Exceeding limitations

[Canucit]

I agree with gravity

 

[GVFlyer]

I agree with gravity

I think I do.

Probably the only other person, besides the author, to understand Philosophiae Naturalis Principia Mathematica, where Sir Isaac Newton explains his laws of conservation of energy and gravitation, was Alfred Einstein.

GV






~

 

[GVFlyer]

Let me preface my remarks by saying that I know nothing about Citation limitations or how they were derived.

There are margins in all aircraft, but there is no way for you to know what they are, where they are or how they were determined.

For instance, the GV went to Mach 1.07 during developmental test, but Mmo was established by a control reversal at Mach 0.955 when rudder Cl beta went positive (pushing right rudder would cause the left wing to drop). Under FAR Part 25, you must back off Mach 0.07 from such an aerodynamically limiting event (or Mach 0.05 if if equivalent safety can be demonstrated through rational analysis). Subsequently, Mmo became Mach 0.885.

If flutter had been encountered we would have been required to reduce Mmo by 15%.

Initially all GV's were flown to Mach 0.95 on production test flights, the G550 now does controlability checks at Mach 0.92.

This is by no means an all enclusive list, other aeroelastic qualities may be limiting. For instance they lost the SJ30 test article (with Carroll Beeler on board) due to inadequate lateral stability at Mach 0.82.

In the thick air (high Q [one half rho V squared] for other than rockets) other factors might be limiting.

In the GV/G550 Vno is 340 KCAS. I've seen 420-430 KIAS during enevlope expansion flights. During these flights there are four or five instrumented engineering work stations manned by flight test engineers monitoring aircraft systems and loads. All such flights are thoroughly briefed on the ground and a safety review is accomplished prior to launch.

The engineers came up with 340 knots for a combination of reasons, among them bird strike protection and reduction of incremental fatigue damage so the jet could have a 20 year warranty on primary and secondary structures.

Not all manufacturers are so conservative in establishing limitations.

It is foolhardy for your boss to ignore the limitations that the manufacturers established principally to keep him (and you) safe.

His kind of flying harkens back to the early days in Learjets when Lear almost lost their certification. Lear pilots would disable the overspeed warning system below 10,000 feet so that they could go 300 knots to avoid icing, then forget to enable the system later. Subsequently, at FL450, without the system to warn them, a number of these pilots exceeded the maximum allowable speed in the Lear's narrow window between compressibility effects and stall then departed controlled flight.

I don't think you're going to get his attention. Time to update the resume.


GV

 

[charter dog]

GV:

Thanks for that concise summary on the "most limiting factor" concept as it applies to flight test work. My admittedly light reading of part 25 reveals this to be a recurring theme throughout the certification requirements. Good explanation!

As to Albert Einstein, I have read his book Relativity explained so that anyone can understand it twice and don't yet feel I grasp the general theory any better than when I began! The man truly had no concept of how far beyond the reach of a person average intellect his mind soared. He must have understood the "mechanical universe" as described by Newton and others pretty well indeed before he set out to form his theory of relativity. Yet simple everyday tasks eluded his grasp. Truly amazing!

Sorry about the thread drift.

While there may indeed be times when it is appropriate to disable certain warning systems under certain circumstances, this clearly does not appear to be one of those circumstances. Our young friend has quite a dilemma on his hands. I get the impression he wants to do the right thing.

There was a young kid some of us knew around the airport who was worried about flying in a certain Lear 24 with a certain captain. He was so excited to actually have the job, he went anyway. If only anyone had known the whole story, he might still be with us. The cause will never be known because they went straight in at 500+ knots and there was nothing left to investigate.

Sorry to bring up this bummer of a story, but this situation brought that memory back.

Best,

 

[Lead Sled]

There was a young kid some of us knew around the airport who was worried about flying in a certain Lear 24 with a certain captain. He was so excited to actually have the job, he went anyway. If only anyone had known the whole story, he might still be with us. The cause will never be known because they went straight in at 500+ knots and there was nothing left to investigate.

Sorry to bring up this bummer of a story, but this situation brought that memory back.

If you're in this business long enough you will have similiar experiences. It seems that there is never any shortage of guys who know more than the designers, engineers, and test pilots.

Stuff like this can be career limiting in more than one way. (Based on the principle that if you spend enough time in a barnyard you'll eventially get cow crap on the cleanest of boots.) I just finished up an international procedures course and spent a couple of days sitting next to a guy who was in the B-52 squadron up at Fairchild AFB when some Lt. Colonel drove one into the ground during an airshow practice killing himself and 3 others. (You all remember the video, the B-52 hit the ground during a steep turn too close to the ground. There was a pretty good article about the incident in one of the recent issues of Flying Magazine.) Merely being in the same squadron as that guy caused enough problems for my friend that he eventially left the Air Force. He is now one of GVFlyer's compadres in Savannah.

Corporate aviation is really a very small world. After you've been in it a while you know a lot of people and develop a lot of connections regardless of what you fly. This will work to your advantage or disadvantage. If you are known as a good guy and a good stick, willing to help people out, it will be good for you at some point in your career. (Based on the principle of what goes around comes around.) If you become known as a jerk, well that also will come back at you during your career - sooner or later. You also don't want to become known as one who condones bad practices. There are two guys in the cockpit when the circuit breaker is being pulled and when the speed is intentionally allowed to creep past the barberpole. If you stick around this guy long enough you may end up getting a taint on yourself. Bizjets cost a lot of money to own and operate. Nowadays, most people are pretty particular about who they give the keys of their jet to.

Don't make the mistake of thinking that it's somehow OK because he's flying just a little too fast. That's just like being a little out of the CG envelope or a little overweight.

Our friend has a dilemma - having a job sitting in a Citation so soon in his career is something that most guys aren't able to accomplish. It's really too bad that he has to fly with a jerk. If I were in his same exact situation, I would like to think that I would have the heuvos to call the guy on his flying practices and stand my ground. The obvious drawback to this position is that you will probably end up out on the street - there is no reasoning with guys like that and with the people who hire them. Doing the right thing doesn't always give you the result you want.

Good luck to you.

'Sled

 

[XTW]

Our young friend has quite a dilemma on his hands. I get the impression he wants to do the right thing.

Thankfully he is concerned. Doing the right thing will help keep him around to become our "old friend".

Ditto on updating the resume.


X

 

[Wang Chung]

If you stick around this guy long enough you may end up getting a taint on yourself... there is no reasoning with guys like that and with the people who hire them. Doing the right thing doesn't always give you the result you want.

Geez, how true. Throughout my career I've always felt that associating with a direputable operation will reflect on me and my character more than the operation itself. I've left a couple companies because of this, and not on the most optimal terms either. I don't regret it, though.

We've all dealt with guys like this - the ones that are impervious to reason. It's a no-win situation and you're asking to get violated or killed. Blast out the resumes and network your way into something better, and do it before something REALLY bad happens or before you have a knock-down drag-out run-in with this guy. Leave on your own terms, and on the best terms you can manage, and do it soon!

 

[falconpilot]

Falcon 50 can go .99 and do steep turns... Never did it.... Just saw the video..

 

[Lead Sled]

Falcon 50 can go .99 and do steep turns... Never did it.... Just saw the video..

Sorry to disappoint you, that wasn't the airplane. It must have been the sim cam video from my first sim session. The sim instructor promised me he would erase it. :0

'Sled

 

[PHX767]

Hmmm... I flew with a guy like the CA described when I was at FLOPS. He left under less than savory circumstances. Since found something, I am sure. First initial wouldn't be M, would it?

Anyway, this bozo in my case pulled some of the same crap and after a few episodes of me objecting to his behavior, I finally said, "When we land I am a) going to beat the tar out of you, b) call the Fleet manager, c) refuse to get in another plane with you. He took it to heart. Next time we were assigned together, he greeted me like a long lost brother. I replied with, "yeah, and you try any of the same old stuff and I am outta here." What a tool. Yes, I called the FM anyway and followed up with a letter. Still took a while to fire him, and more bizzare events.