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Boeing 777 departing Dubai nearly had a major incident after takeoff

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Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#121

Post by trhway »

>Emirates is telling pilots not to set the altitude to zero on approach, for fear of the next crew not changing that.

that sounds like a typical result of Six Sigma/5 Whys/. If one thinks a bit (note: not a part of any such methodology) there is a reason why previous - ie. landing - crew sets the target altitude to that of that target airport... I wonder whether there is a narrow specialization - ie. the managers doing safety analysis of take offs are different from that of landings :)

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#122

Post by inglor_cz »

Daishiman wrote: post #2

Why are knots used in aviation over kph?

At the very beginning, aviation had to solve the very same problems that sailors used to encounter at sea (navigation, precise position), so they naturally used the same algorithms and equipment.

That is how naval terminology entered the lexicon.

By now, it is so deeply ingrained that switching the entire world (well, there are exceptions) to the metric standard would likely cause some preventable loss of life.

At least the knot/mile system is fairly internally regular. We tolerate a much less regular one, with a lot of weird exceptions (the Gregorian calendar) out of inertia.

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#123

Post by zeristor »

So does someone monitor each and every flight for anomalies like this?

Or is there some software that takes in the data from each flight and spots differences like this, there could be several more instances in the global data if this is a manual process.

Could be an interesting little project, although I guess the data isn't publicly available.

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#124

Post by nomel »

wpearse wrote: post #87
dehrmann wrote: post #66

I'm surprised commercial planes don't do full software reset before each flight, and especially before a new crew takes over. Checklists only get you so much.

The checklists bring the aircraft back to a known state. One 777 pilot commented to say that this issue should have been caught by at least two checklists, implying that neither checklists had been followed. Tangentially: if my 2006 Mercedes is reset (battery disconnected) it needs to idle for 20 minutes to re-learn the idle pattern. The vehicle then needs to be driven around for a bit to re-learn driving patterns. I…

> The checklists bring the aircraft back to a known state.

No, it doesn't, clearly. It provides a procedure that can be followed to put it to a known state, but its existence does not put it into a known state, with certainty. A reset puts it into a known state, with certainty. That known reset state probable wouldn't be useful, but can be set to be least-damaging, where a checklist can then be used to then put it into a "good" state.

My assumption is that many planes don't allow a reset to be trivial, since levers and whatnot are involved.

I also assume the FAA/military has done research into this and, probably, found that requiring a manual checklist resulted in stricter adherence to the checklist.

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#126

Post by usrusr »

jcrawfordor wrote: post #44
leetcrew wrote: post #32

Earlier quoted context omitted.

seems slightly odd to use an angular unit for airspeed; the linear equivalent would technically depend on altitude. I guess airplanes don't actually fly high enough for that to matter.

It was only ever approximately accurate anyway, a NM is no longer an arc minute because that is inconsistent even along lines of latitude, so it had to be pinned to 1.852km. Aviation, broadly speaking, inherited all of its navigation techniques from the maritime world. In particular, prior to radio methods and to some extent today aviation navigation is based primarily on dead reckoning periodically corrected by obse…

Ironically the metric system suffers the same theoretical "error" as the not-an-arc-minute-anymore NM because the meter was originally defined by taking the distance from pole to equator (to the best of their knowledge at the time) and then shifting the decimal point to get something human scale.

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#127

Post by kchoudhu »

omegant wrote: post #82
onphonenow wrote: post #16

The memo from Emirates about not setting altitude in system to airport altitude is so weird. I really hope that's not the actual message Emirates is putting out there. It doesn't matter was in system. You run your checklists and configure for your own flight / your own departure etc. Memo should be to training / recruitment - where did you find these pilots to fly a 777? So they obviously didn't pre-flight the flight…

It goes way beyond checklist stuff. Imagine having an intermediate system in your Tesla, one between fully manual and the autopilot. This system uses the navigation capabilities of the autopilot to draw in the big screen some squares that guide you to your destination without the need to look outside. Something you may find in a videogame. This system is helpfull and easy to use, and allows you to pay attention to mo…

This rings true. I live in Doha and a very good family friend is an instructor in the local flag carrier's training program.

He was recently bemoaning the following situation:

1. There was a go-around on some flight or other (for good reason!)

2. Management interpreted this as a failure, and announced that every go-around will now have a full post-mortem with involved pilots requiring more sim time.

3. Pilots now think go-arounds are now off-limits. Oops!

This is a very, very common pattern in the Middle East. When the waterfall goes as planned, service is excellent. When exceptions happen, management freaks out and adds more layers of regulation to make sure the exception can't happen again, failing to recognize that exceptions are sometimes good. For benign stuff like customer service, you get frustrated customers. For important stuff like air safety... well, you end up with close calls or crashed airplanes.

Centralized decision making is a hell of drug.

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#128

Post by hammock »

omegant wrote: post #82
onphonenow wrote: post #16

The memo from Emirates about not setting altitude in system to airport altitude is so weird. I really hope that's not the actual message Emirates is putting out there. It doesn't matter was in system. You run your checklists and configure for your own flight / your own departure etc. Memo should be to training / recruitment - where did you find these pilots to fly a 777? So they obviously didn't pre-flight the flight…

It goes way beyond checklist stuff. Imagine having an intermediate system in your Tesla, one between fully manual and the autopilot. This system uses the navigation capabilities of the autopilot to draw in the big screen some squares that guide you to your destination without the need to look outside. Something you may find in a videogame. This system is helpfull and easy to use, and allows you to pay attention to mo…

The systems you describe exist. Backup cameras, blind spot indicators, etc

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#129

Post by argvargc »

munchler wrote: post #29

Why is it even possible to enter a desired altitude of 0 feet into an automatic pilot? As a layman, it’s hard for me to imagine why anyone flying a 777 would want to maintain an altitude of zero at full speed for more than a few seconds (if that).

This seems a very important question, and I'm not finding answers to it satisfactory.

To elaborate, why isn't an autopilot "aware" of whether the aircraft is taking-off/landing or in-flight?

It seems completely mad that an automated flying mode could be engaged in such an obviously suicidal way on a modern bulk carrier aircraft, without so much as a blaring warning and red flashing lights.

Re: Boeing 777 departing Dubai nearly had a major incident after takeoff

#130

Post by elihu »

selectodude wrote: post #91
csunbird wrote: post #73

Earlier quoted context omitted.

Disclaimer: My experience in piloting is just a couple of hours flying planes in kerbal space program. Wouldn't that much speed cause the plane to ascent naturally, even with zero pitch, just by the body lift? (Although, it is quite possible that real life planes have negative body lift, I have no idea)

They probably were given a command to stay at 4000 above ground (AGL) level after takeoff. The plane was to level off until further instructions from ATC. Since the plane was set to sea level on takeoff, the plane tried to level off at 4000 ft above sea level which…is not good. The plane was pitched down to descend.

Isn't the airport in Dubai barely above sea level anyways? I mean, if the difference between ground level and sea level is less than a hundred feet, then it seems like it wouldn't account for a plane thinking it was at 4,000 feet when it was really at about 200.
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