QANTAS emergency landing - forced change in altitude. WHY?

reply to post by mattguy404


The plot thickens....

So now we are fairly positive it was not a simple zeroG fall caused by turbulence, that it was some form of instrument/systems failure that caused the plane to dive dramatically, or that it was a deliberate manoeuvre designed to avoid something . Although the former is more likely in terms of Occams Razor, we must look at the fact that QANTAS has an almost squeaky clean record, coupled with it's recent incidents that would have definitely made QANTAS look carefully at their planes and therefore the likelihood that they would miss something that could potentially cause such a serious incident, in my personal opinion, is low.

Hmmm...hope that makes sense.

reply to post by sir_chancealot


Its called CAT (Clear Air Turbulence) Its not the fall its the landing, the in flight equivalent of going over an atmospheric water fall. Picture flying off the edge of a or out of an air pocket in to an area of much less pressure, aircraft falls due to reduced lift, then abruptly stops falling when hits denser air below. i.e leap off waterfall big belly flop in pool below shortly after.

Sorry no aliens/UFO's or conspiracy here.

I am flying on an International Qantas flight, on an A330 no less, tomorrow.

It took me a good 20 minutes to even click on this link, and I am kind of glad I did but still unnerved.

I hope and pray the more sensible reasoning behind this latest 'incident' is true.

Qantas's recent track record in the last few months is what is giving me the antsy feeling I am getting. I don't know or can even imagine what is the cause for all these "technical problems" other than poor maintenance.

I may have to speak with someone in charge before we fly

All jokes aside, sending up some prayers or even positive thoughts for me and everyone on board would be appreciated


edit to add - anybody know if flying from Tokyo, Japan to Sydney, Australia would have the plane taking a route where these 'air pockets' that cause such turbulence hit ?
Just curious.

Not sure I even wanna actually know I may just check back after I have landed safely.




[edit on 7-10-2008 by ImJaded]

reply to post by Kryties


So the evidence is a lack of evidence. OK - I see how that works

reply to post by dave420


It has been established in the previous page that it could not have been turbulence because that would just cause the plane to 'fall' hence the passengers also 'fall' in a zero g environment. It takes a deliberate negative g dive in order to make passengers smash into the ceiling hence turbulence can be ruled out as the cause.

This leaves instrument/systems failure or a deliberate attempt to avoid something in the air by diving.

So just stay seated with my seat belt fastened tightly the entire flight ?

Ok

reply to post by ImJaded


Hehe yeah you could do that if you want mate. Twould make for a terribly uncomfortable trip though and the chances of another systems failure occuring will be slim. You can believe that if that was the cause QANTAS engineers will be losing a lot of sleep over the next week making sure it does not happen again.

Of course if it was something they were avoiding then chances are also good that it will not occur again on your flight.

EDITED for spelling and typo's

[edit on 7/10/2008 by Kryties]

reply to post by Kryties


Thank you kind sir, your words are comforting given that I am gonna do my damndest to get bumped up to 1st class and plan to be horizontal most of the flight haha

CLEAR AIR TURBULENCE -(CAT) exists and is well documented and defined. It has been such a problem, a specific CAT Radar was developed. However, it was expensive to fit.


If Qantas are remaining tight lipped, could it be because the aircraft involved was not fitted with CAT Radar, because Qantas had made a decision that it was not worth the money?

The facts, were they to be proven in a court of law, that CAT predictor radar was available, and had not been fitted due to cost considerations, and that people were thereby injured would constitute negligence. Damages would be substantial.

That explains the "Duh!" response of Qantas so far...

exo

Originally posted by Snappahead
Maybe they were dodging the UFO that's loitering around waiting for the 14th

.

My thoughts exactly!

An update

Source: www.atsb.gov.au...

The aircraft was flying at FL 370 or 37, 000 feet with Autopilot and Auto-thrust system engaged, when an Inertial Reference System fault occurred within the Number-1 Air Data Inertial Reference Unit (ADIRU 1), which resulted in the Autopilot automatically disconnecting. From this moment, the crew flew the aircraft manually to the end of the flight, except for a short duration of a few seconds, when the Autopilot was reengaged. However, it is important to note that in fly by wire aircraft such as the Airbus, even when being flown with the Autopilot off, in normal operation, the aircrafts flight control computers will still command control surfaces to protect the aircraft from unsafe conditions such as a stall.

The faulty Air Data Inertial Reference Unit continued to feed erroneous and spike values for various aircraft parameters to the aircrafts Flight Control Primary Computers which led to several consequences including:

* false stall and overspeed warnings
* loss of attitude information on the Captain's Primary Flight Display
* several Electronic Centralised Aircraft Monitoring system warnings.

And so on an so forth it goes. However as far as I know, these aircraft have not been grounded, as apparently the fault is considered "rare"(Source: ABC Radio). Apparently the investigation is ongoing but I am surprised that this issue doesnt warrant grounding and repair, regardless of how rare it is. I would have thought this would be critical to the airline and the manufacturers duty of care & reputations.

Anyone with an aerospace background wish to comment on this information? I wont pretend to be an expert.

Sounds like that model needs something like a firmware upgrade at the very least, a better handling of the situation where 1 of several inertial references is vastly at odds with the others indicating an error. These systems have multiple layers of redundancy built-in and always did so it seems the problem is in the error handling rules.

Grounding them until the changes are implemented is hugely preferable to losing a plane and the consequent human cost.

reply to post by Pilgrum


Well thats the thing isnt it. You wouldnt ground a fleet of aircraft if the real cause had nothing to with the equipment itself, but a third parties influence on that equipment.

EM phenomena have long been related to UFO's. They are also related to alot alleged projects the Government are working on(maybe in places like Exmouth)

When you have an aircraft which is fly by wire, and you physically have no control over your aircraft control surfaces, any EM interference is going to knock your bird clean out of the sky. As illustrated perhaps?


Edit: Having a look at google earth, the incident(According to ATSB reckoning) occured only 100 nautical miles from Harold Holt base.



[edit on 15/10/2008 by Gaderel]

OWERFUL signals from a secretive naval base are being probed as a possible cause of a Qantas jet plunge last week.

Air safety investigators say they will look into claims that signals from the base, used to communicate with US and Australian ships and submarines, may have interfered with the Qantas Airbus’s computer.

The plane plunged 200m in seconds during the emergency, injuring more than 70 passengers and crew.

The naval communications base is at Exmouth in Western Australia’s north, 30km from Learmonth, where the Qantas Airbus A330-300 made an emergency landing last week.

There were 303 passengers and 10 crew aboard when the plane suddenly lost altitude, hurling people around the cabin and forcing the pilot to land.

The Australian Transport Safety Bureau said yesterday it would examine whether powerful electromagnetic signals from the communications base could have caused the emergency. (more)

Originally posted by sir_chancealot
If a plane just "falls", the only thing that can happen is zero Gs. Everyone will become weightless. You won't be violently thrown to the ceiling (gravity doesn't take "longer" to pull you down than the plane itself). However, if the pilot put the plane into a negative G dive (for whatever reason) then people WOULD be thrown to the ceiling.

I think you are confused. You're confusing a Keplerian Trajectory with what a sudden, externally influenced, downward "push" in altitude. Put a quarter inside of a box with the top open and violently push/pull it toward the ground, what do you notice? The box, of course, is accelerating faster than gravity but the quarter is not. If the downward acceleration is great enough, and the box was closed, the quarter would be pressed against the top of the box for the duration and then slammed to the bottom once acceleration ceased. However, if you just drop the box with the quarter in it, that won't happen and both the box and the quarter will fall at the same time.

The plane is not "falling" when it hits turbulence, rather, it is being pushed down (or up) by a more dense or faster moving pocket of air, so it is experiencing that force plus gravity. Depending on how long this lasts, and how powerful the acceleration, the forces acting would have you hit the ceiling - much like the quarter in a box - and continually press you against it until the downward acceleration stopped - after which, you would likely be slammed against your seat or other people.

If the passengers in the plane, or anything else, is not secured somehow to the body of the plane, when it goes down, they go up, if it goes left, they go right, etc...

The plot thickens with another update.

I love it when they mention "top-secret"





Check out: Naval base link to jet plunge

Investigators are considering the possibility that transmissions from the top-secret joint US-Australia naval base near Exmouth may have caused a Qantas aircraft to dive suddenly last month, seriously injuring a flight attendant and at least 13 passengers, the Australian Transport Safety Bureau said today.