Bremspropeller

AIM-4 on a USAFE (Bitburg AB) pre-slat F-4E in '74: https://www.airliners.net/photo/USA-Air-Force/McDonnell-Douglas-F-4E-Phantom-II/195878/L?qsp=eJxtjrEOwjAMRP/FcxZIVSAbXRhh4Acsx0Ck0ka2B6qq/07TSExsd/cs381A42D8sfuUGQIoo9ALHGQUfCuEGTAJCT6sQ01Uz47t/uB%2B4MIDy38EwftT4x3oKNZNa0FE4zMRZ%2BMINb9KZCmIlbbmZ1nS7IpmuVXr29XGpLnH7Q0bph6W5Quekz8m

I decided to play around with some mod-objects at Gaziantep:

Thanks for the clarification! The reason why I wrote "minimum radius" is that for all practical purposes, max turn-rate for fighters of this generation is always in the ~400-450kts region and adding drag (slower, more AoA and using combat flaps) won't increase turn-time at all. Hence it was the ony thing making sense in my mind.

I just took a plunge into my wall of books and I stumbled about this curious little fact: 07 January 1944: Egon Mayer (Kommodore JG 2, inventor of the frontal attack tactic) claimed four Viermots (3x B-24, 1x B-17) this day within a time of about ten minutes (13:05 through 13:16, his victories 95 through 98) according to Jochen Prien's Jagdfliegerverbände (Vol 13/IV p.169). I cross-checked this with Eric Mombeek's JG 2 unit history, which also has an entry of four kills by Mayer this day, the last kill clocked at 13:18, though. It also has the information of being killed at an altitude 1500m, which indicates a "final destruction". Mayer would have been flying a plain-Jane Fw 190A-6 or A-7 at the time, not extra guns or armor. Those four kills are also reflected in Donald Caldwell's DAY FIGHTERS (p.179). There's probably a few more of those curiosities, but I think this serves well enough as an initial data-set to answer the question.

The fact that "Herausschüsse" (shooting a bomber out of the formation) and "final destruction" of a Viermot gave you points for the Ritterkreuz, should tell a story. You'd normally not stick around the bombers and try to shoot down more for several reasons: - escort fighters lingering in the vicinity - you spent a good deal of your gas just climbing to altitude and getting to the point of intercept - your air base may be 30mins away at reduced power settings (not too much fuel aboard the german fighters) - the emotional and psychological drain of attacking a formation of 600-800 bombers with maybe 20-25 bombers in firing range during the critical part of the attack - the most fficient way of attacking bombers was a head-on attack, and re-positioning after the attack (turning around, getting ahead again and turning in) ussuallytook too long and too much gas - apart from the threats above - there's no refly button,so you'd play it little cooler and even "sore throat" pilots ("Halskrankheit" - those who were just afew kills short for the Ritterkreuz) might not be too eager to stick around, though they'd usually accept the greater risk when dealing with fighters (and frequently payed the price for it, or ther wingmen did) Unfortunately, the website Luftwaffe.cz is down at the moment, so looking for kill-claims of the top Viermot killers isn't available atm. I'd generall expect up to two bombers killed or heavily damaged to be possible, but any more is a real exception. The Sturmjäger later had a different tactic - approaching from behind with increased armor and more firepower. They might have a couple of multi-kill missions. But generally, I'd still not expect to see three Viermots killed in a singe mission too often. Rather combinations of kills, HSS and final destructions.

Good point!

Form training is progressing well.

I tried to do some quick & dirty test, flying to several different positions and showing the stick-deflection. The "suck in" is noticeable during the last couple of seconds where going fwd of some point, holding position required throttling back a bit. track Probably not the cleanest test-piloting at work here but the stick-deflection vs position and the "suck in" should be evident. Edit: Nevermind, track was corrupted. I'll have to do it again.

Yeah, I already wrote that: So did you run the numbers and come up with figures?

The "suck in" happens when you're really close (next to the leader's wing tip) and then going forward. You'll reach a point where you'll suddenly need much less power to maintain position. I'll see if I can possibly record a track during the next days. That effect also exists when tanking (in other aircraft) where you kind of have to breach a wall of additional drag some distance behind the drogue, only to come back on power to not suddenly outpace the tanker. The position where it switches over is quite unstable.

It's Klaus Hünecke's "Das Kampfflugzeug von Heute - Technik und Funktion" by Motorbuch Verlag. My copy is of the second issue from 1989. It's one of the best books on the broad topic of fighter design in German - and you won't need to be overly fluent in greek letters to read it. Highly recommended!

Hi folks, I have stumbled over an issue that seems to be rooted in 3rd party skins: When using those, the F1 player cannot see the effect of the search light. Other players - when in multiplayer - can see the effect, though. See here for what the player can see using a skin - I tried two different skins, both from the DCS user files section: PL_Skin.trk Skins I tried were the "Ghost" HAF skin and the eralier of the "Lorraine" skins. See here for what the player can see (works fine!) when using a standard skin: PL_noSkin.trk

Trouble is, that's not how it works. Your picture shows an SR-71 intake, which is mixed (external and internal) compression. That's not the case with the MiG-21, which uses an external compression intake. With the cone at max fwd position, it becomes a fixed intake (as in: it can't move any more fwd and make up for a higher Mach number). The result is shown in the lower left corner of this illustration: It will swallow the oblique shock from the cone, which in turn combines with a new oblique shock, formed by the intake-lip. The combination will lead to several rather strong shocks and flow-separation, critically disturbing the air reaching the compressor interface. That and it will have a lower recovery factor (compression), compared to the optimun, shown bottom right. The only way of mitigating this is chosing a shock-cone angle that will always have a Mach-angle greater than the intake-lip. This has to be bought with greater shock-losses and spillage drag, though. There's no free lunch and there's no oversimplifications that work. ____ the unlimited index means free-stream Mach and "Entwurf" means "design"

I did. It's significantly oversimplyfying things and stops before the compressor, which is the crucial part. Who said there was? It's just a bit more complex than in your little movie there. The compressor needs the right amount of air at the right pressure, temperature and desity to maintain stable airflow over the blades at given RPM and not stall or surge. If your intake is messing up and the pressure-recovery suddenly drops because it swallows the oblique shock*, turning it into a fancy pitot inlet, there is a discontinuity in temp (goes up), pressure (recoverable stagnation pressure goes down) and desity (goes down), changing your local AoA over the compressor blades and may be inducing a good old stall. Having VSVs (IGVs) and a good bleed system makes things a little easier because they can taylor the flow a little better to what the engine can handle right at this moment, but their reaction isn't instantaneous either. And the F-8 was able to attain the same (even a slightly higher) Mach without a centerbody and just the nose of the airplane assisting in creating an oblique shock and pre-compressing the air before entering the fixed inlet. You don't really block the airflow downstream, the throat-area reaching Mach 1 just gives the intake (or pipe, or whatever) it's max attainable mass-flow. No matter how much upstream pressure you are putting into the system, the mass-flow will not increase but air will start bypassing the intake, causing spillage-drag. But mass-flow itself isn't the issue here, it's a combination of local pressure, temperature and density that determines whether the compressor-blades can handle the air flow, or not. And that, in turn is dependant on what the intake upstream does and if it's operating in a stable condition or if there's instabilities. ___ * Normally, that condition should not be easily reachable by just accelerating, but it might be attainable for some aircraft.

We did that last week when checking out the police light, which reminds me of re-testing something that came to my mind. Seemed like you didn't have an issue in the F-14 flying next to me.

I have been wondering about that, too. But then again, there's p.118 of Mirage F1 vol.2 by Lela Presse - pilot was a demo pilot. "...Autres atouts du Mirage F1 pour une presentation en vol: son rayon de virage plusque correct a 290nd grace au becs et volets, sa capacite a voler sur la tranche sans perdre d'altitude a partir de 360nd (il remonte meme des 400nd) et la possibilite de terminer une boucle complete mais pas tres ronde en moins de 4300ft." So with my preschooler level of Francais, that translates into: - minimum radius turn at 290kts - able to knife-edge pass at 360kts and even climbing at 400 (you'll have to be faster in game!) - minimum loop radius 4300ft if you don't mind going slow over the top. Same pilot also mentions having attained M2.27 on a particularily cold day without the LIM lamp going off, during an intercept exercise for his BCP* with all four F1Cs reaching that Mach while intercepting eight 2e Escadre MIIICs out of Dijon. They only recognized that after the flight, looking at the tapes/ data ("enregistreur de vol"). ___ * brevet chef de patroille - I guess that translates into during a "flight lead upgrade" mission

It seems to have, if you turn up the map-light. Not sure if that's what it's supposed to look like, though, as the clock-face is illuminated in dim white light (probably just stray light) and iId expect it to be red/ orange as the rest of the indications.

What the video does not explain is that the cone's finite geometry constraints (read: how far can it travel?) do also constrain the attainable Mach of that intake. At some point, the cone will reach maximal forward travel and an increase of Mach will now put the oblique shock inside the intake, as opposed to on the intake-lip. At first, the intake will be able to tolerate that to a certain amount, but at some point, the oblique shock will be too far down the intake, and the whole thing will quit. That's exactly what happened to a couple of SR-71s and Concordes (mostly during flight test for the latter). I believe there have been a number of losses on the SR-71 due to an intake-unstart, because the aircraft cannot handle the sudden amount of asymmetric thrust at Mach 3+. The Concore fares a lot better, but it also has a digital engine control and the ramp-system allows for some overboard-bleed downstream of the ramps. IIRC, the surge-doors on the MiG-21 only open inwards and hence they could not help here, bleeding excessive air overboard. This video goes a bit deeper into the SR-71 intake system and he mentions the bleeds, as well as the max compressor inlet temperature. For reference, in the F-104 that temperature is 120°C! The shock-cone-schedule in the 71 is interesting, and it's different to other aircraft.

Thanks for the insight, Kermit. In terms of high Mach turns, you'd also lose some G due to the CoL coming aft and robbing you of effective stabilator travel. I was more interested in the "engine out" behaviour, though. Many aircraft-types have exceeded their limit Mach during their service-time*. So just defning an arbitrary number, where the engine stalls or will go out may not be overly realistic - at the same time, exceeding the limit numbers willingly on every single flight (which is what you'd see then) also isn't quite realistic. It's hard to define the middle ground between being forced to stay within the boundaries of the envelope and completely gaming the game. Especially since every gamer defines this boundary differently. Generally, there's a couple of scary things conspiring against the pilot if he's willing to exceed max Mach by some substantial margin: - the shock-heating will lead to structural creep - the CoL travelling aft and the thin air lead to lower dampening of pertubations; usually in Yaw this becomes limiting quickly - if you fly through an OAT pertubation (and hence a signifigant instant shift of Mach), your intake might unstart as it's mismatched with the actual Mach** - if you swallow your intake-shockwave your compressor will burp, leading to all kinds of different outcomes ___ *For example there's a quote by an F1C pilot having gone to M2.27 during an intercept exercise with the whole flight and nobody even recognized it - only after the flight, they'd found out they had been going much faster than the normal limit - the LIM light (wired to the TAT sensor) didn't come on as the atmosphere was particularily cold that day ** Lots of interesting stories of SR-71 and Concorde concerning this phenomenon

It used to seem like in the other airplanes before that one patch that made it worse. Granted, but flying close formation on the wing now really requires you to mix in almost half a throw in roll, which I believe is a bit overblown for two similar aircraft.

The wakes in close formation requiring almost half a stick-deflection in roll to cope. It used to be way less pronounced and two or three patches ago, the effect doubled.

It might be a former EGAF PF which was going to be exported to Iran when the deal was cancelled due to the german reunification. The camo-scheme does fit the bill very well. IRIAF never flew PFs or FLs, unless some iraqi aircraft have made th run for Iran. Shouldn't all FLs have their brake-chute housing at the base of the fin, as opposed to at the ventral fin as this one?

Certainly not. It's overdone IMHO, and it is annoying.

The deflection-angle of the leading edge devices (certainly the inboard droops) is too small. Check the aircraft above at full flaps against this B:

Great info, thanks Hiromachi!