doing was ok. From this point on there was no way of detecting the error until the top altitude bust.
captainsmiffy
Agree with your thoughts completely and yet this whole issue (i.e. does the new phraseology leave a little bit too much unsaid between ATC and flight crews?) was not mentioned in the discussion of the report. Ironic considering the AAIB took it on 'to highlight safety lessons' the NTSB thought were not there to learn!
The problem is even more diabolical than you suggest. As the crew obviously did NOT know the phraseology, the PM's R/T WAS incorrect as he should done as you suggested and stated that they were planning to climb to FL310 until told otherwise by ATC, which clearly would have sounded odd so he omitted this. ATC on the other hand heard what they expected to from a crew familiar with the procedure. That ATC did not query the lack of a planned altitude likely confirmed in the crew's minds that what they were doing was ok. From this point on there was no way of detecting the error until the top altitude bust.
captainsmiffy
Agree with your thoughts completely and yet this whole issue (i.e. does the new phraseology leave a little bit too much unsaid between ATC and flight crews?) was not mentioned in the discussion of the report. Ironic considering the AAIB took it on 'to highlight safety lessons' the NTSB thought were not there to learn!
Last edited by xyze; 28th Nov 2015 at 10:44.
The controller should have checked the cleared level immediately after the crew failed to report it
Climb Via/Descend Via Speed Clearances Frequently Asked Questions
The pilots are not supposed to report the top level.
(Disclaimer: that document may be out of date).
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I am a little puzzled.
SID heights restrictions are normally programmed into the FMS automatically when the SID is selected. Departures are normally flown in VNAV. Fortunately I have never tried it but if you were to make that same error say out of Heathrow and put FL310 in the alt sel the aircraft would level off automatically at the SID altitude of 6000. Even if hand flying the flight directors would level you at 6000. So my question is did they push the alt sel to clear the initial level off altitude or do IAH SIDS not have level off altitudes programmed into the FMS? If the latter is the case then why not as it would prevent this exact scenario.
SID heights restrictions are normally programmed into the FMS automatically when the SID is selected. Departures are normally flown in VNAV. Fortunately I have never tried it but if you were to make that same error say out of Heathrow and put FL310 in the alt sel the aircraft would level off automatically at the SID altitude of 6000. Even if hand flying the flight directors would level you at 6000. So my question is did they push the alt sel to clear the initial level off altitude or do IAH SIDS not have level off altitudes programmed into the FMS? If the latter is the case then why not as it would prevent this exact scenario.
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I am a little puzzled.
SID heights restrictions are normally programmed into the FMS automatically when the SID is selected. Departures are normally flown in VNAV. Fortunately I have never tried it but if you were to make that same error say out of Heathrow and put FL310 in the alt sel the aircraft would level off automatically at the SID altitude of 6000. Even if hand flying the flight directors would level you at 6000. So my question is did they push the alt sel to clear the initial level off altitude or do IAH SIDS not have level off altitudes programmed into the FMS? If the latter is the case then why not as it would prevent this exact scenario.
SID heights restrictions are normally programmed into the FMS automatically when the SID is selected. Departures are normally flown in VNAV. Fortunately I have never tried it but if you were to make that same error say out of Heathrow and put FL310 in the alt sel the aircraft would level off automatically at the SID altitude of 6000. Even if hand flying the flight directors would level you at 6000. So my question is did they push the alt sel to clear the initial level off altitude or do IAH SIDS not have level off altitudes programmed into the FMS? If the latter is the case then why not as it would prevent this exact scenario.
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Boards and Busts
The comments posted about the report and incident, including those which take a stab at stating larger questions raised by the incident in a general sense, impel me to ask:
1) If it is accepted as fact that the NTSB gave the incident too little emphasis - given the several potential extra-holey Swiss cheese scenarios implicated - do those knowledgeable about such investigatory safety boards think that the NTSB's broad mandate which includes railroads and pipelines is a root cause of its limited attention span? As the forum community includes a pretty extensive non-U.S. contingent, and other countries appear to have safety agencies for aviation as such . . .
2) I had always thought that take-off, climb-out and ascent toward cruise Flight Levels - while immensely mysterious to such as an SLF - were less challenging, to the aviators, than executing a successful and safe approach, at least in many instances. But here, the front-end of the operation was out of alignment . . . is it correct that a bust of a cleared altitude on ascent toward cruise Flight Level is not typical, even highly atypical?
What all the factors involved in this incident say about the need to change the nuts-and-bolts of R/T and charts and ATC procedures, I don't know. What these factors say about perceptions about a need to tighten up on training standards and procedures of air carriers, I also don't know. But hoping those who do know what they're talking about might comment further.
WR 6-3
1) If it is accepted as fact that the NTSB gave the incident too little emphasis - given the several potential extra-holey Swiss cheese scenarios implicated - do those knowledgeable about such investigatory safety boards think that the NTSB's broad mandate which includes railroads and pipelines is a root cause of its limited attention span? As the forum community includes a pretty extensive non-U.S. contingent, and other countries appear to have safety agencies for aviation as such . . .
2) I had always thought that take-off, climb-out and ascent toward cruise Flight Levels - while immensely mysterious to such as an SLF - were less challenging, to the aviators, than executing a successful and safe approach, at least in many instances. But here, the front-end of the operation was out of alignment . . . is it correct that a bust of a cleared altitude on ascent toward cruise Flight Level is not typical, even highly atypical?
What all the factors involved in this incident say about the need to change the nuts-and-bolts of R/T and charts and ATC procedures, I don't know. What these factors say about perceptions about a need to tighten up on training standards and procedures of air carriers, I also don't know. But hoping those who do know what they're talking about might comment further.
WR 6-3
