Check-Six Forums

Jaguar a écrit : ↑

dim. juil. 17, 2022 5:36 pm

Edit : spoiler n'est pas égal à aérofreins ?!?
Je sens que je vais apprendre un truc là

Jaguar a écrit : ↑

dim. juil. 17, 2022 6:33 pm

Et le F14 uniquement aérofreins du coup

diditopgun a écrit : ↑

dim. juil. 17, 2022 7:16 pm

Sur Tomcat les spoilers se déploient à l'atterrissage sur piste (quand le switch qui va bien est dans la bonne position).
En vol seul les DLC (Dynamic Lift Control) qui utilisent une partie des spoilers sont utilisable quand le train est sorti. Uniquement lors de la phase d'appontage pour aider à corriger le plan de descente. C'est ce qu'on voit sur la photo de DeeJay.

Jaguar a écrit : ↑

dim. juil. 17, 2022 7:20 pm

Moi je trouve que c'est nawak pourtant je suis vraiment pas le mec le plus pointilleux !
En revanche j'avais attaqué la descente en supersonique...

Après chacun son avis, c'était juste un test d'opportunité, pas une recette hyper rigoureuse

PS : j'étais en live weather en effet

jojo a écrit : ↑

dim. juil. 17, 2022 8:11 pm

A vérifier, mai je pense que les spoilers sur les ailes sont aussi utilisés en dissymétrique pour le contrôle en roulis.
C'était aussi le cas sur Mirage F1, Jaguar et Tornados par exemple.

diditopgun a écrit : ↑

dim. juil. 17, 2022 11:04 pm

Moi ça n'a pas ralenti puisque les ailes ont fini par se replier d'elle même et au delà d'une certaine vitesse l'aérofrein rentre également de lui même...

do agree with you mostly but it all depends on what users “expect” as opposed to what the reality is. I saw a recent YouTube review where the guy compared the DC Designs F-15 to that in DCS World. He showed how the DC Eagle remained under smooth control at very low airspeed ( landing configuration ) whereas the DCS Eagle was under buffet stall and rattling about at the same low airspeed. Sounds right, right?

Wrong.

The real F-15C often displayed its low speed handling traits as part of the airshow circuit, making a low-speed, gear-down pass at less than 200 knots while swinging left and right into knife-edge banks. The combination of power, huge aerodynamic lift from the fuselage and early fly-by-wire technology allowed it to handle like a Cessna at low airspeeds, despite its huge size. Short story - DCS was wrong, DC was right But as the YouTuber had no knowledge of any of this, he just assumed the DCS version was right, as so many others erroneously do.

Another great example is engine power. The F-15E’s engines produce 20,000lbs of static thrust at sea level in maximum afterburner, and that’s it. Right?

Wrong.

All engines are affected by velocity. At an airspeed of Mach 0.9, RAM air pressure both into the engine and also over the fuselage and into the exhaust plume increases thrust by over 40% - meaning those engines in the F-15E can produce 30,000lbs of thrust at sea level when at Mach 0.9. This is why our jets can seemingly do the impossible, accelerate in high-G turns, something that some YouTubers have also identified as a “bug” or “error”. Even the F-14A Tomcat, lightly laden at sea level, would accelerate in a high-G turn with the TF-30s at zone-five afterburner - and that comes from an F-14A pilot, not me. Our F-14 will do the same. Down low, the F-14A could out-rate the F-16 in a turning fight, the F-15 also - up high, the tables were reversed and the Eagles and Falcons would hold court. But below somewhere around Mach 0.7, do the same high-G turn and all the jets will bleed energy as folks are mostly used to seeing them do all the time in less accurate models.

Concorde famously used this phenomenon ( as does ours ) by slightly closing the reverse thrust bucket doors when at Mach 1.7. The airflow was directed off the wings and into the exhaust, producing so much extra power that the crew could shut off the afterburners and “super-cruise” up to Mach 2.

The same goes for how an airplane “handles”. The F-14 was a big, heavy, cables and wires controlled airplane, so it should feel so, right? Wrong. It was trip-wire sensitive at higher airspeeds, especially with those wings back, and wallowy and heavy only at landing, precisely as ours is. It needed a lot of stick movement to get it to respond but it was a fighter and it handled like one, sharp enough in the right hands to stay in the fight with little A4s and F5s at Top Gun. But, even so, handling should be the same all the time, right? Wrong. Performance in winter will outstrip that of precisely the same airplane in summer, as colder air temperatures can boost performance enormously, something I’ve seen in real life as pilot-in-command of a little PA-28. Climb rate in winter was double what it was in summer ( up to 2,000ft per min once in perfect, crisp cold air ). Same goes for all airplanes. So many simmers say “the flight model feels off from the last update”, with no thought as to whether that last flight / update was conducted at a different time of year. I very much doubt any other sim models these atmospheric considerations anywhere near as accurately as MSFS does.

Aerodynamics, engines and other factors are vast subjects and most users of all sims are not aware of them, relying on very basic data from Wikipedia or similar as their reference. I think some of those YouTubers I mentioned get their information from their Top Trumps card collections. CodenameJack’s method is to get the real-world figures, input them into the flight model, then massage them until the MSFS aircraft matches the real airplane throughout the flight envelope - roll rates, pitch rates, acceleration, G-limits, you name it, all are matched to real-world charts from the actual aircraft operating manuals. We then get pilots of the real thing to assess them, where possible.

DCS is great at what it does, but it’s far from the “ideal example” that many seem to hold it up as.