Challenger Jet down in Truckee CA 7/26/21

3393RP said:
Sounds on the camera footage appear to reveal the aircraft struck trees before engines were throttled up, then it went down.
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dtuuri said:
When you can't see unlighted objects below MDA or beyond circling limits at night you need to be intimately familiar with local terrain in order to know when/where to descend. The only requirement for lighted obstructions, IIRC, is +/- 10° of the runway centerline, so you'd be advised to maintain MDA until positioned there. At, say, 500' AGL it's quite do-able. At 1500' AGL that would put you beyond circling limits at the same glide angle, no? In the mountains (ASE?) at night, circling MDAs are too high to make a normal descent to the runway without intimate local knowledge. A Learjet landing at Eagle infamously hit a mountain during a night visual approach when it extended the downwind in order to lose excess altitude, as what you are suggesting would be required. While not the same scenario, the principle is the same: If you fly higher than you need, you need more space to lose the excess. In the dark, that sounds like a bad SOP to me.
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Camera showed him fully inverted and very nose down when he struck the trees, so obviously an uncontrolled rolling moment rapidly ensued as a result of his maneuvering to align his aircraft with the intended runway.
 
Charles Lindsay said:
Too close to the landing g runway while circling to land invites yanking and banking and exceeding critical angle of attack resulting in a typical base to final stall spin scenario, while a wider more appropriate stabilized descent to a landing is less likely to end up that way.
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According to the VAS video he came in on a left base. Last speed readout was 140 KTS. Did you see the METARS bracketing the crash time? A half hour before they showed a small headwind, a half hour later it was a strong, gusty tailwind. Could a microburst have been involved do you think?
 
Charles Lindsay said:
Camera showed him fully inverted and very nose down when he struck the trees, so obviously an uncontrolled rolling moment rapidly ensued as a result of his maneuvering to align his aircraft with the intended runway.
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I want to see this camera shot, where is it?
 
Charles Lindsay said:
Crashing was likely the result of the flying pilot in the situation of being pressured to get down, and going below minimum descent altitude while too close to the landing runway, thus being boxed in by lower than minimum visibility in smoke conditions and the terrain, while yanking and banking at unfavorably slow approach speed...causing him to exceed critical angle of attack and ending up in a stall spin crash west of the field.
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Yours is a legitimate theory ..... there was a discussion by a highly experienced pilot who said his tower had advised good visibility (3 miles) .... yet when he descended through the smoke layer he almost lost his ground reference .... managed to break thru and land OK ..... but once on the ground he said visibility was great and he wondered why he had experienced the earlier marginal conditions.
 
dtuuri said:
I want to see this camera shot, where is it?
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Me too. But first, please pardon my engagement in speculation about the chronology that transpired. I mean no disrespect to the decedents.

The audible sequence of events from the security camera progressed from the unmistakable sound of the aircraft striking what had to be trees (because it continued to fly), followed by a brief application of throttle and the engines spooling up, then the actual crash.

When the aircraft entered its final death throes, the sounds generated lasted an unusually long period of time. Judging from the amplitude and duration of the sounds, it was as if it hit the ground, broke apart, then the sounds paused momentarily as large pieces of it were tossed back into the air, then the sounds returned as the wreckage hit the ground again and tumbled to its final resting spot.

While this grade of speculation is excessive even for POA crash analysis standards, I can't imagine any other explanation for the intermittent pauses in the breakup.

I won't comment on airmanship decisions and skill of the crew. It's a damned shame when people die in a crash, especially passengers that had no part in decision making or piloting the aircraft. Whether it's a Piper PA-28-140 or a Gulfstream G-550, the people that ride in the back trust their safety to the crew. It's an awful thing when fate and circumstances conspire to place them in harm's way.
 
Hits close to home. I practiced circling approaches at Truckee for my C510 type rating.
RIP
 
dtuuri said:
According to the VAS video he came in on a left base. Last speed readout was 140 KTS. Did you see the METARS bracketing the crash time? A half hour before they showed a small headwind, a half hour later it was a strong, gusty tailwind. Could a microburst have been involved do you think?
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I'd still like to know what speed they were at/should have been at during the circle. By the VAS video, they were circling at 180-190 (although I don't know how much to trust that). Cat C circling only goes up to 140 kts. Cat D 141-160 (IIRC) and Cat D isn't authorized for that approach.
 
Sluggo63 said:
I'd still like to know what speed they were at/should have been at during the circle. By the VAS video, they were circling at 180-190 (although I don't know how much to trust that). Cat C circling only goes up to 140 kts. Cat D 141-160 (IIRC) and Cat D isn't authorized for that approach.
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Isn't this readout 6700' MSL and 140 KTS?

Challenger on base.JPG​
 
The video is going to show groundspeed. Indicated airspeed may be much less. Even in calm wind where 180 GS = 180 KTAS, at 7400 MSL that's around 160 kias. 140 ktas would be about 125 kias. So they may not be quite as fast as it seems.
 
Sluggo63 said:
Yeah, but in this one they've already started their circle and are showing 180.
View attachment 98929
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Yeah, that's a sign they were behind the plane but since the reason for speed limits is to stay within the protected area and since their course is toward the runway I don't see it as a factor.
 
Charles Lindsay said:
Camera showed him fully inverted and very nose down when he struck the trees, so obviously an uncontrolled rolling moment rapidly ensued as a result of his maneuvering to align his aircraft with the intended runway.
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Are you talking about the security cam footage? Where you can see the reflection in the windshield of the Jeep? I watched that several times, and if that is the video you are referring to, I'm not sure how one could come to the conclusion they were inverted. They may have been, but there's nothing conclusive from that video (that I could see) that would indicate that.
 
First time poster / long time private pilot. In listening to the approach and tower tapes there were two times at which the pilot seemed overly casual / familiar with the controllers. A "See ya!" right before switching from approach to tower and and a jocular "looking forward to seeing you on the ground" to tower, which even the tower controller chuckled at. Just my observation that the pilot didnt sound as serious / focused as one would expect given the smoke and weather in the vicinity.
 
RussR said:
The video is going to show groundspeed. Indicated airspeed may be much less. Even in calm wind where 180 GS = 180 KTAS, at 7400 MSL that's around 160 kias. 140 ktas would be about 125 kias. So they may not be quite as fast as it seems.
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Absolutely, but (if that video is accurate), they’re still 20 knots over the maximum speed to circle there.


dtuuri said:
Yeah, that's a sign they were behind the plane but since the reason for speed limits is to stay within the protected area and since their course is toward the runway I don't see it as a factor.
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Well, yeah. Behind to the point that they were fast, if they were were even legal to begin the approach.

Chicken or egg? Are the speeds set to stay in the protected area, or is the protected area created because of the speeds that were set?

The fact is that the impetus for the new circling areas being developed was due to an accident where a 767 hit a mountain circling and the old circling criteria didn’t take TAS into account (there were many more problems on that flight, not just the protected airspace). But 140 KIAS was the Cat C limit whether you were circling at 700 MSL or 7000 MSL. Now as the circling MDA goes up, so does the protected airspace. It’s baked into it. If they were circling at Cat D airspeeds, they should be at the Cat D MDA, which doesn’t exist on this approach.
 
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Sluggo63 said:
Absolutely, but (if that video is accurate), they’re still 20 knots over the maximum speed to circle there.
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I'm not saying it was a great approach. It does appear they were still working on slowing down and getting configured as they began the circle.

But I don't think the radar display alone gives us enough information to assert whether or not they were too fast for Cat C. The screen capture you posted shows 7400 MSL and 180 kts GS. Using the actual METAR information, I recalculated the likely indicated airspeed. Given that it was a hot day, 33 degrees, and the barometric pressure and a high density altitude, I get 180 ktas = 153 kias at 7400 MSL. ATC radar groundspeed only shows GS in tens, so 18 = 180. But presumably it uses standard rounding, so it could be anywhere from 175 - 184, which would equal about 148 - 157 kias. So potentially not much above the max Cat C 140 kias. Add a little tailwind component and it's possible they were actually within Cat C airspeed requirements.

Not saying that's the case, only that without the FDR, we don't have enough information to tell.

And the screen shot posted by @dtuuri shows 140 GS, clearly within the IAS for Cat C, so they were likely still slowing down, which of course is certainly not the definition of a stabilized approach.

What we CAN tell from the ATC radar is that they were below the Circling MDA from the very beginning of their circle.
 
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Palmpilot said:
The NTSB has released the preliminary report:

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103554/pdf

Avweb article on it:

https://www.avweb.com/aviation-news/ntsb-releases-preliminary-report-on-truckee-challenger-crash/
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They withheld the good stuff, namely the contents of the FDR/CVR. As a result, the report is barely worth reading.

Also, CAROL is really annoying. Amongst a whole host of complaints, there's no more timestamp to indicate when the report was authored.
 
MauleSkinner said:
Have you ever seen a preliminary with FDR/CVR data?
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I suppose not, but the point still stands: not much to see in the prelim, and even less than before the switch to CAROL.
 
asicer said:
I suppose not, but the point still stands: not much to see in the prelim, and even less than before the switch to CAROL.
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There is never anything in a prelim. Just a simple one pager with the basic facts, mostly already released to the media. "On this date at this time, this airplane crashed at XXX. X crew and X passengers survived, injured, died. WX was... NTSB/FAA personnel may or may not have traveled in the course of the investigation."

No conclusions, no details, etc. That information doesn't get released for 1-2 years.
 
midwestpa24 said:
There is never anything in a prelim. Just a simple one pager with the basic facts, mostly already released to the media. "On this date at this time, this airplane crashed at XXX. X crew and X passengers survived, injured, died. WX was... NTSB/FAA personnel may or may not have traveled in the course of the investigation."

No conclusions, no details, etc. That information doesn't get released for 1-2 years.
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This one is five pages.
 
Palmpilot said:
This one is five pages.
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But the idea is still the same. These days, the preliminary report doesn't usually contain much that we can't get through other means.

ATC Comm - liveatc.net
Ground track and speed - flightaware.com
Weather - METARs
Number of people/fatalities - news reports
Aircraft type/registration - google

So the preliminary reports anymore are rather unenlightening, because we already knew most of the information.
 
Palmpilot said:
The NTSB has released the preliminary report:

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103554/pdf

Avweb article on it:

https://www.avweb.com/aviation-news/ntsb-releases-preliminary-report-on-truckee-challenger-crash/
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That’s a long one. Usually not that much detail in a prelim. It shows the flight track of the holding pattern the pilot flew. Obviously not over ALVVA. Pilot is trying to hold over something on the Final Approach Course, probably AWEGA but the turn is kinda late.
 
weilke said:
Because you know, this killed like dozens of school children and stuff.
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The airshow being cancelled is moth likely due the fires in the area. A windshift can put truckee under LIFR in hurry. unfortunately the ktrk is sandwiched between the dixie fire and the caldor fire, both of which are producing plumes of smoke that are the size of a small state.
 
Captain Sweet T said:
The airshow being cancelled is moth likely due the fires in the area. A windshift can put truckee under LIFR in hurry. unfortunately the ktrk is sandwiched between the dixie fire and the caldor fire, both of which are producing plumes of smoke that are the size of a small state.
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But they can (and did) blame it on the crash.
 
MauleSkinner said:
But they can (and did) blame it on the crash.
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And an 'abundance of caution'. Because you know, there is always a risk of other business jets falling out of the sky because its an air-show.
 
weilke said:
And an 'abundance of caution'. Because you know, there is always a risk of other business jets falling out of the sky because its an air-show.
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Or they are worried about crazy locals damaging planes at the show.
 
Final report is out (pdf)

I think they glossed over the fact that they got a late instruction to hold at ALVVA, blew the hold, prematurely turned toward AWEGA and ended up high and fast. This was a strong link in the error chain.
 
Accident Case Study: Conflict in the Cockpit was just published based on this crash

 
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