Korean airline emergency landing goes wrong and many killed (1 Viewer)

[cammerjeff]

IIRC The black boxes have their own independent power supply (ie onboard batteries whose sole purpose are to power the recording devices and the location transponders), but if the devices that send the information to the black boxes stopped sending at 4 minutes before the crash then saying that the black boxes stopped recording might be an imprecise way of saying what happened - ie the sending devices stopped sending so there was no incoming data for the black boxes to record. Maybe?

Thomas, I agree that it is possible that the Boxes stopped receiving data, so they had nothing to record, that is probably what happened now that I think more about it.

But in my experience (and granted the last time I worked on a Boeing Product was in 2006, so almost 20 years ago now) the batteries on the black boxes did not power the boxes themselves, they only powered the underwater locating beacons. But as already stated we will have to wait for the authorities to eventually find out what happened, and then inform us.

 

[ThomasP]

Actually, I just had a thought (yeah, yeah, I know ) - when was the Jeju 737 built? IIRC the requirement for independent and/or onboard power supply did not take effect until around 2011(?). I do not know if retrofit was/is a requirement, so If it was built before then it may not have the independent and/or onboard power supply set-up.

I do not mean to harp on the subject, or cause undue speculation, but the first thought I had when I read about the recorders stopping 4 min before the crash was that the only way that is supposed to be able to happen (with the independent and/or onboard power supply system) is via kinetic energy effect - either from blast, mechanical penetration from foreign objects, being crushed, or extreme high-G impacts, with failure due to the last two causes extremely unlikely due to the design.

 

[MiTasol]

 

[Alan Stevens]

Eastern Air Lines Flight 375 crash occurred on October 4, 1960. The Lockheed L-188 Electra aircraft, registered as N5533, crashed shortly after takeoff from Logan International Airport in Boston, Massachusetts.

The aircraft encountered a large flock of starlings, which were ingested into three of its four engines, causing a loss of power and control. The plane crashed into Winthrop Bay, resulting in the deaths of 62 of the 72 people on board.

This incident remains one of the deadliest bird strikes in aviation history.

 

[MiTasol]

And that led to a number of regulatory changes. At least two of the engines that autofeathered were still developing considerable power but the system detected a drop of more than x% so automatically shut them down and feathered them. This was quickly rectified on all other Electra's by changing the system so that only one engine can autofeather and this later became a regulatory requirement on all transport category aircraft. In the case of that Electra the other engines that autofeathered were still producing enough power that the aircraft could have safely made a circuit and landed.

As someone said earlier - many (most) aviation safety improvements were written in blood. Unlike the auto industry, in many cases the rectification comes before the regulatory changes.

 

[Thumpalumpacus]

If they don't have them already, they should have batteries inside the armor.