Hi Lyman,
Originally Posted by
Lyman
"Had no effect..." "Played no part in the crash...". "The lack of the spacer was not relevant..."
All demonstrably untrue statements.
I'm sorry, but my reaction to that is:
Certainly not!
For those to be demonstrably untrue, we need far more than "just" one pic.
Do we have more? In fact yes, see below.
Originally Posted by
Lyman
If in evidence (it is), and also an abnormal, we can assume there is a possibility it played a part in the tragic crash.
Yes, we
could assume that, but
only if the "wobble" was present for a "long" time. Was it? What elements do we have? Let's see:
- 1 picture showing what looks like the wobble, that you attributed to the missing spacer (likely, I agree); this pic also show the broken runway light; hence we know that the pic show the runway at ~2,800 meters.
- other pictures
not showing the "likely wobble", or not clearly at all, taken from earlier parts of the runway;
- a rather complete description from the BEA, quoted below:
1.12.1.8 Tyre tracks
From Slab 161 level to Slab 232 level, that is between 1,807 and 2,340 m, the mark of a deflated tyre with an incomplete tread was observed.
This mark was parallel to the runway axis (at about 3.8 m) then diverged at about 2,200 metres.
When this mark disappeared at about 2,340 m, its displacement from the centreline was about 8 m. This corresponded to the right front tyre of the aircraft’s left landing gear.
Further on, some irregular tyre tracks from the left landing gear were noted up to the broken edge light (2,800 metres).
After that point, the tracks become intermittent then disappear at about 2,830 metres from the runway threshold.
OK, so, probable wobble @ 2,800m,
but no wobble on the pic showing the soot on the runway. The soot on the runway, where was it? Easy:
A mark 15 m x 15 m identified as probably being kerosene was noted around line 163, 1,820 metres from the threshold. Then, traces of soot, produced by incomplete combustion of kerosene, were apparent on the runway 1,860 m onward from the origin (Slab 168). These were large and dense up to 2,300 m and then became less dense and rich in carbon up to taxiway S4, at 2,770 metres. The traces, which were on average 7 m wide, were initially centred on the damaged wheel ground mark and progressed towards the left.
On the pic showing the (dense) soot on the runway,
no indication of wobble at all. Only tracks from the (already destroyed/destroying) #2 tyre.
=> No wobble @ somewhere between 1,860 m and 2,300 m.
=> Shown on the picture, and confirmed in the BEA's text (§ 1.12.1.8, quoted above)
At that time (and even considering 'only' the lower value of 1,860 m despite said §),
the aircraft is already on fire, meaning the strip/tyre/fuel leak/ignition events already took place.
To be sure, let's search where other relevant items were noted relative to the beginning of the runway:
1,642 m -> the first parts found are from the water deflector, from slab 139 and onwards;
1,740 m -> the titanium strip, at slab 152;
1,740 m -> a big part of tyre (transversally cut) at same slab 152;
1,820 m -> the unburnt kerozen mark at slab 163;
1,860 m -> the first traces of soot (hence: fire);
1,950 m -> the other 'fitting' part of the transversally cut tyre at slab 180.
1,957 m -> signs of an explosion and a piece of concrete separated from the runway (my comment: that shows that the leak/fire was not due to this 'explosion' whatever it really was -
EDIT it was not the tyre explosion, as noted in appendix 6 of the final report (which provides a pic): "The explosion could be explained by the forward propagation of the combustion zone").
=> this clearly shows that the fire ignited
one kilometer before the only picture we may consider as conclusive of a wobble (@ 2,800 m)...
=> ... and
460 m before the first "irregular tyre tracks" were noted by the BEA (@ 2,340 m).
This is why, I think, the BEA concluded (rightly) that the lack of the spacer - even if one can discern indications it made the bogie wobble around 2,340 to 2,800m from the runway beginning - was not relevant to and played no part in the final outcome, which was sadly certain as soon as the fire broke.
QED.
Regards,
AZR.