@ Machinbird, Owain Glyndwr,

With your's teacher definition of dutch roll, Owain Glyndwr, the pilot does never need to do something to stop it. The yaw damper or the raw stability of the frame does the work. Once more "do nothing"...

With my teacher's definition of dutch roll (which has been more a flag in my brain than a complete definition -I told the context to emphasize that fact) , it works only if there is a dutch roll problem, not only a dutch roll...

1 vs 1.

The first order - surely more complex for the total plane- has already an oscillating output after an oscillating input - turbulence, yawcdamper failure, etc. -, and the pilot gives a second oscillation to try to stop the dutch roll "problem", starting resonance.

Semantics? Agreed.

Now we all know that after the AA587 we do not need to redefine Va. We need Va for what it isx not more, not less.

What we need is a new point of view that does not exist in our regulations of certification concerning RESONANCE. It could be builded on Machinbird's post and enhanced from his first text and his experience of PIO and high level flight experience. His post with Bode figure with numbers is a good beginning of what we have to think about the dynamic system.

In any case what is missing in our certification and knowledge is a quantified reference to dynamics of the transient parts of the plane's oscillation, Pio and other APC.

Resolving easy differential equations when flying (as I did) or reckoning dutch roll characteristics before computers (as you did 50 years ago) needs notthing more that what Richard Feynmann taughted to all his student : have no hesitation on basics calculations, integrals, aso.:ok:

So-called “posers” are one thing, but I have no problem with those with legitimate ignorance who are seeking knowledge. In truth, sometimes, a different perspective breaks down a lot of barriers.

Those who have been here for longer than just a while probably know that I have a well-deserved reputation for posting L-O-N-G posts. I believe the reason is that in one aspect of a former life I used to teach “communications” – and one of the quotes I used often was “The most often committed error in the art of communications is the mistaken belief that it has taken place.” This gives rise to the 3-aspects of communications: 1) what I say; 2) what you hear; and 3) what I intended to say. As a result, I often find myself using a lot of words – explaining the same thing somewhat differently, in an attempt to reduce the potential of errors by me in speaking, and the potential of errors in hearing by those who are listening. If there are some here who are attempting to learn something from the knowledgeable contributors who participate, but to those contributors these "knowledge-seekers" sound like “posers” in that attempt, I would say “back up and play it straight.” There are some here, who admit they are not aviators, but still are intrigued by some aspect or another of this job function – be it life style, fears, triumphs, or whatever else may be interesting to those on the other side of the glass. It’s been my experience, that if I wanted to know something about a particular job function or profession – about which I know little – trying to sound like an “insider” will, either earlier or later, fall on its face. So in the interest of time, I usually just blurt out what I’m after and why I’m asking. Usually, I get more information than I can process – and in the interim of wading through all the jargon and lexicon to get to a place I can understand, I’ve often generated some very good friendships.

When I’ve had an interested student ask the kinds of questions that students ask (either academically or aerodynamically) – through my attempt to provide that student something that can be usefully understood, I usually find myself trying to explain the same thing differently, most often using different words each time (which is what generates my reputation for using a lot of words) – and sometimes doing that, I am able to see the issue from such a different perspective, revealing a lot more of the subject, and providing me a better understanding of the situation, which, in turn, does 2 things: first – I learn more about the specific subject for my own use; and 2) I find a better way of expressing what it is the questioner really wants to know.

It may be true that I will fail to break through to any who may be lurking behind some false façade of “aviator.” However, maybe, just maybe, instead of trying to finesse a conversation with someone the questioner believes would not respond unless it were to a perceived equal, that questioner may feel somewhat more encouraged to simply and openly ask the question. I think those questioners would be quite pleasantly surprised.

One other thing – I’ve also found that sometimes the questioner is a closet-wannabe. There should be no guilt in being a “fan” of other persons or of interesting professions – and more often than not, the open fan is often accepted as at least a guest, if not a distant relative, at the “family” dinner table. One can simply NOT have too many friends – regardless of their background.

Do you keep that correspondence with your "Certificate of Awesome" signed by Neil Armstrong and Chuck Yeager? :rolleyes:

Horatio Barber, who flew the first aeroplane freight (Osram bulbs), wrote
"The Aeroplane Speaks"
for pilots and trainee pilots of the Royal Flying Corps in 1917. (It can be downloaded for those interested in what was taught, then.. Perhaps a HTBJ of its day.)

I have talked to and seen Bob Hoover several times and what a gentleman. Reading his book he would have had the sound barrier record if he hadn't done a buzz job that pissed off the commander so Chuck Yeager got it.

They have been at the Reno Air races the last 13 years I have been there and have Bob Hoovers autograph on his book. He used to fly into Flabob Airport in Riverside Ca. to see Art Scholl who I flew aerobatic instruction for and always landed his Shrike on one wheel even if nobody was looking. It was great flying back then. Everybody knew how to handfly and autopilots were a luxury but no one needed one. Today is different for the new people. We need to make new pilots real pilots not programers. Bottom dollar thinking probably won't let this happen again.

While 'posers' can present a problem, limiting to actual pilots would seriously limit valuable inputs and different points of view. I make no secret that I'm not a pilot (although I would have liked to be, and nearly was - but that's another story). But I do have 36 plus years experience as an engineer in Boeing Commercial Aircraft - working at one time or another 727, 737, 747, 757, 767, and 777. In short, I know a lot about 'how planes work' (at least Boeing planes), and I'd like to think that knowledge brings something valuable to the discussions. Unfortunately I often have to censor myself, because I know things that I'm not allowed to make public. Oftentimes it's considered Boeing proprietary/sensitive, in the case of air safety investigations we can get in big trouble for releasing unauthorized information before the official stuff comes out (e.g. I know stuff about Asiana that I can't repeat).

I also value the pilots input on what we do. I've known and worked with lots of Boeing test pilots over the years - some well known, others not so much - but getting input from the guys (and gals) that fly these planes on a day to day basis has a special value.

Dozy, I may very well be in error but I have reasons to believe flarepilot may very well be a reincarnation of our friend SSG, lately going by the Teldorserious handle. Flarepilot made the claim earlier in this thread that the Sabreliner 40 had a placard in the cockpit advising limiting control movement to 50% when above 40,000 feet. Only trouble is the operators of the aircraft I've talked to have never heard of it, and nor the FAA.

But I do have 36 plus years experience as an engineer in Boeing Commercial Aircraft

.. which is why we don't have an exclusive pilots' club and warmly welcome folks such as your goodself to the sand pit.

Could these things kill again?:}

Depends on one's agenda; if one believes that main lessons of AA587 are: never use rudder for roll when yoke is more than enough and never rapidly cycle any control as it is completely useless and potentially lethal, then differences in breakout force and force gradient between two principally similar systems are really moot point. Now if one wants to malign A300 and perhaps even complete Airbus range, than this difference really must be blown out of all proportions.

Up to what is written in manuals and not a bit more. Be gentle to your aeroplane as much as you can so you can be tough to her when things get hairy without fear of breaking anything due to accumulated fatigue? Naaah, not in training manual.

Rhino?

I'm afraid I agree with this one. Seemingly he firmly believed his actions were appropriate without stopping and checking whether they really were.

Given the quality of arguments in it, no surprise it turned out to be self-defeating prophecy.

Insufficient basic knowledge. One can have long and successful even while being pretty ignorant or even very wrong about some basic aeronautical facts. Pilot who thinks rudder is always used to deal with wake vortex just needs to avoid wake vortices.

Completely unsubstantiated claim.

Complete and utter lie. Slatless aeroplanes have no problems when de-iced properly. Whoever believed this paranoid rant would be severely mislead.

This appeal to emotions sucks at large. I do hate the people who try to pervert the lessons that should be learnt form demise of our colleagues as it increases the risk of the same crash happening again.

Completely unrealistic target. There is a limit in making aeroplanes fool-proof and safeguard under one condition can easily turn out to be lethal under other.

Just ask usual contributors about evils of envelope protection :E or if more realistically inclined, read DP Davies treatise on stick pushers.

Makes me wonder if it was so easy, why did the unlucky F/O bother with exerting 140 lbs push?

Sheer panic.

Misunderstanding, as it is usual on PPRuNe. FBW protection can stop distracted pilot from getting the aeroplane into irrecoverable attitude but that's about it. Many times it was proven that one can stay well clear of protections and still wreck the aeroplane.

I think you have misspelled "reason" there. Protection form resonance brought about by totally unnecessary and useless control inputs would have fallen afoul of this proposed regulation.

Quotes from tdracer:
"I make no secret that I'm not a pilot (although I would have liked to be, and nearly was - but that's another story). But I do have 36 plus years experience as an engineer in Boeing Commercial Aircraft - working at one time or another 727, 737, 747, 757, 767, and 777. In short, I know a lot about 'how planes work' (at least Boeing planes), and I'd like to think that knowledge brings something valuable to the discussions."

Precisely the kind of input pilots need to challenge their assumptions.

"...I also value the pilots input on what we do. I've known and worked with lots of Boeing test pilots over the years - some well known, others not so much - but getting input from the guys (and gals) that fly these planes on a day to day basis has a special value."

Looking back at my unremarkable career, some of the most rewarding dialogues I had were with engineers. Some of them were grizzled flight-engineers, but right now I'm talking about ground engineers. Admittedly, in my case they were mainly line-maintenance people; except in my earlier days on conversion courses, when some of the guys teaching us a/c systems had been production engineers on the same a/c. They've all since been supplanted by CBT, and what the powers-that-be think we "need to know"; more's the pity.

"Unfortunately I often have to censor myself, because I know things that I'm not allowed to make public. Oftentimes it's considered Boeing proprietary/sensitive, in the case of air safety investigations we can get in big trouble for releasing unauthorized information before the official stuff comes out..."

roulishollandais (above) expresses the concerns of many of us, but I'm assuming that anything operators need to know urgently will be promulgated to them by the usual bulletins (senior moment: can't remember what they are called!). The only snag is that, in rare cases, the incident might not be manufacturer-specific. Operators of comparable a/c from a rival manufacturer might also need to be warned.

Speaking more generally about commercially sensitive information, there is a perception in British aviation circles that, in the past, efforts to share knowledge for mutual benefit have rarely been reciprocated by American manufacturers (without mentioning any names). It's a truism that the Brits have been better at coming up with new ideas than they are at producing something that sells in large numbers. That's why we think it's a bit rich when Boeing supporters fume about Airbus's sales successes.

Perhaps, in some after-life, all you Boeing and Airbus engineers - not to mention the Russians and all the others - will get together, realise how similar your aspirations and expertise are, and create even better aircraft. But that kind of cosy, utopian relationship is not, admittedly, what got Apollo 11 to the Moon and back.

roulis

Pas d'accord! Well not entirely d'accord anyway.

My gripe is that the pilot giving a second oscillation is actually the problem since it is the pilot actions that in this case start off or aggravate the resonance.There are folks here that would think it presumptuous for a mere engineer, no matter how well qualified, to offer any advice on how to fly airplanes, but luckily Dave Davies has already done it, very concisely and very precisely:

Clearly, Davies at least regards the correct method as a type of open loop process. Note also his remarks on the difficulty of suppressing dutch roll oscillations by the use of rudder.

I know very well that if a pilot decides to actively control a dutch roll using aileron then unless he properly adapts his internal transfer function to match the open loop dynamics of the airframe there is a risk that at some value of pilot gain the root locus of the closed loop system might cross over into the negative damping region. [That piece of jargon ridden technological gobbledygook translates as "If the pilot tries to chase the dutch roll and gets his timing wrong he could end up in a PIO or APC situation"]

From what you have written this might have been the case on that Learjet?

Here I do disagree with you. The object of certification is to avoid any resonance not devise rules to tame it. In fact the existing regulations do just that:
Part 23, against which I believe that Learjet to be certificated, is slightly different :

If that aeroplane was a susceptible to dutch roll problems as your posts suggest then it must be on the limit for certification surely? Arguing from that case to a need for another set of requirements strikes me as an extrapolation from the particular to the general - and rather like extrapolating from a single spot point, that is a dodgy process.

Speaking more generally about commercially sensitive information,

Which, I understand is why the Brits, doing the right thing with respect to the knowledge gained with the Comet problems ... basically were dudded by the 707 in short order ...

Quote:
Originally Posted by Machinbird
The problem is that the force and travel required to activate the rudder to its limits were minimal, and thus it was easy to excite a yaw oscillation by relatively small repetitive rudder inputs.

If you will remember, it only took about 30 lbs of force to reach the limit at that speed-that isn't much at all.
He was attempting to get the rudder moved as quickly as possible and was trying to help it along :}.
Or perhaps he was just spooked by the extreme yaw.

Assuming they only have rudder position indications on the FDR and not force indications, the 140 lb estimate would come from rudder rate acceleration tests.

Well, to be fair in civil terms the US had the edge in terms of airframe tech in the inter-war years. Lessons learned during the war meant that the UK held an edge in R&D by the early 1940s, which was shared with and bequeathed to the Airbus project in the 1970s - in part via the Concorde project.

While it's true that the R&D "sharing" with the US in the postwar years skewed decidedly one way - it's also true that due to political and business machinations it was as much the fault of the parties on this side of the Atlantic as anyone. Of course the main issue with the mass-production side of things was difference in size of the potential civil airliner market following the war. A populace undergoing an austerity drive was never going to be able to afford airline travel easily, whereas the postwar growth of the US economy - along with the sheer size of the country - meant that air travel was not only within the reach of more of the population, but became a practical necessity for many.

Anyways - an interesting subject, but off-topic. So I'll leave it there for now.

OK, flarepilot. Here is what a very highly experience aviator (and Saberliner 40 pilot) has to say re your Sabre 40 assertions.

Okay, I have to call BS on this statement:

Quote by flarepilot "Flying it very high by hand was the most demanding flying I've ever idone, but I got the hang of it."

All Sabres were a delight to fly by hand no matter the altitude. So he is one of the worse pilots that has ever flown one, or he is a liar. The only types aircraft I have flown that may have been easier to fly by hand regardless of the altitude, is the Falcon 50/900 series and the Lockheed Jetstar.

Also, the military version of the Sabre 40, the T-39 had no auto-pilot* and were flown single pilot by the US Air Force. Hardly something that they would allow in the "demandingy flying" aircraft that someone had ever flown. One other thing, the wing on the Sabreliners was essentially the same wing as on the F-86 and F-100, both of which had no auto-pilot and were obviously were single pilot aircraft.

So at this point, I believe that the question about the aileron restriction is immaterial. As with the statement of his that you posted, goes a long way of proving this guy a 'Walt'.

With 500 hours in the Hun and about the same in the Sabre 65, I'd agree that both are pleasant to handfly at any altitude. The Hun had its moments, but that comes with the environment of any TAC fighter. No such restriction in my memory, but who would use 50% of control authority at high altitude/high Mach anyway?

Lie. Both Dryden and LaGuardia (Skopje and Pau too) accidents featured non-adherence to de-/anti-icing procedures so there was no reason to change them.

True, but why using rudder at all? Why rapidly reversing it?

The are rules and procedures during an investigation regarding the release of information - for several reasons. As we noticed on the recent Asiana crash there is a certain media frenzy that occurs - release of information that has not been properly vetted can have far reaching effects (even if it's a joke about the pilots names :mad:). There can be potential liability concerns - releasing partial or out of context info could result in slander and lawsuits (I've been the target of a slander lawsuit - it's no fun even when you can document what you said was accurate). So there is a process to release information in a controlled manner via the investigating agency (e.g. NTSB in the US). If there is something that poses an imminent threat to other aircraft, then it's the responsibility of the investigating agency to make that information public so that appropriate measures can be taken.

After the 787 Heathrow fire, many on here where complaining that Boeing wasn't forthcoming with information - short answer is the manufacturer is effectively gagged during the investigation - ALL public information is supposed to come from the investigating agency. For Boeing to release information could have gotten them in big trouble.

I was involved in the investigation of the BA 777 that 'landed short' at Heathrow (I was in a Boeing Safety Review Board meeting on an unrelated subject when a co-working showed me a picture of the crashed 777 on his laptop and said 'just happened!' :sad:). Anyway, within about a week we had a pretty good idea that ice had blocked the fuel/oil heat exchanger. But it took a couple months to validate that theory (rig testing and the such). If we'd released information implicating the Trent fuel system, and that turned out to be wrong - there would have been hell to pay :yuk:. The good news is that the designers were able to work on the fix even before the cause had been firmly established.

Some of you certainly remember the fiasco after the Chicago DC-10 engine separation and crash - when everyone though it was because of a broken bolt instead of damaged structure?:ugh: It's certainly good to get information out quickly, but you need to make sure it's the correct information.:ok:

Owain,
I have really nothing against Davies formulation ! Thank you for quoting it here. The only thing I see in my method (perhaps Davies did it for himself but did not express it here) is to get quantification instead of global words which can be misunderstood by pilots who revendicate to be stupid...
My bold show the words I did quantify :
I am seeing too that Davies's method is a step by step method effectively as you said it it can be seen as on open loop action, mine is continuous in the closed loop.
When Davies says "watch the rolling motion", I do the same but quantifying. Despite Davies's lack of precision we both know that we must read in the beginning of the transient response the clue to start the correction before the transient part is finished. He does not suggest to the pilot to start asap the correction, but when he feel "good and ready". But I understand that prudent formulation and choice of Davies, so long as pilot don't want to reckon some precisions... :
Exactly ! Probably my teacher had a sudden thought to that risk at the moment he was speaking of root locus and decided him to say his sentence.

It seems that Chris's method on B727 is Davies's one like but less developped in the formulation I found in the Yaw damper thread ?

Why did Learjet not adopt Davies's method and stay wrong with the rudder use, and reversal use, and brutality use ?

Stopping the bad divergent oscillation is not all : probably your aircraft wants to play it again ! that divergence had a cause, and watching the motion quantatively helps to fly safe at home avoiding a new divergence with your jammed yaw damper...

The final object of certification is to do the aircraft safe for the wanted use. Today we have to increase air safety despite crashes statistics are getting better. All the crashes which can be avoided have to get progressively suppressed. Changing certification rules can perhaps help, and if it should help why not try ? Perhaps it could improve the speed of information from engineers to pilots ?
Writing operational rules may sometimes be included in certification. I remember when Concorde has been built some people said the bang should not be listen on the continent, so it was not possible to certify it. But thinking that the sound energy was decreasing with distance finaly it could be certified if respecting operational rules like not focalising turns, and respecting some distance of the coasts, and determining quantitatively point at which Concorde should start acceleration to M 1.

Chaps, can we return once again to playing the ball rather than the player ?

The KAVP T-39 accident with Gen O'Malley and his wife had nothing to do with Sabre high altitude handling and everything with no anti-skid installed and risk analysis of the airport. Can't speak to the 40, but the 65 was docile everywhere. Bob Hoover, who did shows with it would agree.

The T-39s were typically flown by first assignment pilots out of UPT who had a better record in it than in the Lears that followed.

Clandestine, I am not as worried about Airbus systems as much as junior pilots with no experience never geting any real hands on flying experience. Some day they will need real hands on flying experience or it will a be repeat of AF 447. Our generations had to handfly and welcomed the challenge. I don't like where we are headed. Many others here don't either. None of us old school pilots were too concerned if everything went south because it was just an inconvenience, now it is turning into an emergency.

Clandestino, does not Airbus teach pilots with loss of IAS that holding last attitude and power and getting out UAS checklist is the answer or do the French rely on Airbus automation? If not, we do it differently on the west coast. Works fine.

Of course if the auto pilot clicks off you need someone that knows how to hold an attitude and not just pull up.

flare pilot,

Yes, very different slat arrangement, it doesn't have slats. The 65 had a Raisbeck "supercritical" forward section grafted onto the basic wing. Super in "supercritical" meant one needed to be super careful in icing. Bit like the wing on the CL600 series--fine, if you followed the book in icing conditions. But, if the leading edge section had the least bit of contamination that created sonic flow, it stalled abruptly especially if a rapid rotation brought the wing to stall AOA in ground effect (IGE). Big steaming bowl of Not Good, see G650 accident and all the CL600 accidents. All abrupt, asymmetrical stalls IGE.

Playing the ball. Flare pilot, I'll quite happily eat crow if you can scan the relevant page from the flight manual and post here. I repeat SCAN the relevant page. Only because no one I've talked to has heard of it. Up to the challenge? Until then then.

roulis


I’m really not sure what point you are trying to make here. If it is a plea for a mathematical definition of acceptable dutch roll characteristics then such things already exist and are used by engineers in the design stage to establish whether yaw dampers are needed (almost always they are) and to define the control laws under which they will operate. Search for lateral directional handling criteria and you will get a bucketful. (or MIL-F-8785C)
If you are looking for something to use in flight then I think that would not be very practical; besides which I am sure that pilots don’t need a set of memorised numbers to tell them that the aircraft is doing something they don’t like!


I haven’t a clue! You’d have to ask the Learjet test pilots or whoever decided on that recovery technique.

I agree that in a divergent situation it may, probably will, happen again; but telling the pilot to watch the motion like a hawk to prevent build up of any roll oscillation is surely not the solution? In this regard prevention is better than cure.
Can we agree that a divergent dutch roll is only likely to build up if the aircraft is either naturally unstable in that mode or if the dutch roll is so lightly damped that inappropriate pilot inputs may drive it unstable? In either case the aircraft would be deficient against the certification requirements that call for it to be controllable without the use of exceptional piloting skills. Under modern certification rules (FAR 25.1309) the allowable probability of any system failure is linked to the consequences of that failure. So if yaw damper failure would result in a Hazardous situation, i.e. one :

then the failure probability would have to be Extremely Remote that is to say less probable than once in every 10^7 flight hours.
This being the case, I think that the introduction of quantified criteria for the pilots to monitor is not necessary.

Well you won’t find anyone to disagree with those sentiments on this forum! But I have found over the years that if you have a problem it is best to attack the major contributors first. Today the major players in accident statistics by far are LOC and CFIT. The latter is being addressed and the rates are coming down, but I’m not so sure about LOC. There are a lot of things in there where better communication between the engineers and pilots would pay dividends, which is why I read with dismay some of the us vs them comments on these pages.
Even so, you would struggle to find any instance of an accident attributed to a divergent or neutral dutch roll characteristic. [I exclude the subject of this thread because the natural dutch roll was well damped (yaw dampers still operative) and because of the inappropriate control inputs]

Alas! The one thing that has come out clearly in these discussions is the virtually complete exclusion of trained pilots from the certification rules. Until that blockage is removed there is, I fear, little chance that changing the rules would speed the passage of information.


Ooops! This is an anonymous forum

What's the link for the DC-9 manual with the limitations you mention?

flarepilot - regarding Hoot Gibson you said you remember what he said 32 yrs ago on 60 Minutes. CBS put out a report on the accident that took an entire hour. It wasn't 60 Minutes but a special report. Interviewed passengers, crew, etc. Is that the report you recall watching?

Bubbers, you've answered your own question, because if the Airbus's systems detect a UAS condition, then the automation will automatically disengage. The old UAS procedure is available in the AF447 report, but the gist of it was to maintain a pitch of no more than 5 degrees and use appropriate power settings. I believe it has since been revised to read more simply, but in practice it's much the same.

What has changed for both Boeing and Airbus manuals since AF447 is the approach to training for stall handling - which was considered inadequate across the board as it relied purely on avoidance on approach to stall and had no advice or instruction for recovery when a stall developed (consequently meaning that a significant chunk of airline pilots had not practiced recovery from a stall since their PPL days).

misd-again: I think this is the report you're referring to:

I also had the pleasure of being able to call Jim Webb a good and personal friend of mine for quite some time when he was actively training and checking EAL DC-9 pilots in Miami and in Atlanta. He had a unique ability to be able to tell what a pilot was doing and, from that, developing his own way of dealing with any problems or misconceptions his student was displaying. I lost track of him starting around 1980-1981. Later, I did learn that he had retired from EAL but was not able to find him after that. I too have a signed copy of his “Fly the Wing” – and have very fond memories of evenings in the bar on 36th street – across from the EAL Training Facility in Miami.

Dozy - that's the report. Interviewed in Costa Rica. No mention of the rudder. Memory, especially 32 yrs after the fact, is tricky.

flare - perhaps the DC-9 speeds given are Va at that altitude?

Well, okay here we go.

I'll fess up and admit that I am that "some guy". I have flown, for a living not just a single flight, the Sabre 40/60, the Sabre 80 and the Sabre 65. I have have hand flown all of them from takeoff, climb, cruise at FL-450 and approach/landings. Of my 21,000 plus hours of flying time, over 3,000 of those hours are in Sabreliners. My last flight in a Sabre 40 was in 1984, last flight in a Sabre 65 was in 2005.

You are wrong about the aileron limitation of using more than one half aileron deflection above any altitude. The only aileron limitation of the Sabre 40/60/80 is:

From page 1-16 of aircraft limitations in the Flight Safety International Sabre 40/60 pilot training manual, last updated 1982, paragraph H, Maneuvering Limitations;

DO NOT USE MORE THAN ONE-HALF AILERON DEFLECTION ABOVE 225 KNOTS.

This limitation was not, repeat not, due to any structural concerns of the airframe. The FAA added this limitation due to the fear of the FAA that the rapid roll rate of the Sabreliner 40 was too rapid for the average civilian pilot at any airspeed above 225 knots*. The FAA decided that the risk of loss of control could result from a full aileron deflection at any speed above 225 knots, resulting in possible lost of control of the aircraft.

The Sabre 65 has no such restriction.

I will now state for the record; the Sabre 40/60/80/65 are very delightful to being hand flown, regardless of altitude (including FL-450), airspeed and in any configuration.

Only two other aircraft that I have flown that can equal that statement, any and all Falcons and the Lockheed Jetstar (-8 and the 731).

Therefore, in my opinion, a highly experienced opinion, any pilot that struggles to hand fly a Sabre 40, at any altitude or airspeed is either a very poor pilot, a very inexperienced pilot or has never done so.

Your choice to make.

Oh, edited to add.

The US Navy bought a number of Sabre 40s from the open market a few years ago. Then these 40s were flown to Perryville, MO to be completely overhauled and modified to Navy specs. One of the modification was the additions of small vortex generators on the wing in front of the ailerons, to increase the roll rate at full aileron deflection, at any speed under VNE, to increase the already impressive roll rate. These Sabre 40s are now T-39Ds.



* Which means that a FAA test pilot scared himself during the certification flights of the Sabre 40.

Hold up. The facts stated by Flarepilot were merely the opinion of an inexperienced pilot with a poor memory of what he is actually talking about?

So your answer is a very inexperienced pilot . Fair enough, would have helped if you had said so at the start.

The Sabre 40 was the third aircraft I was typed in, the Jet Commander and Lear Jet (Lear 24) were the first two. After hand flying the Jet Commander at altitude, it was a pleasure hand flying the Sabre 40. The Lear 24 was not all that bad, but the 40 was much easier, nicer and more comfortable.

No, the Sabre 40 and 65 was in corporate flight operations and the Sabre 80s were ex-FAA flight check aircraft that I flew while I was flying for the US Marshal Service.

As for your point, I'm unsure of just what point you were attempting to prove. All I am responding to is your statement that flying the Sabre 40 was extremely difficult as compare to other aircraft that you have flown. Which indicated to me that you had experience hand flying other jet aircraft at that altitude. But now I understand that you did not have any previous experience hand flying other aircraft at that altitude, which makes what you posted very understandable.

Well … when someone is operating out of panic, there is virtually no time where the person would “stop to check” anything. They are also not doing what they’re doing out of a belief that whatever it is would be proper or not. When someone is panicked they do whatever they do out fear and/or supremely heightened anxiety. There is no, or exceptionally little, conscious awareness of what they are doing. Their actions are formed from what some might call “a reservoir” of physical actions, the knowledge of which is buried in that person’s subconscious.

Someone on this forum has mentioned something called the “startle factor” – which has come to be something that psychologists (primarily experimental psychologists) have described as the “blinding” period of time that starts when something happens and continues until the time the participant recognizes that something has happened – and it is usually an extremely short period of time. However, when that participant does consciously recognize that something has happened, as far as I know, there is no standard of performance from that point forward. If the event is recognized, there may (or may not) be an action, or multiple actions, that could be satisfactorily taken to resolve the situation. The question is whether or not those actions would be effective only if taken in the proper sequence, and if so, will that person have the cognitive understanding of that requirement, and be able to logically take those steps, in that order? From here, comes the question of what to do … how to train … so that those who might be at risk for encountering unknown and unexpected events that could have tremendously serious consequences … could be expected to properly and successfully respond to the circumstance that generated the startle.

As someone whose career has been primarily devoted to education and training, I can say that, so far at least, I have seen nothing that equals the repetitive practice of doing something the right way, in the right sequence – over and over and over and over. The only variation that should be included (and it SHOULD be included) is the VARIABILITY of the initiating circumstances where each such variable initiation would result in the person having to respond with the appropriate steps, taken in whatever sequence that will get the situation to the desired level of completion. In aviation, I believe that this would be most logically accomplished by having pilots exposed to having their airplane experience “upset conditions” (including approaches to, and the development of, aerodynamic stalls) through as many variations as would be logically possible. The plan should be to have those pilots follow a logical process to maintain, or regain and then maintain, their airplane in a recognized and desired condition (i.e., position, attitude, altitude, airspeed, and configuration). To me, pilots practice doing this all the time when they are operating through the use of the primary and secondary controls to maintain (or regain and maintain) straight and level, un-accelerated flight. This training should focus on using all the available indications – mostly the flight instruments – ALL of the instruments – as well as the cues provided by sound, visual, and body position in space. And, when the pilot has developed a process that seems to be functional in all of the situations presented - the training should shift to achieving the same results but limiting the references to which the pilot may refer in taking the actions that he/she believes to be appropriate. And, in case you miss my meaning here, I'm talking about limiting the number of instrument references available. Of course, constant and vigilant observation, input, and correction (when necessary) remains a requirement for instructors during this training.

To my knowledge, this is the only way that pilots can be properly prepared - both mentally and physically - for something to occur for which there is no anticipation, and possibly no recognition. And it should be stressed that knowing "why" or "how we got to this position," is not as important as knowing "what to do now."

Lord Spandax. Time will prove that flarepilot is our dear old SSG, aka teldorserious, who has never sat at the controls of any aircraft. Serial sciolist. Does spin a good yarn I must admit, which sucks people in. His claims are becoming more breathtaking with each new identity. Next we'll hear how he made ace status in the Vietnam war flying an F-4, or perhaps how he walked on the moon.

Congratulations ace on getting a fact partly correct. You've reached a high point in your contributions.

Yes, but in the case of the Sabre, except for the 65 which does not have that restriction, it was more about pilot capability rather than a structural issue.

Also, the 65 not having that restriction was the reason I had to look up the limitations. I could not say for sure that the 40 had any control movement restrictions or limitations.

Well that and being an old fart. :p


Actually above FL-400 or FL-410, depending on which pressure controller one had in the 40 and FL-410 for the 80 and 65, all occupants in the aircraft must wear an O2 mask, not just the pilots.

That's what the limitations are. I'm sure every Sabre operator complied with that. ;)