Missing 777

[k0ua]

Except that IF you are having a fire and redirecting to another airport, why would you be saying "Good Night" at the handoff rather than "Mayday, Mayday, we are on fire and need to redirect to airport X" so that airport X can clear the way for you to get in and get the rescue equipment warmed up just in case?

Aaron Z

That is the $64,000 question that has plagued all of these theories.

 

[RobertBrown]

Except that IF you are having a fire and redirecting to another airport, why would you be saying "Good Night" at the handoff rather than "Mayday, Mayday, we are on fire and need to redirect to airport X" so that airport X can clear the way for you to get in and get the rescue equipment warmed up just in case?

Aaron Z

Thanks for not pruning my post.
Using my powers of deduction.....I am left to decide that perhaps the fire burned through the communication wires after the pilot signed off, later he is discovering the fire or subsequent smoke.
How else would it make sense?

 

[aczlan]

Thanks for not pruning my post.
Using my powers of deduction.....I am left to decide that perhaps the fire burned through the communication wires after the pilot signed off, later he is discovering the fire or subsequent smoke.
How else would it make sense?

Edit: The plane made the course change AFTER the signoff at 1:19AM and AFTER the Transponder was turned off at 1:21AM, but the change was programmed into the Flight Management System BEFORE 1:07AM and 12+ minutes BEFORE the signoff. Timeline from CBS (see ~0:28 for where they talk about the programmed course change): http://www.cbsnews.com/news/from-ta...al-a-timeline-of-malaysia-airlines-flight-370/

Aaron Z

 

[murphy1244]

Where can I find this Timeline? First I've heard of one.

 

[westcliffe01]

I think that any course deviation from the one filed would have been questioned by ATC and there would have been no "good night" conversation or handover under that scenario. Any time an airliner on a filed flight plan makes a course or altitude change they will talk to ATC first for clearance, even (and especially) if it is an emergency. When operating in "controlled airspace" you can't just do what you like.

Identifying Classes of Airspace:

• Class A: all airspace between 18000' and 60000'. Not identified on charts. (mnemonic: Above everything)
• Class B: airspace around large regional airports. Identified on charts by thick blue lines. (mnemonic: Big airport)
• Class C: airspace around large city airports. Identified on charts by thick magenta lines. (mnemonic: City airport)
• Class D: airspace around small airports. Identified on charts by blue dashed lines. (mnemonic: Dashed line)
• Class G: uncontrolled airspace. From the ground up to the next overlying airspace (usually E). (mnemonic: near the Ground )
• Class E: controlled airspace. Floor is 14,500' MSL, and extends up to the next overlying airspace (A, B, C or D). (mnemonic: Everywhere else) Exceptions:
  • Class E floor is 1500' AGL if surface is above 14,500' MSL
  • Class E floor is 1200' AGL (or more) if inside shaded blue line
  • Class E floor is 700' AGL if inside shaded magenta line
  • Broken blue lines differentiate Class E floors when floor is above 700' AGL

As you will see by attached chart example, there are LOTS of V airways crossing that chart and unless you want to be talking to ATC the only way you can legally cross one is below 1200ft AGL.

Sorry if I was unclear. As I understand the timeline, the plane turned off course (towards this other airport) about 10 minutes BEFORE the "Good Night" radio transmission, thus evidencing that the radios were fully functional for at least 10 minutes after the plane made a major turn off course so as to (per the aforementioned blogger) head to an alternate airport for an emergency landing and well after the first beacon stopped transmitting.

Aaron Z

 

[aczlan]

I think that any course deviation from the one filed would have been questioned by ATC and there would have been no "good night" conversation or handover under that scenario. Any time an airliner on a filed flight plan makes a course or altitude change they will talk to ATC first for clearance, even (and especially) if it is an emergency. When operating in "controlled airspace" you can't just do what you like.

Well, the plane DID change course fairly dramatically with a new waypoint programmed into the Flight Management system.
That waypoint was added before the last automatic data transmission at 1:07AM.
At 1:19AM, someone (Copilot?) sent the "All right, Good Night" transmission.
At ~1:21AM, the transponder was shut off
At that point, it was out of the Malaysian ATC control and far enough out to not show up on ATC radar without its transponder.
It then made a left turn and was tracked by Malaysian Military radar just after 2AM, with it disappearing from there around 2:15AM
The engine transponder stopped reporting engine status at ~8:15AM

A couple of stories:
The search online for missing Malaysia Airlines FLIGHT MH370 | Mail Online
Malaysia Airlines Flight 370: Possible debris from missing plane spotted in Indian Ocean - CBS News
http://www.nytimes.com/2014/03/18/w...-cellphone-calls-from-missing-passengers.html

Aaron Z

 

[bcp]

There is no mechanical connection between the pilot and the control surfaces. No cables. No pulleys. No rods. Nada. Nothing but sensors, wire and computers to convey the movements of the pilots controls, convert them into data, transmit them to the other parts of the plane, then convert them back into mechanical force at the control surfaces through hydraulic and electric systems.

Had to do some more research to clarify what I thought I had heard. I guess it might be "sort of" flyable with a computer failure.

From:
http://www.davi.ws/avionics/TheAvionicsHandbook_Cap_11.pdf

11.5.2 Mechanical Control
Spoiler panel 4 and 11 and the alternate stabilizer pitch trim system are controlled mechanically rather
than electrically.


From:
question about 777 flight controls [Archive] - PPRuNe Forums

Part of post 1:
I was wondering if the 777 fbw controls allow for manual reversion.

Part of post 2:
The above modes still require electric power. When it is not available, the mechanical backup you refer to is used to control the plane.

It consists of cables from the flight deck to selected spoilers, and the stabilizer. As far as I know, there are no cables to the rudders.

Part of post 8:
The only control surfaces mechanically connected to the flight deck on a 777 are a pair of flight spoilers and the horizotal stab trim system.


Bruce

 

[dirt ditch]

 

[dirt ditch]

 

[RobertBrown]

Sorry if I was unclear. As I understand the timeline, the plane turned off course (towards this other airport) about 10 minutes BEFORE the "Good Night" radio transmission, thus evidencing that the radios were fully functional for at least 10 minutes after the plane made a major turn off course so as to (per the aforementioned blogger) head to an alternate airport for an emergency landing and well after the first beacon stopped transmitting.

Aaron Z

This time line has a significant variation from the one you are referring to. According to CBS, the significant change in course happened 2 minutes after the sign off. The transponder stop transmitting after the pilot said "all right good night".
From takeoff to final satellite signal - a timeline of Malaysia Airlines Flight 370 - CBS News