KAPF - Naples Florida - Challenger crash on highway

[MLHeliwrench]

Reports of a Challenger radioing in while on approach saying both engines quit and could not make it. Crash landed on highway, hitting vehicles and/or wall and erupting in to a large fireball.

Video from pilot of plane that was next to land. Video Post (https://www.reddit.com/r/aviation/comments/1amxw1n/challenger_lost_both_engines_and_crashed_on/)

Video from car driving by https://twitter.com/mariaducato/status/1756058954788990988/

Safety Network info page Link (http://aviation-safety.net/wikibase/351596)

[Lake1952]

Unverified reports say, 5 on board, three survivors.

https://www.flightaware.com/live/flight/N823KD/history/20240209/1730Z/KOSU/KAPF

https://winknews.com/2024/02/09/plane-crash-i-75-collier-county/

[BFSGrad]

Rough transcript from LiveATC. Non-accident aircraft comms not included.

HJ823: Hop-a-jet 823 is with you on a right downwind for a 5-mile final ah runway 23

KAPF: Hop-a-jet 823, roger, make a right turn back toward the airport, [?] departure ahead Challenger jet, runway 23 cleared to land, wind 220 at 12, gust 16

HJ823: Alright, Challenger jet departing, we’re turning back towards the airport and cleared to land runway 23, Hop-a-jet 823

HJ823: OK, ah, Challenger, ah Hop-a-jet 823, lost both engines, emergency, making an emergency landing

KAPF: [?] got that emergency, cleared to land runway 23, is that Hop-a-jet 823?

HJ823: We’re cleared to land but we’re not going to make the runway, we’ve lost both engines.

[EXDAC]

Over 2,000 fpm descent half way through the base to final turn. The fire seems to indicate this was not fuel exhaustion.



https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/839x641/naples_ads_b_3df97c29368457862e689659cdc6c742c111c48c.png

[island_airphoto]

What the heck other than bad fuel or no fuel takes out both engines at the same time?

[lpvapproach]

What the heck other than bad fuel or no fuel takes out both engines at the same time?
short of switching it off, not a lot
Where did it top up fuel last

[nomorecatering]

Video of survivors evacuating the aircraft
https://www.youtube.com/watch?v=zpddfgXsiNQ

[West Coast]

What the heck other than bad fuel or no fuel takes out both engines at the same time?

Birds perhaps. Not suggesting that was the cause, just a possibility.

[slacktide]

What the heck other than bad fuel or no fuel takes out both engines at the same time?

Looking at the airplane's pneumatic diagram, one way the engines are tied together is through the 10'th stage bleed manifold, but there is a check valve that should isolate them. A bad 10th stage bleed check valve could cause a compressor stall and engine flameout at low power settings when you start the APU, which could account for an engine failure in this phase of flight. Having 2 check valves on 2 different engines fail on the same flight? That seems extraordinary unlikely. It was a quick turnaround at OSU so they would not have had time to do any maintenance, so a common mode maintenance failure seems unlikely.

A similar issue (corroded 5'th stage check valve sticking open due to extended duration storage) was causing multiple in-flight engine shutdowns at top of descent on the 737NG after bunches of them were poorly stored at the beginning of COVID. It is complete pure luck that there were no dual engine flameouts. https://www.federalregister.gov/documents/2020/08/11/2020-17469/airworthiness-directives-the-boeing-company-airplanes

[605carsten]

Nah… quick quick turn in Columbus, respectfully I would seriously look at their fuel numbers for an out and back.
(12 years on 604/605 myself)

edit to add, I dont want to read too much into the flames.. remember there is always an amount of unusable fuel that remains so hard to say at this point

[605carsten]

Looking at the airplane's pneumatic diagram, one way the engines are tied together is through the 10'th stage bleed manifold, but there is a check valve that should isolate them. A bad 10th stage bleed check valve could cause a compressor stall and engine flameout at low power settings when you start the APU, which could account for an engine failure in this phase of flight. Having 2 check valves on 2 different engines fail on the same flight? That seems extraordinary unlikely. It was a quick turnaround at OSU so they would not have had time to do any maintenance, so a common mode maintenance failure seems unlikely.

A similar issue (corroded 5'th stage check valve sticking open due to extended duration storage) was causing multiple in-flight engine shutdowns at top of descent on the 737NG after bunches of them were poorly stored at the beginning of COVID. It is complete pure luck that there were no dual engine flameouts. https://www.federalregister.gov/documents/2020/08/11/2020-17469/airworthiness-directives-the-boeing-company-airplanes

no, you dont transition the bleeds(its manually done in the 604/5) until APU is up and running and also switching 10ths off is approved for ops if you have no APU (limitation of pulling two bleed sources at same time off engine) if you want to use Anti-ice for takeoff or landing

[Sikorsky]

Surprising to see that cars just pass the burning aircraft without stopping to offer help.

[El Grifo]

Glad to see at least one of the pax managed to escape with her hand luggage !!!

El G.

[605carsten]

And via the baggage hold door non the less.. only option really on that side considering the angle and flames

[AmarokGTI]

Surprising to see that cars just pass the burning aircraft without stopping to offer help.

Priorities. Gotta go DTO nearest lawyer’s office and commence suing the crew for the emotional distress.

[AmarokGTI]

no, you dont transition the bleeds(its manually done in the 604/5) until APU is up and running and also switching 10ths off is approved for ops if you have no APU (limitation of pulling two bleed sources at same time off engine) if you want to use Anti-ice for takeoff or landing

Genuine Q - (generally speaking) are the fuel cut off switches protected by anything or just toggle switches? From prior experience - Hard to judge off Google images incase specific aircraft have had mods / STCs etc.

[605carsten]

No toggle switches like the Global.. they are simply triggers on the back of the thrust levers that need to be pulled to go to cutoff.. hmm so you are thinking like that Falcon20 crew many years ago with worn latches and flamed both out when going back to idle?

[FUMR]

Glad to see at least one of the pax managed to escape with her hand luggage !!!

El G.

Firstly, it's not an airliner with hundreds of passengers. Secondly there's no emergency slide involved. Thirdly on a private jet an item of hand luggage may well have been within easy reach. Natural human reaction to try and save your worldly goods, especially if they are right next to you. I saw nothing in that clip that would have impeded their escape. I'll now get flamed but I honestly think this is a slightly different scenario to a full airliner and it's human instinct. No cabin crew screaming at you to leave everything and get the heck out.

[Flch250]

DEF?
https://www.ntsb.gov/advocacy/safety-alerts/Documents/SA-079.pdf

[AmarokGTI]

No toggle switches like the Global.. they are simply triggers on the back of the thrust levers that need to be pulled to go to cutoff.. hmm so you are thinking like that Falcon20 crew many years ago with worn latches and flamed both out when going back to idle?

Yeah I guess.. I’m not saying it happened, but I am wondering whether aircraft design would allow that to be a possibility.

[Flch250]

The teardrop to the left and then back around to the right appears to to shown here. Looks reasonable. Whatever happened, happened fast, and perhaps when exiting the turn and lining up with final. A time when power would be reduced after the turn.

Just tickled my memory. I was PNF in BOS TCA IFR on approach to landing. Captain threw both AC master power and avionics (next to each other, non guarded) to off. This was out of the blue and for no reason. The entire panel and AC went dark. We obviously worked it out.

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1640x1174/img_0229_7945d585f248b4e91baf05cfd517f0d3d9e804e5.jpeg

[island_airphoto]

DEF?
https://www.ntsb.gov/advocacy/safety-alerts/Documents/SA-079.pdf
Yikes!
When I first heard of that I thought the airplanes were getting fueled with diesel, not that DEF was going in the jet fuel, presumably in the mistaken impression it was Prist or similar.
* IIRC diesel works fine until it gets cold and gels up, so filling the whole plane with it would be more likely to cause issues at altitude than back down in the warmer air.

[MLHeliwrench]

Firstly, it's not an airliner with hundreds of passengers. Secondly there's no emergency slide involved. Thirdly on a private jet an item of hand luggage may well have been within easy reach. Natural human reaction to try and save your worldly goods, especially if they are right next to you. I saw nothing in that clip that would have impeded their escape. I'll now get flamed but I honestly think this is a slightly different scenario to a full airliner and it's human instinct. No cabin crew screaming at you to leave everything and get the heck out.

not to mention / they showed discipline having to exit through the baggage compartment, past their luggage.

[B2N2]

Glad to see at least one of the pax managed to escape with her hand luggage !!!

El G.

Judge not lest you be judged.
One of the survivors was the FA and she got the two pax out through the luggage compartment.
They would have never known that by themselves.

https://www.fox4now.com/naples/pilots-survivors-in-deadly-naples-plane-crash-identified

[JamaicaJoe]

Nah… quick quick turn in Columbus, respectfully I would seriously look at their fuel numbers for an out and back.
(12 years on 604/605 myself)

edit to add, I dont want to read too much into the flames.. remember there is always an amount of unusable fuel that remains so hard to say at this point

If the fuel were dangerously low, would the deceleration upon the approach, the turn, banking, flaps, wheels down, etc cause the fuel to slosh forward and away from the fuel pickups? This to explain the sudden loss of both engines. Perhaps the crew terribly calculated the fuel load due to few passengers and the reserve was miscalculated as a result. But then why would they ignore fuel warnings and land at any one of the 100's of Florida Alternates??

[EDLB]

Low on fuel after a 2h12 minutes flight? Very unlikely. They would have told ATC from a fuel emergency and there are plenty of airports on their route. Somehow the dual engine failure came unexpected for the pilots until the last minutes.

[JanetFlight]

Could it be some sort of core lock, I humble ask?

[BAe 146-100]

I knew personally the FO, feels silly saying Co pilot as he was a ultra experienced Captain 25000 hours plus, ex Us Airways A330 captain and ex Virgin America. He has flown so many types, last I heard from him he was on the MD80 and there is no one i would feel safer up there than him. RIP Ian a true family man and aviator until the end, see you down the road buddy.

Something must have gone bad and at very short notice, the rest of the flight looks normal. Prey to god it wasn’t low fuel, it seems on the base turn they powered up and there was nothing left to give .

[WITCHWAY550]

The riddle here is what can cause both engines to fail, maybe simultaneously, and is considered a fuel starvation when in fact there was plenty of fuel in the tanks? I believe the answer would point to the collector tank. Small in capacity but is essential to enable the fuel to be delivered to each power-plant from any of the 4 other tanks, wings/fuselage or aux, and tail tank (which was already empty as it would normally be.

[WITCHWAY550]

So who owned and maintained that aircraft? Hop-A-Jet states "leased aircraft". Thats not too unusual. Registered owner, in name, matches a North Carolina company under FAA imposed money fines. 6 digits. WAS THIS ALL LEGAL?

[B2N2]

Sure it’s legal, why would it not be?
Lots of aircraft out there that are owned by a private owner under an LLC for instance then leased to a charter company.
The aircraft will require a conformity inspection and approved by the FAA to be added to the fleet.

[Ambient Sheep]

I knew personally the FO, feels silly saying Co pilot as he was a ultra experienced Captain 25000 hours plus, ex Us Airways A330 captain and ex Virgin America. He has flown so many types, last I heard from him he was on the MD80 and there is no one i would feel safer up there than him. RIP Ian a true family man and aviator until the end, see you down the road buddy.

I'm sorry for the loss of your friend.

[Kulwin Park]

The video shows #2 engine tailcone already burnt, am I correct? Whereas #1 engine looks normal.

[Compton3fox]

There is a suggestion that fuel icing may have been at play here. 350 gallons uploaded in OSU but without anti ice agent. May or may not be a factor but a possibility... They flew down at FL400.

[B2N2]

There is a suggestion that fuel icing may have been at play here. 350 gallons uploaded in OSU but without anti ice agent. May or may not be a factor but a possibility... They flew down at FL400.

What is your source for that fuel quantity pls?

[WITCHWAY550]

So my post regarding the legality of that trip should not be construed as a possible contributor to the tragic accident. That wasn’t not my intent. What I saw online regarding the ownership of that aircraft and the fact that there seems to be evidence of some significant FAA fines is a separate matter, if true. I am focused on the cause. I flew the 601-3A for about 7 years so I am recall the systems, to some degree. My theory is that they may have been aware that the collector tank was not getting fuel to it so in that way the engines would flame out. Only the FDR would know. There was a “calmness” in the crew call to the tower that “they would not make the runway”. That’s as far as anyone can or should go in this speculation. As anyone of us can agree on is that this real cause will be interesting. I am also sorry for the loss of two pilots this way.

I believe that to be from the post crash fire. My opinion.

[601]

without anti ice agent
Fuel heaters?

[605carsten]

Low on fuel after a 2h12 minutes flight? Very unlikely. They would have told ATC from a fuel emergency and there are plenty of airports on their route. Somehow the dual engine failure came unexpected for the pilots until the last minutes.

obviously not.. but look at bigger picture and short turnaround after repo up from Florida.. apart from a poster saying they uplifted 350 but who knows at this point.

[B2N2]

obviously not.. but look at bigger picture and short turnaround after repo up from Florida.. apart from a poster saying they uplifted 350 but who knows at this point.

Obviously an hour is sufficient time to refuel.
In range call to the FBO that you’ll be doing a quick turn and the fuel truck is waiting at your parking spot. Fuel is also cheaper in OSU then in FXE.

[WITCHWAY550]

Frankly I give no significant conclusion to this information. Most likely it is or could be misdirected. This does not explain the crash. I am curious about this:

1. N823KD is registered to East Shore Aviation LLC but with a South Florida address.
2. East Shore Aviation LLC is also the name of a North Charleston, S.C., aviation company that was fined by the FAA a few years ago ($157,654).

This may or may not be associated. I don't know.

B2N2, you and I both call South Florida home and presumably you have had a career in somebody's cockpit. Stuff like this happens frequently, especially down here.

Again I don't draw any "accident scenario" based on that however when the Challenger (coincidental type) ran off the runway in KTEB some years ago the trail of ownership and operational authority was very convoluted.

Sympathies to the families of the pilots.

[rippey]

There is a suggestion that fuel icing may have been at play here. 350 gallons uploaded in OSU but without anti ice agent. May or may not be a factor but a possibility... They flew down at FL400.

I never flew the 604, but have several thousand hours in the 601. We always took negative fuel unless pre-mixed was the only option - challenger has fuel heaters. Also the fact there was no icing inhibitor makes a situation where the fuel was contaminated by DEF unlikely. In previous cases of DEF related engine damage I believe the prist tanks on the truck were accidentally filled with DEF.

[BFSGrad]

Could it be some sort of core lock, I humble ask?Core lock on the CF34 doesn’t cause engine shutdown. Instead it complicates engine restart following a shutdown. For core lock to occur, N2 has to stop rotating.

[JanetFlight]

Core lock on the CF34 doesn’t cause engine shutdown. Instead it complicates engine restart following a shutdown. For core lock to occur, N2 has to stop rotating.
Thanks for the info, BFS

[island_airphoto]

There is a suggestion that fuel icing may have been at play here. 350 gallons uploaded in OSU but without anti ice agent. May or may not be a factor but a possibility... They flew down at FL400.
Ice would seem to be a factor at FL400 much more than landing in Florida, unless you had some weird 1 in a million thing happen where an ice ball built up slowly and then melted all at once.
The idea that they just ran out would also imply the crew staring at fuel gauges headed toward the Big E didn't bother to mention it or land and buy more.

[MichaelOLearyGenius]

There is a suggestion that fuel icing may have been at play here. 350 gallons uploaded in OSU but without anti ice agent. May or may not be a factor but a possibility... They flew down at FL400.

BA38 at LHR?

[Boegrrl]

If the Flight Dept is hard over on fuel costs it would be tragic. The final fuel slips are already under review.

[BFSGrad]

BA38 at LHR?Wasn’t the cause of the BAW38 accident unique to the Rolls Royce Trent engines?

[MLHeliwrench]

Almost pulled it off. A little too much left to right momentum. So close. RIP

Landing Video (https://x.com/BNONews/status/1757181949418918273)

[Jet Jockey A4]

[QUOTE=MLHeliwrench;11595877]Almost pulled it off. A little too much left to right momentum. So close. RIP

Landing Video (https://x.com/BNONews/status/1757181949418918273)[/QUOTE ]Yes what a shame! RIP guys.

[BFSGrad]

Almost pulled it off. A little too much left to right momentum. So close. RIP (https://x.com/BNONews/status/1757181949418918273)I do wonder if the PIC was planning for the golf course just on the other side of the sound wall (Wyndmere Country Club) and very late in the descent realized he didn’t have the altitude to clear the sound wall and attempted to then align with I-75.

[PukinDog]

Not the first Challenger to suffer a dual-engine flame out. 1994, a 601-3A at FL 410 over Nebraska about 2.5 hours into their flight. Fuel contamination (water). Here's a link to the report; https://reports.aviation-safety.net/1994/19940320-1_CL60_N88HA.pdf

[Ikijibiki]

Dashcam video of the plane crashing on the freeway.

https://nypost.com/2024/02/13/news/shocking-dash-cam-video-shows-private-jet-crashing-onto-florida-highway/

[Lake1952]

After watching the dash cam video, it might have been better to try for the median strip? The pavement pretty much guaranteed an encounter with vehicles. Granted, the crew was between a rock and a hard place with no great choices .

[FUMR]

After watching the dash cam video, it might have been better to try for the median strip? The pavement pretty much guaranteed an encounter with vehicles. Granted, the crew was between a rock and a hard place with no great choices .

And next to no time! I'm not a pilot but having just looked at options on Google Earth, my decision would have been the I95 knowing full well it wasn't ideal but the best that there was. At least they saved the passengers and F/A. Feel really sorry for the pilots. They tried their very best.

[Jet Jockey A4]

I never flew the 604, but have several thousand hours in the 601. We always took negative fuel unless pre-mixed was the only option - challenger has fuel heaters. Also the fact there was no icing inhibitor makes a situation where the fuel was contaminated by DEF unlikely. In previous cases of DEF related engine damage I believe the prist tanks on the truck were accidentally filled with DEF.

The Challenger 604 does not have fuel heaters as per say… the fuel/oil heat exchanger’s primary function is to cool off engine oil and yes heat the fuel in the engine and does not heat up the fuel in the wings… the reason why you cannot fly with bulk fuel colder than -37C. https://hosting.photobucket.com/images/b79/mlab601/IMG_1540.jpeg?width=1920&height=1080&fit=bounds (https://hosting.photobucket.com/images/b79/mlab601/IMG_1540.jpeg?width=1920&height=1080&fit=bounds)

[EDLB]

Will the recorders shed more light into the cause?

[EXDAC]

I have seen no reports that indicate anyone on the highway was injured. I see nowhere on the golf course that is longer than 1,000 ft before hitting obstructions. The median has a cable or other barrier and is barely more than a wingspan wide between carriageway edges. The Southbound lane is about 110 ft between the median barrier and the wall and almost all obstructions except the wall are moving in the same direction as landing.

The touchdown (ground impact) seems to have been on the roadway but to have resulted in collapse of the right MLG then shortly after the left MLG as the aircraft leaves the paved surface. Did MLG collapse cause rupture of the wing tanks?

The crew had less than a minute to sort this out. I'd say they did a damn good job that three on the aircraft survived and no one on the ground was killed. Very sorry the pilots were not so fortunate.

[MechEngr]

The plane crushed a small truck. The driver somehow didn't die.
https://winknews.com/wp-content/uploads/2024/02/Plane-Crash-I-75-Naple-2-9-24.jpg

In hindsight the canal was the least obstructed choice. It's shallow enough to prevent sinking and wheels up would have been less traumatic. Width wise is a bit tight, but doable. Engines over wings so they don't scoop water. However I can see the option of setting the plane down on a nice concrete landing area would be very attractive, so second guessing doesn't show the choice from the front seats was fundamentally flawed. It's been done successfully by others, but the traffic here was far denser than those previous landings and the plane much faster than similar attempts. Coasting a 172 off at the next exit is far simpler than this.

Had they not hit the truck they might have managed to straighten it out, but the collision with the truck looks to me like it forced the plane to roll (as in roll-pitch-yaw) towards the wall.

[Jet Jockey A4]

I have seen no reports that indicate anyone on the highway was injured. I see nowhere on the golf course that is longer than 1,000 ft before hitting obstructions. The median has a cable or other barrier and is barely more than a wingspan wide between carriageway edges. The Southbound lane is about 110 ft between the median barrier and the wall and almost all obstructions except the wall are moving in the same direction as landing.

The touchdown (ground impact) seems to have been on the roadway but to have resulted in collapse of the right MLG then shortly after the left MLG as the aircraft leaves the paved surface. Did MLG collapse cause rupture of the wing tanks?

The crew had less than a minute to sort this out. I'd say they did a damn good job that three on the aircraft survived and no one on the ground was killed. Very sorry the pilots were not so fortunate.

Reported that two people in a vehicle were injured.

[RatherBeFlying]

Google Maps coupled with 20/20 hindsight shows a number of lagoons in the area, two quite sizable to the NE & SW of the I-74 interchange to the North of the crash location, that may have been reachable.

Precious little think time available to a startled crew.

[B2N2]

In hindsight the canal was the least obstructed choice

Google Maps coupled with 20/20 hindsight shows a number of lagoons in the area, two quite sizable to the NE & SW of the I-74 interchange to the North of the crash location, that may have been reachable.


Blessed are children and the ignorant.
I don’t think either of you have the faintest idea what an utterly stupid suggestion you’ve made.

[RatherBeFlying]

Blessed are children and the ignorant.
I don’t think either of you have the faintest idea what an utterly stupid suggestion you’ve made.
I eagerly await enlightenment from your knowledgeable explanation.

[AirportPlanner1]

I eagerly await enlightenment from your knowledgeable explanation.

In that part of the world you’ll be an alligator’s lunch

[megan]

In that part of the world you’ll be an alligator’s lunchAin't that the truth, had one living outside the sim centre at the Sikorsky plant WPB awaiting any errant pilot.

[IFMU]

Ain't that the truth, had one living outside the sim centre at the Sikorsky plant WPB awaiting any errant pilot.
We had an incident with the Cypher UAV some years ago at the Sikorsky WPB plant and it ended up in the canal. Scared off the gators for a bit, which was good as we had to pull the thing out.

I suspect the Challenger would have made a bigger splash.

[punkalouver]

I used to do freshwater scuba diving in Florida when I would go down for sim training(plus one manatee encounter swim). I dived at several springs and a river where there actually was an alligator on the riverbank that we passed in the boat. I think the alligator attack thing is overblown. Yes, there are attacks but compared to the number of scuba dives/swims, the proportion of incidents is small. In other words, if you ditched your aircraft in the water and survived the crash, you would likely survive the possibility of an alligator attack. Bottom line, considering a ditching is not a stupid suggestion. Therefore, to decide not to ditch and choose a much riskier option would be foolish.

I guess many people have this idea of a human touching the water and multiple crocs immediately starting to swim over like a James Bond movie. Perhaps similar to many people automatically thinking of a crash when they think of an airliner.

For reference....."There were 401 unprovoked alligator attacks on humans in Florida between 1948 and 2021. Out of these 401 incidents, 25 led to fatal attacks. Most Florida alligator attacks occur near fresh water sources like lakes, ponds, and rivers. Florida witnesses an average of 7 unprovoked alligator attacks on humans per year".

7 attacks on probably millions of people going for a swim/scuba dive.



(29) LIVE AND LET DIE | Crocodile Farm - YouTube

[EDLB]

From the video it looks that the PF planned to make it over the wall of the interstate, but found in the last seconds, that he could not make it and had to correct the glide path. Unfortunately he crashed with still some lateral energy into the wall. A forced landing from base leg without power and without enough energy to make it over densely populated ares is every pilots nightmare.
There are most times no good options. Here they had about 60 seconds. You run your memory items and at the same time look for some spot which promises survival.

In the safe armchair it is easy to claim why they did not do this and that.

[rippey]

Question for current 604 drivers - would you expect to see the ADG out in this scenario? The video is blurry but I can’t see the ADG. My experience is limited to the 601 and Globals, but in both of those the ADG or Rat would deploy immediately following double engine failure. I am guessing that in the 604 the apu generator is brought online in a standby mode when the APU is running and in this case automatically takes the electrical load when the engine driven gens drop off, preventing the ADG from deploying?

[JRBarrett]

Question for current 604 drivers - would you expect to see the ADG out in this scenario? The video is blurry but I can’t see the ADG. My experience is limited to the 601 and Globals, but in both of those the ADG or Rat would deploy immediately following double engine failure. I am guessing that in the 604 the apu generator is brought online in a standby mode when the APU is running and in this case automatically takes the electrical load when the engine driven gens drop off, preventing the ADG from deploying?

That is likely. SOP for a Challenger is to start the APU during descent (usually below 10,000 feet), and transfer the bleed air for the packs from the engine 10th stage to the APU bleed air. The APU generator would remain in standby, but would come online immediately if both engine generators failed.

[island_airphoto]

I used to do freshwater scuba diving in Florida when I would go down for sim training(plus one manatee encounter swim). I dived at several springs and a river where there actually was an alligator on the riverbank that we passed in the boat. I think the alligator attack thing is overblown. Yes, there are attacks but compared to the number of scuba dives/swims, the proportion of incidents is small. In other words, if you ditched your aircraft in the water and survived the crash, you would likely survive the possibility of an alligator attack. Bottom line, considering a ditching is not a stupid suggestion. Therefore, to decide not to ditch and choose a much riskier option would be foolish.

I guess many people have this idea of a human touching the water and multiple crocs immediately starting to swim over like a James Bond movie. Perhaps similar to many people automatically thinking of a crash when they think of an airliner.

For reference....."There were 401 unprovoked alligator attacks on humans in Florida between 1948 and 2021. Out of these 401 incidents, 25 led to fatal attacks. Most Florida alligator attacks occur near fresh water sources like lakes, ponds, and rivers. Florida witnesses an average of 7 unprovoked alligator attacks on humans per year".

7 attacks on probably millions of people going for a swim/scuba dive.



(29) LIVE AND LET DIE | Crocodile Farm - YouTube (https://www.youtube.com/watch?v=-LrbTd69iwI)

I went to flight school in Florida. I never even thought about alligators as a factor for emergency landings. I did managed to get chased by one once, I swam across a river and it followed me the whole way.Obviously it could have caught me anytime it wanted to. They are not crocodiles and are not nearly as nasty. There are Florida crocs, but they are quite rare.
In fairness to the pilots, it isn't like they had time to study Google Earth.

[FUMR]

I do wish the the armchair pilots would just stay quiet about what they could have done. I'm personally convinced that they did what they could under the circumstances they found themselves in, with the intention of trying to save their passengers (which they did) and themselves (which unfortunately they didn't). They had precious SECONDS to make a decision while some of you "experts" pontificate for hours in your armchairs about what they should have done! It's an absolute disgrace. Oh, by the way, I am not a pilot!

[Jet Jockey A4]

Question for current 604 drivers - would you expect to see the ADG out in this scenario? The video is blurry but I can’t see the ADG. My experience is limited to the 601 and Globals, but in both of those the ADG or Rat would deploy immediately following double engine failure. I am guessing that in the 604 the apu generator is brought online in a standby mode when the APU is running and in this case automatically takes the electrical load when the engine driven gens drop off, preventing the ADG from deploying?

601/604/605 and 650 work the same way… if the APU was running it’s generator would be on standby and stay in that mode even with a dual engine failure.

The ADG should deploy automatically and provide limited electrical power but if you want the APU’s generator to take over and feed the electrical power, you need to select a switch that will change the power source.

[rippey]

601/604/605 and 650 work the same way… if the APU was running it’s generator would be on standby and stay in that mode even with a dual engine failure.

The ADG should deploy automatically and provide limited electrical power but if you want the APU’s generator to take over and feed the electrical power, you need to select a switch that will change the power source.

Thanks for the clarification, it’s been a minute since I’ve flown a challenger - and that was a 601 which if I recall had a limitation that the APU gen could not be used in flight unless both engine gens had failed - so even after we started the APU and transitioned the bleeds descending through 10 we left the APU gen switch off until after landing. That limitation may have been removed if the APU was upgraded to the -150.

[RatherBeFlying]

Swimming with Casper the alligator

[B2N2]

I eagerly await enlightenment from your knowledgeable explanation.

That canal is along Collier boulevard and has many bridges to residential neighborhoods East of there.
Even if you’d manage to avoid the bridges it’s not wide enough to accommodate a Challenger meaning the wings would be ripped off and the fuselage likely ending submerged or even worse inverted and submerged.
None of the man made lakes there are big enough for a successful ditching and mostly surrounded by homes and other obstacles.
Best option would likely have been the center median but it looks from the video they didn’t have enough time to maneuver.
There is also an overpass maybe half a mile from the crash site.

[RatherBeFlying]

SW of the I-75 interchange North of the crash site is a rectangular pond some 700 metres or ½ mile long by 150m wide:
https://maps.app.goo.gl/94AUrvacQ7QYkx4t7

There are a few aerators that are likely more flexible than the barrier wall. And reduced fire hazard.

As for the median, it slopes to the central drainage ditch such that the wings might touch before the gear. In addition there is a 3-wire barrier likely designed to prevent semis from crossing the median.
​​​​​​

[B2N2]

SW of the I-75 interchange North of the crash site is a rectangular pond some 700 metres or ½ mile long by 150m wide:
https://maps.app.goo.gl/94AUrvacQ7QYkx4t7

There are a few aerators that are likely more flexible than the barrier wall. And reduced fire hazard.

As for the median, it slopes to the central drainage ditch such that the wings might touch before the gear. In addition there is a 3-wire barrier likely designed to prevent semis from crossing the median.
​​​​​​

The pond you refer to is well to the North of the impact site and the cable barriers are waist high and intended to stop/deflect personal vehicles and light trucks, not full size semi’s.



http://www.swfltim.org/Document%20Archives/CSM/Handouts/I-75%20Cable%20Barrier%20Presentation.pdf

[FlyMD]

When I saw all the traffic on the highway, and the plane's wingtip hitting the wall on the side of the road, I started wondering if the grass median in the middle of the lanes would not have been the better option.. thoughts?

[Geriaviator]

Plenty of advice on what the crew could have done from those who may not have been in their situation. I wouldn't know how to handle a bizjet but I have a four-inch scar plus 40 stitches to demonstrate my skills following engine failure in a light single at 1000ft. Below me were small fields with stone walls to form a very effective arrester barrier. Believe me the damn thing comes down where IT wants to, not in central median, traffic lane, bridge or lake. I think the crew did a great job.

[FUMR]

When I saw all the traffic on the highway, and the plane's wingtip hitting the wall on the side of the road, I started wondering if the grass median in the middle of the lanes would not have been the better option.. thoughts?

Already been mentioned and eliminated!

[B2N2]

Already been mentioned and eliminated!

Discussed and certainly not eliminated.
If you can call it that considering I’m arguing with (according to their profiles) SEL and Glider pilots and probably retired non-pilots about where to land a jet after dual flame out.

[RatherBeFlying]

As for the median, we would need to know the depth, width and slope to determine whether a wingtip would contact before the gear. One wingtip contacting before the other would trigger high yaw and roll rates. I would be most pleasantly surprised if a similar aircraft remained in the median. The worst case would be being deflected into oncoming traffic.

The median barrier could be high enough to breach the wing tanks and add to forces directing the accident aircraft into oncoming traffic. Perhaps the median could work out for a high wing single.

As for the 700m pond, it was about a mile closer to the point where power was lost. People with access to appropriate sims could see if either large pond could be made from the power loss point. The NTSB might decide to research this on a sim. Often several crews are run through accident scenarios on a sim. The "success" rate would be interesting data.
​​​​​​

[Timmy Tomkins]

We can speulate on their options to the ying yang and never really know; only the 2 pilots knew what the situation really was in that cockpit. What is of more interest is the possible cause of the double flameout. Does anyone have info on the fuel state on departure for example?

[WITCHWAY550]

ripped,

I would have sent this privately as it does not directly relate to this accident but I wanted to share. I did fly the 601-3A for about 7 years but this is not about that. It's about RAT's and HMG's. Again not related. My younger brother flew for United. About 20 years ago on a EZE-MIA night flight they lost electrical power south of Columbia. B767 ETOPS. They were unable to get RAT (I think that's what the 767 has, if not HMG). System design prevented auto deploy (apparently no manual deploy) because the system sensed normal AC power from both gen's. Problem was the ground. Both the AC and DC system share the same grounding bracket which had a little bit of corrosion breaking the ground. Google Cast BP Witcher and United Airlines. It was flight UAL 854/EZE-MIA/13 April 2004.

[FUMR]

Discussed and certainly not eliminated.
If you can call it that considering I’m arguing with (according to their profiles) SEL and Glider pilots and probably retired non-pilots about where to land a jet after dual flame out.

Landing a glider as opposed to a Challenger I would hazard a guess is somewhat very different!

[BFSGrad]

What is of more interest is the possible cause of the double flameout.
Short video clip bouncing around the internet demonstrating the plausibility of inadvertent engine shutdown on a CRJ. Video shows the left seat pilot reaching across the rear of the thrust levers for the flap handle while the right seat pilot pulls thrust levers to idle. However, the engine shutdown interlocks (red switches) on the back of the thrust levers are actuated by pressing against the left seat pilot’s right forearm, allowing the unintentional movement of the thrust levers through idle to fuel cutoff.

FDR will certainly show if this was the case.

[rippey]

Short video clip bouncing around the internet demonstrating the plausibility of inadvertent engine shutdown on a CRJ. Video shows the left seat pilot reaching across the rear of the thrust levers for the flap handle while the right seat pilot pulls thrust levers to idle. However, the engine shutdown interlocks (red switches) on the back of the thrust levers are actuated by pressing against the left seat pilot’s right forearm, allowing the unintentional movement of the thrust levers through idle to fuel cutoff.

FDR will certainly show if this was the case.

Possible, however in biz jets operated by two experienced captains 99% of the legs are flown with the PF in the left seat.

[resetjet]

Stop with the "they should have landed here or there". If you have ever gone down at low altitude with no power you simply look ahead and pick the best thing in about 3 seconds. Interstate would be high on the list anyway.

As for the why, likely fuel exhaustion or birds. Simply not enough fire spread with a wing ripped off spilling 30 mins reserve fuel all over the place as the airplane spun around. It ignited on impact probably due to massive compression like a diesel engine. Charter ops usually have a decent fuel contract at the home base and try to buy as little as possible while out. This 2 leg trip would have been possible without a stop, but no room for error. They would have known as the EICAS would have told them. As far as frozen fuel no way. It would have been good and warm from the oil heat exchangers. Could have been an issue with fuel quantity sensors. And they had less then they thought, but still both engines failing at same time has me perplexed. Even with exhaustion its unlikely for them to fail at the same time.

Birds? Naples has pelicans, trust me small birds do little to these engines. I have hit a ton with no issues. But its plausible.

Single engine failure and shut down the good engine? Possible.

You cannot restart those engines without apu running. On a charter I would expect them to start it on landing to save hours and fuel. As for the rat, it will deploy when no power to main bus if I remember correctly. I had to deploy one for testing and as soon as you turn off power from both gens, it deploys. Not sure if apu is running, but I think it won't as the main bus is powered.

If you had a dual at low altitude you would not have enough time to start the apu and therefore pick a landing spot.

Fuel contamination is possible.

CF34 engines are bulletproof and can take a lot of abuse. Not like the old Lears that a blue jay would flame you out.

Very experienced pilots, but everyone I know will tell you of a low fuel situation at some point in their career. You always make it until you don't.

There are so many possibilities off the top of my head, but I know what a gallon of diesel looks like on a bonfire. The wall was pretty burnt up not near resting place so a lot of it may have exited there and burned up and nobody got it on film. I can only expect whatever it was they did a good job saving 3 lives. Any of these problems where they were would have ended in disaster regardless of pilots and maybe much worse.

[scifi]

Quote.... I started wondering if the grass median in the middle of the lanes would not have been the better option.. thoughts?

Well No.... Landing straight down the middle of the carriageway, in between vehicles, would have been just Ok.

[Geriaviator]

In the correct lane of course. Don’t want any head-on do we?

[EDLB]

Unlikely that it was a known low fuel situation kept from ATC. They would have chosen a higher pattern it they new that flame out was imminent. But you never know like on LMI2933.
I do not believe that a 25kh pilot or FO would maneuver himself into a Challenger glider ops corner.

[WITCHWAY550]

I am interested in knowing what the FDR and CVR shows, as we all are.

My feeling and what the evidence in a very limited way shows is first both engines quit, presumably simultaneously. I can only attribute lack of fuel to that as a “reasonable” contributing factor.

Both engines are fed by the single tank that has no quantity indicator. Instead it has low level warning annunciator. Probably red. From that indication to no fuel remaining in the collector tank would be in part determined by the combined fuel flow and possibly by either no fuel transferring or insufficient fuel flow from the main wing tanks. Either because they were empty or some other reason the fuel was not able to flow into the collector.

I would best say the annunciation of that Low Level does not leave the crew with much to go on unless they anticipated it because they initiated a flight with not enough fuel for the flight. If they were tankering extra then they had enough fuel and we go back to the low level in the collector tank. This should be as critical of an indication as a smoke or fire warning. You see it you act on it.

However they were close in, setup for landing, and no other options and that warning just did not or would not and could not alter their plan. They had a plan to land and they were committed by that point. I take a concerned approach to their transmissions once both engines failed. Professional and extremely “normal” in tone. I don't know if one would expect anything else than that from a crew that is experienced as this crew was.

Finally I would say that if this theory proves to be the reason, aside from not knowing why the collector tank went dry, a lot of this will make better sense.

[maui19]

Interesting ww550. You could certainly make a case that they knew they were cutting it close on fuel, which was why there was so little surprise evident in the last transmission. Only time will tell.

[megan]

Both engines are fed by the single tankFuel system is divided, engines receive their supply from their respective collector tank, no single tank supplies both engines in normal operation.


https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/1168x710/ch2_25dd553eed7837db202b2c8cd2f112177bf2d5de.png

[WITCHWAY550]

This is a helpful post. I flew the 601-3A (actually the very first 601-3A delivered) for about 7 years. 3-5 times to Europe annually. I do not believe the collector tank is internally separated into left engine/right engine feed. For sure there are 2 separate fuel lines, actually 3 including the APU, from that tank to its respective engine but I believe the collector tank is but one tank feeding engines and APU. I could be wrong but that's how I recall it.

[EXDAC]

How would any aircraft meet the requirements of 14 CFR Part 25 with a single collector tank feeding both engines?
"§ 25.953 Fuel system independence.Each fuel system must meet the requirements of § 25.903(b) (https://www.ecfr.gov/current/title-14/section-25.903#p-25.903(b)) by—

(a) Allowing the supply of fuel to each engine through a system independent of each part of the system supplying fuel to any other engine; or

(b) Any other acceptable method."

25.903 -
"(b) Engine isolation. The powerplants must be arranged and isolated from each other to allow operation, in at least one configuration, so that the failure or malfunction of any engine, or of any system that can affect the engine, will not—

(1) Prevent the continued safe operation of the remaining engines; or

(2) Require immediate action by any crewmember for continued safe operation."

[BizJetJock]

From the 604 Operating Manual:
FUEL TANK SYSTEM (CONT'D)
Components and Operation
Main Tank System
The left and right main tanks are integral-type fuel tanks (wet wings) that supply fuel to their
respective engines via two collector tanks. Flapper valves in the wing ribs prevent fuel from
surging toward the wing tips. The main tanks may be refueled by pressure or gravity. The APU’s
normal fuel supply is from the right main tank.
Collector Tanks
Two collector tanks, situated at the lowest point of the center auxiliary tank, are considered
part of the main tank system.
The 601 was the same, but that's not relevant to this thread.

[Pilot DAR]

I drove past the crash site yesterday. The pilots made the very best of a really poor choice of places to put it down. If the highway was as busy then, as it was today, it was great that there were no citizen injuries. Otherwise, maybe the golf course, but houses would have been in the path in any case. The concrete wall is still smashed, and well blackened. The highway shoulder pyloned off, but I did not see any slide marks in the pavement. A pile of contaminated soil is tarped by the side of the highway.

A bad situation, but could have been so much worse....

[WITCHWAY550]

As I see from your comments that the 604 and the 601 have the same design for the collector tank. If you know is there an associated EICAS message for low fuel in the collector tank(s)? As I know the Gulfstream 5 and 550 have such a warning. Now how would someone know which collector tank is "low"? I don't know.
I believe there may be some relevance if in fact both engines quit at the same time (some floating remarks about the possible inadvertent shutdown by one of the two pilots during the manipulation of flaps, etc) if it was in fact fuel starvation AND there was fuel remaining in the wing tanks, sufficient fuel. I did have a close friend with our local FAA (South Florida) tell me that there was a theory that in fact the control/thrust levers somehow travelled to the cutoff position. That would be significant if true obviously.

[B2N2]

One of the working theories that are floating around involves inadvertent activation of the fuel shut off/ cut off switches.
Either by RH pilot reaching under the thrust levers for the Thrust reverser switches or the LH pilot reaching under the thrust levers for the flap handle while power is reduced by the flying pilot.


https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1600x1079/image_d8191489e054880a2f4e8d724b11594886f56869.jpeg

[EXDAC]

As I see from your comments that the 604 and the 601 have the same design for the collector tank. If you know is there an associated EICAS message for low fuel in the collector tank(s)? As I know the Gulfstream 5 and 550 have such a warning. Now how would someone know which collector tank is "low"? I don't know.

According to documentation on the 605 the collector tanks are considered to be a part of their respective main tank and have no independent fuel quantity sensing, indicating, or alerting. It seems likely that the 604 is similar.

ref - https://www.smartcockpit.com/docs/CL605-FUEL_SYSTEM.pdf

[EXDAC]

According to documentation on the 605 the collector tanks are considered to be a part of their respective main tank and have no independent fuel quantity sensing, indicating, or alerting. It seems likely that the 604 is similar.

604 fuel system here - https://www.smartcockpit.com/docs/CL_604-FUEL_SYSTEM.pdf

[EXDAC]

One of the working theories that are floating around involves inadvertent activation of the fuel shut off switches.

May not be a good theory as the 604 does not appear to have fuel shut off switches that are separate from the thrust levers. I have never operated a Challenger, or even been in the cockpit, but seems hard to imagine how both thrust levers could have accidentally been pulled past the gate into Shut Off position unless both gates had failed.

ref - https://www.smartcockpit.com/docs/CL_604-AIRPLANE_GENERAL.pdf

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/773x642/cl_604_thrust_levers_b0e8f1a27cd39b9b22653b7c848994f168fa560 a.png

[BFSGrad]

NTSB Aviation Investigation Preliminary Report - N823KD (https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193769/pdf)

[josephfeatherweight]

Thanks for posting the Preliminary Report - no mention of CVR (recovery/prelim analysis) in this report?

[Jet Jockey A4]

NTSB Aviation Investigation Preliminary Report - N823KD (https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193769/pdf)


Well the plot thickens… It seems everything so far was working normally with no fuel anomalies.

[DIBO]

It seems everything so far was working and normalnot sure I catch your drift, looks to me this was not 'normal':
A preliminary review of the data recovered from the airplane’s flight data recorder revealed that the first of three Master Warnings was recorded at 1509:33 (L ENGINE OIL PRESSURE), the second immediately following at 1509:34 (R ENGINE OIL PRESSURE), and at 1509:40 (ENGINE). The system alerted pilots with illumination of a “Master Warning” light on the glareshield, a corresponding red message on the crew alerting system page and a triple chime voice advisory (“Engine oil”). Page 2 of 7 ERA24FA110 This information is preliminary and subject to change. Twenty seconds later, at 1510:05, about 1,000 ft msl and 122 kts, on a shallow intercept angle for the final approach course, the crew announced, “…lost both engines… emergency… making an emergency landing”

[josephfeatherweight]

The "L ENGINE OIL PRESSURE" and "R ENGINE OIL PRESSURE" are the first messages that appear when the engines shut down - for any reason. Eg. selected off OR starved of fuel.

[hopper123]

Looks like a normal inflight shutdown.

[BFSGrad]

The "L ENGINE OIL PRESSURE" and "R ENGINE OIL PRESSURE" are the first messages that appear when the engines shut down - for any reason. Eg. selected off OR starved of fuel.
Not unexpected.

While the preliminary report doesn’t allow for any conclusions it certainly provides compelling information that reduces the likelihood of certain potential accident causes; e.g., fuel exhaustion, fuel starvation, fuel contamination, dual-engine bird strike.

One curious finding regarding the inadvertent engine shutdown scenario is the thrust levers being found near the idle stop position and the #1 fuel control unit being found at the idle position and the #2 forward of the idle stop.

[B2N2]

May not be a good theory as the 604 does not appear to have fuel shut off switches that are separate from the thrust levers. I have never operated a Challenger, or even been in the cockpit, but seems hard to imagine how both thrust levers could have accidentally been pulled past the gate into Shut Off position unless both gates had failed.

ref - https://www.smartcockpit.com/docs/CL_604-AIRPLANE_GENERAL.pdf

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/773x642/cl_604_thrust_levers_b0e8f1a27cd39b9b22653b7c848994f168fa560 a.png



https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/547x387/img_2600_05ac1190c399fc1d80c3329ebe4e40f38e58ab0d.jpeg
Left (white) thrust reversers switches
Middle (red) fuel cut off switches
Right (blue) flap selector

it is very much feasible to have your arm in the way either left to right or right to left when the thrust levers are pulled back.

[605carsten]

May not be a good theory as the 604 does not appear to have fuel shut off switches that are separate from the thrust levers. I have never operated a Challenger, or even been in the cockpit, but seems hard to imagine how both thrust levers could have accidentally been pulled past the gate into Shut Off position unless both gates had failed.

ref - https://www.smartcockpit.com/docs/CL_604-AIRPLANE_GENERAL.pdf

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/773x642/cl_604_thrust_levers_b0e8f1a27cd39b9b22653b7c848994f168fa560 a.png

First of all, many small to midsize biz jets use a similar style of trigger that needs activating to get over shut off gate, so thats normal. I would say we are back in the realm of finding out if RHS pilot was PF as then the accidental catching of both triggers (that need lifting) on PM arm as he reaches around to select full flaps at same time PF comes back on throttle levers.. hey presto you can now shut both down. Next thing is frantically trying to lift back into idle position again in seconds prior to crash. (As indicated by prelim report). Also flying from the RHS is fairly normal too in bizjet world to maintain practice of flying in both seats.

[MechEngr]

Did I miss it or did the report ignore they ran over a truck and nearly flattened it? I wonder about it because the truck is independently steered and could have prevented the aircraft from straightening up on the highway.

[galaxy flyer]

Not unexpected.

While the preliminary report doesn’t allow for any conclusions it certainly provides compelling information that reduces the likelihood of certain potential accident causes; e.g., fuel exhaustion, fuel starvation, fuel contamination, dual-engine bird strike.

One curious finding regarding the inadvertent engine shutdown scenario is the thrust levers being found near the idle stop position and the #1 fuel control unit being found at the idle position and the #2 forward of the idle stop.

First thing a pilot does after a gear up landing is put the gear handle down. First thing I’d do in the event of an inadvertent dual engine shutdown is put them back in idle, try a restart or catch it before it wound down.

[megan]

United and Delta both had 767 inflight shutdown of both engines because of inadvertant operation of the fuel shut off switches shortly after take off, Delta at 1,600 feet, system subsequently reengineered. A repeat here as suggested?

[Chiefttp]

There was an incident years ago on a 757 or 767 where one of the pilots put his cellphone in the area in front of the fuel shutoff switches. When the auto-throttles commanded a thrust reduction, as the thrust levers moved backwards the cellphone was squeezed between the thrust levers and the fuel shutoff switches, and this caused the fuel cutoff switches to shutoff the fuel to both engines. Could a similar situation developed here.

[605carsten]

There was an incident years ago on a 757 or 767 where one of the pilots put his cellphone in the area in front of the fuel shutoff switches. When the auto-throttles commanded a thrust reduction, as the thrust levers moved backwards the cellphone was squeezed between the thrust levers and the fuel shutoff switches, and this caused the fuel cutoff switches to shutoff the fuel to both engines. Could a similar situation developed here.

No, because the CL does not have cutoff switches of that nature. They are on TLs.. see pic
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/646x695/e706ceb9_75d3_4390_bfe9_9b28946c5ec4_c2b404e7e1a022a58f18212 c11f533821b0e8fcc.jpeg

RHS dude looks out of sidewindow back at runway for typical US style visual slamdunk, asks for full flaps at same time retarding levers to idle to get speed change under way asap… also Challengers have crap autothrottles (if installed!!) so really only good as cruise controls as too slow for rapid changes for visual maneuvering

[josephfeatherweight]

also Challengers have crap autothrottles (if installed!!)
​​​​​​​Absolutely correct.

[dragon6172]

Did I miss it or did the report ignore they ran over a truck and nearly flattened it? I wonder about it because the truck is independently steered and could have prevented the aircraft from straightening up on the highway.
Very doubtful the truck driver ever saw the aircraft before it hit them.

[RatherBeFlying]

After the airplane came to rest, the cabin attendant stated that she identified that the cabin and emergency exits were blocked by fire and coordinated the successful egress of her passengers and herself through the baggage compartment door in the tail section of the airplane. Kudos to cabin attendant and designers who put in the extra door.

[MechEngr]

Very doubtful the truck driver ever saw the aircraft before it hit them.
Steered independently as in the resistance to sideways movement by the truck tires if the truck is not aligned with the motion of the aircraft would tend to independently steer that portion of the aircraft in contact with the truck in a direction the pilots were not intending to go. If that was the nose of the plane then the main gear would follow that change in direction and cause the plane to depart from the intended landing direction.

The truck would be acting more like an out-of-control roller skate. I would have mentioned the truck driver as an agent in the steering if that was what I intended to convey.

[galaxy flyer]

Kudos to cabin attendant and designers who put in the extra door.

How else would bags be put in the compartment?

[josephfeatherweight]

Kudos to cabin attendant
Absolutely agree. The cargo door is not a designated emergency exit. A fantastic job to assess the main door, overwing exit and think (very quickly) outside the box and head for this exit, guiding the pax to safety. Phenomenal job.

[EXDAC]

How else would bags be put in the compartment?

Isn't the fact that the baggage door could be reached from the cabin of more importance than the fact there was a baggage door?

[galaxy flyer]

We’ve been briefing pax and F/A on the baggage door as a third means of egress for years, but it was put there to load bags. Most bizjets use a baggage door, it’s not an airliner.

[BFSGrad]

...if RHS pilot was PF as then the accidental catching of both triggers (that need lifting) on PM arm as he reaches around to select full flaps at same time PF comes back on throttle levers.. hey presto you can now shut both down.A question for our erudite 601/604/605 drivers: if this scenario occurred, is there any plausible way to recover an engine in sufficient time (~1000 ft AGL, landing configuration, dropping like a stone) to avoid contact with terra firma?

[josephfeatherweight]

A question for our erudite 601/604/605 drivers: if this scenario occurred, is there any plausible way to recover an engine in sufficient time (~1000 ft AGL, landing configuration, dropping like a stone) to avoid contact with terra firma?

I would say, there is probably not sufficient time to recover the engines in this scenario.
But I would also add, that the chance of this happening to BOTH thrust levers is extremely remote. I say this having flown as PM from the LHS of a 604 (and actuated the flaps) on many occasions.
The CVR would likely reveal much more - was it recovered/useable?

[BFSGrad]

The CVR would likely reveal much more - was it recovered/useable?Preliminary report noted “FDR revealed” L/R engine oil warnings. Thus assume good FDR data. This crash far more forgiving to FDR/CVR than N605TR (Truckee) crash and latter yielded good FDR/CVR data. If N823KD FDR same type as N605TR, then thrust lever (TL) position not FDR parameter. For N605TR, TL position was estimated from N1. However, N605TR FDR did record engine fuel flow as a direct parameter. If same for N823KD, then FDR should make clear if TLs were pulled over gate to shutdown.

[605carsten]

Absolutely agree. The cargo door is not a designated emergency exit. A fantastic job to assess the main door, overwing exit and think (very quickly) outside the box and head for this exit, guiding the pax to safety. Phenomenal job.

evenmore so when you realize almost everybody who runs commercial bizjets upto 19 pax never have qualified F/A’s.. just cabin servers with some training but nothing to the level of airlines. Its my biggest peeve in this business (same for EASA and FAA)

[Yancey Slide]

evenmore so when you realize almost everybody who runs commercial bizjets upto 19 pax never have qualified F/A’s.. just cabin servers with some training but nothing to the level of airlines. Its my biggest peeve in this business (same for EASA and FAA)

I wouldn’t say “never”, I know of at least a few ex-UA cabin crew who are now doing charters instead. It’s definitely rare, but not necessarily unheard of.

[605carsten]

I wouldn’t say “never”, I know of at least a few ex-UA cabin crew who are now doing charters instead. It’s definitely rare, but not necessarily unheard of.

Which is awesome but they are bringing their own knowledge and experience with them.. they are likely not being trained nor qualified in the legal sense to act as crew. Thats why its “easy” to pick up work as contract cabin servers on both 91 and 135 gigs..

[Yancey Slide]

Which is awesome but they are bringing their own knowledge and experience with them.. they are likely not being trained nor qualified in the legal sense to act as crew. Thats why its “easy” to pick up work as contract cabin servers on both 91 and 135 gigs..

Not arguing that there shouldn’t likely be some additional training requirements. Just observing that there are examples of trained people working in that side of the industry too.

[FLHerne]

What the heck other than bad fuel or no fuel takes out both engines at the same time?

A fairly recent incident - A321 fuel tanks mistreated with biocide (37 times too much!) after a period of layup during COVID.
Not total failure but serious problems with both engines in flight:
AAIB Formal Report: G-POWN, Engine malfunction after takeoff from London Gatwick Airport

[I can't make it a link, not enough posts on here]

[EXDAC]

However, N605TR FDR did record engine fuel flow as a direct parameter. If same for N823KD, then FDR should make clear if TLs were pulled over gate to shutdown.

In what way do the recorded parameters distinguish between loss of fuel flow due to fuel enhaustion and loss of fuel flow due to operation of shut off valves?

Edit to add - I assume fuel quantity, if recorded, would be a clue.

[aeromech3]

How else would bags be put in the compartment?
We’ve been briefing pax and F/A on the baggage door as a third means of egress for years, but it was put there to load bags. Most bizjets use a baggage door, it’s not an airliner.
1990's VIP Gulfstream's, I was operating as Flying Spanner/2nd Cabin crew member, security,baggage handler and door operator, Jeppesen manual handler, we had more than one passenger that would send ahead van's full of luggage and shopping; first load larger pieces behind net area in front of RPB (spy hole blocked out), load on top of water tank, back load into toilet compartment and galley, close baggage door then fill remainder of space to ceiling; some pieces were brought in through passenger door; in no way was this an emergency exit, forward compartment housed flight kit, safe, more Jeppesen's and crew bags.
Despite the Gulstream having larger than most cabin windows including over-wing exits, we always doubted due the size of most of our passengers hat they could egress that way and if tried would block the remaining persons!
Thoroughly enjoyable experience as we got away with it

[BFSGrad]

In what way do the recorded parameters distinguish between loss of fuel flow due to fuel enhaustion and loss of fuel flow due to operation of shut off valves?

Edit to add - I assume fuel quantity, if recorded, would be a clue.
I would expect fuel flow to be a discrete, simultaneous L/R event for engine shutdown compared with an erratic event with L/R variation for fuel exhaustion.

Again assuming similarity with N605TR, the FDR collects data for Fuel Qty-Aux and Fuel Qty-L/R/Tail.

[EXDAC]

Again assuming similarity with N605TR, the FDR collects data for Fuel Qty-Aux and Fuel Qty-L/R/Tail.

Thanks for that reference. The NTSB docket for the N605TR investigation says the recorder was L-3/Fairchild FA2100 and includes the full parameter list. That recorder is referenced in several 605 "for sale" ads so it seems reasonble to assume it was standard fit.

[605carsten]

I would expect fuel flow to be a discrete, simultaneous L/R event for engine shutdown compared with an erratic event with L/R variation for fuel exhaustion.

Again assuming similarity with N605TR, the FDR collects data for Fuel Qty-Aux and Fuel Qty-L/R/Tail.

In this case the engines failed within 1 sec of each other.. so simultanous as you can get.. no way in heck that tallies with BOTH collector tanks empty at almost exactly same time…

[EXDAC]

How did this fuel shut off design ever get certified if it is so vulnerable to inadvertent activation when aircraft is flown from the right seat? Is this design weakness emphasized when converting to type?

[605carsten]

How did this fuel shut off design ever get certified if it is so vulnerable to inadvertent activation when aircraft is flown from the right seat? Is this design weakness emphasized when converting to type?

well, its never happened before and its not as weak or as strong as many other types of cutoff.. Sh*t happens (like having a camera push an Airbus joystick nose down during seat positioning etc..).. people getting in and out of seats in flight have caused more kicking of switches and Levers and heck even the Global has a fence either side of the switches after a checklist slid off glareshield on rotation and whacked both off in testflight phase. But early days so lets see what the outcome is of CVR

[galaxy flyer]

How did this fuel shut off design ever get certified if it is so vulnerable to inadvertent activation when aircraft is flown from the right seat? Is this design weakness emphasized when converting to type?

Once in how many million hours/cycles of almost 3,000 600-series models, this isn’t a problem for airworthiness, based on the known facts.

[605carsten]

Once in how many million hours/cycles of almost 3,000 600-series models, this isn’t a problem for airworthiness, based on the known facts.

yep, complete non-issue.. remember same system is used on all the CRJ airline series.. with again F/Os only flying from the right seat.

[resetjet]

I would say, there is probably not sufficient time to recover the engines in this scenario.
But I would also add, that the chance of this happening to BOTH thrust levers is extremely remote. I say this having flown as PM from the LHS of a 604 (and actuated the flaps) on many occasions.
The CVR would likely reveal much more - was it recovered/usable?

if the apu were running and you were flapless, gear up and 250kts……maybe. But i believe they knew there was no reason to do so. The would have punched the igniters before n2 spooled that far back i assume. I believe based on this report and observations of the crash they ran out of fuel. They uploaded 350 gallons. No idea what they had on board, but 350 gallons is less then half of what they would have needed. No fuel in one of the engine lines is tells the tale. Pump lost prime. Low fuel and manoeuvring to land can easily starve both engines. The other thing is the amount of fire is not enough.

This is really gonna shake up the industry and may lead to more regulation. All this online selling of flights has brought prices too low and coat cutting has gone too deep. Taking minimum fuel on a vfr day is consistent with this theory. I really hope I am wrong but from where i sit, everything leads to this. I cant begin to tell you how reliable these engines are. Like I said, most pilots have their low fuel stories. You always make it until you don't.

[punkalouver]

and heck even the Global has a fence either side of the switches after a checklist slid off glareshield on rotation and whacked both off in testflight phase.

Any more info on this incident?

[RickNRoll]

Preliminary report is out now.

Possible fuel contamination.

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193769/pdf

https://www.youtube.com/watch?v=-_yTXcC4Rr4

[EXDAC]

Preliminary report is out now.

Possible fuel contamination.



I saw no reference to possible fuel contamination in the preliminary NTSB report. Your post appears to link fuel contamination to the NTSB report and I think that is misleading.

[MechEngr]

Two places imply fuel contamination:

"About 16 ounces of liquid with an odor and appearance consistent with Jet-A fuel was drained from the aft tail fuel tank; the sample contained about ½ ounce of what appeared to be water."

"The fuel from the fuel filter bowl and heat exchanger displayed a yellowish tint, while the other fuel samples were clear"

[galaxy flyer]

if the apu were running and you were flapless, gear up and 250kts……maybe. But i believe they knew there was no reason to do so. The would have punched the igniters before n2 spooled that far back i assume. I believe based on this report and observations of the crash they ran out of fuel. They uploaded 350 gallons. No idea what they had on board, but 350 gallons is less then half of what they would have needed. No fuel in one of the engine lines is tells the tale. Pump lost prime. Low fuel and manoeuvring to land can easily starve both engines. The other thing is the amount of fire is not enough.

This is really gonna shake up the industry and may lead to more regulation. All this online selling of flights has brought prices too low and coat cutting has gone too deep. Taking minimum fuel on a vfr day is consistent with this theory. I really hope I am wrong but from where i sit, everything leads to this. I cant begin to tell you how reliable these engines are. Like I said, most pilots have their low fuel stories. You always make it until you don't.

You have no idea what the fuel on board at KOSU was, but have concluded fuel exhaustion based on what, exactly? Having been in private jet ops, we are more likely to be far as few operators look at fuel burns and loads as airlines do—there’s not much saving to be had.

Oh, after a two-hour flight, the fuel burn at both engines was such that the two independent wing tanks ran out at within one second of each other? Is that your contention?

how do you account for dusty tanks creating such an impressive fire—the plane is largely consumed, the road and the sound barrier heavily scorched. No fuel equals no, or little, fire

[BFSGrad]

I saw no reference to possible fuel contamination in the preliminary NTSB report. Your post appears to link fuel contamination to the NTSB report and I think that is misleading.
The possibility of fuel contamination was introduced directly by the JB video (post #145) rather than the NTSB preliminary report, which simply describes the fuel characteristics at multiple locations without drawing any implications.

Regarding the 1/2 oz of water in the tail tank, unclear how that could result in either engine failure. From the 604 fuel system description in post #102, the 604 draws from the mains until 93%, then keeps the mains at 93% by drawing from the tail and aux tanks until those are empty. Thus, assuming the mains were less than 93% upon arrival at KAPF, any contamination in tail or aux tanks would have been irrelevant.

Regarding the yellow tinted fuel from the #2 engine, OK, but not an explanation for dual engine failure.

[MechEngr]

Too little so far to tell the significance but it's 1/2 ounce in a 16 ounce sample, not 1/2 ounce in the tank.

[605carsten]

Water in tail tank is misleading as the post 149 above mentions ref fuel burn schedule. Besides.. with 2 independent systems, having both shut down within a second of each other is pretty unrealistic.

[605carsten]

I saw in Juans youtube comment section about how nobody flies from RHS in the Challengers, but please remember the CRJ series is same triggers for shutoff hence a million airline F/Os fly regularly from the Right Seat so maybe a few CRJ captains can chime in with their views?

[EXDAC]

Too little so far to tell the significance but it's 1/2 ounce in a 16 ounce sample, not 1/2 ounce in the tank.

My interpretation is different.

The report says - "About 16 ounces of liquid with an odor and appearance consistent with Jet-A fuel was drained
from the aft tail fuel tank; the sample contained about ½ ounce of what appeared to be water."

My interpretation is that they were able to collect only approximately 16 ounces of fluid from the aft tail tank. It was essentially empty.

[EXDAC]

Ref - https://www.ntsb.gov/about/Documents/MajorInvestigationsManualApp.pdf

"Flammable liquids and gases -- Can ignite or be hazardous if skin contact is made or if vapors are inhaled. Have the airplane defueled before going near it and record the amount of fuel that is removed. Instruct personnel that smoking will not be permitted at the accident site."

[galaxy flyer]

My interpretation is different.

The report says - "About 16 ounces of liquid with an odor and appearance consistent with Jet-A fuel was drained
from the aft tail fuel tank; the sample contained about ½ ounce of what appeared to be water."

My interpretation is that they were able to collect only approximately 16 ounces of fluid from the aft tail tank. It was essentially empty.

The aft tanks aren’t used for flights under 3 hours, then it’s a mix of fuselage and aft tanks based on CG consideration.

[resetjet]

You have no idea what the fuel on board at KOSU was, but have concluded fuel exhaustion based on what, exactly? Having been in private jet ops, we are more likely to be far as few operators look at fuel burns and loads as airlines do—there’s not much saving to be had.

Oh, after a two-hour flight, the fuel burn at both engines was such that the two independent wing tanks ran out at within one second of each other? Is that your contention?

how do you account for dusty tanks creating such an impressive fire—the plane is largely consumed, the road and the sound barrier heavily scorched. No fuel equals no, or little, fire

Yes no computed fuel burns like airlines do….so maybe they burned more then they thought they would. Savings depends on any fuel contracts. Was the fuel indicator system working properly?

2 engines will fail at the same time if super low and maneuvering.

i dont know what you mean by dusty tanks, but jet a VAPOR will self ignite just like diesel when compressed. Liquid is mol not compressable.

that is not an impressive fire. It was consumed over time, like any vehicle fire. I am looking at the fact that the right wing was torn off. There should have been 150 gallons or much more in there. The plane hit and spun which should have littered the highway with fuel. Go pour a gallon of diesel on a campfire and the answer will be quite clear.

no fuel in the fuel line is also key. The other engine likely primed up after they leveled but at that point n2 had degraded.

that and 5000 hours in this series most as pic. With no obvious engine damage, and i cannot begin to tell you how bulletproof these engine are
Dual engine flameouts are super rare.

and for those worried about 1/2oz of water, forget it. Comtamination after 2 hr flight….possible, but those engines will burn corn oil mixed with water and still run. It would have to be alot of water.


ntsb witheld alot in that report. They know way more. Just threw us a bone.

[605carsten]

I just have a hard time believing they would BOTH fail within a second of each other.. but considering they flew back at FL400 (FL410 is max)which the airplane hates unless really light, means we cant really eliminate the fuel load either.

[resetjet]

I just have a hard time believing they would BOTH fail within a second of each other.. but considering they flew back at FL400 (FL410 is max)which the airplane hates unless really light, means we cant really eliminate the fuel load either.

well the fuel system does balance the tanks keeping them fairly equal. So in theory with little in them and a slight negative g or a bank or both might do the trick. Once the pump cavitates its game over even if momentarily. Not sure what is recorded to the FDR but you would think there would be a low fuel caution. But like i said, NTSB already knows. They are withholding alot.

[rippey]

I just have a hard time believing they would BOTH fail within a second of each other.. but considering they flew back at FL400 (FL410 is max)which the airplane hates unless really light, means we cant really eliminate the fuel load either.

604 should have no problem making it to 400 with 3 in the cabin and trip fuel+alternate+reserve. Disclaimer - my estimation based on over a decade on a 601 and being pretty sure the 604 wasn’t ‘worse’.

Other posters have mentioned 350 gal not being enough, which is true, but if you called the FBO in Ohio that they used and asked what the minimum uplift to waive the ramp/handling fee was I would not be surprised if they said 350 gal. Pretty standard ops for 91/135 is to tanker from home base (or other location with cheap fuel) and only take the minimum needed to waive elsewhere.

[BFSGrad]

Other posters have mentioned 350 gal not being enough, which is true, but if you called the FBO in Ohio that they used and asked what the minimum uplift to waive the ramp/handling fee was I would not be surprised if they said 350 gal. Pretty standard ops for 91/135 is to tanker from home base (or other location with cheap fuel) and only take the minimum needed to waive elsewhere.No need to make that call. The KOSU FBO website lists the minimum fuel purchase to waive fees by aircraft size. For the Challenger 604, to avoid the $600 ramp fee, the minimum fuel purchase is 350 gallons.

[galaxy flyer]

Yes no computed fuel burns like airlines do….so maybe they burned more then they thought they would. Savings depends on any fuel contracts. Was the fuel indicator system working properly?

2 engines will fail at the same time if super low and maneuvering.

i dont know what you mean by dusty tanks, but jet a VAPOR will self ignite just like diesel when compressed. Liquid is mol not compressable.

that is not an impressive fire. It was consumed over time, like any vehicle fire. I am looking at the fact that the right wing was torn off. There should have been 150 gallons or much more in there. The plane hit and spun which should have littered the highway with fuel. Go pour a gallon of diesel on a campfire and the answer will be quite clear.

no fuel in the fuel line is also key. The other engine likely primed up after they leveled but at that point n2 had degraded.

that and 5000 hours in this series most as pic. With no obvious engine damage, and i cannot begin to tell you how bulletproof these engine are
Dual engine flameouts are super rare.

and for those worried about 1/2oz of water, forget it. Comtamination after 2 hr flight….possible, but those engines will burn corn oil mixed with water and still run. It would have to be alot of water.


ntsb witheld alot in that report. They know way more. Just threw us a bone.

18 years flying bizjets, including all models of the Bombardier line, never flew without a computer flight plan. The odds of both engines flaming out at the same moment due to fuel exhaustion is approximately zero, dual flameouts are so rare this is actually a unique event in truest meaning of unique.

You’ve never heard the term “dusty tanks” for out of gas? Really? There was more fire than empty tanks would produce. Ever see video of planes without fuel crashing? Pretty much nothing except flying dust and debris, zero fire.

[galaxy flyer]

604 should have no problem making it to 400 with 3 in the cabin and trip fuel+alternate+reserve. Disclaimer - my estimation based on over a decade on a 601 and being pretty sure the 604 wasn’t ‘worse’.

Other posters have mentioned 350 gal not being enough, which is true, but if you called the FBO in Ohio that they used and asked what the minimum uplift to waive the ramp/handling fee was I would not be surprised if they said 350 gal. Pretty standard ops for 91/135 is to tanker from home base (or other location with cheap fuel) and only take the minimum needed to waive elsewhere.

Any TOGW below 39,000#, you can cruise at F400, no problem. Just a flight plan, 800# payload, KRSW as ALTN, 0+45 holding and 2000# extra fuel. TOGW is 36,000#, ETE 2+09. Pretty close to what they would have flown.

[resetjet]

18 years flying bizjets, including all models of the Bombardier line, never flew without a computer flight plan. The odds of both engines flaming out at the same moment due to fuel exhaustion is approximately zero, dual flameouts are so rare this is actually a unique event in truest meaning of unique.

You’ve never heard the term “dusty tanks” for out of gas? Really? There was more fire than empty tanks would produce. Ever see video of planes without fuel crashing? Pretty much nothing except flying dust and debris, zero fire.

unusable fuel in the 604 would produce that amount of fire.

Have you heard about the former ntsb inspector speaking out how the penny pinching by these types of operators is the cause of this accident?

[rog747]

A very sad accident with the loss of two very experienced Pilots.
A great feat for the Stewardess to quickly open the rear baggage hold door as the escape route for her passengers.


This accident below, which pretty much has gone under the radar, also almost made it down on a Freeway.
In 1971 a Paninternational Airlines BAC 1-11 515FB airliner D-ALAR made an Emergency Landing on the Hamburg-Kiel Autobahn when both engines failed within 90 seconds of take off from Hamburg Airport.
Shortly after takeoff from runway 34 at Hamburg-Fuhlsbüttel Airport, as the aircraft climbed to 1000 feet on it's way to Malaga Spain with 115 Passengers and 6 Crew, both of the Rolls Royce Spey jet engines failed and the Captain quickly decided his only choice was to make an emergency landing on the Bundesautobahn about 4.5 km from Hamburg Airport.
During the forced landing, on the southbound carriageway to avoid heavy traffic out of Hamburg, Captain Hüls was just able to avoid a collision with a nearby high-voltage line.
An oncoming couple in a Fiat 500 managed to scurry under the plane safely.
The unpowered BAC 1-11 crashed into the road near Quickborn at 150 knots and ten tons over its permitted landing weight.
The nose and right main landing gears collapsed, causing the aircraft to deflect to the left and collided with an overpass bridge and multiple concrete pillars.
The T-tail was sheared off.
The left wing struck an emergency telephone and the guard rails, the forward fuselage with the cockpit separated ending up in a ditch.
The rest of the fuselage skidded to a halt, initially remaining intact resting against an oak tree, but subsequently caught fire and burned out.
A Cabin Crew member and 21 passengers were killed in the crash, while all other 99 occupants escaped.

CRASH OF A BAC 111-515FB IN HAMBURG (https://www.baaa-acro.com/crash/crash-bac-111-515fb-hamburg-22-killed)

Probable cause:
It was determined at the subsequent Investigation that the tank for the Water-Injection engine thrust-augmentation system (used to cool the engines to increase performance for the high maximum takeoff weight of 47 tonnes) was that the contents of five canisters had inadvertently been refilled with a mix of water and Jet A1 Kerosene fuel, instead of with all Demineralised Water.
Spraying this additional jet fuel into the engines caused them both to overheat and fail shortly after take-off.

Crash on the highway - In German - Use Google Translate for English (https://www.faz.net/aktuell/gesellschaft/ungluecke/flugzeugunglueck-vor-50-jahren-das-wunder-von-hasloh-17514862.html)


https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1900x1324/76169754_8e6c599558c025f94bf6c23bbd71875ed6cf5f36.jpg

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1900x1324/76169750_08bc3a3040d9d6ddbb03ddf7086dc74d1eddd7ec.jpg

[BizJetJock]

If the collector tanks ran dry, on each side you would get multiple CAS messages:
MAIN EJECTOR FAIL (White)
FUEL LO PRESS (Amber) Which would bring on both
FUEL PUMP ON (Green), rapidly replaced by
FUEL PUMP (Amber) as it detected no output pressure.
So finally six messages, accompanied by multiple chimes from the Master Caution
It would then be around a further 30 seconds before the engines actually flamed out, as the fuel in the lines is drawn in.
After the engines flame out, it is another 10 seconds or so before you get the ENG OIL PRESS red message and associated voice warning.
Since none of these are mentioned in the report I think we can rule out fuel exhaustion.

[galaxy flyer]

unusable fuel in the 604 would produce that amount of fire.

Have you heard about the former ntsb inspector speaking out how the penny pinching by these types of operators is the cause of this accident?

See post on EICAS messages that would post if there was fuel exhaustion. Which is what my manual confirms. I haven’t flown the 605 is years, so went thru it and there would be at least six messages in addition to OIL PRESS LO. If you have a hard-on for 135 Florida ops, fair enough, but stick with facts.

Despite what you think, unusable fuel in a 604 would not be near enough to produce a fire capable of destroying the entire airframe. Theres only a couple dozen gallons at most.

[EXDAC]

If fuel exhausion is eliminated - Unsupported by EICAS messages and perhaps by fire size
and
If accidental shut off is eliminated - Proven design with millions of flight hours on various types including PF in right seat
what is left?

I'm actually not impressed by "never happened in millions of flight hours". I used to work on Design Assurance Level A aircraft systems for which the acceptable probablilty of catastrophic failure was 10^-9. That's 3 orders of magnitude less probable than never in a few million.

https://en.wikipedia.org/wiki/AC_25.1309-1#:~:text=Classification%20of%20failure%20conditions%20by%20 severity,-The%20concept%20of&text=Failure%20conditions%20having%20Catastrophic%2C%20Major ,Probable%20(10%E2%80%935).

[galaxy flyer]

Agreed on “one in a million” but I don’t think independent DAL Level A includes throttles or pilot interaction with throttles. After all, we have to shut off the engines on a variety of cases and we can’t preclude ****ting them off. The 767 hs had accidental in-flight shut downs by crews as has the Global during test where a clipboard “did it”. Guards were 8nstalled on the Hlobal and Boeing re-designed the engine control switches in the 757/767 family.

FADECs I’m familiar with include a rapid restart to provides a means of restarting, if the switch moves rapidly from RUN to OFF and back to RUN.

[EXDAC]

I have not handled these throttles or the shut off interlocks so genuine questions -

How many hands are needed to intentionally shut off one engine?
How many hands are needed to intentionally shut off both engines simultaneously?
Has it been verified that an arm placed in the worst possible position behind the thrust levers can lift the unlock levers (triggers?) if thrust levers pulled to idle position?

Yes, flight test sometimes reveals issues that no one had ever considered. We were close to starting cert demos for the 717 when the flight crew reported a spontaneous change in baro setting. It was confirmed by data review and had the potential for causing a major delay in the program. Fortunately there were cameras on the flight deck and it was shown that the baro set knob had been rotated by the Jepp plates binder as it was passed over the glareshield. Glareshield was extended to guard the knobs and cert completed on schedule.

[galaxy flyer]

One, One, it’s been demonstrated in a YouTube video that an arm behind the throttles can be placed to unlatch the releases, one or both. But, it was suspected and done in the sim, not in the plane.

[Chwhit]

See post on EICAS messages that would post if there was fuel exhaustion. Which is what my manual confirms. I haven’t flown the 605 is years, so went thru it and there would be at least six messages in addition to OIL PRESS LO. If you have a hard-on for 135 Florida ops, fair enough, but stick with facts.

Despite what you think, unusable fuel in a 604 would not be near enough to produce a fire capable of destroying the entire airframe. Theres only a couple dozen gallons at most.

Nothing to say the previous messages didn't display. Report might only have disclosed the last two.

[WITCHWAY550]

Most likely yes but here is another question. If I recall correctly (CL601-3AS/SN 5003/1990-1999) the fuel shutoff red throttle located "paddles" would not allow a normal 0r abnormal engine shutdown if you activated either one of those levers before the actual throttle was actually positioned to the furthest aft travel as possible. If you pushed that lever prior the throttle would not allow further travel to cutoff. So if that is true the throttles would have been moved to full idle, then the accidental encounter with the left seat pilots arm as he reached to the flap handle, then the right seat guy pulled further on the throttles in an attempt to be at idle. Any active CL pilots comments?

[BFSGrad]

I have not handled these throttles or the shut off interlocks so genuine questions -

How many hands are needed to intentionally shut off one engine?
How many hands are needed to intentionally shut off both engines simultaneously?
Has it been verified that an arm placed in the worst possible position behind the thrust levers can lift the unlock levers (triggers?) if thrust levers pulled to idle position
There is a YT video of an Endeavor CRJ-900 shutdown showing the FO first shutting down the #1 engine with one hand, then shutting down the #2 engine with one hand. My impression watching that video is that it would not be much of a “stretch” to actuate both red shutdown switches with the fingers of one hand while simultaneously bridging the thrust lever knobs with the thumb of the same hand and pulling both engines to shutdown.

Regarding “has it been verified…,” many CRJ and Challenger pilots (so claimed) across multiple forums have stated it is possible. There is also a video short that can be accessed on PoA that demonstrates the scenario (still available, watched just moments ago).

[EXDAC]

Two posters have referenced a video showing an arm can release the shut off latches but no links were provided. Any chance a link can be provided to one, or both, videos? My searches do not find it/them.

[BFSGrad]

Two posters have referenced a video showing an arm can release the shut off latches but no links were provided. Any chance a link can be provided to one, or both, videos? My searches do not find it/them.
My reference comes from a link contained in the Pilots of America topic on this accident. It is a link to an iCloud URL so I don’t want to post it here. I’d treat it as “click this link at your own risk.”

[B2N2]

Two posters have referenced a video showing an arm can release the shut off latches but no links were provided. Any chance a link can be provided to one, or both, videos? My searches do not find it/them.

https://m.youtube.com/watch?si=e6IDt-f4nyej6V7j&v=oLq829q3g4o&feature=youtu.be

[WITCHWAY550]

There is nothing good about a fatal crash except the lesson learned. It can be stated that pilots in the right seat do not often fly the plane from the right seat except 121 and maybe with some frequency 135. For the most part 91 ops switch seats. At EAL I flew right seat DC-9 for nearly 5 years. I would advocate a “must do” on, an occasion, is to operate a complete flight with the PF in the right seat if you can. One night departing TEB for London as we waited for the passengers i moved the left seat full aft. That’s where it failed and there was nothing we could do to move it forward. We flew the trip with PF in the right seat. What a significant diversion from our otherwise routine ops. So in this case a new to the aircraft pilot in the right seat. Nothing bad about that. Considering the total number of CF34 engines on Canadair’aircraft there is an extreme frequency of PF in the right seat especially with the Commuters. I would imagine at the 121 level, training and actual, there may be those that teach with a caution to this possibility. Seems real. I still believe you would need to have those levers “on the stops” to go further to shutdown, inadvertent or on purpose.

[605carsten]

Being cleared to land, tight on base to final for a US slam dunk visual, ask for full flaps as you retard back to idle to get a speed change/trend under way.., easy to be back on the stops at same time an arm is in the way..

[WITCHWAY550]

I would agree. You could go back to idle with those CF34's and expect to get the thrust you need, when you need it. Given you are on approach, lower to the ground, almost all the drag you can put out there with the final flap call you will soon need some power to stabilize it all. I go back to what I said. A lot less frequency of PF's in the right seat in that type of operation except there was a new guy. If this is what happened why was he not in the left seat or just let the left seat guy be the PF. I further thought about the likelihood that things like this and perhaps well known by the 121 guys that flew or fly the CRJ's, but not the 91 guys. No "pass-thru" of that sort of valuable knowledge. Or did Canadair or GE ever put out a warning on that. I still think its certain that those throttles had to be back to the stops, then the call for full flaps (or thereabout the time) then the arm goes across then, for what ever reason, the PF pulls back on both throttles without knowing he was already at idle.

[EXDAC]

Being cleared to land, tight on base to final for a US slam dunk visual, ask for full flaps as you retard back to idle to get a speed change/trend under way.., easy to be back on the stops at same time an arm is in the way..

Several references to US "slam dunk visual" but base for this approach was about 5 NM from threshold. The FAF for RNAV 23 is 4.8 NM out.

Just how far out would you want base leg to be on a visual in this aircraft type?

[605carsten]

Depends what his status was in the company.. if he with his low time in type is restricted to the RHS per their 135 ops manual, then thats were he will sit and fly.. just because you are PIC rated in a 91 sense doesnt give you right to sit in the left seat for 135. In my 135 and previous EASA AOC ops, we dont allow F/Os to fly from left until more experienced, as there is no tiller in the RH so you as PIC cant do nuthin if they decide to clip a wing going in and out of crowded FBO ramps.. My experience is also many Captains feel very uncomfortable acting as PM from the Left.. with handover of controls and taking them back after landing on the roll out.

[BFSGrad]

Several references to US "slam dunk visual" but base for this approach was about 5 NM from threshold. The FAF for RNAV 23 is 4.8 NM out.
The N605TR accident report documents Bombardier’s approved circle-to-land procedure: 1.5 nm lateral from runway on downwind, 15-30 seconds past threshold (~1 nm) before beginning continuous base-to final turn. N823KD’s flight path was well outside the dimensions for a circle-to-land approach; i.e., 4 nm lateral from runway, 5 nm from threshold rolling out onto final. Bit of a stretch to characterize that as slam dunk.

I occasionally see 121 jets turning inside the FAF for visual approaches at my local airport. Don’t think they’re slam dunking.

[BizJetJock]

The thrust levers definitely have to be at idle before the catches are lifted to shut down the engines. If you reach the stop with them already lifted even partially the balk is still there and you cannot reduce below idle. There have been cases on other types with a similar arrangement of the balk being so worn that it didn't work, but I have never heard of it on a Challenger. Of course CRJs do many, many more sectors in their life so the possibility of a worn out mechanism is greater.
Which brings us to the video posted above. We tried to duplicate this in a 604 sim, and even intentionally could not get the geometry to lift both catches at exactly the right time. It was extremely difficult to do even one, and that required a very unusual seating position for the PM to have their arm in the position shown in the video.

[WITCHWAY550]

Thank you for that.

[aeromech3]

Ground running an L1011, after start the throttle was moved just a little, but the engine accelerated towards T/O power; the cut off switch worked fine; RR stated it could not happen, but some months later came back with the FFR strip report that a failure had allowed full throttle internally.
I recall the cut off switches are a simple design much like you would have found in 1960 car dashboards with a sprung forward position for extra cold start fuel flow the guards were simple too, 1/2 moon type fences.
I was surprised from above B J J entry, to learn the throttles need to be retarded so achieve cut off on this Challenger, fire handles are a lot slower in my circumstances.
What need was there for these larger switch paddles on the Challenger beats me!

[island_airphoto]

So to summarize: If they had actually run out of fuel, it would have been obvious on the panel and on the FDR?
Re the setting of the thrust levers: I was harassed by the FAA over a plane in a field with the fuel valves turned off. I mentioned a few times that is part of the emergency landing checklist for that airplane, got the guy to sound the 1/2 full tanks, and he went away. Would this have been intentional by the pilots on "short final" to the road?

[galaxy flyer]

MAIN EJECTOR PUMP FAIL (L/R), FUEL BOOST ON (L/R), FUEL BOOST FAIL (L/R), all due to no fuel pressure, ie no fuel. Where exactly the sensors are located, I’m not sure. The chances of fuel exhaustion at the exact same moment are very small, the two OIL PRESS lights came on within one second of each other.

The EICAS indications are recorded in the FDR.

[1southernman]

Ground running an L1011, after start the throttle was moved just a little, but the engine accelerated towards T/O power; the cut off switch worked fine; RR stated it could not happen, but some months later came back with the FFR strip report that a failure had allowed full throttle internally.
I recall the cut off switches are a simple design much like you would have found in 1960 car dashboards with a sprung forward position for extra cold start fuel flow the guards were simple too, 1/2 moon type fences.
I was surprised from above B J J entry, to learn the throttles need to be retarded so achieve cut off on this Challenger, fire handles are a lot slower in my circumstances.
What need was there for these larger switch paddles on the Challenger beats me!

My experience on small jets was older Citations...The TLs had triggers mounted such that you pulled up on the trigger to move the TL in or out of cutoff...So you had to pull the TL all the way back to the stop for shutdown...I believe the Challenger "paddles" work the same way...They're not fuel shutoff switches like the BUS or levers like Boeing...So in the event of a stuck TL the only way to shutdown would be activating fire fighting stuff...B

[aeromech3]

Thanks 1southernman, that explains a lot, most aircraft I have had the pleasure of working on, if you forgot to check the throttle levers were at idle before start, you would wonder why the idle was high :oh:.
Seems to me that Murphy's Law is the likely answer.

[JCWeisz]

KPHL 2004 flying CRJ200 (CL65) - similar type. 10000 feet inbound for landing, 300 hour copilot slaps throttles back to idle. Single Engine oil pressure light illuminates as engine spools down. Declare emergency and proceed with engine restart checklist. Engine restarts and continue with normal landing and shutdown. Turns out throttle was rigged incorrectly. Missed clue that throttle had to be advanced slightly forward of idle stop to get a light off during startup. FCU did not meter enough fuel to maintain idle when throttles were moved abruptly back to the stop. Dual engine failure would be challenging at low altitude - took almost 30 seconds for restart on one engine. Note - Philly ATC put us back in line when we notified them of engine restart.

[resetjet]

KPHL 2004 flying CRJ200 (CL65) - similar type. 10000 feet inbound for landing, 300 hour copilot slaps throttles back to idle. Single Engine oil pressure light illuminates as engine spools down. Declare emergency and proceed with engine restart checklist. Engine restarts and continue with normal landing and shutdown. Turns out throttle was rigged incorrectly. Missed clue that throttle had to be advanced slightly forward of idle stop to get a light off during startup. FCU did not meter enough fuel to maintain idle when throttles were moved abruptly back to the stop. Dual engine failure would be challenging at low altitude - took almost 30 seconds for restart on one engine. Note - Philly ATC put us back in line when we notified them of engine restart.

this is correct and crj’s. Have alot more cycles. There was a problem with the mechanism being worn and a service bulletin being issued. Unlikely in this case.

[resetjet]

See post on EICAS messages that would post if there was fuel exhaustion. Which is what my manual confirms. I haven’t flown the 605 is years, so went thru it and there would be at least six messages in addition to OIL PRESS LO. If you have a hard-on for 135 Florida ops, fair enough, but stick with facts.

Despite what you think, unusable fuel in a 604 would not be near enough to produce a fire capable of destroying the entire airframe. Theres only a couple dozen gallons at most.

you are correct. A yellow caution would have occurred along time ago. But you must also know that with two engines shutdown a whole list of very confusing eicas messages would also occur. Was there any mention of the other messages(a full screen). No as the ntsb is witholding it.

[resetjet]

The thrust levers definitely have to be at idle before the catches are lifted to shut down the engines. If you reach the stop with them already lifted even partially the balk is still there and you cannot reduce below idle. There have been cases on other types with a similar arrangement of the balk being so worn that it didn't work, but I have never heard of it on a Challenger. Of course CRJs do many, many more sectors in their life so the possibility of a worn out mechanism is greater.
Which brings us to the video posted above. We tried to duplicate this in a 604 sim, and even intentionally could not get the geometry to lift both catches at exactly the right time. It was extremely difficult to do even one, and that required a very unusual seating position for the PM to have their arm in the position shown in the video.

that has been my experience as well. As a 121 captain i had this happen many times, never shutting even 1 engine down. You need to go to idle stop, lift the levers quite a bit, then go to stop. The youtube video shows a very unrealistic scenario. Go to idle. Lift levers and then go to cutoff. However anything is possible, it is a logical explanation and would solve alot of problems, but is not without problems of its own. How hard is it to do. Would you immediately advance to idle cutoff and punch ignitor a/b? I would. Would it restart? I dont know. I guess we will have to wait and see. If no low fuel messages, and no fuel contamination it seems logical. I still say not enough fire. Plus jet a you can throw a match in a 5 gallon bucket and it will
go out. The only thing that makes it explode is being mixed with air and compressed. However that would happen with 200 gallons left, just alot more fire.

[ATOguy]

you are correct. A yellow caution would have occurred along time ago. But you must also know that with two engines shutdown a whole list of very confusing eicas messages would also occur. Was there any mention of the other messages(a full screen). No as the ntsb is witholding it.
Why would the NTSB withhold it?

[resetjet]

They never say every message. It would appear from their initial report that fuel starvation has been ruled out, as there was no mention of lack of fire, low fuel warnings, etc…. so thats one answer. The cutoff is the most likely cause, but having so many flights in the left seat reaching around to grab the flaps, i just cant see it. But its all impossible until it isnt. The big problem i have is both engines being starved of fuel(for whatever reason) at the same time. Both cutoff is consistent with this. I guess we will find out in a year and a half when the docket is published.

[WITCHWAY550]

I think your observation nearly connects the 2 dots I started out thinking. IF the collector tank was empty then no power and in that area less fire. Already commented however that tank is actually 2 individual tanks. So this theory/speculation might exceed all probabilities. In the end it is either system, pilot or a poorly designed failled part.