Quote from EMIT:
"What will have been very unusual for the crew will have been the over the nose visibility during the low speed, low altitude pass - the pitch attitude was so high that the trees may well have been hidden just behind the nose - cutoff angle over the nose, if I recall correctly, was 15 degrees down."
Yes, as I commented in an earlier
post:
"Pitch rose through +10 deg at about t -13. No particular significance in +10, but my guess is that, assuming the pilot's eye height was adjusted (using the seat-height adjustment) to the recommended level, the trees would not have been visible through the windshields after that. Also, not many pilots are used to the perspective at that kind of attitude - except on T/O. At t -7 pitch was about +14. Unfortunately I don't have an A320 AWOPS guide to hand, which might help with the relevant geometry."
I added:
At about t -8 the co-pilot warned the captain of some pylons ahead. They were very much further away than the trees, so one can assume that either the co-pilot could not see the trees, or that the steep deck-angle caused him to think that the a/c was higher than the treetops.
EMIT is right. At that deck-angle, the PF would inevitably have been flying on instruments. The A320 RA readings are presented (like most EIS cockpits) in purely digital form - at the bottom of the PFD.The trend of the readings is therefore more difficult to interpret than would be the case with an analogue (dial) presentation. The synthetic voice normally calls the
transits of 100, 50, 30, 20, and 10 on a landing approach. If the RA reading hesitates (due premature flare, or passing over a gully), the value can be repeated. The former happened, in effect, during this fly-past, which is why the CVR records the "Thirty" announcement several times.
Quote from CONF_iture (my emphasis):
The pilot version is that he was following the altimeter set on the QFE of Habsheim and was indicating 100 ft all along. He also said he has never heard the RA announcements. That can be the reason he did not pull harder earlier during the initial phase of the low pass.
Thanks for that. The DFDR trace shows the a/c consistently lower, eventually below 30 ft QFE. No pilot expects a baro reading to be that accurate, which is the main reason that,
AFAIK, radio-altimetry is mandatory for any AWOPS procedure with a decision height below Category 1 minima (~ 200ft).
The geometry of the pilots' ability to see the trees would benefit from the diagrams in an AWOPS guide. However, there is another aspect of geometry which is interesting: the difference in the pilots' eye-height above the ground, and the RA reading.
The four rad-alt TRx antennae on the A320 were mounted on the bottom of the rear fuselage, just forward of the fuselage tapering area. Examination of the a/c profile diagram shows that, at a pitch angle of +13.5 degrees, the pilot eye height above flat ground would be about 25 ft higher than the RA reading. At the final pitch angle of about +15, the tail-cone and tapering part of the rear fuselage would have been the first to touch any horizontal series of treetops. At that stage, the engine nacelles would have been between 5 and 10 feet clear. (However, we cannot assume the treetops were all the same height.)
So the pilot's eye would have been over 25 ft above the tree-top that the a/c first struck...
Also, FWIW, the static ports that sense the static pressure for the ADCs that feed the altimeters are not far below the pilots.