'Contact lost' with Malaysia Airlines plane

[esmozz]

I am pretty sure autopilot can activate landing gear. I imagine it is triggered by altitude.

A reasonable assumption but actually, no. No aircraft that I am aware of has an autopilot function that lowers the landing gear and definately not the B777.

 

[Tuppy_Glossop]

Yep, I see my assumption has fallen flat, soz. I only ever did unmanned avionics, honest guv

Edit: and even then only on TCAS

 

[Chuk_Chuk]

-Structural failure: In the event of a suspected structural failure and the need to descend to a safe altitide quickly (for example a bomb going off onboard), the crew could have elected to lower the gear to increase the rate of descent without increasing airspeed.

I don't care about the wider arguement you two are having but on this point, I've never heard of the landing gear being used as a method of increasing the rate of descent without increasing airpseed. Wouldn't the air brakes serve the same purpose and be more suitable?

 

[esmozz]

Yes, but you're not looking at the whole picture. You're looking at a brushstroke.

I think my point (possibly badly made) is that to much is being read into this information - I don't think it really tells you much either way. It also points to an inconsistant narrative - either the pilot wanted the aircraft to sink without a trace or he wanted it breakup. There are better ways to achieve both that don't involve a high speed touchdown with gear down.

I am aware of the other factors in this incident and its seems to me, without ever finding the aircraft we will never really know. However, its worth pointing out that in any aircraft accident there are always parties with deep pockets who's interest it is to blame the pilot.

Which is why the cause of pilot suicide should be proved beyond reasonable doubt (at least)

 

[Trig]

And remember, there are some airlines that are calling for single pilot routes..

 

[Chuk_Chuk]

And remember, there are some airlines that are calling for single pilot routes..

A good mentour pilot video on the topic.

 

[Trig]

-Structural failure: In the event of a suspected structural failure and the need to descend to a safe altitide quickly (for example a bomb going off onboard), the crew could have elected to lower the gear to increase the rate of descent without increasing airspeed.

How does that make sense in your head?
You have structural issues and somewhere, a light bulb goes off and lowering the gear makes sense to you, increases drag and increases the chances of damaging the gear itself...

 

[esmozz]

I don't care about the wider arguement you two are having but on this point, I've never heard of the landing gear being used as a method of increasing the rate of descent without increasing airpseed. Wouldn't the air brakes serve the same purpose and be more suitable?

It's a widely accepted method of doing so. If my IT skills were up to the job of posting a picture of the passage in the flight crew training manual I use, I would but I can't seem to post pictures here.

Air brakes (more correcly speed brakes) are much less effective than landing gear at increasing descent rates (particulary at lower airspeeds, which you would want to maintain in the case of suspected structural failure)

 

[esmozz]

How does that make sense in your head?
You have structural issues and somewhere, a light bulb goes off and lowering the gear makes sense to you, increases drag and increases the chances of damaging the gear itself...

I have about 5000 hours as Captain on the B737 and many other hours on other types - I can assure you its a standard procedure in certain situations.

 

[Chuk_Chuk]

It's a widely accepted method of doing so. If my IT skills were up to the job of posting a picture of the passage in the flight crew training manual I use, I would but I can't seem to post pictures here.

Air brakes (more correcly speed brakes) are much less effective than landing gear at increasing descent rates (particulary at lower airspeeds, which you would want to maintain in the case of suspected structural failure)

Sounds like someone needs to design better speed brakes if they are out performed by the landing gears

Is there not a risk of damaging the landing gear bay doors? Or is there a max speed at which you are allowed to do this?

 

[mid_gen]

Sounds like someone needs to design better speed brakes if they are out performed by the landing gears

Is there not a risk of damaging the landing gear bay doors? Or is there a max speed at which you are allowed to do this?

There's an airspeed limit.

It's not that landing gear is a more efficient braking method than airbrakes, it's the fact you need them to land on. That they are very effective airbrakes is a bonus secondary function.

 

[Lysander]

I think my point (possibly badly made) is that to much is being read into this information - I don't think it really tells you much either way. It also points to an inconsistant narrative - either the pilot wanted the aircraft to sink without a trace or he wanted it breakup. There are better ways to achieve both that don't involve a high speed touchdown with gear down.

I am aware of the other factors in this incident and its seems to me, without ever finding the aircraft we will never really know. However, its worth pointing out that in any aircraft accident there are always parties with deep pockets who's interest it is to blame the pilot.

Which is why the cause of pilot suicide should be proved beyond reasonable doubt (at least)

Hmm this is a fair point. Why lower the gear if you want it to sink.

OK, let's look at the Reddit thread for some fun:

His thoughts are interrupted when an alarm sounds in the cockpit indicating the fuel that has been keeping MH370 in the air is almost exhausted. Captain Shah surveys the navigation information that indicates he has not quite reached his hoped for destination, Diamantina Deep. The fuel in the Boeing 777 is almost gone. While he won't reach his planned destination, the fuel running out does provide one benefit he thinks, the likelihood of any fireball upon impact will be greatly reduced, which will ensure that there isn’t smoke on the horizon for distant ships to see, and any resulting fuel slick on the surface of the ocean will be eliminated. Captain Shah reduces the altitude of his Boeing 777 to a few hundred feet above the surface of the southern Indian Ocean. The sun has appeared above the horizon out the left side of the cockpit, illuminating the surface of the sea below. He looks out the cockpit window and can see almost no swells at this point in the southern Indian Ocean. The high pressure system in the area means relatively light winds without whitecaps on the ocean's surface. Captain Shah then goes down the checklist he has brought with him, and makes a few last setting changes on MH370. He opens the same outflow valve he had used so many hours ago, and ensures that the APU is set to maximize water ingress and allow water to quickly enter the plane after it has ditched, hoping that the plane will sink quickly, should it somehow remain mostly intact upon landing. He sets the gear and the terrain override switches to OVRD.

Then sets his flaps to maximum at 30 to allow the plane to fly slow to 170 knots and sets the pitch to 10 degrees nose up, while at the same time throttling the engines back to idle as the big plane approaches the sea below. He hopes that the gentle glide path towards the surface of the Indian Ocean below and the slow speeds will keep the plane as intact as possible to reduce the amount of floating wreckage that a high speed impact would create and to ensure that that the emergency beacon that activates upon impact water sinks with the wreckage, reducing the chance of detection. The nose of MH370 begins to drop towards the surface of the Indian Ocean and the dark depths below that he hopes will hide his guilt.

It is time for the last part of his careful plan to be put into action. Captain Shah knows that even though he has been extremely thorough in his plans to get to this location undetected, there is still a possibility that the wreckage may be discovered. Perhaps a piece of floating wreckage is found by a passing ship, giving away enough information for them to locate the wreckage of flight MH370 at the bottom of the sea. But he also knows that there will be absolutely no way to confirm who was at the controls throughout the long saga because of his silence during the last two hours of the flight has left no voice on the cockpit voice recorder. That is unless his physical remains are found inside the cockpit section of the wreckage.

Captain Shah rises one last time from the Captain seat. The seat that has brought him significant pride and happiness in his 53 year life, and a life that will be over in a matter of minutes, as his final flight begins the slow glide to the sea below. Alarms are sounding in the cockpit, as the Boeing 777 tries to call attention to anyone who might be able to stop what is happening, but the only person alive to hear the warnings is now immune to their call. Captain Shah quickly runs to the back of the cockpit and opens the secure cockpit door that has kept him separated from the worst of the evidence of what his actions have wrought. He puts his ear to the door to see if there could possibly still be someone alive, but there is still no sound from behind the door. He pulls back the door, and steps into the passenger compartment, pulling the cockpit door closed behind him…

As the Boeing 777 slowly descends through the last few feet of air above the deeps of southern Indian Ocean, the only sound that the cockpit voice recorders picks up are the sounds of warning alarms...

Hmm the thread suggests that lowering the gear would be a bad idea.

 

[esmozz]

Sounds like someone needs to design better speed brakes if they are out performed by the landing gears

Is there not a risk of damaging the landing gear bay doors? Or is there a max speed at which you are allowed to do this?

I had to google it as the speed on the B737 I fly are different from the B777 (in fact there are different speeds for lowering, retracting and flying with the gear extended)

But a speed of 270Kts / Mach 0.82 is the speed limit in all cases on the B777 - this is probably at or just below the cruising speed of the B777. In reality if I had to fly such a manoeuvre I would let the speed wash back to 250kts before initating a descent.

 

[mid_gen]

Hmm this is a fair point. Why lower the gear if you want it to sink.

OK, let's look at the Reddit thread for some fun:






Hmm the thread suggests that lowering the gear would be a bad idea.

There's something just....ick....about real life disaster fan fiction.

 

[Lysander]

There's something just....ick....about real life disaster fan fiction.

Haha, I don't think it's fan fiction. If you read from the start you'll see it's a theory for what happened to the flight.

 

[esmozz]

There are some fairly big problems with that account. Not least because, from memory, there is evidence from satellite handshake data that one of the engines shutdown and then re-started.

The explanation for this is that one engine flamed out due to fuel starvation. This caused the the aircraft to naturally bank in the direction of the failed engine - which caused a temporary movement of fuel in the tanks to allow the engine to auto-relight for a brief period and as part of this relight it sent startup data via satellite as it was designed to do.

From this we can infer the aircraft made an unpowered landing. It also raises any number of other questions about what happened.

 

[Penfold101]

Haha, I don't think it's fan fiction. If you read from the start you'll see it's a theory for what happened to the flight.

That’s pretty much the same thing at this point…

Assuming he wanted the plane to disappear without a trace, it would make sense for him to try and land it on the surface as gently as possible. The higher speed he ditches at, the more chance there is of the airframe breaking up and wreckage floating on the surface. Given the minimal debris that has been found so far, and that one piece was a flaperon, I’d suggest he came in low and slow onto the ocean with flaps deployed.

In all aircraft I’ve worked on you get a warning horn if the flaps go beyond a certain angle without the gear extended, so possibly he did this purely to silence the noise and tell the aircraft that it’s in a landing configuration, otherwise lots of other alarms will being off such as ground proximity.

There’s a chance the gear will be ripped off when it touches the water, but they’re just going to sink to the ocean floor anyway and are designed to detach in a specific way without destroying the surrounding structure.

 

[danlightbulb]

Is there a link to that reddit story? How does it say he killed everyone on board?

 

[mid_gen]

Is there a link to that reddit story? How does it say he killed everyone on board?

You should probably just head to the fiction section in your local bookshop, it'll be more interesting, and better written.

 

[Lysander]

Is there a link to that reddit story? How does it say he killed everyone on board?

Hypoxia.

Here's the link:

Reddit - Dive into anything

www.reddit.com