Bombardier 605 crash yesterday.

[WTON]

Truckee-Tahoe...https://www.sacbee.com/news/local/article253040428.html

[Checkerboard 13]

KRNV TV report w/ ATC audio and bystander post-crash video:
https://mynews4.com/news/local/small-plane-crash-sparks-brush-fire-near-truckee

[B2N2]

There is only one RNAV approach to the longer runway 11, landing 29 or using one of the approaches for the shorter runway would require a circle to land.
They reported LUMMO inbound for the RNAV 20 circle for runway 11.
Circling minima are the same as the MDA for the RNAV 11.
It appears they may have overshot the final for runway 11.
AirNav: KTRK - Truckee-Tahoe Airport (http://www.airnav.com/airport/ktrk)


https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/750x1084/dcb8c2bb_7633_4b6c_aa2d_8f88b3a840ce_17b8e0230adfe5644d0b3e3 a28937330def8ddc8.jpeg

[EatMyShorts!]

They probably overshot the final, pulled harder to tighten the turn and the rest became sad news.

In this video you see (a little bit) and predominantly hear the crash, quite sad. Viewer discretion is advised: YouTube Video off CCTV camera recording

Here's the flight track on FlightAware: https://flightaware.com/live/flight/N605TR

[BFSGrad]

They probably overshot the final, pulled harder to tighten the turn and the rest became sad news.
Agreed. Echoes of N452DA and N13622.

[B2N2]

I’ve never been there but a buddy of mine is an experienced biz jet driver and he refuses to go in there unless the weather is clear.
According to my sources two crew and three pax perished.
Sad.

[340drvr]

Audio of the plane and ATC shows they were indeed going for the Rwy 20 approach - circle to rwy 11.
Conditions at the time were pretty marginal for circle-to-land, smoke, storms in the area:
METARs at approx. time (2018Z) of crash:

KTRK 262050Z AUTO 28011G16KT 04SM BKN023 33/08 A3013 FU RMK VIS 3 1/2/V5 FU BKN023 ACFT MSHP
KTRK 261945Z AUTO 09005KT 04SM BKN023 32/06 A3014 FU RMK VIS 3 1/2/V5 FU BKN023

[GBO]

The flight radar plot is interesting.



Entering the hold at AWEGA didn’t occur until LUMMO.

Speed in the hold is around 370 knots.

Commencing the approach at AWEGA, the aircraft was around 1700 feet too high and too fast (300 knots).

Rate of descent to LUMMO (FAF) was around -2750 feet/min.

Back on 3.5 degree profile at LUMMO (FAF) but speed still too fast (240 knots).

When visual, tracks for left base runway 11.

Speed reduces quickly on base.



Did they deploy the flight spoilers at AWEGA to “get down” and forgot to stow them for landing?

[Charlie Foxtrot 00]

The flight radar plot is interesting.



Entering the hold at AWEGA didn’t occur until LUMMO.

Speed in the hold is around 370 knots.

Commencing the approach at AWEGA, the aircraft was around 1700 feet too high and too fast (300 knots).

Rate of descent to LUMMO (FAF) was around -2750 feet/min.

Back on 3.5 degree profile at LUMMO (FAF) but speed still too fast (240 knots).

When visual, tracks for left base runway 11.

Speed reduces quickly on base.



Did they deploy the flight spoilers at AWEGA to “get down” and forgot to stow them for landing?

According to the ATC recording, he was cleared to hold north of ALVVA on the 340 bearing. This may not have been issued until he was already over or near ZILTO at 370kts ground speed. The aircraft then turned toward ALVVA, still at 370kts GS. Upon reporting established (never executed a course reversal), he was given direct AWEGA and cleared for the approach. While on the approach, he requested a circle to land to 11.

Cat D circling is NA for that approach.

High, fast, late instructions, task saturation.

Derived IAS in the overshooting base to final turn would have been in the mid to high 120 range.

[galaxy flyer]

Do you have a link to that radar track? Because none of that shows in the Flight Aware track log, granted ADS-B may be different, but FA shows 250 KIAS at 10,000 and slowing.

[Charlie Foxtrot 00]

Do you have a link to that radar track? Because none of that shows in the Flight Aware track log, granted ADS-B may be different, but FA shows 250 KIAS at 10,000 and slowing.

I can’t post links yet due to my noobishness, but look up N605TR on Flightradar24. From there, I also created a KML of the 3D flightpath that can be imported to Google Earth.

[armchairpilot94116]

Six confirmed dead in jet crash near Truckee-Tahoe Airport (msn.com) (https://www.msn.com/en-us/travel/news/six-confirmed-dead-in-jet-crash-near-truckee-tahoe-airport/ar-AAMFZBr?ocid=msedgdhp&pc=U531)

[B2N2]

Cat D circling is NA for that approach.

High, fast, late instructions, task saturation.

Derived IAS in the overshooting base to final turn would have been in the mid to high 120 range.

Lets not get carried away here.
A Challenger jet is not a Cat D aircraft as far as approach category.
Very much possible that 14,000 plus high temperatures created a density altitude of 20,000+
TAS increases over IAS at 2%/1000’ so we could be looking at a TAS which is 40% higher then IAS.
250kts IAS would equate a TAS of 350 plus or minus wind.
A groundspeed of 350kts+ doesn’t mean this was a crew just blazing through the skies.

[Chronic Snoozer]

Lets not get carried away here.
A Challenger jet is not a Cat D aircraft as far as approach category.
Very much possible that 14,000 plus high temperatures created a density altitude of 20,000+
TAS increases over IAS at 2%/1000’ so we could be looking at a TAS which is 40% higher then IAS.
250kts IAS would equate a TAS of 350 plus or minus wind.
A groundspeed of 350kts+ doesn’t mean this was a crew just blazing through the skies.

Where is that "like" button PPRuNe?!

[B2N2]

Forgot to mention that max holding speed in FAA land is 230 IAS < 14,000’ and 265 IAS > 14,000’ so it would be reasonable to assume they were flying those speeds which would equate to a TAS of 322 or 371 respectively.
Give or take a couple of kts.

[340drvr]

With all due respect to those the died, oh boy, here we go:
"We are very fortunate... that the plane went down between areas that were defendable and wouldn’t burn,” he said. “We’re also extremely lucky that plane didn’t hit a school bus full of sixth-graders. Something needs to change. This can’t continue.” (from the msn article posted above.)

[Charlie Foxtrot 00]

Lets not get carried away here.
A Challenger jet is not a Cat D aircraft as far as approach category.
Very much possible that 14,000 plus high temperatures created a density altitude of 20,000+
TAS increases over IAS at 2%/1000’ so we could be looking at a TAS which is 40% higher then IAS.
250kts IAS would equate a TAS of 350 plus or minus wind.
A groundspeed of 350kts+ doesn’t mean this was a crew just blazing through the skies.

I hear you, but we can just pull the FD valid for that time instead of guessing:

FBUS31 KWNO 261357
FD1US1
DATA BASED ON 261200Z
VALID 261800Z FOR USE 1400-2100Z. TEMPS NEG ABV 24000

FT 3000 6000 9000 12000 18000 24000 30000 34000 39000

RNO 9900 9900+18 1409+12 1411-07 1517-17 182031 192242 212154


FBUS31 KWNO 261958
FD1US1
DATA BASED ON 261800Z
VALID 270000Z FOR USE 2000-0300Z. TEMPS NEG ABV 24000

FT 3000 6000 9000 12000 18000 24000 30000 34000 39000

RNO 2712 3108+21 3606+12 0508-06 1516-17 152231 162441 162553


Can we agree that the temp at 14,000’ was likely around +6C with winds variable but no more than 10kts? PA was likely a little lower given the local altimeter, but even with a 14,000PA, DA would have only been about 16,100. So a TAS of 360 (being conservative) would have produced a CAS of 293.

Based on the ground track, I’m more interested in whether he was set up to hold at ALVVA or AWEGA. I need a better time stamp to match the calls made on the ATC tape, but my initial thought is that he called established when he was within 10° of the reciprocal to a 340 bearing hold to the north, but at AWEGA rather than the assigned ALVVA. Eventually he did track inbound on the 160 to AWEGA for several miles. This also seems to be where the adjustments were made to speed.

Could that just have been an artifact of getting assigned direct AWEGA after calling established passing ALVVA? Sure. Better data will prove either theory.

[BizJetJock]

A Challenger jet is not a Cat D aircraft as far as approach category.
Er... yes it is. This is a TERPS approach in the USA, max IAS for circling in Cat C is 140kts. Min speed for circling in a Challenger is 150 kts, so it is Cat D.

So they should not have been even considerin a circling approach.

[Charlie Foxtrot 00]

I had a post earlier showing the FD for RNO on the date in question. Unfortunately, I don’t think it posted for whatever reason. Suffice it to say that at FL200, indeed the IAS may have been below the hold speed limit for that altitude.

However my point was not that the limit was exceeded, rather that due to the ground speed of the aircraft and when the hold instructions arrived, there wasn’t a lot of time to brief, program, and execute the hold, then properly transition to the approach.

Upon receiving instructions to fly to ALVVA and hold north on the 340 bearing. 5TR flew southbound for a few minutes, then executed a right turn toward ALVVA at the same presumed IAS and FL200.

Upon reaching ALVVA, 5TR was cleared to 14,000, a descent which began immediately. 5TR then began a right (!) turn toward AWEGA (versus a course reversal on the west side of the 340 bearing from ALVVA to enter the instructed hold). As 5TR got to within about 10° of an inbound course to AWEGA (!), he reported established in the hold. At this point he was roughly 5.75nm from AWEGA at 16,600’ He then flew approximately a 160 inbound course to AWEGA.

18 seconds later, he was cleared direct AWEGA, cross at or above 12,000. At this point he was roughly 4nm from AWEGA at 16,000’, 311kts GS.

He crossed AWEGA 45 seconds later at 14,000’ and 294kts GS.

My presumption is that the high (not illegal) speed and a relatively late hold clearance led to task saturation, which, after misidentifying and flying the hold at the incorrect fix, led to a slam dunk approach without much time to consider the (lack of) circling minima and execution thereof.

[Mad (Flt) Scientist]

With all due respect to those the died, oh boy, here we go:
"We are very fortunate... that the plane went down between areas that were defendable and wouldn’t burn,” he said. “We’re also extremely lucky that plane didn’t hit a school bus full of sixth-graders. Something needs to change. This can’t continue.” (from the msn article posted above.)

Also in that article:
... concerns about the frequency with which aircraft depart and arrive at the airport, pointing to reports of planes appearing to travel low ...

I don't know how people expect aircraft to get to and from airports without flying "low".... airport NIMBYism jumping straight in after a fatal accident ...

[Zaphod Beblebrox]

A review of the first post of the approach plate shows that a circling procedure is not authorized at this airport in Category D.

[RAWLAW]

I agree with Charlie Foxtrot. Absolutely. Starting high and fast and the IAF for a "not so simple" approach had "go-around" written all over it and compressed the situation beyond normal limits. Perhaps the PIC had no previous experience at that airport. I would venture to say it is likely he was tankering enough fuel for the next flight. He also had the highest airport temperature at that time. Not even sure who the SIC was but this morning the PIC was identified along with the passengers on board. Any accident is bad enough but this was just tragic from the start.

[B2N2]

Er... yes it is. This is a TERPS approach in the USA, max IAS for circling in Cat C is 140kts. Min speed for circling in a Challenger is 150 kts, so it is Cat D.

So they should not have been even considerin a circling approach.

I was not aware of a min circling speed.
A quick glance does not list it in the Limitations section. I have no experience in the airplane type. Do you have a reference?
Requesting the approach for 11 could have avoided the problem.

[Raffles S.A.]

The SmartCockpit site Challenger 605 circling approach diagram says says circling approach at the start of downwind Flaps 30 and speed Flaps 30 speed + 10 KIAS.

What was their weight and what is the corresponding flaps 30 speed? I haven't found that yet.

[my salami]

The SmartCockpit site Challenger 605 circling approach diagram says says circling approach at the start of downwind Flaps 30 and speed Flaps 30 speed + 10 KIAS.

What was their weight and what is the corresponding flaps 30 speed? I haven't found that yet.

Regardless of whatever the speed was, it's still Cat D.

MS

[B2N2]

The FAA recently published revisions to the Aeronautical Information Manual (AIM), including clarifications of “approach category” and its application in determining the appropriate straight-in or circling minima on an instrument approach.

Previous AIM language required pilots to use the next higher approach category if it was necessary to maneuver at a speed above the upper limits of the aircraft’s defined approach category.

The revised language advises a pilot is never required to use the next higher approach category.


https://nbaa.org/aircraft-operations/airspace/aim-revision-clarifies-approach-category-and-related-procedures/

[Zeffy]

B2N2

The more significant quote from that NBAA advice (https://nbaa.org/aircraft-operations/airspace/aim-revision-clarifies-approach-category-and-related-procedures/) would have been
In order to remain in protected airspace, it is still recommended – but no longer required – that pilots use the next higher approach category if possible, Boll explained.


In other words, the obstacles don't care if a jet is certified as Cat C or D.

If a pilot needs to circle at speeds above 140 KIAS for whatever reason - configuration, icing, a jammed stab, turbulence, whatever - s/he would be wise to respect the Cat D line of minima.

[maninbah]

Er... yes it is. This is a TERPS approach in the USA, max IAS for circling in Cat C is 140kts. Min speed for circling in a Challenger is 150 kts, so it is Cat D.

So they should not have been even considerin a circling approach.


https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/828x1593/543b0c00_e0d7_402b_b8a6_222fa46009d4_1f54d64555c96562b672b37 8384a423202ca7eef.jpeg
FSIMS.FAA.GOV States Cat C for the 604 & 605 ?

[armchairpilot94116]

https://youtu.be/FDMRPcVNcR0

comments are pretty good
but nobody really knows why yet

[double_barrel]

I have never encountered "FU" conditions, but I understand that smoke haze significantly affected viz at the time of the crash despite a theoretical good viz.

I have flown into Truckee as pax looking over the crews' shoulders in a Citation X, straight in, downwind onto 11. It's tight, hot and high. I struggle to imagine a "circling approach" in such an aircraft. It does look a lot like a typical general aviation overshoot-stall -spin, I wonder if misleading visual cues due to smoke contributed.

[B2N2]

Let’s clarify a couple of things:

1. An airplane is assigned an approach category based on its Vref at max landing weight. Lack thereof it’s Vso x 1.3
2. If the approach speed is lower due to lower actual landing weight the Category does not change as in “we’re light today so we use the Cat C minima”.
3. If the approach speed is higher for whatever reason ( configuration issues or malfunctions)it is prudent to use the higher Category minima and restrictions.

Which leads to the following:
It is not illegal for a Cat C aircraft to fly a higher speed even though Cat D is Not Authorized.
The approach is not authorized for Cat D (large) aircraft that’s all that means.

Now it would be prudent to take note of the restrictions or limitations on the Approach plate………
If we find ourselves in a situation where we have to fly a higher speed.
This would be a highlight item during a approach briefing in the cockpit.

I’m still curious why they choose to fly the approach that required circling instead of the offset approach to RWY 11.

[maninbah]

The ATC audio identities the controller offering the pilot either Rwy 11 or overhead downwind 29… pilots choice. Metar 30 mins prior to arrival posted on this website would have favored Rwy 11. 30 mins after the accident, Metar would have preferred Rwy 29. KTRK is tight and unforgiving sad to say…3 1/2sm FU. 3sm needed to circle Cat C. One would have to be on the RNAV 20 at YAKYU (2.6 from MAP and 3.2 from the airport) no less than 7200ft and circle inside an obstacle at 6817ft on the extended Rwy 11 centerline - not easy even at Ref + 10 …if the wind had already shifted to the west over the surrounding terrain and not known (or requested) prior to the commencement of the circle… … a difficult challenge for even the best skills.. if the MAP is reached at only 0.8 from the field, circling for 11 would be unlikely. It appears that the flight track was west of the RNAV 20 approach (even west of I-80) suggesting a visual approach was occurring inside of LUMMO.

[BizJetJock]

Some real numbers for one of the 605s I fly:
Operating weight with 2 pilots - 27,151lbs
Zero fuel weight with 4 pax and some bags - 28,250lbs
Absolute minimum fuel for flight planned arrival - 2,000lbs. Most pilots are comfortable with 3k+, and they could have been tankering, but this gives us the lowest speeds.

Vref for 30,250lbs at 4500ft elevation - 121kts
For a more likely 32,000 - 126kts
The FCOM says that circling should be done at the Flaps30 speed +10kts. Unfortunately, nowhere is the Flaps30 speed defined. If you take it as being the speed you get from the FLAPS FAIL checklist at Flaps 30, then you get speeds of 138 and 143 respectively. Most operators fly as they have been trained by CAE and FSI and use 150 unless the weight requires more.
So it is theoretically possible to get below 140 if they were light enough, but in practice not likely.
I hadn't spotted the AIM change. They have changed "must" use the higher category minima to "should". In my book, "should" suggests you need quite a good reason not to, and the Boss wanting to get to his summer home doesn't seem good enough, particulary given that even the Cat D protecterd area is quite tight to do any kind of sensible circuit. Everyone who has done the JFK and Memphis circles in the Challenger sim knows that it is rarely a stable approach in anyone's book!
Obviously we need to wait for some facts, but sadly i think that this will demonstrate that pushing things to the limit just because it is legal doesn't mean it is a good idea.

[B2N2]

Obviously we need to wait for some facts, but sadly i think that this will demonstrate that pushing things to the limit just because it is legal doesn't mean it is a good idea.

Like button ^^^
Barely legal is rarely a good idea.

[EDML]

Question: From what I know the A/C category is determined using the Vref and not the specific speed flown in a circling approach. Correct?

[Klimax]

Question: From what I know the A/C category is determined using the Vref and not the specific speed flown in a circling approach. Correct?

The simple answer to that would be, yes. Just note that for the certification of the aircraft and when determining the aircraft category, the Vref on a straight-in approach and landing (not a circling approach (turning)) at Aircraft Max Landing Weight is used.
Since the circling approach requires banking (turning) during the maneuvering to land, the aircraft speed needs to be increased (above Vref) to increase the safety margin. The pilot will therefor need to use a speed with an increment during the circling approach, and depending on aircraft performance and operational procedures (Manufacturer or Operator), this speed may be higher than the MAX maneuvering speed depicted (for that aircraft performance category) on the approach chart. Accordingly, the operator may decide to perform the approach in a higher aircraft category (in the case of this accident Cat D) and using the minima's and performance criteria (such as circling protection area etc.) associated with that higher category.

[Miles Magister]

B2N,

I politely have a different view to you about approach categories. My understanding is that the pilot should fly the category procedure for the speeds being flown at the particular point in the arrival and approach, they vary during the different segments of the arrival and are speed brackets both in PanOps and TERPS. The categories have a maximum and minimum speed for each category at that point in the approach, you fly the category for the speed you are flying.
The information is available in Jepp etc but can also be found here Aircraft Approach Categories (https://www.skybrary.aero/index.php/Approach_Speed_Categorisation). The category as determined by the Vref at the time it is flown is used to ascertain the approach minima. The other sector categories must be determined according to the speeds flown at the time because the obstacle clearance is related to turn radius at the speed being flown and also visibility are calculated in accordance to the speed being flown.

MM

[B2N2]

MM, respectfully I don’t think we’re disagreeing on the core of the issue. We’re just getting there through different avenues.
The aircraft is Cat C so it is legal to fly the circling approach.
Cat D are not authorized to circle even if they are light and use a Cat C speed.
The aircraft is still Cat D and therefore prohibited.
Now….a crew flying said Cat C aircraft are legal to fly a higher speed and it would be prudent to use the higher Cat D minima.
Which in this case would indicate they should not accept the circling approach as cleared by ATC.
Vref is Vref by its definition, it’s not a stall speed. One knot below Vref does not mean instant doom and neither does a standard rate turn at Vref.

Now from the discussion here it appears normal circling speed for the 605 is 150kts which means the crew should have used the Cat D minima and at the lack thereof………

[armchairpilot94116]

https://youtu.be/VT6Z--HNqlM

[Abbey Road]

Audio of the plane and ATC shows they were indeed going for the Rwy 20 approach - circle to rwy 11.
Conditions at the time were pretty marginal for circle-to-land, smoke, storms in the area:
METARs at approx. time (2018Z) of crash:

KTRK 262050Z AUTO 28011G16KT 04SM BKN023 33/08 A3013 FU RMK VIS 3 1/2/V5 FU BKN023 ACFT MSHP
KTRK 261945Z AUTO 09005KT 04SM BKN023 32/06 A3014 FU RMK VIS 3 1/2/V5 FU BKN023

I would just like make couple of obsevations about the conditions reported in the METARS above ...

Truckee's published airfield elevation is 5904 feet, where the International Standard Atmosphere (ISA) temperature would be 3.306.degrees Celsius, but on the day it was 32 to 33 degrees Celsius. That would make the Density Altitude for those two METARS as 8990 feet and 9149 feet respectively, differing substantially from the physical airfield elevation. Aircraft of any persuasion are going to experience a notable increase in true air speed (TAS) in conditions like this and, therefore, an increased ground speed (GS)

These sort of airfield and meteorological characteristics require careful planning and briefing of the resultant effects of the TAS and GS, allowing more time and track miles (distance over the ground) to get an aircraft safely prepared and configured to fly an approach to landing.

Whilst there are details we have yet to learn about what went on in the cockpit of this accident aircraft, it is pretty much a given that planning for the substantial Density Altitude would need to have been conscientious to lead to a safe outcome.

[EatMyShorts!]

You don't have to agree with all of Dan's views and opinions, but I think he verbalizes the circumstances of this accident quite well:

https://youtu.be/qeUwYhVtlDc

[maninbah]

You don't have to agree with all of Dan's views and opinions, but I think he verbalizes the circumstances of this accident quite well:

https://youtu.be/qeUwYhVtlDc

Knowing the PIC personally I believe it is him that can be heard making the radio calls. Has anyone been able to locate the SIC details on the FAA airman registry as I can not. It is hoped that the PIC was not flying and talking on the radio or even that with a difficult circling approach it was not the right seat SIC trying this with a left hand circle. Normally one pilot is flying and the other on the radio…..

[fitliker]

How much distance does a 605 need to slow down from barber pole to Vref over the fence ?

[Spooky 2]

How much distance does a 605 need to slow down from barber pole to Vref over the fence ?


What would that have to do with this accident??

[Mad (Flt) Scientist]

To avoid giving me a heart attack each time I open PPrune, could someone (OP or a mod) please add a DATE to the thread title?

[Zeffy]

NTSB preliminary (https://kesq.b-cdn.net/2021/08/Report_Truckee-NTSB.pdf)

Both recorders recovered.

[Abbey Road]

To avoid giving me a heart attack each time I open PPrune, could someone (OP or a mod) please add a DATE to the thread title?
I agree, wholeheartedly! This is a problem common on internet forums, with words 'today', yesterday' and similar used in thread titles. Consequently, the usefulness of the thread becomes limited very soon thereafter, because if particular specifics about an incident are not known e.g. registration, aircraft type, exact location, it makes searching for the thread quite difficult.

A bit more thought on the title, by those who start such threads, would be an enormous help to all. Please.

[EatMyShorts!]

In another forum the following format for thread-titles was introduced, it is mandatory there.

Either:

date | flight number | aircraft type | airport (ICAO) or name of city/region/locility | short description of event
or
date | name of airline + aircraft type | airport (ICAO) or name of city/region/locility | short description of event

Information that is unknown at the type of creating such a thread will be shown with three question marks ???.

[formulaben]

Mods, what say you? This seems like a good policy.

[PPRuNe Towers]

Try going back to the first post.

[BFSGrad]

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The first officer’s (FO’s) improper decision to attempt to salvage an unstabilized approach by executing a steep left turn to realign the airplane with the runway centerline, and the captain’s failure to intervene after recognizing the FO’s erroneous action, while both ignored stall protection system warnings, which resulted in a left-wing stall and an impact with terrain. Contributing to the accident was the FO's improper deployment of the flight spoilers, which decreased the airplane's stall margin; the captain’s improper setup of the circling approach; and the flight crew’s self-induced pressure to perform and poor crew resource management, which degraded their decision-making.

N605TR Final Report (https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103554/pdf)