Most Efficient BVR climb and Highest performance Speeds

[ARM505]

25 minutes ago, Bremspropeller said:

What does the range indicator on the fuel gauge actually indicate? Neither my 29G manual, nor the manual coming with the module do actually explain it. Is it something like "800kg of fuel at 10km from the airfield, using X flight profile"* or some other definition? The way I read it so far, it's the max range to flameout but not acconting for wind ("air miles"). Is there any deeper meaning to it?
_____
*random numbers

 

The Alan Wise 'Flight Manual' just states:

"The available flight range computer is used for computing and indicating the available flight range by reference to the information on the fuel reserve and consumption and true airspeed"

So...not much help on the specifics of what those variables might be, where they're obtained from, or how it's calculated. I couldn't find any other reference, but then again, it's not like it's easily searched (I only have the actual book, not an electronic copy).

[Pavlin_33]

1 hour ago, Bremspropeller said:

You're all using an awful lot of words for finally agreeing with me: The MiG-29 has no range - even at high altitude, it falls short.

Let me put in your terms: F-15 has a horrible range compared to 777ULR. It's payload is also not good at all and it can't carry any passengers.

[Bremspropeller]

2 hours ago, ARM505 said:

The Alan Wise 'Flight Manual' just states:

"The available flight range computer is used for computing and indicating the available flight range by reference to the information on the fuel reserve and consumption and true airspeed"

So...not much help on the specifics of what those variables might be, where they're obtained from, or how it's calculated. I couldn't find any other reference, but then again, it's not like it's easily searched (I only have the actual book, not an electronic copy).

That's about the same the 29G manual states. Sadly, the "optimum" switch is not working yet, so I can't determine how much those figures change. It seems it's not giving out specific information or a calculation in regards to ground-speed like the FPAS in the Hornet, so it's just a thumb'o'meter.
 

[zerO_crash]

You really don't get it. No matter what flight profile; if I can get at least 1200km on internal fuel alone (and I am able to squeeze out more), than that is not short legs. We'll just have to disagree on that.

 

This discussion is complex, hence why you cannot simplify it in a few words. The way you evaluate it, however, is flawed at best. We derailed btw. completely from the main thread.

[Temetre]

This talk reminds me of the F4. Realtively high thrust compared to same era planes, but also inefficient engines at low/medium altitudes. Otoh you can stretch range a lot by flying optimally and high altitude. 

So a good range advantage over older interceptors, but the combination of fuel fraction and 'all around' engine efficiency is weaker compared to other jets like the F14B/16/18 or so. Requires more careful flying if you need some range than some other planes.

 

If that means 'can go far' or 'no range' is more of a semantic discussion, and dependant on what you compare it too.

[Bremspropeller]

32 minutes ago, zerO_crash said:

You really don't get it. No matter what flight profile; if I can get at least 1200km on internal fuel alone (and I am able to squeeze out more), than that is not short legs. We'll just have to disagree on that.

We don't. 1200km (650NM) on internal fuel with high altitude cruise (say FL400) is an abysmal range.
We also just established that the range-indication is a slot-machine, not taking wind into account.

19 minutes ago, Temetre said:

If that means 'can go far' or 'no range' is more of a semantic discussion, and dependant on what you compare it too.

Sure.
But we're talking about a tactical jet over here. That means employing the jet not in some kind of arbitrary "the designer wanted you to do this"-mission, but in an actual tactical engagement with requirements dictated by the sitaution at hand. Under those circumstances, we'll have to see what the jet can do, rather than what it could do if we'de be sticking to some ideal design mission dreamt up by some higher echelon staff officer.

The jet can loiter at low speed and high altitude for a bit. But it not anywhere near outperforms the opposition.
It just can't carry enough internal fuel to cash in on the airframe's good properties.

Leaving out the rough-field intake louvers and taking more gas instead would have been the better design choice.
That's pretty much the direction they later took - which is kinda weird if they'd thought they had "enough range" before.

[zerO_crash]

31 minutes ago, Bremspropeller said:

We also just established that the range-indication is a slot-machine, not taking wind into account.

1 hour ago, Temetre said:

 

Again, you are judging something by your own square metric. It's not a slot machine - if it was, it wouldn't be in the aircraft. From my personal experience, it is incredibly accurate. What you have to understand, is that it doesn't give you the range across the ground, rather, it gives the range of the jet in the current state (all things considered). As such, the jet will travel further/less in air during windy days, in order to reach it's destination across the ground. Also, you have to remember that there is a slight error to be incorporated into the indication, given that the weather might be completely different 200km away (which the jet has no way of knowing). Remember, this is pre GPS- and weather radar- era.

 

Still, if I set the engine on a given thrust-setting and maintain altitude, then the km I'm passing, are most often 1:1 with those passed according to the map/INS/NS430. That's my experience with it.

[Bremspropeller]

3 minutes ago, zerO_crash said:

What you have to understand, is that it doesn't give you the range across the ground, rather, it gives the range of the jet in the current state (all things considered). As such, the jet will travel further/less in air during windy days, in order to reach it's destination across the ground. Also, you have to remember that there is a slight error to be incorporated into the indication, given that the weather might be completely different 200km away (which the jet has no way of knowing).

I know, hence I wrote "air miles" on the last page, which is exactly that.

[zerO_crash]

Exactly, so not a "slot-machine". That'd be too random.

[AeriaGloria]

8 hours ago, ARM505 said:

The Alan Wise 'Flight Manual' just states:

"The available flight range computer is used for computing and indicating the available flight range by reference to the information on the fuel reserve and consumption and true airspeed"

So...not much help on the specifics of what those variables might be, where they're obtained from, or how it's calculated. I couldn't find any other reference, but then again, it's not like it's easily searched (I only have the actual book, not an electronic copy).

The variables are current fuel consumption. 
 

It divides remaining fuel by current fuel consumption and uses TAS to find distance flown until tank empty