RVBottomly
PATRON
Asotin County Washington (KLWS)
Whoa! Miles of flat ground to the West, I've never seen an airliner turn east from BZN.
Oops, darn it...
- Thread starter Anne
- Start date
Whoa! Miles of flat ground to the West, I've never seen an airliner turn east from BZN.
jk
Registered User
over there
For curiosity, looking at Mike’s screen shot and using flight aware to check the flights tracking I noticed some anomaly’s….
This equipment has no record of flying out of, or to for that matter BZN. ?
The Delta flight # is a regularly scheduled flight from-to BZN.
NO Irregular flight tracking for either.
The depicted routing shows a southeast departure.
Why the deviated flight track on the screen shot? Was there a GA in close proximity or just terrain. Wonder how close this flight actually was to terrain?
??
RVBottomly
PATRON
Asotin County Washington (KLWS)
Just from personal recollection, the Bridgers are high and approximately 7-8 miles from the runway. At 200 knots, it's not a lot of room. In the 70s, in crisp VFR, we often saw Frontier enter a left downwind between the mountains and the airport, but Northwest would never do that. I can't imagine an IFR departure heading towards the mountains. SE departure leads over a dip in the mountains and is normal.
RVBottomly
PATRON
Asotin County Washington (KLWS)
BC12D-4-85
SPONSOR
Fairbanks, AK.
If interested look up the A321's EGPWS display and enabling procedure. Someday the equipment installed and cause for the route flown will be available.
Gary
Gary
skywagon8a
MEMBER
SE Mass MA6
I have never been to Bozeman, so this is just speculation on my part.
This is the Bobkt Four Departure from Bozeman. https://aeronav.faa.gov/d-tpp/2205/00059BOBKT.PDF
Just for this discussion, I'm assuming this is what he was supposed to follow. The procedure calls for flying straight out heading 123* (runway heading?) to 4980' then direct (basically a straight line) to cross Japer at or above 8000' before turning to a track of 085*.
It appears the left turn to 085* was initiated when passing the initial 4980' instead of climbing to "at or above 8000'" first. Then the terrain alerting system warned them of the obstruction which "woke" them up. Not pointing fingers, but sometimes even airline pilots have their heads where the sun doesn't shine. Perhaps there was a preflight nav system programming step missed? I never flew an Airbus, but it is possible the programming person just skipped one step. "Climb heading 123° to 4980, (this one) then direct to cross JAPER at or above 8000, then on track 085....."
This reminds me of another similar incident which I've simplified here, on the west coast of South America during the 90s when an American Airlines B-757 was "cleared for an approach". Instead of following the safe route to the airport, the pilot punched in his "navigation keyboard" "direct to" the airport. In this case there were mountains between the plane and the airport. There were no survivors.
A simple keystroke entry error in both cases.
mvivion
SPONSOR
Bozeman,MT
Pete, a friend here who is retired Boeing pilot told me he’s jumpseated many times in and out of BZN in buses. His THEORY is that possibly the pilot flying this leg programmed the route correctly, but had his/her heading bug set to a north heading. Then, when engaging the AP, selected heading bug instead of programmed route.
Your theory sounds more logical, but I know nothing about Airbus systems in any case.
In this case, the old story “A miss is as good as a mile” applies. That ridge they missed contains a lot of rock at 9000.
MTV
skywagon8a
MEMBER
SE Mass MA6
I too know nothing about Airbuses, but have a lot of Boing time. Your friend has a point. The pilot may have just tapped the wrong button after engaging the autopilot.
mvivion
SPONSOR
Bozeman,MT
ADS-B made no difference on this one, well covered by radar.
But, your point is well taken. Down here, though, lots of radar too.
MTV
"News" has little real information for those of us wanting to learn and avoid the same. Who knows what/where/how?
https://www.alaskasnewssource.com/2022/05/29/civilians-rescue-two-adults-7-month-old-plane-crash/
https://www.alaskasnewssource.com/2022/05/29/civilians-rescue-two-adults-7-month-old-plane-crash/
mvivion
SPONSOR
Bozeman,MT
Yeah, but the rescuers…..DAMN! “Tethered himself to his four wheeler and entered the river”. Some tough Hombre there!
MTV
kase
SPONSOR
Billings MT
pa11driver
MEMBER
Small point, but the heading bug in an Airbus essentially reverts to aircraft heading after 60 seconds if the auto pilot is not in heading mode.
mvivion
SPONSOR
Bozeman,MT
Good intel. I have no idea how all that magic works, and I still can’t see how that could get so far out of whack. A fellow I spoke with last night said he checked (somewhere) and that tail number supposedly hasn’t been to BZN in a month. Whatever that means. He’s saying the track is false……
MTV
why do you bother to repeat crap like that, unnamed person, unnamed source, 'supposedly'. heretofore this was an interesting discussion
mvivion
SPONSOR
Bozeman,MT
sjohnson
FRIEND
Boise, ID
Flight Aware shows N101DQ flying from Bozeman to Atlanta on May 12, departed at 3:05 MT. Looks like the track is credible.
Attachments
mvivion
SPONSOR
Bozeman,MT
Yes, that was the source the track. It’s hard to believe a crew could make that big a screw up and the systems didn’t alert earlier. Then again, pilots are human and focus and determination can overcome most any electronics.
MTV
frequent_flyer
Registered User
Arizona, USA
I worked on development of avionics systems for MD-11, MD-10, B777, B737NG and other types. Each had an avionics system that was advanced for it's day but all of them are hopelessly inadequate in terms of situation awareness compared to modern general aviation cockpits.
Much has been written on "automation mode confusion". It will continue to kill crews and their passengers as long as pilots are prepared to blindly follow "the magenta line".
RVBottomly
PATRON
Asotin County Washington (KLWS)
I'm inclined to believe our eyewitness (or ear-witness) on the ground who reports the airliner being two miles from the ridge.
BC12D-4-85
SPONSOR
Fairbanks, AK.
Maybe that's why some crew bring their own nav devices?
Gary
Gary
mvivion
SPONSOR
Bozeman,MT
Same here. But man, at 200 kts, to follow that track, there was some G happening.
MTV
MTV
aktango58
FRIEND
18AA
In the early 70's, 73 I believe, Alaska Airlines 727 hit the mountain on the approach into Juneau. A lear, then a National Guard Twatter did it later in the 80's.
The approach is a localizer/DME approach that utilized two DME's. Every crew made the same mistake- had the wrong DME fix reading in the cockpit. Most likely they were all on HOLD for the one, but the numbers showing in the display were for the correct one, but again the selector was set to hold.
The fixes are only about 5 miles different, but that puts the rocks 100' above you instead of 1,000' below.
Proper navigation management is not new. Even highly trained folks mess up. Build habits to check each detail when you have time. Maybe take an extra turn in a hold if needed.
