The Citation X doesn't get near that state at FL51, let alone lower altitudes. Unless of course you pull the throttles back so it doesn't have thrust... at which point that's pilot error of a significant level.

And is also dangerous when flying near the coffin corner.Cheers,- jahman.

I don't know why people make the coffin corner out to be some dangerous thing. Many jets fly thousands of hours a day in this area and don't crash. It's not hard to control aircraft speed which is why most business jets don't have auto-throttle. It's an unnecessary complexity to have one on board.

I don't know why people make the coffin corner out to be some dangerous thing....

Maybe becasue of this? ;-)Cheers,- jahman.

Maybe becasue of this? ;-)Cheers,- jahman.

Yes I know what the coffin corner is. When flying up high there is not as much drag so the aircraft doesn't decelerate as rapidly to stall and it has less power so it is hard to get it to accelerate quickly up to MMO. So even though you may have 40-50 knots of airspeed available you really have to be asleep to break the envelope. When flying up there 99% of the time you can level off at cruise altitude and just barely move the throttles to maintain the correct power setting. Out of all the flying I have done jet flying has been the easiest (except for hand flying an ILS. Those needles move quick!)

A uch better description is gien in;http://rgl.faa.gov/R...E/AC61-107A.pdfIt contains some intersing quotes:In recent years, a number of corporate jet airplanes have been involved in catastrophic loss of control during high-altitude/high-speed flight. A significant causal factor in these accidents may well have been a lack of knowledge by the pilot regarding critical aspects of high-altitude, MACH flight.Maximum operating altitudes of general aviation turbojet airplanes now reach 51,000 feet. It is, therefore, logical to expect these types of accidents to continue unless pilots learn to respect the more critical aspects of high-altitude, high-speed flight and gain as much knowledge as possible about the specific make and model of aircraft to be flown and its unique limitations.The sleek design of some turbojet airplanes has caused some operators to ignore critical airspeed and MACH limitations. There are known cases in which corporate turbojet airplanes have been modified by disabling the airspeed and MACH warning systems to permit intentional excursions beyond the FAA certificated VMO/MMO limit for the specific airplane. Such action may critically jeopardize the safety of the airplane by setting the stage for potentially hazardous occurrences. [My emphasis]

Yes I know what the coffin corner is. When flying up high there is not as much drag so the aircraft doesn't decelerate as rapidly to stall and it has less power so it is hard to get it to accelerate quickly up to MMO. So even though you may have 40-50 knots of airspeed available you really have to be asleep to break the envelope. When flying up there 99% of the time you can level off at cruise altitude and just barely move the throttles to maintain the correct power setting. Out of all the flying I have done jet flying has been the easiest (except for hand flying an ILS. Those needles move quick!)

I'm sure you know what the coffin corner is, but the link I posted is for the consequences (not the definition).If you have 40-50 KN of airspeed available (IAS? TAS?) as you say, then you're not really flying in the coffin corner: Perhaps that explains your not feeling a sense of "impending doom" :-)BTW, as your GWT decreases due to fuel burn your IAS/TAS/Mach number will increase on its own and fly you into the coffin corner.As the FAA circular posted by mgh confirms (great link!), the coffin corner is dangerous enough to warrant a circular from the FAA, not to mention a stick puller (in addition to the stick pusher; I wonder which of the two wins at the coffin corner, or does the stick just pop out of its socket together with a legend on the PFD in large red letters that says "go back to flight school, do not collect $5,000"?)Cheers,- jahman.

A uch better description is gien in;http://rgl.faa.gov/R...E/AC61-107A.pdf...........

Thanks for that link, interesting document.

Don't put too much trust in the Wikipedia article - the diagram is wrong.

I'm sure you know what the coffin corner is, but the link I posted is for the consequences (not the definition).If you have 40-50 KN of airspeed available (IAS? TAS?) as you say, then you're not really flying in the coffin corner: Perhaps that explains your not feeling a sense of "impending doom" :-)

From a Flight Safety manual (The training company for just about every business jet):"The term coffin corner is used to describe the situation in which an airplane has climbed to such a high altitude that the difference between the low-speed stall buffet and the high-speed Mach buffet is only a few knots. Most turbine-powered business airplanes do not have enough thrust to climb to the coffin corner altitude"The newer Gulfstreams, Citations and Lears have the capability to get up high but most of them have at least 20 knots between the two speeds which is plenty of room to not get yourself in trouble.

BTW, as your GWT decreases due to fuel burn your IAS/TAS/Mach number will increase on its own and fly you into the coffin corner.

Yes I know but even after we burn off a couple thousand gallons of fuel we only gain about 3-5 knots of speed.

As the FAA circular posted by mgh confirms (great link!), the coffin corner is dangerous enough to warrant a circular from the FAA, not to mention a stick puller (in addition to the stick pusher; I wonder which of the two wins at the coffin corner, or does the stick just pop out of its socket together with a legend on the PFD in large red letters that says "go back to flight school, do not collect $5,000"?)Cheers,- jahman.

Yes AC's are usually pretty important but some can be down right funny. I wish I could find one that was talking about not testing fuel by drinking it. Unfortunately someone most have tried it to warrant an AC.

...Yes I know but even after we burn off a couple thousand gallons of fuel we only gain about 3-5 knots of speed.

Thanks for the info. That's unexpected, as I would have thought the speed increase to be larger. Nothing like real-world experience!

Yes AC's are usually pretty important but some can be down right funny. I wish I could find one that was talking about not testing fuel by drinking it. Unfortunately someone most have tried it to warrant an AC.

Does that apply to all fuel grades? :-)Cheers,- jahman.

Thanks for the info. That's unexpected, as I would have thought the speed increase to be larger. Nothing like real-world experience!Does that apply to all fuel grades? :-)Cheers,- jahman.

At the college I taught at we decided to call it filling the airplane with juice. We changed them and 100 low lead was blueberry, 100 was green apple and 80/87 was strawberry :(

At the college I taught at we decided to call it filling the airplane with juice. We changed them and 100 low lead was blueberry, 100 was green apple and 80/87 was strawberry :(

Oh, you must have taught at UND!

Oh, you must have taught at UND!

Haha far from it. I taught at a school that didn't ripoff the students :(

At Riddle we joked those that couldn't cut it went to UND...