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  • Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.

    Post 16 Update

    Post 17 Warning

Skysim Mirage III - Underpowered?

Mach3DS

Mach3DS

Charter Member
Recently revisited this beauty. Always loved the Mirages, to me they aren't just airplanes, they are works of art. Recently watched for the first time "Vols Blancs" about the last Swiss Mirages, great film. But it left me asking, does the Skysim Mirage III seem underpowered to anyone? Seems like the takeoff roll is unusually long due to it's lack of acceleration. Are the real aircraft like this? I realize they are pure delta wings, and so naturally takeoff and landing speeds are much higher than "standard" but do they suffer from acceleration issues? Engines really underpowered? Especially true when I have wing tanks, or other ordinance...takes almost the entire length of runway at for example Payern AFB (Swiss) to get main gear off the ground. Everything else about this bird seems more normal. I've tried numerous searches with no luck. Anyone who flies this could you respond? Just found the ISRA Mirage IIIS - How does it compare? Thanks everyone!
 
although i cant speak for the skysim mirage being under powered, i can confirm that whenever you add exxtra weight to any plane such as gas or weapons, it increases the length of runway needed for takeoff dramatically. for every pound of extra weight, you need an extra pound of lift, and you can only get that with speed and distance. take the P-61 for example. with normal combat weight of 29000 pounds, you can take off with full flaps in a little under a thousand feet, now add two external tanks and increase the weight to 31000 pounds and ypur up to 2000 feet of runway, and can only use 2/3ds flaps. increase it further and your up to needing 6000 feet of runway ( over 32000 pounds ). It's not the plane. its the laws of physics..
The mirage may be a little slow on the spool up. that could also cost you runway. but as i dont own the aircraft, i cant say if thats the case..
 
Warchild, yes you nailed it that's my point exactly....Seems as though there is not enough excess power to deal with the increase in weight. However, I just did a little research and found that he Mirage III uses the SNECMA ATAT 09-x Engine family. Rated @ 9,430lbs dry and 13,669lbs in burner. So maybe there really is an excess power issue on takeoff in RL? But, I'm having a hard time with why...A typical Loadout I'll use consists of adding 680 lbs of external stores. I can't believe that 680lbs of stores is going to give me a takeoff roll of close to 7K feet. The jet would burn that much fuel weight just in AB for that short time so it should be a wash, right? I'm familiar with flight in the backside of the power curve, so it's understandable that slow flight in this delta is going to be a beast and you'll need a lot of power to stay slow. I'm just wondering if this takeoff behavior is realistic or not for this particular jet?
 
In my opinion, about the Skysim Mirage III, i observed it really seems underpowered when its wheels are on the ground, then, when airborne, it gains speed quite soon.
 
I could be wrong here, not at the right machine to check for sure. I'm pretty sure however that I've read somewhere that whether you load the visual models of the tanks in the payload section or not you are infact carrying the full external fuel load, thus with a seemingly clean airframe you are in effect hauling 3 external tanks (2x 1300lbs an 1x 700lbs?).
I flew it myself a couple of days back and found I was using almost the full runway at Payerne, though I expected this as I'd loaded her up with tanks and 9L's.

Craig
 
fallenphoenix1986 said:
I could be wrong here, not at the right machine to check for sure. I'm pretty sure however that I've read somewhere that whether you load the visual models of the tanks in the payload section or not you are infact carrying the full external fuel load, thus with a seemingly clean airframe you are in effect hauling 3 external tanks (2x 1300lbs an 1x 700lbs?).
I flew it myself a couple of days back and found I was using almost the full runway at Payerne, though I expected this as I'd loaded her up with tanks and 9L's.

Craig
Click to expand...
Hopefully you read it in the manual because that's where I wrote it. :icon_lol: Even used some red ink in that section. Since all external stores are built into the model already (and therefore any external stores layout is available without needing individual MDL files) the max capacity for the fuel tanks is pre-loaded into the aircraft.cfg [Fuel] section as well. So if you don't change that you will be taking off with the fuel weight of two 374 gallon wing tanks and a 286 gallon tank on the centerline. And that's going to require a lot of runway for a 1960's era Atar 9C engine.

I've seen video of a IIIRS taking off from Payerne with 110 gallon wing tanks and a slightly larger center tank and she was barely off the ground when she cleared the net at the end.

:ernae:
 
Thank you fsafranek!!! This is exactly what I was missing...I was scratching my head about it...I was working when I wrote the 1st post, and was wondering if it was in the manual...haven't read it in a while...:salute: I'll perform my due diligence now! :)
 
Skysim Mirage is the best!!!!!! Your an amature and know nothing about delta's or flying them, if you think that.... HOW VERY DARE YOU!!!
 
peter12213 said:
Skysim Mirage is the best!!!!!! Your an amature and know nothing about delta's or flying them, if you think that.... HOW VERY DARE YOU!!!
Click to expand...

I'm a real world pilot with a degree in A.Sc. and I hold Commercial License so I'm pretty familiar with advanced aerodynamics -- and this is a PC simulator, NOT REAL LIFE. This aircraft while modeled beautifully, and hard work put in by it's creators, is not a real airplane. Therefore it is fallible. It does not meet any standard of authenticity. With that said, it's purpose is for entertainment and the love and joy of flying...which it has achieved perfectly. Thank you to it's creators, I enjoy it thoroughly! The purpose of my post was to identify if the REAL LIFE Mirage III had similar behavior. "Similar" being the key word. Seeing as the question as to why I felt the aircraft was underpowered has been answered in that the creators modeled in weight by default, I feel much more confident now, as to why the aircraft behaves the way it does, and what steps I can take in the future. No need for insults.
 
Rick:
Your right, it is an entertainment product, but, sometime back in 2003 Microsoft saif the five words that really torqued a bunch of us into action. "As real as it gets" was as far from the truth as it gets, and we were pissed. We wanted that reality. So we had to make it for ourselves. If you spend a couple hundred hours in an A2A accusim bird, by the time you step into its real life counterpart, your gonna have a whole lot of real world stuff about it memorized. Same goes for a lot of other peoples work in FSX. Berndt Stolle's, JohnC's, Fliger747's, and even my own usually. It isnt like climbing into a real plane and flying it, but it isnt all that different from flying a predator or global hawk.

With the Mirage, it's going to boil down to one of two things. The mean aerodynamic chord, or the spool up rate. If the MAC isnt calculated precisely, you can end up with all kinds of things from a complete lack of lift, to so much lift the plane doesnt stay on the ground. As for the spool up rate, well, thats where i have to question if its underpowered or not. You see, a few years ago, I started working on an F-111 ( one of the fastest birds in the american arsenal ) and teamed up with a pig driver from Australia ( he now drives C-130s i learned ). THAT plane, requires sixteen seconds for the engine to fully spool up. You would think it was underpowered ( until it shoots you across the sky at mach 2.3 )but it's not.. Again, watching videos of Phantoms taking off out of Phan Rang, we see an extremely fast plane needing almost the entire runway. So its hard for me to say if the Mirage is underpowered or not.
Pam
 
Hey, your welcome.. John was kind enough to help me with the props on then C-27. The man definitely knows his trade :)..
Pam


PS.. Mark let me use his old flanker 33 to create an aggressor group for VUSN, which never worked out, but that flankers and the work i've done on it taught me a lot, and led to other planes such as the Iris F-22.. Mark does good work, and i like it.. :)

PPS. I wish Mark would do the SU-30MKH/SU-37 with active canards.. Man could zi do some things with that :D
 
warchild said:
Rick:
Your right, it is an entertainment product, but, sometime back in 2003 Microsoft saif the five words that really torqued a bunch of us into action. "As real as it gets" was as far from the truth as it gets, and we were pissed. We wanted that reality. So we had to make it for ourselves. If you spend a couple hundred hours in an A2A accusim bird, by the time you step into its real life counterpart, your gonna have a whole lot of real world stuff about it memorized. Same goes for a lot of other peoples work in FSX. Berndt Stolle's, JohnC's, Fliger747's, and even my own usually. It isnt like climbing into a real plane and flying it, but it isnt all that different from flying a predator or global hawk.

With the Mirage, it's going to boil down to one of two things. The mean aerodynamic chord, or the spool up rate. If the MAC isnt calculated precisely, you can end up with all kinds of things from a complete lack of lift, to so much lift the plane doesnt stay on the ground. As for the spool up rate, well, thats where i have to question if its underpowered or not. You see, a few years ago, I started working on an F-111 ( one of the fastest birds in the american arsenal ) and teamed up with a pig driver from Australia ( he now drives C-130s i learned ). THAT plane, requires sixteen seconds for the engine to fully spool up. You would think it was underpowered ( until it shoots you across the sky at mach 2.3 )but it's not.. Again, watching videos of Phantoms taking off out of Phan Rang, we see an extremely fast plane needing almost the entire runway. So its hard for me to say if the Mirage is underpowered or not.
Pam
Click to expand...

Pam, I appreciate this kind of conversation. Thank you. I find that most people here are very friendly. You included. I believe you fully understood my point, and fully appreciate the time, energy, and just plain hard work it takes to put out a fine product like the mirage and especially the likes of VRS or A2A birds. These groups/individuals are very talented. I THOROUGHLY enjoy and love flying the virtual skies. I thank all them for their efforts and in no way intended to belittle or downplay their work. I'm always up to talk shop! thanks everyone!
 
Chaps,

pretty sure that Peter's outrage at the comments of what may be one of his favourite models should be taken in jest. "HOW VERY DARE YOU" is how some gay men might show their displeasure at someone. Personally "I'm not bovvered"

Put "HOW VERY DARE YOU" in to youtube (no pun intended) and look for Derek or Catherine Tate and I think you'll see what he means.
 
SOP with the RAAF 111O Mirage was a lengthy take off roll and a warning to "Punch out if you lose power at or beyond V2 and (when landing) crossing the threshold on final".
The really hot version (and in retrospect one that was wisely not adopted) was our one and only Avon powered prototype.
I gather the powers that be decided the lengthy development time taken for the 'Avon Sabre' was not going to be repeated on the Mirage.
:kilroy:
 
I'm past this statement. I harbor no ill feelings. Sometimes it is difficult to determine if one is being sarcastic or not in a forum post, unless it is made perfectly clear. So I hope Peter realizes I'm in no way offended. After all the comments I'm more enlightened about the Mirage III from Skysim than I was before, and that was the point of the whole topic; to generate positive discussion to help me solve what I thought was an inconsistency. :mixedsmi:
 
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