Comments on: Out With a Bang

By: David

David — Thu, 23 Jan 2025 16:13:08 +0000

Hi Patrick. Any updates from you in light of this video by “Pilot Debrief”? David

By: Speed

Speed — Wed, 22 Jan 2025 00:23:12 +0000

By: Loreant Sargeant

Loreant Sargeant — Sun, 19 Jan 2025 12:09:59 +0000

That was very memorable. The Jeju Air plane was landed in the wall, 750 meters next to us.

By: Robert Cassidy

Robert Cassidy — Thu, 16 Jan 2025 06:11:35 +0000

Rod and Lurk,

The Boeing 737-800 was not flying very after the bird strike?

The last four minutes of the CVR and FDR on that particular incident aircraft is missing.

In the Boeing 737NG Quick Reference Handbook (QRH) or Emergency Procedures Checklist for pedestrians
Chapter 6
approximately Page 6.2 Loss of Both Engine Driven Generators
approximately page 6.4 APU is not available
(in other words no electrical system available)
approximately page 6.7 there is this:
Note: Fully charged batteries supply a minimum of 60 minutes of standby power.
(in other words DC electrical power for some absolutely necessary systems)

“Any single electrical failure external to the recorder does not disable both the cockpit voice recorder and the flight data recorder.

It has an independent power source—
(i) That provides 10 ±1 minutes of electrical power to operate both the cockpit voice recorder and cockpit-mounted area microphone;
(ii) That is located as close as practicable to the cockpit voice recorder; and
(iii) To which the cockpit voice recorder and cockpit-mounted area microphone are switched automatically in the event that all other power to the cockpit voice recorder is interrupted either by normal shutdown or by any other loss of power to the electrical power bus . . .”

At 8:54 a.m., the plane was authorized to land at Muan International Airport. The flight crew were warned at 8:57 a.m. about the potential for a bird strike. The crash occurred between 9:03 and 9:07 a.m.

By: Rod

Rod — Wed, 15 Jan 2025 20:56:20 +0000

Come to think of it (& further to my post of yesterday):
Why not also a simple solid-state voice recorder powered by the same source as the rest of the aircraft’s electrical equipment but with a battery that takes over if that source stops? It would be very small (low mass, low inertia) & could be protected from extreme g-forces, heat & pressure in the same way present recorders are, only it’d be located just above the cockpit, say. It might not survive every crash, but we wouldn’t have what we seem to have way too often: oh-oh the power was cut off; gosh, too bad, eh?

By: Rod

Rod — Tue, 14 Jan 2025 22:43:38 +0000

Thanks, Lurk. I’m aware that if something relies on a power supply that’s cut, it won’t work. And electrical systems can fail, or be shut down by the crew.
But I’ve always wondered if the following wouldn’t be possible:
1) power source (battery) within the CVR that kicks in when outside power is lost;
2) power source (battery) for cockpit microphones that kicks in when outside power is lost;
3) some wireless form of transmission from cockpit to recorder that survives the disappearance of the aircraft’s electrical system.

By: Speed

Speed — Mon, 13 Jan 2025 17:56:31 +0000

From Aviation Week, January 11, 2025

Key Data Missing From Jeju Air FDR, CVR

The final 4 min. of voice and flight parameter data from the Jeju Air flight that crashed Dec. 29 was not captured on either onboard flight recorder, the South Korean Ministry of Land, Infrastructure and Transport (MOLIT) said Jan. 11.

“We have confirmed that all data stopped recording on both devices,” a MOLIT statement said. “We plan to determine the cause of the data not being saved.”

The Boeing 737-800’s damaged flight data recorder (FDR) was sent to the National Transportation Safety Board (NTSB) in Washington for data extraction. The cockpit voice recorder data was extracted in Seoul, but when investigators realized some data was apparently missing, they sent the device to the NTSB for further analysis.

https://aviationweek.com/air-transport/safety-ops-regulation/key-data-missing-jeju-air-fdr-cvr?

By: Lurk

Lurk — Sun, 12 Jan 2025 20:15:05 +0000

Rod >the thing everybody was counting on to explain this disaster has failed. Is there some sort of Iron Rule of electronics…

Yes there is, but not the one you want. The iron rule is, “Without power nothing works.” That *may* be an explanation for why all the CVRs/FDRs stopped recording at exactly the same time rather than any break in connector or cabling.

*If* there was a total power failure it *might* explain why the crew tried to land the aircraft as quickly as they did.

It is just possible the two surviving crew maybe able to supply useful information but the best thing to do is to sit back and wait for the investigation to complete.

By: Rod

Rod — Sat, 11 Jan 2025 10:47:51 +0000

»”The analysis revealed that both the CVR and FDR data were not recorded during the four minutes leading up to the aircraft’s collision with the localiser,” the transport ministry said in a statement, referring to the two recording devices.

“Plans are in place to investigate the cause of the data loss during the ongoing accident investigation,” the ministry said.«

This is what I mean. Once again, the thing everybody was counting on to explain this disaster has failed. Is there some sort of Iron Rule of electronics that it’s not possible to build a device that will reliably record data until forcibly disconnected from the source of that data?

By: Speed

Speed — Thu, 09 Jan 2025 14:55:20 +0000

From FlightGlobal …

Crashed Jeju Air flight-data recorder dispatched to USA

The FDR was sent to the USA on Monday 6 January, where the National Transportation Safety Board will attempt to download data from the device, according to South Korea’s official Yonhap news agency, quoting a South Korean government official.

…

The cockpit voice recorder was in better condition than the FDR, and two hours of voice recordings have already been successfully downloaded and converted to sound files.

In a daily update on 6 January, South Korea’s Ministry of Land, Infrastructure and Transport said that components from the crashed aircraft, such as its CFM International CFM56 engines and the cockpit’s upper panel, have been transferred to a hangar where they will be examined.