Canadian Visual reference requirements and AC624 report
I am surprised there has been no comment about this aspect of the AC624 accident report. If you read it in detail, 138 people missed almost certain death by less than a second, and escaped only because by good luck that the runway is at the top of a slope. They were well below runway level for several seconds, and it just avoided being the worst civil air accident in Canadian history.
Pretty clearly, the immediate cause of the accident was continued descent below MDA without the pilot having enough visual cues to either reach the runway safely or determine that the aircraft was not properly placed to do so. But there's nothing in the analysis, causes or risk findings about the fact that apparently Canada does not adhere to ICAO standards regarding visual references.
Annex 6 etc is very simple: at DH/MDA the visual cues "should have been in view for sufficient time for the PILOT to HAVE MADE an assessment of the aircraft position and rate of change of position, in relation to the desired flight path". The assessment process ENDs when the aircraft reaches DH/MDA.
But the CAR visual reference requirement is different: ".... visual aids that, when viewed by the pilot of the aircraft, ENABLE THE PILOT to make an assessment of the aircraft position and rate of change of position, in order to continue the approach and complete a landing", and any one of the listed items will meet that requirement.
If you can START an assessment at DH/MDA, presumably it can have two possible conclusions - the flight path is satisfactory, or it is not. In the latter case, surely you have to go around - but by definition you are below the height at which a safe instrument go-around can be made.
From this report it not only seems entirely acceptable under CAR to have a decision process STARTING at the MDA, but in effect to have it made by committee of 2, and not just "the pilot" who will be doing the landing. The report consistently refers to "the flight crew" (both pilots) rather than the pilot (actually responsible for making the landing) making these assessments below MDA.
A short recap: at MDA, the F/O says he can see some lights. The Captain commits to landing and then STARTS making his own assessment. A debate occurs, with both talking about what they can see. The F/O becomes unhappy and calls for a go-around, with which the Captain subsequently concurs. The go-around starts from a height when the aircraft should be in the flare, only 15 feet above runway level, but is actually well short of the runway.
This seems to be in accordance with CARS and the conflict with Annex 6 doesn't get a mention in the report. The fact that AC did not include the words about assessing the flight path doesn't seem to materially affect the outcome - what else would you use the cues for? (Though this omission seems to be another item that had slipped through TC's supervision.)
The report also says AC has now removed the "lights only" call, which presumably leaves only ""no contact" or "runway in sight". Since typical DH/RVR ratios don't expect the runway to be in sight at DH, (e.g in Cat 1 at 200ft the aircraft is 3000 ft from the threshold with 550m/1800ft RVR), what does the PM now call if only approach lights are visible? "No contact" or "runway in sight"? Neither of which is true?
Last edited by slast; 8th Jul 2017 at 15:47.
Reason: typo