Another one! 1000 in Australia

[donv]

Aerial mapping operation, although it's not clear to me from the track that they were doing a mapping run at the time...


https://aviation-safety.net/wikibase/347569?fbclid=IwAR08jOFX2zuWs-76DLL4leyuiBMTAUYWcvToJDF9OURGNyuR1fgPIohsLAc

FL280, cruising along (showing 225 or so knots groundspeed, hard to know if they had a headwind or were just going slow for some reason related to their mapping operation), and then basically fell out of the sky.

https://www.flightaware.com/live/flight/VHHPY/history/20231104/0045Z/YTWB/YBMA

Incidentally, although FlightAware shows 5:32 as the flight time, if you look at the track it appears the accident took place around 3:30, so they probably didn't run out of fuel.

[Adam Frisch]

Hmmm, very strange. Sure hope it's not another tail failure because then it would start to look like there's something there that needs scrutiny.

[donv]

One of the articles mentions that they were just transiting, not actually running their mapping operation.

I believe 96051 was one of the airplanes converted to a 695B, as well.

[Bruce Byerly]

Hmmm, very strange. Sure hope it's not another tail failure because then it would start to look like there's something there that needs scrutiny.

I don’t know of a “tail failure” that wasn’t precipitated by a wing failure, do you?

[donv]

Do you know anything about this one, Bruce?

[donv]

I'm wondering if they flew into a thunderstorm. It is spring in Australia, and I don't know what sort of ground radar they have in that area. FlightAware doesn't show anything, but if there was no ground radar there then FlightAware wouldn't know.

EDIT: interestingly enough, flightaware now does show areas of weather where they were...

https://www.flightaware.com/live/flight/BDOG370/history/20231104/0045Z/YTWB/YBMA

[Bruce Byerly]

I'm wondering if they flew into a thunderstorm. It is spring in Australia, and I don't know what sort of ground radar they have in that area. FlightAware doesn't show anything, but if there was no ground radar there then FlightAware wouldn't know.

EDIT: interestingly enough, flightaware now does show areas of weather where they were...

https://www.flightaware.com/live/flight/BDOG370/history/20231104/0045Z/YTWB/YBMA

I sure don’t and I hate mystery.   There has to be more known given radio calls, wx, etc. The plane hadn’t been back to the US since new as far as I know. Could be as simple as depressurization but why did it slow down, and why was ROC all over the place, etc?

[appleseed]

It is hard to be confident that you are looking at the actual weather they are flying in. I couldn't find any time stamped archived weather regarding convection, winds aloft, or turbulence sigmets.

I'm viewing it as a long repo flight, into significant headwind.

The descent to 15,000 may have been to check winds at lower altitude. It looks like they increased ground speed from 210kts up to 245ish with the descent. But probably fuel flow goes from 450 up to 650. More efficient at 28,000.

Can any of you Jetprop guys talk about the fuel system and the risk of flameout due to...
underfueling,
misconfiguring fuel selectors or pumps,
If you were distracted, how easy is it to overlook a low fuel indication/warning?

[donv]

That descent seems to be part of their profile-- maybe equipment calibration or something?

Here is a flight on the same route from a few weeks ago:

https://www.flightaware.com/live/flight/BDOG370/history/20231023/1930Z/YTWB/YBMA

The fuel in a Jetprop is very hard to mismanage. One tank for each engine, with an interconnect. You can get it out of balance, but that's about it-- and the accident occurred about 3+30 into the flight, so they shouldn't have run out. And they didn't say anything on the radio.

The indication of low fuel is an annunciator light, but again pretty hard to miss, unless you were asleep.*

I'm still going with they flew into a thunderstorm, but I don't have much confidence in that guess.

*Incidentally, there is some speculation this was a loss of pressurization accident. I'm doubtful, because it doesn't fit the profile (they didn't fly past their destination or anything), and I believe, not sure, that this was a 695B, in which case it would have had an emergency pressurization system.

[Bruce Byerly]

That descent seems to be part of their profile-- maybe equipment calibration or something?

Here is a flight on the same route from a few weeks ago:

https://www.flightaware.com/live/flight/BDOG370/history/20231023/1930Z/YTWB/YBMA

The fuel in a Jetprop is very hard to mismanage. One tank for each engine, with an interconnect. You can get it out of balance, but that's about it-- and the accident occurred about 3+30 into the flight, so they shouldn't have run out. And they didn't say anything on the radio.

The indication of low fuel is an annunciator light, but again pretty hard to miss, unless you were asleep.*

I'm still going with they flew into a thunderstorm, but I don't have much confidence in that guess.

*Incidentally, there is some speculation this was a loss of pressurization accident. I'm doubtful, because it doesn't fit the profile (they didn't fly past their destination or anything), and I believe, not sure, that this was a 695B, in which case it would have had an emergency pressurization system.

I hear hypoxia and the plane in one piece.

[donv]

Was it a 695B? I thought that for Australian certification, they all had to be converted to (or originally built to) 695B specs?

[JMA]

Just curious, does it seem like an uptick of Commander crashes in recent years?
Quick Aviation safety network seems to validate it somewhat?

980- 2001-2018: x2 accidents, 2018-2023: x5 accidents
1000- 2001-2012: x0 accidents,  2018-2023: x5 accidents
690- 2018-2023: x24 accidents

[donv]

Yes, I think that's right. And I think there are a number of factors, most of which are not the airplane. The big one, in my opinion, is that more Commanders are being used for stuff like firefighting, which is inherently more dangerous than flying from point to point. Then there is the question of pilot experience, which I would guess on average is lower than it used to be.

[JMA]

Think thats dead on Don.
Hate to see it but reading some of the NTSB findings there is a lot of 'pilot error' as the cause.

[donv]

Sounds like Bruce was right about hypoxia, but still what a weird accident! No weather around, apparently...

https://www.atsb.gov.au/publications/investigation_reports/2024/report/ao-2023-053