SMQ of the most recent fighters

[SukhoiLover]

The SMQ ( Summarized Maneuverability Quotient ), is a mathematical formula that gives you a better idea of a fighter real maneuverability.

SMQ= ( Ct/w / Sal ) × 1,000

Ct/w- Combat thrust to weight ratio
Sal- Specific area loading

Does anyone know whats the SMQ of the Typhoon, F-22, Gripen and Rafale?

[valkyrian]

My friend, this is a very nice question. Where did you find this formula?

If my memory serves me well, i have seen such a similar parameter in Andrei Fomin's book "Flanker Story".

There was a diagram where the Specific Excess Power (SEP) was divided by the aircrafts' total projected area. I think this is the Sal in your formula. That was making sense, since the biggest the frontal projected area, the biggest the power required to "move" it.
I'll check again in the book for the SMQ parameter. But no matter what it is, keep in mind this :

Since the Thrust parameter is in your formula, the SMQ varies according with altitude and speed.
A turbofan, like the AL31 or the F110 has a greater by pass ratio than, say the F119 or the F404, therefore, subsonically and at low altitudes are performing better than supersonically and at hi altitude.


What i am trying to say, is that a fighter X may have  a better SMQ than a fighter Y, but under another set of conditions, this is very likely to change.

[SukhoiLover]

My friend, this is a very nice question. Where did you find this formula?

If my memory serves me well, i have seen such a similar parameter in Andrei Fomin's book "Flanker Story".

There was a diagram where the Specific Excess Power (SEP) was divided by the aircrafts' total projected area. I think this is the Sal in your formula. That was making sense, since the biggest the frontal projected area, the biggest the power required to "move" it.
I'll check again in the book for the SMQ parameter. But no matter what it is, keep in mind this :

Since the Thrust parameter is in your formula, the SMQ varies according with altitude and speed.
A turbofan, like the AL31 or the F110 has a greater by pass ratio than, say the F119 or the F404, therefore, subsonically and at low altitudes are performing better than supersonically and at hi altitude.


What i am trying to say, is that a fighter X may have  a better SMQ than a fighter Y, but under another set of conditions, this is very likely to change.

Exactly Valkyrian, i forgot to say this, but i´m more interested in the dogfight SMQ of these fighters.

I got to know the SMQ in : Famous Russian Aircraft, Sukhoi Su-27 by Yefim Gordon.

[Webmaster]

SMQ= ( Ct/w / Sal ) × 1,000

Ct/w = kgf/kg, so that's the same as P/G in Fomin's book, but he distinguished between takeoff and combat weight.
Sal, if valkyrian is right, and I believe so, it's the same as G/Spp
however Fomin also notes the midsection area and airflow-wash area
 
SMQ = (P/Gc) / (G/Spp) x 1,000 is then:

Su-27SK = 7.1
F-15C = 6.8
F-16C = 5.4
F-18C = 4.8
2000-5 = 4.2
EF2000 = 6.9
Rafale = 6.3

So there you have your parameter. But if we use airflow-wash instead of projected area, then we get these:

Su-27SK = 20
F-15C = 20
F-16C = 16
F-18C = 14
2000-5 = 12
EF2000 = 18
Rafale = 16

So I don't know which is closer to those SMQ values you have?

* All calculated using Fomin's data...

[SukhoiLover]

Thanks webmaster

Yes, the values are similar to those in Yefim Gordon´s book, however, he didn´t calculate it for either the Rafale and the Typhoon, and since i couldn´t find some of the essential data to make the calculations i came here and asked you guys.

[Webmaster]

It's with data from 2000 though at the best. I guess Mr Gordon knew they weren't accurate anymore, so left them out of his newer book...

[iluveagles]

So it is the higher number that means greater maneuverability and the lower not as good or vice versa?