Lion Air 737 MAX 8 Crashes in Indoesia

[ant_321]

I agree that Boeing should have informed crews but do you think it would have made a difference in this case? They essentially had an unscheduled trim incident. Every plane I’ve ever flown has had memory items for that, including the 737. The crew on the previous flight got it right, the second not so much. I think the real question in all this is, how did the aircraft get signed off by maintenance without such a serious issue being fixed. “Could not replicate on ground” maybe?

[pelmet]

I agree that Boeing should have informed crews but do you think it would have made a difference in this case? They essentially had an unscheduled trim incident. Every plane I’ve ever flown has had memory items for that, including the 737. The crew on the previous flight got it right, the second not so much.

A good way...or one of the ways that one should look at this is.....there can be lots of information given that is nice to know, not need to know and there can be different angles to looking at accidents for conclusions(eg....an aircraft 1 pound overweight and therefore illegal, yet successfully taking off for years from a long, sea level runway then crashed at a short high elevation runway). Perhaps what the info was given to the pilots in the QRH section for this type of scenario will be important and whether this info was used successfully by the previous flightcrew.

I think the real question in all this is, how did the aircraft get signed off by maintenance without such a serious issue being fixed. “Could not replicate on ground” maybe?

My favourite logbook entry from maintenance...."ground check serviceable". Well it didn't work in the air which can be a lot different environment than on the ground for certain snags. I remember one aircraft type where the elevator trim would become inoperative in flight(including the back-up trim which was a separate motor). Always had a ground check serviceable reply. Turns out they used the wrong grease in the system which would freeze up the system in the very cold temps at altitude, but eventually thawed enough to work in the lower altitudes/after landing. Some entertaining possible theories came out of that snag until it was finally fixed.

[W5]

I agree that Boeing should have informed crews but do you think it would have made a difference in this case? They essentially had an unscheduled trim incident. Every plane I’ve ever flown has had memory items for that, including the 737. The crew on the previous flight got it right, the second not so much. I think the real question in all this is, how did the aircraft get signed off by maintenance without such a serious issue being fixed. “Could not replicate on ground” maybe?

Swapped around for troubleshooting

[goingnowherefast]

That's up among my least favorite words to see in a logbook. Guarantees the reoccurrence, just don't know where.

[Eric Janson]

Very interesting discussion about this accident on PPRuNe.

One of the items posted is this video of the Boeing Stickshaker going off for 5 minutes.

https://www.youtube.com/watch?time_cont ... rjTUvhpBlE

This will drown out the sound of the stab trim moving and is extremely distracting.

It's quite possible the crew didn't notice the uncommanded nose down trim inputs.

They really need to recover the CVR.

[pelmet]

From a Nov. 26 article headline I just clicked on...…

"Pilots Get More MCAS Details; Troubleshooting Procedures Unchanged".

Have any procedures changed yet? Or is this just a case of a lot of headlines of people saying they didn't know some details about a system but it really doesn't matter in terms of what to do if there is a problem.

[ant_321]

From a Nov. 26 article headline I just clicked on...…

"Pilots Get More MCAS Details; Troubleshooting Procedures Unchanged".

Have any procedures changed yet? Or is this just a case of a lot of headlines of people saying they didn't know some details about a system but it really doesn't matter in terms of what to do if there is a problem.

You hit the nail on the head. There is already unscheduled trim memory items and a checklist.

[GARRETT]

This guy explains things pretty well I think.

https://www.youtube.com/watch?v=zfQW0upkVus
https://www.youtube.com/watch?v=1sZfeFJ9n0I

[pelmet]

They really need to recover the CVR.

As an update from a little while back......

"Indonesian Navy divers have recovered the cockpit voice recorder (CVR) from Lion Air flight 610, a Boeing 737 MAX that crashed into the sea Oct. 29, 2018.

Photos show the heavily scratched CVR after its recovery, although it is not yet known if the device is damaged. Local media reports indicate the CVR was found buried in mud at a seabed depth of 30 m (98 ft.), about 50 m from where the flight data recorder (FDR) was found.

The Boeing 737 MAX aircraft crashed soon after takeoff from Jakarta, killing all 189 passengers and crew. The FDR was located and recovered within days of the crash, but mud, strong currents and other factors impeded the search for the CVR. Tracking signals had been detected from the CVR in November. The 90-day battery life of the device’s tracking beacon was due to expire around the end of January.

Lion Air called off its search for the CVR on Dec. 29, 2018. However, the effort was relaunched with assistance of the Indonesian Navy.

The CVR could shed more light on what happened during the final flight of the Lion Air aircraft. Other evidence, including data retrieved from the FDR, indicates the pilots were struggling to control the aircraft prior to the crash. According to a preliminary report, the aircraft’s automatic trim system kept pitching the aircraft down because of faulty inputs from angle of attack sensors."