crazytony · HackerTrans

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As far as weights go, the 707 and the 767-200s that hit the towers were fairly close in size, weight and fuel capacity and that is demonstrated by both towers surviving their impacts. The problem was the fire and specifically the inability to fight the scale of the fire effectively.

crazytony

2 yıl öncediscuss

One other compounding problem is that Delta's headquarters and main traffic patterns are on the east coast. Crowdstrike affected all the airlines at roughly the same time. This gave them roughly one to two fewer hours to respond before they hit their morning peak flights.

As someone else pointed out, they probably weren't ready by the time they needed their systems for the morning rush so they went to their business continuity strategy (manual). This has a throughput and recovery time penalty and obviously it compounds the longer they are in that mode.

I think what we're finding with the Southwest meltdown and now the Delta meltdown is that the big airlines just don't have the manpower or scheduling slack to accommodate going into business continuity. I do think this should be investigated. Hopefully financial penalties incentivize action but time will tell.

crazytony

2 yıl öncediscuss

Funny you should mention WN. Delta's meltdown is the exact same scenario as Southwest. Crew scheduling is messed up, they don't have a way of tracking where employees are, if the employee is legal, etc and so the operation grinds to a halt

crazytony

2 yıl öncediscuss

Have spent all my afternoon and all evening on a bridge trying to support flailing systems. Was supposed to be on a plane in 5 hours to start my vacation. Guaranteed it's not gonna happen.

With hearing 911 and other safety critical systems going down, I hope that the worst that comes out of this is a couple delayed flights and a couple missed bank payments.

crazytony

2 yıl öncediscuss

This rollercoaster is not over yet. There's a crowdstrike issue causing windows machines/servers to brick globally and this industry is heavily windows dependent. It may or may not be related to the Azure issue but it's suspicious to me.

https://www.reddit.com/r/crowdstrike/comments/1e6vmkf/bsod_e...

crazytony

2 yıl öncediscuss

Looking at flightradar24, the only real upset I see is the turn over the southern Sierra Nevada range which is also ~55 minutes before arrival into OAK.

Wonder if mountain waves play any part in this incident? It's the only thing I can think of that could possibly generate a dutch roll without continuing flight stability issues. (They could have also turned on/off something like the yaw damper in the cockpit but that's not specifically called out int he report)

I can't imagine the standby PCU causing this incident unless there was some kind of electrical or pneumatic issue causing it to engage.

But 737 + PCU issues (yes, I know it's been redesigned) is never a good day.

Hopefully we'll get a NTSB report on this one.

crazytony

2 yıl öncediscuss

This is extremely disingenuous. A dutch roll if identified and corrected is not structurally dangerous to an aircraft but it typically signifies something wrong with the control surfaces which is a larger issue. In the majority of the cases, it's the yaw damper that's a problem (my suspicion in the 737 case).

JAL 123 crashed because hydraulic pressure on all 4 hydraulic lines and 90% of the vertical stabilizer and 100% of the rudder were lost due to an explosive decompression of the aft pressure bulkhead. Dutch rolls ensued because of the loss of lateral direction control.

The KC-135 crashed because the rudder power control unit on the rudder was faulty and the pilots failed to identify the problem. They then used alternating rudder inputs to recover which caused the structural limits of the vertical stabilizer to be exceeded its structural limits and separate (along with the rest of the tail).

The Air Transat flight (961) had the entire rudder separate from the aircraft most likely due to stress fractures. This caused the aircraft to have extremely limited lateral directional control which caused the dutch rolls.

crazytony

2 yıl öncediscuss

Radar, planning software and routing have all gotten much, much better in the last decade.

I believe even as late as 2007 or 2008, ATC was limited in the deviations it could do due to the track system still in use in certain areas. Once the ARTCC/TRACONs were updated, ATC in the US now has way more capability and capacity to re-route traffic around storms. I forget when the last ARTCC refresh/rebuild happened.

crazytony

2 yıl öncediscuss

I'm really at a loss on this news. All the employees at airlines in the US I know of have this drilled into them on a regular basis and it's just taken for granted that you report incidents when they happen (even when someone falls: report it!) and the incident will get investigated.

It just confounds me (but explains a lot) that the manufacturer of the aircraft the airlines operate does not share a similar safety culture given that they are in a similar ecosystem (airlines report issues to the manufacturer and the FAA/NTSB all the time)