News and theories about the missing Malaysian plane

Malaysa 370

No problem whitepointer, i didn't feel insulted.

Yes navygate, its an ELT, i thought EPIRB was the newest acronym, my bad.

For those interested, i checked with the autopilot code writers, and the plane should not stall under no power and autopilot. It will be ‘pitch’ limited (Alpha limited), nose up, wings level, where it is “flying’ stably, but descending fairly rapidly at about 120-150kt’s IAS.

The engine/struts are fused such that they will not depart the plane when skidding along concrete (a runway) at 220kt’s, a possible no flaps landing speed. If the engines hit an obstruction (concrete bollard?) the fuses will shear, and the engines depart without the wing tanks being penetrated by anything. There is a ‘dry bay’ in the wing tanks just above the strut to ensure this.
If the plane landed against the back of a wave like this, the engines might not come off, they are really hollow ducts. If the plane landed against the ‘front’ of a wave, the engines would surely not depart.
The 777 has an approximate volume of 21135cu ft, and weighs about 300,000lb empty. Approximately 6700cu ft are sealed, liquid proof fuel tanks in the wings. The rest is mostly pressure sealed body. It would float. I can only assume the typhoon that went through there shortly after the incident must have damaged it enough so it sank. I hope it isn't suspended at, say, 1,000ft deep, and drifting with the currents.

Plan “B” will be using a towed side scan sonar to ‘map’ much larger swathes of the ocean floor. It doesn't' have the resolution of the present submersible, but is much faster. I am quite amazed they didn't go for this option as soon as they detected the ‘pings’ but there are only so many such devices available. I also assume the US navy are pre-occupied with Europe at the moment.

As i understand it, getting a direction on a ‘pinger’ is pretty difficult, as the sound waves are subject to all sorts of distortions, and distance is a guess.

Including all costs, maintenance, support personnel, transport to and from, are all usually quoted to the press, if only for dramatic effect. In fact, many armed forces regard these searches as an extended exercise, though they do try to recover costs if it was a hoax or something.

 

So do I, 'cos I can't imagine what kind of magic would be needed to achieve that ! I'm sure submarine designers would like to learn this arcane science though !

 

No worries.
I believe Emergency Position Indicating Locator Beacon (EPIRB) is the marine term while Emergency Locating Transmitter (ELT) is the aeronautical term.
I watched the Discovery Channel documentary on Flight MH370 tonight.
What a disappointment.
I'd give it a 3 out of 10.
Too bad, as I find the "Mayday" programs they produce to be 8 or 9's.
Complacency seems to be the bottom line.
Not uncommon.
Time will tell...

 

The activation rate of the locating transmitters is reputedly about 80% which seems a bit haphazard, I dare say this incident will lead to a thorough review and update of the technology, which seems dated, considering the voice recorders only have two hours duration and then overwrite what has been recorded. Whatever was said in the cockpit at the time of crisis will never be known.

 

The previous Australian national government, in its wisdom, decommissioned the only Aussie ORV (that I knew of) with a swathe mapper before the new one was finished, underwent sea trials and went into use. Ooops. So unless our good international friends provide the gear, there are issues.....

Not that I think the current government is any brighter WRT science, mind you. Just saying - you never know quite when you'll need a bit of kit.

PDW

 

I would imagine they would do several things. Widen the search area might be one, I assume there is a continual process of reviewing the data used to ID current search location, and there are other less favored locations that can be checked. The current search location is based on satellite ping Doppler calculations I understand, those data could be rechecked. Most of this stuff has already been checked over ad nauseum I imagine but I always remember the errors on the Hubble Space Telescope that lead to the first fuzzy images and required a space walk to improve focus on the main mirror.

There are rumors and/or claims going around that the site has already been found. I don't see how rumors that the plane has been stolen for spares or resale can hold up, since plane parts are all serialized and would soon be recognized. There's no sense in the terrorist rumors, the first thin a terrorist wants is to claim credit, there probably has been a few claims of that sort but not from the major terror organizations AFAIK.

This morning's news said the serach are has been 2/3 completed so Plan B, assuming there is one, may be close. .

 

Wow, the speculation is rich AK!

 

Yes indeed Navygate: perhaps we are failing in our duty to provide new theories!

 

No, not at all.
Speculation only adds to that.
Time will dictate reality.

 

Mh-370

Dear Efficency, submarine designers do know how to do this, the 'Picard' bathyscaphe (sic) used gasoline to 'float' their vessel at both chosen depths, and sitting on thermoclines. The ‘Pickard’ worked just like a balloon, but in the water, changing average specific gravity to be lighter or heaver than water. Not very practical for operational submarines, but i am sure they use the principle when they can. I think submariners used to call it, ‘trimming the Ship”, but that was a long time ago. I suspect “Boomers’ probably do this and sit on a thermocline, at least for a while.

The reason i mentioned the numbers was to try to discuss ‘facts’ and give you naval architects some food for thought. There was a famous? case where a ship sank (torpedoed?) in a well documented position off florida, but was eventually found some 350nm away. Apparently the gulf stream had a lot to do with this. i.e. between leaving the surface, and grounding on the bottom, the vessel traveled 350nm. Knowing the current speed, and depth of water, its rate of fall could be calculated.
I notice someone stated how far a light plane drifted between sighted sinking, and it ‘grounding’ on bottom. In the 777 case, this large, low density, object that has only slightly more density than water has several miles to sink before ‘grounding’ on the bottom. I know that airplane parts sometimes sink with so little ‘weight’ (but lots of inertia) that they barley touch the bottom and do indeed get drifted around quite a lot. Their tracks have been seen on the mud for a long time afterward.

The poor activation rate of the ELT’s prompted us to specify that it would be activated mechanically by operating the emergency door operation. You might have noticed the captain saying “arm the doors” over the PA, or something similar. This sometimes included dropping a bar into lugs at the door sill, and probably removing a safety pin as well. Under these conditions, the door will open fast, and the slide/boat will deploy, and the ELT will start, regardless of being in water or not. Condensation, even ‘rain in the plane’ is a big issue flying under certain weather conditions, and therefor water gets in places where we really don't want it. Hence the avoidance of automatic liquid switches for almost anything. We favored ‘hall effect’ switches, from something physically moving when we could.
Note’ not all airplanes have the slide in the door, the 767 for instance has its slide in the overhead cavity, and the door opens upward.

 

Yes, well my knowledge of bathyscapes is rudimentary to say the least, I too probably can't spell it properly, but the idea that a plane could sink to 1000 feet, then stop, seems utterly improbable. Unless it hit the bottom at that depth.

 

This is the spookie option and something I thought from Day 1. What or who was on that plane that a group or government would take such action to obtain?

Did it have 10mt of gold in the hold, was there some state secret, some stolen device, was there a key target person being transported to China? Who or what of sufficient value to take this risk and murder the crew and passengers?

I don't think the authorities have any idea where the plane crashed over the sea, to me it's a blind ally and it's hope before the let down 'sorry folks we tried our best but...'. Furthermore, send them all off in the wrong direction so folks will completely forget the stolen and landed theory. Give them a few phantom pings to cling to.

Sorry for being miserable but without divine intervention they're not going to find a shattered, disintegrated 777 at 5,000ft down in some of the world's most wild and fastest moving water. At some stage, fantasy becomes reality.

 

Mh-370

RHP, i love this one. The other 'best' is the theory the malayan jet fighters shot it down because it was thretining to crash into the 'twin towers', and the malayans are covering up. Perhaps better, but slightly less likely, is the story that is is landed quietly somwhere being converted into a 'bomber'. Kind of joking, but i did do a long exercise on converting the 767 into such one.

 

Or a spy plane like Korean 007 years ago!

 

The search of the cuurent best-guess location will be over in a few days, but it is by no means certain that the plane's remains are anywhere near that location. Ae might as well resign ourselves to the fact that the search will almost certainly continue for years if the recorders aren't located this week.

There is a debris field covering about 5 by 3 miles (8.0 km × 4.8 km) around the wreck of the Titannic and the main parts of the hull are over a half-mile apart. Plane parts are considerabley lighter than ship parts, hit the water at a much faster speed and are flimsier too, so there are most likely lots of tiny bits scattered over miles of ocean floor, some of which drifted with the significant current.

Would a good place to hang a beacon or recorder for future designs be on an engine, if there's emough room? Engines are often found in one piece even for a land crash . . .