Heroes and Villains

[mikael]

Chris,

yes, it's my impression that it has gone overboard. As far as I know the cases have all been in fighting sports. But at Olympic level, and for a country with old traditions in martial arts; a country that, in whatever way, wants to be at the top. Obviously, it's a tough world.

But actually, the particular coach that I mentioned has appeared in lengthy interviews by several TV stations, and he thus have had the opportunity to explain how he sees the case. Although it has not been stated explicitly who's right and who's wrong, it's my impression that with those interviews, it has been "written between the lines" that, this may have gone too far now. So hopefully a good balance will be found now.

[Carl]

It seems that the intensity levels of competition and training in sport have steadily increased in recent decades. There are fitness programs advertised that seek to bring military "boot camp" total fitness to aspiring poolside Adonises and Venuses. Some of these fitness methods would have been rejected as silly in ancient Sparta.

Either young athletes have become soft or acceptable training methods too extreme. Everyone should choose for themselves whether total devotion to athletic success is worthwhile. Maybe fun is a better goal.

[Deleted]

Sept 25, 2018 4:24:17 GMT mikael said:

Sept 24, 2018 14:27:04 GMT @lucio said:

QUOTE: "Lucio, the neutrally stable fighter aircraft is a good example."

This qualification brought me back to my flight mechanics course, another life ago.

Airplanes have a complex definition of stability. That above (“neutral”) refers to the static variety, which in aircraft context represents a weaker form of stability. It deals with the tendency of the airplane after the disturbance to return, or not, to the equilibrium configuration – the usual definition. Then there is the dynamic stability, which is concerned with the time history of the motion after hitting the disturbance. Static stability is a necessary condition, but it is not sufficient for the airplane to be dynamically stable.

That is not the whole story. There is manoeuvrability, handling and control, too.

Depending on circumstances, a small degree of instability can be tolerated, or even deliberately design an aircraft to be quite unstable, in which case a reliable automatic stabilization system will be required; the pilot will not be able to fly (to control, specifically) the airplane on his own.

From the bible [Airplane Stability and Control, Abzug & Larrabee, 2002, 2nd Ed., p. 34-35]:

3.10 The Counterrevolution

…

A justification of sorts for the counterrevolution is the tremendous flexibility provided stability and control designers with the new breed of digital flight control systems.

Literally, it is now possible to have an airplane with any sort of flying qualities that one can imagine. Tiny side sticks can replace conventional yoke or stick cockpit controls. Right or left stick or yoke controls no longer have to apply rolling moments to the airplane. Instead, bank angle, constant rolling velocity, or even heading change can now be the result. By casting off the bonds of the rigid MIL-F-8785 specification, a procuring agency can take advantage of radical, innovative control schemes proposed by contractors.

The ability of advanced flight control systems to provide any sort of flying qualities that can be imagined brought a cautionary note from W. H. Phillips, as follows:

    The laws of nature have been very favorable to the designers of control systems for old fashioned subsonic,     manually-controlled airplanes. These systems have many desirable features that occur so readily that their     importance was not realized until new types of electronic control systems were tried.

Don Berry, a senior engineer at the NASA Dryden Research Center, had similar views:

    We have systems capable of providing a wide variety of control responses, but we are not
    sure what responses or modes are desirable.

[mikael]

Sept 27, 2018 4:54:12 GMT @lucio said:

Airplanes have a complex definition of stability.

Lucio, regarding this word (stability) and its use, I think Richard Bellman (the American mathematician) hit the nail on the head when he wrote as follows:

" ... the concept of stability, that much overburdened word with an unstabilized definition."

[Deleted]

  He's spot on.

[Deleted]

This detour is getting quite compelling. I knew Bellman from uni – among the thirty exams, I had also Optimization (where I ‘met’ Bellman), Control Theory, Applied Electronics (last exam I did, ‘cum laude’) and Avionics. Further research below:

Designing a civil aircraft is a quite different business than designing a military one, say a fighter. Military aircraft often perform extreme manoeuvers involving large disturbances, therefore requiring nonlinear stability analyses. Military aircraft Flying Qualities are addressed in MIL-STD-1797A (US military specs for fighter’s flying qualities), which supersedes the MIL-STD-8785 quoted above in my previous post. In studying the stability of military aircraft, design considerations (e.g., small disturbances involving linear treatment similar to civil aircraft) are initially used; but additional features associated with large disturbances and involving nonlinear treatment must also be considered. These include the following.

1. inertial pitch and yaw divergence in roll manoeuver

2. aerodynamic yaw departure at high angles of attack

3. wing rock.

Considerable data generation is required to initiate studies in these areas. Technology demonstrator aircraft would offer considerable insight into these problems. Even designing a technology demonstrator would require extensive wind-tunnel and CFD analyses at the conceptual stages, as configuration is still unproven and little or no statistical data in use. Wind tunnel test results may override CFD analyses but, in principle, they should complement each other.

There are yet other problems arising from weapons being released simultaneously or asymmetrically, causing sudden CG (centre of gravity) shift that could severely affect aircraft stability. Provision has to be made for quick recovery by fuel transfer completed in a short time – this is microprocessor-based management that is incorporated in FBW technology (fly-by-wire, effectively to control the aircraft through computers). Stealth of aircraft is a source of additional constraints to aircraft configuration. These constraints present considerable challenges to the resolution of stability issues. The F117 Nighthawk (first all-stealth design) is a classic example of such consideration – it is an unstable aircraft, which cannot fly without FBW.

The F117A Nighthawk is the world’s first operational aircraft, specifically designed to exploit low-observable stealth technology. The unique design of the single-seat F117A provides exceptional combat capabilities. It is about the size of an F15 Eagle and has quadruple redundant fly-by-wire flight controls. The F117A can employ a variety of weapons and is equipped with sophisticated navigation and attack systems integrated into a state-of-the-art digital avionics suite that increases mission effectiveness and reduces pilot workload. Detailed planning for missions into highly defended target areas is accomplished by an automated mission planning system developed specifically to take advantage of unique stealth capabilities.

en.wikipedia.org/wiki/Lockheed_F-117_Nighthawk

The parallel with F1's arms race is all too evident.

I would have cut it in aerospace too.  

[Jamie]

Fascinating chaps 👍

[Carl]

Is the language too guttural? The words too verdammt lange?  I'm half German, have ridden with Brunhilde and can speak candidly.

Austria is a wonderful country for the most part. I spent six weeks in Seefeld in Tirol when it was wonderfully small. Germany had a difficult birth, suffering interference from tribal warfare and operas celebrating Götterdämmerung, but has steadily matured since.

To reach higher plateaus, Austria should expatriate the remorseless Helmut Marko and Germany the relentless Toto Wolf. Red Bull has almost perfected an altered energy drink that can power a Mercedes-Benz, so neither would suffer by also being stateless. They could find homes with Williams or McLaren.

Helmut Marko enjoys being detestable and relishes the prospect of one day choking on his own bile. Toto Wolf tries to finesse the emasculation of his number two driver, but I wonder if Valtteri Bottas will recover his competitive spirit.

If Mercedes team orders turn later this year in token consolation, Bottas should park his car, radio "verpiss dich" to Toto and drive next year for Audi in the Deutsche Tourenwagen Meisterschaft. Hamilton deserves to be champion, but regaining self-respect is worth any attendant trouble.

[Carl]

Loving the sport while hating those, beginning with the perfect Richard III, Ecclestone, who control it, is like a modern Geoffrey Chaucer tale of chivalrous knights, comfortable and better protected in carbon fibre. Fortunately for the assault against evil, current villain Chase Carey is fluent only in corporate doublespeak and could never rise to the level of scornful abuse suffered by King Arthur during Monty Python's siege of the French castle. With good fortune and righteous downforce we will prevail, given adequate sponsorship, and the imprisoned grid girls shall be freed.