The clues about the cause of the ugly Qantas laundry drop at Manila last Friday are falling into place.
On 24 April CASA issued an airworthiness directive with an enforcement date of 5 June requiring urgent inspections of the supports that held oxygen bottles in place on Boeing 747s like the one that was only an hour into a Hong Kong-Melbourne flight with 365 people on board when it made an emergency descent into Manila with a large load of passenger luggage plugging a gaping hole below the cabin and forward of the wing.
This AD as they are called was CASA’s immediate response to disturbing news from the Federal Aviation Authority in the US warning that some of these supports might fail, releasing high pressure oxygen bottles and risking a leak.
The rack that held oxygen bottles on QF 30 is in fragments near the fuselage rupture and two of the scuba-dive-sized bottles are missing.
There is no sign of fire. Or of a massive explosion, since even one of those bottles, if detonated, would most likely have blown the forward section of the jet apart from the main body, just like the bomb on a Pan Am flight which detonated in the same area of the cargo hold over Lockerbie in Scotland on 21 December 1988.
But experts say the release of a stream of high pressure oxygen on its own could ram a bottle through the fuselage of any jet, whether brand new or riddled with rust.
The question remains unanswered as to whether the fuselage blew first, because of an undetected imperfection, or over repair as some engineers have speculated, causing the luggage container to get sucked backwards to the hole and slamming into the oxygen bottle rack in the process, or the bottles initiated the failure by falling out of their supports and ‘going off’.
This morning’s new directive from CASA, for all oxygen bottles in the 747s to be checked, is a solid belt-and-braces follow up.
Now the outstanding queries about QF 30 include whether the original AD was complied with. There have been reports that during the 10-week engineering overtime bans, the papers carried by this jet noted that the oxygen system needed to be checked on a per flight basis.
Even before the maintenance dispute, the jet was flying, again like much of the Qantas fleet, with a long list of time-limited permissible defects.
When Captain John Bartels began the diversion he lost an unspecified range of instrumentals and controls. Qantas has again been lucky to have such a serious incident happen so close to an airport.
Had this occurred say mid way to Johannesburg, or somewhere between Los Angeles and Australia, the jet, forced to fly at less than 10,000 feet would have consumed much more fuel than normal, and it could have all ended rather badly.
The same luck was there when QF 2 lost most of its electrical systems just short of Bangkok on 7 January. That jet had only minutes of battery power remaining. On New Year’s Eve it was on a sightseeing charter over Antarctica, from where it would not have safely returned.
I find it curious that any Crikey criticism of Qantas is almost always quickly refuted by some unspecified experts. I often wonder if some part of the company’s bunker is dedicated to monitoring Crikey & minimising any ‘damage’ by over-the-top rejection of the report or some attempt to discredit the author. I would put nothing past them.
Glen
I chuckled aloud at your comment ” … if the valve on the cylinder started leaking before it failed, then oxygen may have flooded the cargo space, and possibly into the cabin. Passengers would notice a feeling of wellbeing, and so I wonder if anyone of them reported this.”
A feeling of well-being on a Qantas flight?
Another Qantas mechanical failure this morning on a flight from Adelaide to Melbourne. Wheels wouldn’t come down or something. Whatever it was they had to to turn back to Adelaide. The brand is really being trashed.
Dear Crikey
Every other day Crikey sends me tempting emails asking me to be come a paying subscriber.
If I undertake to purchase a subscription to Crikey, will Crikey undertake to ensure that its writers improve their sentence construction and grammar? Avoiding run-on sentences and incorrect use of prepositions would be a good start. Here are two examples from the Ben Sandilands article which really threw me:
“On 24 April CASA issued an airworthiness directive with an enforcement date of 5 June requiring urgent inspections of the supports that held oxygen bottles in place on Boeing 747s like the one that was only an hour into a Hong Kong-Melbourne flight with 365 people on board when it made an emergency descent into Manila with a large load of passenger luggage plugging a gaping hole below the cabin and forward of the wing.”
“The question remains unanswered as to whether the fuselage blew first, because of an undetected imperfection, or over repair as some engineers have speculated, causing the luggage container to get sucked backwards to the hole and slamming into the oxygen bottle rack in the process, or the bottles initiated the failure by falling out of their supports and ‘going off’. “
In the light of other subscriber comments on this article relating to incorrect technical information, you will understand my indecision to commit to Crikey. One might wonder at the pressure your writers are under when they produce sub-standard work.
Looking forward to paying out soon…
I have used oxygen for high altitude unpressurised flying in gliders and i thought it was well known that grease in bottles can cause explosive combustion. I did a simple search and found
http://forums.jetphotos.net/showthread.php?t=44558&page=4
“The combination of grease and pressurised oxygen is explosive. The are famous photos of a P3 Orion where a crew oxygen bottle exploded and rocketed out the side of the aircraft. The aircraft was ultimately destroyed buy the ensuing fire, but this occured on the flight line.
If anyone does not know that precaution they should not be touching oxygen systems.”
So somebody needs to be educated here
I also recall that the apollo explosion was speculated to be due to a grease maintenance error
And i do have a chemistry degree.
Obviously if a bottle explodes the failure is only caused by pulse of pressure rather than a bomb like blast but even so if all of the gas immediately leaves the bottle it is going to do some damage as some pieces will behave like shapnel rather than remain as part of the bottle. If you look at an over pressure accident in a scuba bottle they tend to not totally fragment but bend and split massively .