New Winglets

Keep in mind guys m1.0 is not officially supersonic and most aircraft built to fly that fast have been designed to delay or reduce shockwave, and local pressure spikes untill the entire ac has become at least transonic if not super sonic. This means no boom at 1.0.

I would guess that an c750 could do well more than 1.0 without a boom
 
I did hear that Cessna was planning on announcing a Mmo increase at NBAA this year. I never read anything definitive, however.
 
jwp_145 said:
Funny story: Kenneth Copeland (the tv preacher) came through KRVS in his Citation X when I was a line crewman... his bird had the IR Camera on the nose. I asked the pilot how much drag that produced... his answer? "Do you really think it matters?" haha, he was smiling when he said it.
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:laff:
ANd I know there are rumors about the X reaking mach number 1.0, but I've never seen any documented proof that it actually happened. I've seen a cameraphone picture from an MFD that showed a TAS of 1.0 and the engineer also said that it happened, but I've never seen the proof nor will I probably ever. I had a professor at OSU, my mentor, who had the most spectacular dream carreer at TWA that we all want from 63-1991... he said that a crew inadvertantly broke mach 1.0 in a 727 during the recovery from an upset attitude.
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I've heard that story in class while at Dowling as well as during ground school at XJT. I'm pretty sure there's an NTSB report about it as well.
 
WestIndian425 said:
:laff:

I've heard that story in class while at Dowling as well as during ground school at XJT. I'm pretty sure there's an NTSB report about it as well.
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If you're referring to TWA 841's upset/departure, I believe they only went to .96M max.
 
MikeD said:
If you're referring to TWA 841's upset/departure, I believe they only went to .96M max.
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As Brewster told the story, and Brewster old a LOT of stories, a Captain had pulled a circuit breaker or something that allowed either the slats or the t.e. flaps to come out without the other at the same time as they were designed to... someone noticed, popped it back in, thus the upset attitude.

But as I said, Brewster was old and full of a lot of it!

***EDIT***

WOW SEEMS HE WAS TELLING THE TRUTH!

http://en.wikipedia.org/wiki/TWA_Flight_841_(1979)

Now I remember the story... as Brewster was a TWA 727 CA at this time... the flight crew had pulled a circuit breaker so that they could cruise with only partial deployment of the wings camber-altering devices, for whatever reason is beyond me. Someone noticed it, popped the circuit breaker back in, an everything went FUBAR.
 
May 2009

Cessna president, CEO and chairman Jack Pelton, in responding to a question at an EBACE press conference on Tuesday said, “If the G650 is certified to 0.925, we will be sure it goes back to number two.”
http://www.ainonline.com/airshow-co...in-the-civil-aircraft-speed-crown/?no_cache=1

Aerodynamic design, wind tunneling testing, and airfoil performance, for example, have their foundation with NASA. The Citation X is the fastest, most efficient business jet ever built.
http://ntrs.nasa.gov/search.jsp?R=8...=all&Ntx=mode+matchall&Ns=HarvestDate%7c1&N=0


Yes. The Citation X exceeded Mach 1 during certification flights (So did the GV). In addition, to be certified at .92, an aircraft must demonstrate a maximum sustained cruise speed of .99M. The only public documentation I have ever seen was in a Cessna aircraft book (The one seen in many FBOs).

It is not unusual for Ce750s to exceeded .92 due to mountain waves. It is very much a hazard when crossing the range. Inspections are required, then they are returned to service.


Elliptical Winglet STC Approval Broadens for Citation X
http://www.ainonline.com/news/singl...winglet-stc-approval-broadens-for-citation-x/
 
jwp_145 said:
As Brewster told the story, and Brewster old a LOT of stories, a Captain had pulled a circuit breaker or something that allowed either the slats or the t.e. flaps to come out without the other at the same time as they were designed to... someone noticed, popped it back in, thus the upset attitude.

But as I said, Brewster was old and full of a lot of it!

***EDIT***

WOW SEEMS HE WAS TELLING THE TRUTH!

http://en.wikipedia.org/wiki/TWA_Flight_841_(1979)

Now I remember the story... as Brewster was a TWA 727 CA at this time... the flight crew had pulled a circuit breaker so that they could cruise with only partial deployment of the wings camber-altering devices, for whatever reason is beyond me. Someone noticed it, popped the circuit breaker back in, an everything went FUBAR.
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Yeah, that's Hoot Gibson's incident. True story. Was the FE that noticed it IIRC, and pushed the CBs back in. This incident caused quite a stir because the flight crew claimed to know nothing of the reason why the 727 went out of control, yet evidence didn't support a simple "slat-failure" theory. IE- what the crew was telling the NTSB and what they were finding, didn't jive.

Excerpt:
The evidence involves a fundamental conflict between the flightcrew's statements and the possibilities and probabilities of an unscheduled extension of the No. 7 slat. Although portions of the slat actuator were not found, the evidence indicates that the possibility of a series of malfunctions and failures occurring which permitted the slat to extend aerodynamically or hydraulically is extremely remote. On the other hand, we recognize that if the No. 7 slat did not extend as the consequence of some series of failures and malfunctions in the slat system, then it must have been extended as a result of flightcrew action.

After carefully weighing all evidence related to this accident, the Safety malfunctions in the aircraft's flight control system that would have caused an unscheduled extension of the No. 7 leading edge slat. Moreover, since the airspeed decrease which followed extension of the Nos. 2, 3, 6, and 7 slats during flight tests compares almost exactly with the airspeed decrease experienced by Flight 841 following initial oscillation of its g-trace, which under constant thrust and 1.0-g flight conditions can only be attributed to similar drag producing configurations, the Safety Board concludes that the Nos. 2, 3, 6, and 7 slats were extended as a consequence of flightcrew action.
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Of course, it didn't help that Gibson erased the CVR after landing.....what he claimed to be a "common procedure", but which one would think wouldn't be so common following an accident/incident.....sure makes things look suspect.....

Since our weighing of the evidence involves a rejection of the possibility of an
recollection of his actions following extension of the slats, the Safety Board believes that
the following comments are appropriate: We believe the captain's erasure of the CVR is a
factor we cannot ignore and cannot sanction. Although we recognize that habits can
that the captain's putative habit of routinely erasing the CVR after each flight was not
cause actions not desired or intended by the actor, we have difficulty accepting the fact
after a flight in which disaster was only narrowly averted. Our skepticism persists even though the CVR would not have contained any contemporaneous information about the events that immediately preceded the loss of control because we believe it probable that the 25 minutes or more of recording which preceded the landing at Detroit could have provided clues about causal factors and might have served to refresh the flightcrew's memories about the whole matter.
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Mike D, why on earth would they want to cruise with the slats out? Brewster had once told me but I've long forgotten.
 
jwp_145 said:
Mike D, why on earth would they want to cruise with the slats out? Brewster had once told me but I've long forgotten.
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IIRC, word was the Capt was trying to get more performance from the jet by having the flaps very slightly extended (about 2 degrees, increase wing area w/o drag), but they didn't want the slats to extend at the same time so they pulled the CBs [was apparently a somewhat common practice by some]. Once the FE discovered this, he pushed them in, the slats extended asymetrically due to the speed they were at, and it went from there.
 
Yeah ok makes sense. When my teach told the story he said that the Capt saved the day by throwing the gear, that much I do remember.

As an interesting aside, Brewster was friends with John Testrake, the Capt from the hijacking photo with the gun to his head.
 
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