indonesia LionAir crash

[steve_bank]

Modern aircraft depndingmon size have

1. Battery backup
2. On large planes there is a small turbine electric generator in the tail. You can see the exhaust hole on the tail.
3. A small wind turbine deploys in the airstream to generate electricity.

There was a movie made about a Canaduan commecual jet, Boeing, that ran out of fuel midflight. There was confusion at loading of umnits.

They glided for around 20 miniutes to an andoned airfield and landed.

They got power from the emergency the wind turbine.

I know of one case where a jet lost both engine generators and all emergency power. What saved them was they had manual control of flight surfaces and by design throttle controls are mechanical.

 

[barbos]

Modern aircraft depndingmon size have

1. Battery backup
....
.....

How is that relevant to the topic which discusses the fact that newest Boeing aircraft has had 2 crashes in the first 6 months of its operation? For reference: Boeing 777 (25 years of operation 1,582 built) has never had anything even remotely close to crash due to problems with aircraft.

 

[bigfield]

The terrain map would include the buildings. In hijack mode it would have forced the plane to climb over the towers instead of impacting. And since the Hudson plane wasn't hijacked the pilot could have turned it off.

That's some high-quality hand-waving.

 

[Jimmy Higgins]

The terrain map would include the buildings. In hijack mode it would have forced the plane to climb over the towers instead of impacting. And since the Hudson plane wasn't hijacked the pilot could have turned it off.

That's some high-quality hand-waving.

That's his schtick.

 

[steve_bank]

I worked oat an avionics company supplying Boeing and others. I have been through aircraft certifications.

Bugs do get through, they are usually small. Bugs in electronics do surface years into the field.

The 777 had a complete system mockup with hardware simulation. I was offed a job managing test lab. Now it is more computer simulation, for better or worse.

Test simulations and flight tests are only as good as the test parameters. Complexity has grown plane by plane.

Distributed avionics systems was generally replaced by a central flight computer.A catastrophic bug was bound to happen. They have in the past. Each time safety improves. No consolation to victims' families and friends. Every time you get into a commercial jet there is a calculated probability of an incident.

Failures do occur. Under FAA rules if there is a mechanical or electronic problem there can be work arounds that allow flight. Passengers never know it.

The blocked pitot tube has long been a general problem. I believe it was the root cause of the French crash in the South Atlantic.

The crash off Newfoundland caused by fire due to overload in the power wires fir the In Flight Entertainment System. The wires were too small and fusing was not available in the cockpit. The entertainment systems are the lowest level in avionics. It was not treated as a higher level system and the error crept in.

The Alaska Air crash due to the tail screw gear.

The 747 crashes due to a cargo door problem.


When you fly it is always a risk.

 

[steve_bank]

https://en.wikipedia.org/wiki/Boeing_737_MAX
https://en.wikipedia.org/wiki/Maneuvering_Characteristics_Augmentation_System

The Maneuvering Characteristics Augmentation System (MCAS) is a feature on Boeing 737 MAX aircraft intended to prevent stalls in flaps-retracted, low-speed, nose-up flight.[1] The MCAS uses airspeed and other sensor data to compute when a dangerous condition has developed and then trims the aircraft nose down.

http://www.b737.org.uk/max-spoilers.htm
Can't find if the Max 8 is completely fly by wire. Mechanical controls in parts were replaced by electronics.

https://news.ycombinator.com/item?id=18438849



inamberclad 3 months ago | parent | favorite | on: Boeing Withheld Information on 737 Model, Accordin...


> The automated stall-prevention system on Boeing 737 MAX 8 and MAX 9 models ... can push it down unexpectedly and so strongly that flight crews can’t pull it back up.
I'm surprised that Boeing designed a system that could override the strength of the pilot. I don't know how strong the normal autopilot controls are on a B-737-800 but on lighter aircraft it's a normal part of the preflight to make sure that you can overpower the autopilot with muscle if it fails.

 

[Gun Nut]

I'm surprised that Boeing designed a system that could override the strength of the pilot. I don't know how strong the normal autopilot controls are on a B-737-800 but on lighter aircraft it's a normal part of the preflight to make sure that you can overpower the autopilot with muscle if it fails.

They don't. Not on purpose, that is. A Russian airline went down after the pilot allowed his 5 year old son to sit in the pilot's seat. The plane was on autopilot, but the kid pushed hard enough on the yoke to disengage it, and the plane went into an extreme enough attitude to prevent the kid from being ablet o get out of the seat and out of the way of his father taking control back. There were no survivors of the crash. Finding the kids body in the pilot seat surprised quite a few people.
The point is that the autopilot can be easily disengaged.. even by a 5 year old.

 

[thebeave]

I'm surprised that Boeing designed a system that could override the strength of the pilot. I don't know how strong the normal autopilot controls are on a B-737-800 but on lighter aircraft it's a normal part of the preflight to make sure that you can overpower the autopilot with muscle if it fails.

They don't. Not on purpose, that is. A Russian airline went down after the pilot allowed his 5 year old son to sit in the pilot's seat. The plane was on autopilot, but the kid pushed hard enough on the yoke to disengage it, and the plane went into an extreme enough attitude to prevent the kid from being ablet o get out of the seat and out of the way of his father taking control back. There were no survivors of the crash. Finding the kids body in the pilot seat surprised quite a few people.
The point is that the autopilot can be easily disengaged.. even by a 5 year old.

Yep. There are a few people on youtube who recreate real airplane crashes (and close calls) using flight simulators along with actual cockpit recordings. I remember watching the one you describe above. I was astounded that that actually happened, as I somehow missed hearing about it when it happened IRL.

ETA. Just found it. The video below says the kid was 15 though.

[YOUTUBE]https://www.youtube.com/watch?v=uQh-YSbvB58[/YOUTUBE]

 

[Jimmy Higgins]

I'm surprised that Boeing designed a system that could override the strength of the pilot. I don't know how strong the normal autopilot controls are on a B-737-800 but on lighter aircraft it's a normal part of the preflight to make sure that you can overpower the autopilot with muscle if it fails.

They don't. Not on purpose, that is. A Russian airline went down after the pilot allowed his 5 year old son to sit in the pilot's seat. The plane was on autopilot, but the kid pushed hard enough on the yoke to disengage it, and the plane went into an extreme enough attitude to prevent the kid from being ablet o get out of the seat and out of the way of his father taking control back. There were no survivors of the crash. Finding the kids body in the pilot seat surprised quite a few people.
The point is that the autopilot can be easily disengaged.. even by a 5 year old.

Sounds like given enough time, it'll be an infant who turned off the auto-pilot.

 

[Jimmy Higgins]

The crash off Newfoundland caused by fire due to overload in the power wires fir the In Flight Entertainment System. The wires were too small and fusing was not available in the cockpit. The entertainment systems are the lowest level in avionics. It was not treated as a higher level system and the error crept in.

That was Nova Scotia. It was odd, because I saw it on the news, and recognized the area they were reporting from at Peggy's Cove.

 

[steve_bank]

It has been 20 years since I had contact with Boeing and there are new generations, but ti does not sound like the Boeing I knew.

The simulator did not have the anti stall feature so they did not simulate failures with angle of attack sensors.

Boing sold the new model on requiring little new training. ilot training was a few hours with an app.