I didn't say dash speed isn't useful, you did. I know what happens in operation and I can tell you that combat configured warplanes are not flying around at the wiki V_Max.

-DA 

 

Illustrating what fighter pilots have to worry about in terms of limitations when it comes to speed.

 

From the 1970 edition Mirage IIIE Flight Manual.

 

DarthAmerica        5/13/2009 11:04:50 AM

I didn't say dash speed isn't useful, you did. I know what happens in operation and I can tell you that combat configured warplanes are not flying around at the wiki V_Max. -DA

OK so you want a confrontation? OK what do you want to fight about? FADECS? FOR WHAT. That isn't a question BTW. Look, stop trying to create something from nothing. Fighters do not fly or fight at anywhere near the speeds listed as V_Max on wiki, .mil sites or manufacturers websites when operationally configured. What brief sprints into upper mach numbers they do, are very brief. Unless of course we are talking about aircraft that are purpose built to fly and fight at those sustained speeds. YOU have no idea what I have an idea of. Stop trolling and start debating/discussing. If you don't understand what I'm saying, ask. If you have any kind of real exposure or insight into these issues then you should know exactly what I'm speaking about.

Let me break it down for you so you can get it with an analogy. My bike is powerful enough and geared properly to reach just over 200mph. In 5 years of racing with this machine I've reached that speed about 3 or 4 times and then only for brief moments. Most often, I'm in the 100mph-160 mph range. Similarly, a Rafale may have a listen V_Max of Mx.x but that doesn't mean its routine to fly that fast.

-DA 

You are mystaking me for one of the guys writng about our aircrafts and procedures.

  You bike is fact but it is not a military aircraft, my FZR 1000 Thunderace was 170 mph fast and  i took it to donigton park for a track day where i managed to turn circles around Dukes and ZX9Rs using =Kenny Roberts Senior riding techniques, dragging the rear wheel and carrying a hell of a lot of corner speed, i used to outbrake these sportbike under Dunlop easly...

 

  I dont mystake it for a MS 880 or a Cessna F150 though.

 

  The picture i posted show YOU what parameters are under scrutiny for the pilot to worry about when flying an aircraft from the 70s, the V-Max mentioned in Wiki are invalid here because they do not apply for aircraft with military loads but clean airframes and ewvery single one have the same V-Max limitations for structural load reasons.

 

  Today FADEC take care of engine ware and  DASH speeds can be reached and sustained for much longer than then, this is WHY it is used, the limitation is NOT an engine or aiframe problem (although sustained M 2.0 flight involves a certain amount of kinetic heating) but external loads depending in ther configurations...

 

Another piece of ehard vidence you try to deny, but i would like to see YOU posting anything as genuine as this to make your points other than mentioning a public information vulgarisation internet website, where i happen to write myself when i have time.

 

 It is full of innacuracies and even propaganda depending on the writers...

 

  The parameters shown in this Mirage III manual picture show this to you very clearly, dont tell ME you know better, i havent  seen you anywhere in the AFBs i was and i doubt very much you know better than this book does.

 

  What we know is:

 

  Rafale and Mirage 2000 CAN and DO easly fly at M 2.0 and M 2.2 and some missions requiers DASH speeds in particular high altitude interception, in operation it would be used just as well if necessary. AGAIN, FADEC.

 

Regards, PlG

Why do you keep twisting the debate to FADECS and such? I didn't say these planes aren't capable of M2.0. I said it's a cold day in hell when they actually do it and almost never when operationally configured. Why are you trying to dispute an obvious fact? 

I'll tell you what. Post for me an operationally configured Rafale mission profile that involves M2.0 speeds. Or, alternatively, list for me one example of an air to air interception and subsequent dogfight where a V of over M1.5 was a factor.

 -DA

  Boy YOU are the one trying to dispute and obvious FACT!

  That the limitation you are mentioning doesn't APPLY to military aircrafts in operational conficuration, those who does are all listed in this doc, structural Mach are NOT because WAY higher than that by design.

 

READ again...

 

 

 

 

A2A AIM 9B M 2.0 , M 1.5 with engine Temperature limitations, Firing envelop of the AAM M 1.7.

 

Sure!

 

WHEN are they will be disclosed to public in about 40 years but for the time being, interception over the French territory requiers high climb rate and maximum Mach, we dont have the luxury of 2000 fighters over a small territory... 

 

Limitation remains the SAME in operational configuration and they are those imposed by the external load NOT the airframe and to a mush lower extend the engine as opposed to what you say.

 

Rafale manual would be showing EXACTLY the same to the pilot, weapon configuration vs Mach limits MINUS the engine parameters because FADEC takes care of these and the M88 have NO limitations of the sort from 750 kt sea level to M 2.0 at 55.000 ft.

 

Why do you think these AAMs configuration are quoted with a Mach limit AND firing Mach limit?

 

Dont try to make an airliner of it it become ridiculous.

 

Regards. PlG

 

you evaded Darth;'s request and dodged his point...he asked you to point out an "operationally configured" Rafale....you produced a chart showing launch parametres.  That's not the same thing...can you show, anyone who has actually launched a Matra or Sidewinder at M 1.5 to M2.0?

 

A high mach number is meaningless, most times, because as people keep saying, you never actually USE this dash speed and when you do 'dash" it is far slower than the rated POSSIBLE dash speed because of ordnance, fuel constraints, terrain, or simply that the a/c is old or badly worn.

 

Phantom Over Vietnam is a nice account of an F-4 in Vietnam...THEORETICALLY his Phantom was capable of Mach 2, but as his place was patched, and poorly polished, and had other non-aerodynamic issues, plus the ejector racks, he could NEVER have reached it...Dash speeds, or fanboi dash speeds in high Mach numbers, are based on a clean a/c, polished, at height, with a perfect set-up...pretty much what you WILL NEVER find on an operational a/c.

 

The only a/c who's high speed is relevant is the F-22 and super-cruise...which is apparently the ability to fly high Mach at a sustained pace...that's revolutionary.  But neither the F/A-18 or the Rafale has that capability.

 

Bottom-Line: what is a realistic dash speed for a Rafale, at 500 metres, half a load of fuel, ejector racks or ejectors with ordnance, and two MICA's, and having flown over 20 sorties in the last 14 days?  I'm sure it's far less than it's rated dash speed.

Not really sure why there is an argument about FADECs here.  FADECs were developed so that pilots could slam the throttles around on their jets without risk of stalling or damaging the engines, and to extract optimal performance from the engine in its entire performance envelope.  In that sense a FADEC-equipped aircraft has some advantage over one that does not have a FADEC for flying at high speeds, but the main advantages of a FADEC come into play during subsonic maneuvering, not supersonic dashes.

 

The limitation on dash speed is airframe design, not the engine.  E.g. the F-15 using the same engines as the F-16 nonetheless flies faster (even if the T/W ratio is the same) because of its basic design, its variable inlets, etc.  FADEC or no makes no difference there.

 

A FADEC also does not eliminate engine wear.  The FADEC keeps the engine operating within its limits, but the fact is that running faster will always put more wear on the engine than not.

 

In any case, the real reason dash speed is almost never used isn't any of those, it is simple fuel consumption.  It's nice to have for interception, sure, but in an OCA or strike mission you want to avoid it because the more you use AB the less fuel reserve you have.

 

I was just trying to think of instances of supersonic dogfights.  I know that at various points airplanes in Vietnam and since have gone supersonic at times during engagements, but it is very uncommon.  Even then I don't know of any instance of anyone actually firing at those speeds.

 

One of the more interesting dogfight descriptions is of a 33rd TFW 4-ship of F-15Cs against a pair of MiG-29s and then a pair of MiG-25s on January 17 1991.  The F-15Cs were flying cover for strike packages, and in each case the MiGs were headed for the strikers when the F-15s intercepted them.  The fight with the MiG-29s involved merge speeds of between 550 and 600 knots (so 1200 kts closures) and stayed around 300-450 knots afterward.  The fight with the Foxbats was faster, the Foxbats were going around 700 knots but even so the Eagles never went supersonic and they were able to splash both Foxbats.  (there is a very detailed account of this dogfight in F-15 Eagle Engaged, by Steve Davies and Doug Dildy, Osprey publishing).

 

It may amuse some to know that in the above referenced fight, one of the F-15s executed a 12g turn at 450 knots; the pilot stated that "I seriously overstress the jet" in doing that but it did not cause any problems.

Good way to kill yourself. Compression shockwave effects on a dropped missile's nose  that lights off inside an aircraft's shock cone are BIZARRE.

 

I've seen Raptors do it  successfully, but they were DESIGNED to do it successfully.

 

Herald