Thread: Air Malaysia missing.

Originally Posted by BigBlackDog

Sorry, but the chances of fuel starvation leading to an autopilot control successful ditching would be almost not at all. Generally when the engines fail the autopilot system will drop offline. That's ok, because it is fly by wire so will in general keep itself upright. The boeing FBW system is speed stable, like a conventional airframe. So best case it would have held speed till it hit the water. Even at best glide, or minimum descent speed, the system is not capable of auto landing unless it is told to do so and is on an appropriate approach procedure. So either way it's gunna hit the water real hard. They break apart pretty easily on impact

I am not an expert at all on aircraft ditching, but I have read some about a plane near the surface of the water, an aircraft that has been on auto pilot is already trimmed to fly so will glide an considerable distance once the engine and the auto pilot functions have ceased.

Another factor is as the aircraft drops to the surface there is a cushion of air built up between the wings of the aircraft and the surface ( ground effect ) this has a twofold effect supporting and slowing the aircraft.

The near fully laden Swissair 111 broke up on impact with the sea surface, after it had a cockpit fire ( metalized mylar insulation fueled that fire ), the sea surface was rough and the plane shattered into reportedly over 5,000 parts.
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do a quick google of aircraft that have smacked into the harder bits of the planet and see how intact some of them are. We're not looking for a "well just pull then and buff the underside and shes FF/NOM airworthy" just intact enough for the long term boyant stuff to be trapped, if the wings ripped off and sank its got the same effect ditto for the engine and major section of the panelling, providing the interanal compartment lining remained more or les in one piece it going to have the same end effect. Remember that all the old tuff that ued to hang around and float is now made of cardboard that only floats until it get waterlogged. Food trays, cups, aircraft safety sheets arent even laminated properly anymore they're just gloss cardboard because its cheaper to replace them when someone decides that man salmon is a better than gentlemans peach at encouraging calm when reading the card in an emergancy.

look at the answers to the Question of what happened this way

1. it landed on the ocean in such a way that it didnt leave enough trace evidence to be found once the search was in the area of the point of impact after an event that left the aircraft communications inoperative and all persons incapacitated.

2. It landed somewhere after and sound leaving no trace, after all the onboard coms gear including the automated stuff, and not one person on board tried to end a text message or make a phone call when the plane was near enough to civiliation for mobile phones to work. The plane was then ucesfully hidden away and no one in the whole logistic of that blabbed to his/her mates (we'll just asume that everyone on board was killed after landing or convinced to go a long with the game becue it was a great jape).

which is more likely?

Originally Posted by wrinklearthur

I am not an expert at all on aircraft ditching, but I have read some about a plane near the surface of the water, an aircraft that has been on auto pilot is already trimmed to fly so will glide an considerable distance once the engine and the auto pilot functions have ceased.

Another factor is as the aircraft drops to the surface there is a cushion of air built up between the wings of the aircraft and the surface ( ground effect ) this has a twofold effect supporting and slowing the aircraft.

The near fully laden Swissair 111 broke up on impact with the sea surface, after it had a cockpit fire ( metalized mylar insulation fueled that fire ), the sea surface was rough and the plane shattered into reportedly over 5,000 parts.
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From my last post, yes, it will glide an awfully long way, BUT it is going very fast to achieve that. The wings are most efficient up in the 250knot region.

Ground effect is a thing yes, and a very powerful thing at that. The Russians made a ground effect seaplane with about a dozen engines, could carry pretty well all of australia but could not go higher than a few feet! The effect is considered to be in effect from about 1.5 the wingspan and lower. If you come down at a low descent rate (like 100 feet per minute) with a reasonable amount of power set, ground effect will grab you and you can trundle along in it nicely. It doesn't have enough effect and reach to slow 200 tonnes coming down at over 1000 feet per minute, or 16 feet per second. So yes, it will definitely slow the descent, but not enough or quickly enough to do anything useful.

So I was thinking in the shower Blknight.aus, and I hope that has made it a bit weird! You're right, plane smack into the ground and seem to hold together pretty well often. I hypothesis this - water is soft. When you hit the dirt the energy is deflected. We are taught that in the event of a wheels up landing in a aeroplane (or any emergency in a helicopter that might require a slide on landing) that the harder the surface the better, so long as it's smooth naturally. Landing on a ploughed field, for example, is bad, because you dig in and stop suddenly. When you hit the water you sink into it, which creates more surface drag, quicker transfer of energy etc etc. that is just my opinion that bit though.

And yes, I agree that the likelyhood of it having landed somewhere with all the associated things that would have had to happen to keep it a secret, seems unlikely. I think you're right, and in a way it might not have mattered if it broke up on impact to a degree. Most bits sink eventually. We might not have been even close to looking in the right place for it. Fuel won't stay on the surface for ever either. It was days before they even decided a place to search I seem to recall.

Whatever happened to that plane is weird, whether through a series of unlikely events or foul play

Originally Posted by BigBlackDog

We are taught that in the event of a wheels up landing in a aeroplane (or any emergency in a helicopter that might require a slide on landing) that the harder the surface the better, so long as it's smooth naturally. Landing on a ploughed field, for example, is bad, because you dig in and stop suddenly. When you hit the water you sink into it, which creates more surface drag, quicker transfer of energy etc etc. that is just my opinion that bit though.

And yes, I agree that the likelyhood of it having landed somewhere with all the associated things that would have had to happen to keep it a secret, seems unlikely. I think you're right, and in a way it might not have mattered if it broke up on impact to a degree. Most bits sink eventually. We might not have been even close to looking in the right place for it. Fuel won't stay on the surface for ever either. It was days before they even decided a place to search I seem to recall.

Whatever happened to that plane is weird, whether through a series of unlikely events or foul play

Waters a fickle thing, hit it one way and it plays as near as you like to being a solid, hit it another and its soft and deformable.

The reason your taught to aim for smooth instead of a rough surface is to do with the number of "leading edges" you have to deal with and what that means for the stability and "grip" of the surface and what that means for the motion of the aircraft after impact.

Look at like grip on a tyre but in reverse you want to hit the hardest and smoothest thing you can at the lowest angle you can so that you slide shedding your energy in a slow controlled manner. you don't want to come in flared like you would for a landing approach (unless you're flying a tailwheeler) as thats going to put you in tail first then the front ends going to "slap" down digging everything in nice and hard.

If they ever find it its going to be a great read to find out what happened from the black box, if its till viable

They are wasting their time and money, it will NEVER be found.

The USAF jettisoned a Hydrogen Bomb, 4m Long, 3000KG off Tybee Island, Georgia after a F86 collided with a B47 , They have been looking for it ever since, Its only 25m deep , and the bomb has a radiation signature - still can't find it. AND THEY KNOW roughly where it dropped !!!!


What about Flight 19, the 5 x TBM Avengers that ditched off Miami, 1945. and then a PBM disappeared whilst searching for them.

They have searching (on and off) for 70 something years.

What - still hasn't come back? Must be getting awfully close to out of fuel by now....... :

Originally Posted by goingbush

They are wasting their time and money, it will NEVER be found.

Most likely.

Originally Posted by goingbush

The USAF jettisoned a Hydrogen Bomb, 4m Long, 3000KG off Tybee Island, Georgia after a F86 collided with a B47 , They have been looking for it ever since, Its only 25m deep , and the bomb has a radiation signature - still can't find it. AND THEY KNOW roughly where it dropped !!!!

Have you not seen the Bond film "Thunderball" ?

Originally Posted by goingbush

What about Flight 19, the 5 x TBM Avengers that ditched off Miami, 1945. and then a PBM disappeared whilst searching for them.
They have searching (on and off) for 70 something years.

Yes that's the one the Bermuda Triangle people are resting their hopes on, that those planes never be found....

Originally Posted by wrinklearthur

Hi Dave a question if I may, Are the people that program the automatic pilots 100% perfect in every way and never make mistakes?

Ask Air New Zealand (See https://en.wikipedia.org/wiki/Air_Ne...and_Flight_901).

Originally Posted by wikipedia

The initial investigation concluded the accident was caused by pilot error but public outcry led to the establishment of a Royal Commission of Inquiry into the crash. The commission, presided over by Justice Peter Mahon, concluded that the accident was caused by a correction made to the coordinates of the flight path the night before the disaster, coupled with a failure to inform the flight crew of the change, with the result that the aircraft, instead of being directed by computer down McMurdo Sound (as the crew assumed), was re-routed into the path of Mount Erebus. In Justice Mahon's report, he accused Air New Zealand of presenting "an orchestrated litany of lies" and this charge in the end led to changes in senior management at the airline.

Originally Posted by p38arover

Ask Air New Zealand (See https://en.wikipedia.org/wiki/Air_Ne...and_Flight_901).

So, Ron, you are saying auto pilots don't make mistakes. If you program them to fly into a mountain, they will fly into a mountain.
Fair enough.

Hey, goingbush, they found the Sydney. I've got a book on it.
They also found the Titanic.
They might get lucky.