CRJs

[VectorForFood]

I'm not debating what you saw. I am saying that "I" have never experienced that kind of performance from any commercial aircraft including the grossley over powered DC-8-70 series.
However, from a preformance point of view, a step climb would be unnecessary if the aircraft could reach FL410 with a RoC >1500 FPM climb after burning fuel. The margin over buffet onset would be sufficient to allow a direct climb to final cruse altitude with a final RoC >500 FPM.

What may also interest you, is that just yesterday I witnessed a turbo-prop climbing at 1500FPM to FL336, at which point it slowed to around 200-300FPM on their way up to FL400.

[Schorsch]

I'm not debating what you saw. I am saying that "I" have never experienced that kind of performance from any commercial aircraft including the grossley over powered DC-8-70 series.
However, from a preformance point of view, a step climb would be unnecessary if the aircraft could reach FL410 with a RoC >1500 FPM climb after burning fuel. The margin over buffet onset would be sufficient to allow a direct climb to final cruse altitude with a final RoC >500 FPM.

What may also interest you, is that just yesterday I witnessed a turbo-prop climbing at 1500FPM to FL336, at which point it slowed to around 200-300FPM on their way up to FL400.

Which turbo-prop is certified for such altitudes? You're really sure?

[Ancient Mariner]

I'm not debating what you saw. I am saying that "I" have never experienced that kind of performance from any commercial aircraft including the grossley over powered DC-8-70 series.
However, from a preformance point of view, a step climb would be unnecessary if the aircraft could reach FL410 with a RoC >1500 FPM climb after burning fuel. The margin over buffet onset would be sufficient to allow a direct climb to final cruse altitude with a final RoC >500 FPM.

What may also interest you, is that just yesterday I witnessed a turbo-prop climbing at 1500FPM to FL336, at which point it slowed to around 200-300FPM on their way up to FL400.

Which turbo-prop is certified for such altitudes? You're really sure?

This one:
http://www.nasa.gov/centers/dryden/news ... RC_prt.htm

Per

[Dmmoore]

I'm not debating what you saw. I am saying that "I" have never experienced that kind of performance from any commercial aircraft including the grossly over powered DC-8-70 series.
However, from a performance point of view, a step climb would be unnecessary if the aircraft could reach FL410 with a RoC >1500 FPM climb after burning fuel. The margin over buffet onset would be sufficient to allow a direct climb to final cruse altitude with a final RoC >500 FPM.

What may also interest you, is that just yesterday I witnessed a turbo-prop climbing at 1500FPM to FL336, at which point it slowed to around 200-300FPM on their way up to FL400.

Which turbo-prop is certified for such altitudes? You're really sure?

My question too!
Also. "IF" you are seeing a RoC >1000 FPM above FL350, It would not be sustainable. A typical climb is accomplished by increasing power while maintaining airspeed. RoC's >1000 FPM usually require a trade of IAS for a higher RoC. Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.

[Procede]

Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.

You mean between stall and buffet onset? When climbing too fast, you're more likely to lose speed than gain it.

[flyboy2548m]

Which turbo-prop is certified for such altitudes? You're really sure?

This one is.

http://www.piaggioaero.com/en/products/ ... tazoni.php

That's not to say Multiman isn't full of shit.

[flyboy2548m]

Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.

You mean you might get into the coffin corner, break up and die?!!!!!

[3WE]

Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.

You mean you might get into the coffin corner, break up and die?!!!!!

As I recall, your only choice is to maintain perfect airspeed +/- zero knots and burn off some fuel which then gives you a razor thin margin to do something, but I just don't recall what.....

[flyboy2548m]

As I recall, your only choice is to maintain perfect airspeed/- zero knots and burn off some fuel which then gives you a razor thin margin to do something, but I just don't recall what.....

As usual, you recall wrong. Perhaps you should ask Gabriel?

[3WE]

As I recall, your only choice is to maintain perfect airspeed/- zero knots and burn off some fuel which then gives you a razor thin margin to do something, but I just don't recall what.....

As usual, you recall wrong. Perhaps you should ask Gabriel?

Nope, I belive I am very correct on what the "Break up and die" dude listed as the options...

And, let's leave Gabriel out, as he would most likely attempt to provide a serious and in-depth description of coffin corner and how to deal with it.

[Schorsch]

[Serious] Question:
The CRJ200 and CRJ700 have different wings as far as I know. And the 700 uses slats. So far correct?
Now, how does that influence the behavior in final approach?
The CRJ200 has this characteristic nose down pitch attitude, which I think is due to a mixture of reasons: low wing loading, no slats and (at large airports) pretty oversized runways.
Is the CRJ700 different (different pitch in finals)?
Do the CRJ200 and CRJ700 require different ratings or can Flyboy switch between the aircraft (alike B737NG or A320 family)?

Thanks for input.

[Schorsch]

Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.

You mean you might get into the coffin corner, break up and die?!!!!!

As I recall, your only choice is to maintain perfect airspeed +/- zero knots and burn off some fuel which then gives you a razor thin margin to do something, but I just don't recall what.....

"Coffin Corner" means that there is a small margin between minimum airspeed (above stall) and maximum Mach number before buffeting starts. The AOA range of wings of airliners is fairly small at higher Mach numbers. The coffin corner normally is no issue when factoring in the safety margins, which is a 30% margin versus stall (Vmin = 1.3 Vs1g and CLmax = 1.3*CZmax_buffet).
The notorious coffin corner aircraft was the U-2 by the way. Ask Gary Powers.

[3WE]

Don: Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.

Flyboy: You mean you might get into the coffin corner, break up and die?!!!!!

3ME: As I recall, your only choice is to maintain perfect airspeed +/- zero knots and burn off some fuel which then gives you a razor thin margin to do something, but I just don't recall what....

Scorsch: "Coffin Corner" means that there is a small margin between minimum airspeed (above stall) and maximum Mach number before buffeting starts. The AOA range of wings of airliners is fairly small at higher Mach numbers. The coffin corner normally is no issue when factoring in the safety margins, which is a 30% margin versus stall (Vmin = 1.3 Vs1g and CLmax = 1.3*CZmax_buffet).
The notorious coffin corner aircraft was the U-2 by the way. Ask Gary Powers.

10-4

I wasn't clear that I was trying to QUOTE what the mixed up "break up and die" guy was WRONGLY saying back on AD.com. Something like: "If you get to coffin corner and do anything, you break up and die"

It was funny- not that he was wrong, but 1) that he was so PASSIONATELY wrong, and also 2) that he was a TINY bit correct:

1) Exceeding the maximum speed/getting supersonic can cause a rearward shift in the center of lift, causing a nose-down pitch and potential further speed increases...in SOME cases, with SOME aircraft, this can be an unrecoverable situation and you break up and die.

2) Stalling COULD in SOME instances with SOME aircraft
a. Get you a flame out, or nasty spin and you break up and die.
b. Get you out of whack so you nose over, speed up too much, have the lift-shift, dive, break up and die.

3) Gary Powers and others found that "busting" coffin corner caused scary, unplesant losses of control, but NOT a GUARANTEED "break up and die" nor are you totally helpless if you reach coffin corner.

Back on AD.com, I think the guy said, that the only thing you could do is fly perfectly at coffin corner and burn off fuel and THEN you might GENTLY power back and descend with razor-thin margins.

Yeah, he was wrong, but I think he had it in his head that Vne was something defined totally by the plane being structurally stressed to the breaking point- thus his concept was that any change whatsoever, including throttling back would break the plane since it added a "force" to something "stressed to the max".

Repeating- I'm JUST TELLING THIS STORY FOR GRINS- I don't agree with what the dude said.

[Schorsch]

Don: Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.

Flyboy: You mean you might get into the coffin corner, break up and die?!!!!!

3ME: As I recall, your only choice is to maintain perfect airspeed +/- zero knots and burn off some fuel which then gives you a razor thin margin to do something, but I just don't recall what....

Scorsch: "Coffin Corner" means that there is a small margin between minimum airspeed (above stall) and maximum Mach number before buffeting starts. The AOA range of wings of airliners is fairly small at higher Mach numbers. The coffin corner normally is no issue when factoring in the safety margins, which is a 30% margin versus stall (Vmin = 1.3 Vs1g and CLmax = 1.3*CZmax_buffet).
The notorious coffin corner aircraft was the U-2 by the way. Ask Gary Powers.

10-4

I wasn't clear that I was trying to QUOTE what the mixed up "break up and die" guy was WRONGLY saying back on AD.com. Something like: "If you get to coffin corner and do anything, you break up and die"

It was funny- not that he was wrong, but 1) that he was so PASSIONATELY wrong, and also 2) that he was a TINY bit correct:

1) Exceeding the maximum speed/getting supersonic can cause a rearward shift in the center of lift, causing a nose-down pitch and potential further speed increases...in SOME cases, with SOME aircraft, this can be an unrecoverable situation and you break up and die.

2) Stalling COULD in SOME instances with SOME aircraft
a. Get you a flame out, or nasty spin and you break up and die.
b. Get you out of whack so you nose over, speed up too much, have the lift-shift, dive, break up and die.

3) Gary Powers and others found that "busting" coffin corner caused scary, unplesant losses of control, but NOT a GUARANTEED "break up and die" nor are you totally helpless if you reach coffin corner.

Back on AD.com, I think the guy said, that the only thing you could do is fly perfectly at coffin corner and burn off fuel and THEN you might GENTLY power back and descend with razor-thin margins.

Yeah, he was wrong, but I think he had it in his head that Vne was something defined totally by the plane being structurally stressed to the breaking point- thus his concept was that any change whatsoever, including throttling back would break the plane since it added a "force" to something "stressed to the max".

Repeating- I'm JUST TELLING THIS STORY FOR GRINS- I don't agree with what the dude said.

Although I am not a particular fan of Flyboy, and I think he neither is of me, I guess he didn't mean it serious. A pilot flying transonic aircraft above 30kft knows what a coffin corner is and that you don't break up when you stall.

[VectorForFood]

http://www.airliners.net/photo/Piaggio- ... 1322461/L/
Ceiling of FL430 or so the crew told me, I've now seen them at FL410 and FL400, although painfully slow when compared to the traffic around them... usually 150-200 knots slower at least, much like the early model Citations, what we call a "high level road block"

[Dmmoore]

Wikipedia reports the Avanti's service ceiling ts 12,500 meters (FL410). We all know how accurate Wilki. can be.
By definition, the service ceiling is the point where the rate of climb decays to 100 FPM. This limit is based on weight and is usually quoted for the lightest operating weight complying with FAA requirements.
The aircraft may have an "OPERATIONAL" ceiling. This is not a service ceiling but another limit based on cabin pressure limits or performance limits such as emergency descent.
I should have said "STALL" buffet.

[VectorForFood]

Wikipedia reports the Avanti's service ceiling ts 12,500 meters (FL410). We all know how accurate Wilki. can be.
By definition, the service ceiling is the point where the rate of climb decays to 100 FPM. This limit is based on weight and is usually quoted for the lightest operating weight complying with FAA requirements.
The aircraft may have an "OPERATIONAL" ceiling. This is not a service ceiling but another limit based on cabin pressure limits or performance limits such as emergency descent.
I should have said "STALL" buffet.

Well as we say in our line of work "Don't blame them, they're only pilots"

[3WE]

Bump.

Pop some popcorn, sit back and enjoy.

(Sorry Monchie, this old stuff is just too entertaining, not_to share with our four active members.)

[elaw]

The first time I was around one of the current crop of regional airliners (characterized by propellers having a large number of blades and enclosed in a shroud) I found it highly amusing that they called a tug to push the thing back, knowing full well a couple of big burly guys could have done the job.

Kidding aside I do like flying on those things... the "smallness" doesn't particularly bother me, and the ride is a little more "sporty" than on their larger cousins.

[3WE]

The first time I was around one of the current crop of regional airliners (characterized by propellers having a large number of blades and enclosed in a shroud) I found it highly amusing that they called a tug to push the thing back, knowing full well a couple of big burly guys could have done the job.

Kidding aside I do like flying on those things... the "smallness" doesn't particularly bother me, and the ride is a little more "sporty" than on their larger cousins.

Isn’t “the tug” often a regular little baggage cart tractor vs those things that look like they belong in a massive rock quarry

I’ve definitely had worse rides in bigger planes. I don’t like that they destroyed the turboprop regional business, but somehow or other, it’s been a massive improvement in safety.

/rambling thoughts.

[Gabriel]

but somehow or other, it’s been a massive improvement in safety.

I don't understand why that would be the case, but it is.

[3WE]

but somehow or other, it’s been a massive improvement in safety.

I don't understand why that would be the case, but it is.

Well, they are more capable, fly a bit higher (less time in weather), a lot simpler, and have a little bit more technology: Flat screens, some additional automation, and maybe the "clean sheet, ergonomic, human interface and intuition thing". But that feels like only a partial explanation.

[Not_Karl]

But that feels like only a partial explanation.

Durnked, nekkid pilots fly better (or less worse).

the "smallness" doesn't particularly bother me, and the ride is a little more "sporty" than on their larger cousins.

What about the lavs?

[3WE]

What about the lavs?

I think they are bigger than those on the 737 Max.

[flyboy2548m]

Oh my...

I wonder what Wonnzie is doing these days...