News just reported CRJ crash...

[Crossky]

Icing at 410 is unlikely.

Ok, you make a valid point. I read somewhere there were scattered to broken clouds that night, don't know what altitudes. STD temp at FL410 is -67 C according to standard lapse rate, but I believe it would be higher than that.

I read the NTSB release from yesterday, it looks like Maint replaced the R 14th stage bleed air sensing loop. After a satisfactory test they released the aircraft to service. The plane had a history of ignitor replacements also.

So, my theory of operating with an inoperative cowl and wing anti-ice system appears to be proven false.

My mouth and my theories are shut for now.

 

[Tycer]

3. Info from the paper says people on the ground saw landing lights - that requires AC electrical power which means the APU more than likely WAS running, but even if it wasn't and the people on the ground are not remembering clearly,

Or the ADG was deployed.

 

[Crossky]

The NTSB reported thermal damage to the R engine. Looks like the bleed air system could posibly have been involved after all. The NTSB release is as below.



NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
October 20, 2004
UPDATE ON PINNACLE AIRLINES CRASH IN JEFFERSON CITY, MISSOURI

The National Transportation Safety Board today released the following update on its investigation of the October 14, 2004 crash of Pinnacle Airlines flight 3701 in a residential area in Jefferson City, Missouri, about three miles south of the Jefferson City, Missouri, airport. The crash resulted in the deaths of the two crewmen. The airplane was destroyed by the impact forces and a post crash fire. There were no passengers onboard, nor were there any injuries on the ground.

On October 14, 2004, the aircraft departed Little Rock, Arkansas about 9:21 p.m. (CDT), on a repositioning flight en-route to Minneapolis-St. Paul, Minnesota.

Air Traffic Control
At about 9:43 p.m., the flight crew checked in with Kansas City Air Route Traffic Control Center (ARTCC) and indicated that they were climbing to 41,000 feet. At approximately 9:52 p.m., the flight crew acknowledged that they were at 41,000 feet. At about 9:54 p.m., the flight crew asked for a lower altitude. At about 9:55 p.m. the flight crew declared an emergency. At about 9:59 p.m. the flight crew requested an altitude of 13,000 feet. At about 10:03 p.m., the flight crew reported that they had experienced an engine failure at 41,000. At 10:08 p.m., the flight crew stated that they had a double engine failure and that they wanted a direct route to any airport (According to the Flight Data Recorder both engines stopped operating almost simultaneously at 41,000 feet.) Kansas City ARTCC directed the flight to Jefferson City Missouri Airport. At about 10:13 p.m., the flight crew stated that they had the runway approach end in sight. The last radar contact for the flight was at 900 feet above ground. The plane crashed at about 10:15 p.m.

Maintenance
On October 14, the day of the accident, the airplane underwent maintenance to replace the 14th stage bleed air- sensing loop on the right engine. During a scheduled 7:45 a.m. departure from Little Rock, Arkansas to Minneapolis St.-Paul, Missouri, an Indicating Crew Alerting System (ICAS) message stating "R 14th duct" occurred during take- off and the flight crew (not the accident crew) aborted the take-off and returned to the gate. The 21 passengers were deplaned. The airplane never left the ground. Two mechanics from Pinnacle's Memphis, Tennessee facility did the repair. During a Safety Board interview on Saturday, the mechanics stated that they only replaced the No. 2 (right) engine's 14th stage bleed air sensing loop. The mechanics completed the repair and tested the system. The aircraft was released for flight. On-scene evidence confirms that the repair was done in accordance with the Aircraft Maintenance Manual.

The aircraft was equipped with two GE CF34-3B1 engines. The right engine had accumulated 2,303 hours and 1,971 cycles since new. It was installed new on the aircraft on October 23, 2003. The left hand engine had 8,856 hours and 8,480 cycles since new. It was removed from another aircraft on October 30, 2003 and installed on the accident aircraft on April 6, 2004. Maintenance records indicate that during an A4 check on June 9, 2004, the left engine igniters were replaced. During an A5 check on August 18, 2004, the right engine igniters were replaced. The most recent check was the A5 check performed on August 18, 2004.

Operations
The Operations group traveled to Memphis to interview pilots who had flown with the two crew members and to interview some of the airlines training personnel and managers. There are 10 to 12 interviews scheduled.

Wreckage
On-scene examination of the wreckage shows there was no sign of an in-flight fire on the structure of the aircraft. The airplane was found inverted and separated in several sections. All four major flight surfaces were found at the main wreckage site. The cockpit area was severely damaged by the post crash fire.

During the Safety Board's examination of the engines, it was noted that there was some thermal damage to the No. 2 engine and that will be further looked at during a teardown in Lynn, Mass. The engines will be shipped out today.

The wreckage is being shipped to Rantoul, Kansas.

Since the accident, the operator, Pinnacle Airlines, has placed a new company altitude restriction on the flight ceiling for their CL600-2B19s of 37,000 feet.

Parties to the investigation are Pinnacle Airlines, Federal Aviation Administration, Air Line Pilot's Association, National Air Traffic Controller's Association, and General Electric (GE). The Transportation Safety Board of Canada has sent an accredited representative along with technical advisors from Transport Canada, the agency that certified the aircraft, and Bombardier Aerospace, the manufacture of the aircraft.

NTSB Media Contact: Terry N. Williams, (202) 314-6100, [email protected]

 

[VABB]

Some new info from another board:



Excerpt from a pilot who works with the safety portion of the union:

"Because the plane was empty, the crew probably thought they could fly at 410 no problem. Well the plane stalled and dual engine flameout occured. They recovered around 330 and tried to relight the engines. They spent the next 24 or so minutes getting vectors from ATC. Relight never occured and it looks like it was due to the slow airspeed they were tying to relight at. It sounds like the NTSB will be implementing the rule that CRJ 100/200's are limited to 350. It is a very sad way to learn a lesson, but the 200's should not be up a 410. Sounds like the engines were melted because of the heavy loads of fuel passed through and not enough speed. No checklists were used in the entire 24 minute period. Pinnacle uses memory items."

Actually, the cause of this crash is quite simple. Gravity simply outweighed lift and the ground won.

 

[efiscompmon]

Well, Vabb does have a point.

The ADG cannot power the landing lights.

As indicated, the 14th stage had only their sensor loop replaced; so they wouldn't have been MELed--something that isn't regularly done because the thrust reversers are off of it too.

The igniters were not replaced abnormally early. In a 727, where continuous is selected for every t/o, we replace them even sooner.

In real life, air starting a turbofan is not the easiest endeavor.

That thermal damage could have been me in DTW a while back. Going to the 'zoo with twelve pax and 4000# of fuel--TLAR'ed the thrust levers, hit 103 on the left N1 before the FO trimmed it and lept off the runway in about 3600 feet. Cleared to 10, got a restriction for 8000 at 7000. Stopped the climb at 8600. I love giving IOE.

the operator, Pinnacle Airlines, has placed a new company altitude restriction on the flight ceiling for their CL600-2B19s of 37,000 feet

I believe it's called ballast. Which, had we paid for the mod, we wouldn't have to carry the weight, burn the fuel and bump cockpit jumpseaters. Good job, J.Y.! Just like those two-piece oxygen masks. Scumbags.

 

[enigma]

NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
October 20, 2004
UPDATE ON PINNACLE AIRLINES CRASH IN JEFFERSON CITY, MISSOURI



Air Traffic Control
At about 9:43 p.m., the flight crew checked in with Kansas City Air Route Traffic Control Center (ARTCC) and indicated that they were climbing to 41,000 feet. At approximately 9:52 p.m., the flight crew acknowledged that they were at 41,000 feet. At about 9:54 p.m., the flight crew asked for a lower altitude. At about 9:55 p.m. the flight crew declared an emergency. At about 9:59 p.m. the flight crew requested an altitude of 13,000 feet. At about 10:03 p.m., the flight crew reported that they had experienced an engine failure at 41,000. At 10:08 p.m., the flight crew stated that they had a double engine failure and that they wanted a direct route to any airport (According to the Flight Data Recorder both engines stopped operating almost simultaneously at 41,000 feet.) Kansas City ARTCC directed the flight to Jefferson City Missouri Airport. At about 10:13 p.m., the flight crew stated that they had the runway approach end in sight. The last radar contact for the flight was at 900 feet above ground. The plane crashed at about 10:15 p.m.

I realize that this is a preliminary report, but it contains too many questions.
The published timeline is really a big question. First, it states that the crew reached FL410 at 9:52, then two minutes later (9:54)they asked for lower. Then one minute (9:55) later they declared an emergency. Then, four minutes later (9:59) they asked for 13000ft. Four minutes later (10:03), they told ATC that they had experienced an engine failure at FL410. Five minutes later (10:08) and a full 14 minutes from the initial lower request and 13 minutes after the emergency declaration, they told ATC that they had experienced dual engine failure and asked for vectors to the nearest airport.

I wish the NTSB would either give more complete info, or just withhold any info until they can give more complete inf. From the quoted report, it is fair to ask: why the crew asked for lower but not initially declare an emergency?, was the airplane descending between 9:55 and 9:59?, why they didn't initially report a dual engine failure (when the FDR indicates that both engines failed at FL410)?, did they report a failure but the initial report is just too brief to include all of that info?, why did they ask for 13000ft?, and most bothersome, why did they wait 13 minutes for asking for vectors to the nearest airport?

I hope that the brevity of the report is the cause of my confusion, and that these seeming discrepancies will be resolved when more information comes out.

I'm not questioning the crew, I'm just trying to make sense of this published timeline.

Any ideas?

enigma

 

[hmmm]

13000 is where you can do an engine start off of the apu. Meanwhile on the way down you begin to accelerate from 240 kts at about 25000 to reach at least 300 kts by passing 21000 where you begin to try to windmill start on your way down to 13000.

At 13000 feet bleed air can be extracted from the apu to start an engine while slowing down to aproximately 170 to 190kts depending on weight. This at an ITT of 90 or lower and at least 28% N2 after pressing the start button and a one minute starter motor duration with a start time limit of 25 seconds to acheive a stable idle after moving fuel lever from off to on.

If no start, fuel lever back off and motoring stopped by pressing the stop button and wait 30 seconds before trying again.

All the while airspeed is decreasing and must begin descent again reaching 170 to 190 kts again depending on weight in order to maintain speed.

This is not speculation.

This is right out of the Bombardier QRH. The airline in question uses a direct copy of Bombardiers QRH.

The aircraft was certified for flight at 410 by the manufacturer, the FAA and Transport Canada at the wieght and ISA temp on the night of the crash.


All the above is public information.

 

[N813CA]

41,000 ft which The RJ can and has done many times empty, is not because of the engines. They certify that because the FAA determines the aircraft pressurization can go to that, without structural damage. With a Margin of error.

 

[hmmm]

41,000 ft ---------->They certify that because the FAA determines the aircraft pressurization can go to that, without structural damage. With a Margin of error.

NO! That flat out is NOT the case.

It is FLAT OUT certified and tested throughout ALL regimes for civil passenger use up to FL 410 at the temp and weight on board the aircraft that night.

Their are buffer factors built in and tested in ALL regimes. The aircraft is certified for civil passenger use to that altitude at specific weights and temps.

Thats it.

There is no cert to that altitude just because the pressurization can make it there.

They certify the whole aircraft for passenger use to FL 410 as long as the wieght and temp meet the peramiters listed in the book.

They may have not been able to re-light the engines for some reason.
But the pilots are not the ones who certified the aircraft for that altitude. Transport Canada, FAA and Bombardier did.

There is no reason to doubt that certification so there should be no shirking of responsibility by the authorities that the pilots should not have been there.

 

[CF34-3B1]

I wish the NTSB would either give more complete info, or just withhold any info until they can give more complete inf. From the quoted report, it is fair to ask: why the crew asked for lower but not initially declare an emergency?, was the airplane descending between 9:55 and 9:59?, why they didn't initially report a dual engine failure (when the FDR indicates that both engines failed at FL410)?, did they report a failure but the initial report is just too brief to include all of that info?, why did they ask for 13000ft?, and most bothersome, why did they wait 13 minutes for asking for vectors to the nearest airport?

I hope that the brevity of the report is the cause of my confusion, and that these seeming discrepancies will be resolved when more information comes out.

I'm not questioning the crew, I'm just trying to make sense of this published timeline.

Any ideas?

enigma

Just a guess here, but one reason they may have requested lower before declaring an emergency could be they got too slow in the climb. Remember, mass airflow is critical to these engines. Get too slow, and firewalling the thrust levers will not give you any help. And what was it they used to tell us, the last 10% of the RPM is where 25% of the thrust is? I don't recall the numbers off the top of my head, but the point is, in the -200, you're so low on excess thrust to begin with, that if you get slow at very high altitude, you may very well not be able to accelerate, or even stop a speed decay.

This wouldn't explain why they were unable to relight one or both during the descent though.

My only guess would be some sort of fuel contamination or ice.

Guess we'll just have to wait and see what the NTSB says.

 

[Lear70]

Actually, N-Number guy has a point.

Having had this aircraft at 41,0 on a number of ocassions, I can tell you the PSID is EXACTLY 8.2 when you're there (max pressure differential for the uninitiated).

The aircraft's pressurization system is not designed to take the aircraft higher and would exceed the limitation on said system.

I'm certain all those other factors Mmmm (signature mmmhmmm) mentioned were included in the certification of this aircraft, but pressurization is definitely ONE of the limiting factors to a FL 41,0 ceiling. If they weren't going to put a pressurization system capable of maintaining a higher flight level with the same cabin altitude, I'm certain they had no intention of doing test flights OUTSIDE THE LIMITATIONS OF THAT SYSTEM... that would be kinda foolish.

 

[Toecutter]

13000 is where you can do an engine start off of the apu. Meanwhile on the way down you begin to accelerate from 240 kts at about 25000 to reach at least 300 kts by passing 21000 where you begin to try to windmill start on your way down to 13000.

At 13000 feet bleed air can be extracted from the apu to start an engine while slowing down to aproximately 170 to 190kts depending on weight. This at an ITT of 90 or lower and at least 28% N2 after pressing the start button and a one minute starter motor duration with a start time limit of 25 seconds to acheive a stable idle after moving fuel lever from off to on.

If no start, fuel lever back off and motoring stopped by pressing the stop button and wait 30 seconds before trying again.

All the while airspeed is decreasing and must begin descent again reaching 170 to 190 kts again depending on weight in order to maintain speed.

This is not speculation.

This is right out of the Bombardier QRH. The airline in question uses a direct copy of Bombardiers QRH.

The aircraft was certified for flight at 410 by the manufacturer, the FAA and Transport Canada at the wieght and ISA temp on the night of the crash.


All the above is public information.

The APU CANNOT restart the engines in flight on a 200 series. If you read the QRH, you'll see a note that reads "due to system logic, the apu cannot be used the restart the engines in flight" The only procedures in the QRH are for windmill and crossbleed, however, on the 700, the APU can be used to restart in flight.

 

[rumorhasit]

what is the glide ratio in the crj...?
I guess I don't understand how the accident happened...did they have some control on the way down did they loose control pressure? I understand there is a lot of speculation but how much control of the airplane did they have after both engines go out..?

Is this situation practiced in the sim at all...?

 

[Mmmmmm Burritos]

The APU CANNOT restart the engines in flight on a 200 series. If you read the QRH, you'll see a note that reads "due the system logic, the apu cannot be used the restart the engines in flight" The only procedures in the QRH are for windmill and crossbleed, however, on the 700, the APU can be used to restart in flight.

Yes and no. You can use the APU to restart AN engine only with a double engine failure. The limit is 13000 ft max for this however, so you'd definitely try to windmill start it first on the driftdown. The APU cannot be used to restart an engine with the other engine running.

 

[Mmmmmm Burritos]

what is the glide ratio in the crj...?
I guess I don't understand how the accident happened...did they have some control on the way down did they loose control pressure? I understand there is a lot of speculation but how much control of the airplane did they have after both engines go out..?

Is this situation practiced in the sim at all...?

Jet glide ratios are excellent. They would have control pressure but it would be reduced somewhat. One of the hydraulic pumps is powered by the Air-Driven Generator (ADG), and that pump would power all the primary control surfaces. It's a little sloppy but not tough. We did practice this in the sim and it's a rush to get everything done (at least for 2 new-hire FO's in the sim together!). Definitely not something I'd want to try in the real airplane especially at night. Control issues were not the problem though as long as the ADG and 3B pump were working correctly.

We never actually tried to land the sim out of that situation though. The engines always lit back up.

 

[Toecutter]

Yes and no. You can use the APU to restart AN engine only with a double engine failure. The limit is 13000 ft max for this however, so you'd definitely try to windmill start it first on the driftdown. The APU cannot be used to restart an engine with the other engine running.

I stand corrected.

 

[~~~^~~~]

I think other airlines will follow with altitude restrictions. My observation has been that our IP's and experienced line pilots seem to believe 37,000 is the maximum sensible altitude for the airplane. Although nothing is codified, we are told of experiences of low IAS / Mach resulting in compressor stalls.

Two factors are involved. First, CF34-3B1 is correct that mass airflow is very important to these engines. I have seen the thrust carat react to slowing airspeeds. Simply put, the more air you ram into the front of the engine the more power it makes. Nearly no air in the front of the engine results in compressor stalls, although I will be surprised if they could be so serious as to cause dual flameouts in an engine with variable stators.

The other factor is the supercritical wing. This wing hates to go slow. The L/D curve on the slow side of the wing's envelope is steeper than you might think.

These two factors combined make the RJ a great airplane to be at FL410 if you are at .76 or more. At .68 you are someplace you do not want to be.

Other observations about the report are that this airplane about set a time to climb record for a 200 and that the RT engine may have been damaged during a airstart attempt.

Gossip is that this was a very low time crew. New hire FO and Captain with about a year's time with the operator. Anyone know?

This is a bothersome accident. Airplanes should not have dual flameouts in their certified flight envelope. My prayers are with the friends and families of my fellow RJ pilots.

 

[TonyC]

Enigma,


As I read through the timeline, those exact same questions came to my mind. Why didn't they declare an emergency and announce a dual engine flameout from the beginning, if indeed that's what happened? Did they not know 2 engines failed, or were they trying to hide something, perhaps a mistake they made? And more . . . The problem is, to even ASK these types of questions tends to paint the crew in a bad light.

These and other "why" questions are best reserved for after the investigation is complete. We might not like the answers, and we don't have the "rest of the story," namely the CVR. The cockpit conversation will undoubtedly provide better insight into the actions of the crew.

I'm dying to know, too, but let's be patient and respectful.

 

[TonyC]

GRRRRRRRRRR....


Double post deleted - - daughter interrupted me.


What happened to the fail-safe feature this board used to have that prevented double-posting?



HAVE A NICE DAY !

 

[hmmm]

The APU CANNOT restart the engines in flight on a 200 series. If you read the QRH, you'll see a note that reads "due to system logic, the apu cannot be used the restart the engines in flight" The only procedures in the QRH are for windmill and crossbleed, however, on the 700, the APU can be used to restart in flight.

Guess u didn't know the airplane very well, or you didn't read the QRH, or didn't read it or your other books very well. Maybe its just your memory. I have both the companies and the Bombardier's QRH in front of me at this moment. Direct copies of each other and there is no note anywhere in Emergency or Abnormal procedures like your referred to and they specifically take you through the in-flight APU assisted start procedure.

There is the windmill start.
The starter assisted crossbleed. (Engine to engine.)
Or in the case of the Double flameout the APU start and then if able the starter assisted crossbleed to start the second one.

 

[hmmm]

Actually, N-Number guy has a point.

Having had this aircraft at 41,0 on a number of ocassions, I can tell you the PSID is EXACTLY 8.2 when you're there (max pressure differential for the uninitiated).

The aircraft's pressurization system is not designed to take the aircraft higher and would exceed the limitation on said system.

I'm certain all those other factors Mmmm (signature mmmhmmm) mentioned were included in the certification of this aircraft, but pressurization is definitely ONE of the limiting factors to a FL 41,0 ceiling. If they weren't going to put a pressurization system capable of maintaining a higher flight level with the same cabin altitude, I'm certain they had no intention of doing test flights OUTSIDE THE LIMITATIONS OF THAT SYSTEM... that would be kinda foolish.

ummm hmmm No "Base Hopper" I mean Lear70 just who's side are you on. If the aircraft is certified at the ambient temp and weight at FL410, then it was certificated to operate that night at FL410 and if the engines flamed out it is the entities that certified its responsibility. They shouldn't have flamed in the first place.

The Max DP is EXACTLY 8.7 not 8.2 Mr. Initiated.

And yes pressurization is ONE of many factors.

And yes they due test these factors waaaaaay OUTSIDE the envelope, just ask the resident test pilot now teaching at the sim.

 

[FN FAL]

Enigma,


As I read through the timeline, those exact same questions came to my mind. Why didn't they declare an emergency and announce a dual engine flameout from the beginning, if indeed that's what happened? ........

Could it have been from the startlement of having two engines quit, getting dumped to the emergency power level, having the CWS going off and quite possibly every look up light on the dash illuminated? Plus, without bleed air, wouldn't there be some depresurization occuring at that time?

That's an awful lot of stuff going on at one time. You'll have to excuse the look up light reference, but I don't know the CRJ's at all...it's probably all on a screen with the new glass cockpits.

It would seem to me that there must have been a lot going on at that moment. Maybe all the communications and requests for altitude changes and such might not make sense to us now as we sit in front of computers in a relatively safe environment, but one would have to think that at the moment both engines shut down, it was a very unsettling moment to say the least.

Can anybody clue us in to how things might have appeared in the cockpit of a similar aircraft, similar situation...without any more speculation as to what happened with this unfortunate crew? What I am asking is, what would a person see in the cockpit in regards to changes in cockpit lighting if the plane went down to the emergency power level...if that's what happens when you lose both engines? What kind of bells and buzzers would be going off? Are there look up lights or do you get all your information off of a screen? Would there have been a loss of pressurization? How rapid would that be, and would that alarm be an audiable one as well?

Keep in mind, I just asking to get a sense as to what the cockpit environment would be like as far as sound, systems lost and indications in a double engine flameout...not for additional speculation on the current CRJ crash.

 

[hmmm]

Finally. To answer someone else question above as to why they didn't do some of the declarations over the radio.

THEY WERE BUSY.

On the CRJ the ADG would pop out which is a external generator with a variable pitch prop that would have given almost instant AC power so they would have all flight control and eicas screens up as well as one hydraulic pump hard wired to it.

There would be all kinds of eicas messages coming up to sift through. Some going away as soon as the ADG powered up which might be a second or a few.

The pressurization on the CRJ as certified would begin depressurizing with both bleed air pressure sources flamed out but would depressurize no faster than 500 fpm if the system springs in the two pressurization outflow valves were operating properly and their seals were clean.

The APU could be started at 30,000 for AC generator output and the bleeds could be transferred to the APU at 15,000 but if they did not get the engines started by windmilling at a speed of at least 300 kts passing 21000 they could start the engines off the APU at 13000 but no higher.

Why they didn't start in this case? The engines shouldn't have quit in the first place as certified. Hopefully we will all learn every factor involved here and nobody will hide anything or push aside their responsibility.

 

[Toecutter]

Guess u didn't know the airplane very well, or you didn't read the QRH, or didn't read it or your other books very well. Maybe its just your memory. I have both the companies and the Bombardier's QRH in front of me at this moment. Direct copies of each other and there is no note anywhere in Emergency or Abnormal procedures like your referred to and they specifically take you through the in-flight APU assisted start procedure.

There is the windmill start.
The starter assisted crossbleed. (Engine to engine.)
Or in the case of the Double flameout the APU start and then if able the starter assisted crossbleed to start the second one.

Hmmm,

As I stated earlier, Burritos corrected me on the procedure. I don't fly the 200 anymore, so you're right, I was thinking from memory on single engine procedures and I don't have a QRH at home. Sorry if I offended you.

 

[CatYaaak]

ummm hmmm No "Base Hopper" I mean Lear70 just who's side are you on. If the aircraft is certified at the ambient temp and weight at FL410, then it was certificated to operate that night at FL410 and if the engines flamed out it is the entities that certified its responsibility. They shouldn't have flamed in the first place.
QUOTE]

I don't think anyone's taking "sides" in the matter, just a discussion. It seems that the first statement the NTSB made indicated that the aircraft entered an "aerodynamic stall". If that turns out to be accurate..if that was the first thing that happened.. doing so could certainly flame out the engines, and a subsequent overtemp during an attempted windmilling restart could melt one. Correct me if I'm wrong because I may be getting my engines mixed up, but I seem to recall there is no overtemp protection in that scenario.

 

[hmmm]

Hmmm,

Sorry if I offended you.

Not I. Protecting the families and their memories of these two good people.

 

[paid4training]

what would be the benefit of that altitude?

 

[hmmm]

The only overtemp protection would be an eicas warning and a hand on the thrust lever. But if they maintained .70 kts up to 410 and leveled off there should not have been an overtemp or a stall as certified at the ambient temp and weight that they were flying at.

Speaking from experience.

 

[dondk]

And yes they due test these factors waaaaaay OUTSIDE the envelope, just ask the resident test pilot now teaching at the sim.

So why make such a big deal about FL410? I still find it odd that the NTSB focused on that one issue so quickly.

 

[hmmm]

So why make such a big deal about FL410? I still find it odd that the NTSB focused on that one issue so quickly.

Because they will be looking for reasons to blame the pilots over anyone else.
The FAA for use in this country, Transport Canada and Bombardier certified the aircraft for operation up there and that is where this mess started.
If it was certified for operation at that ISA temp and weight to FL410 there should be no question as to why they attempted to operate at that altitude.
If it was certifed to do it there should be no reason why not.