Mig 29 fuel gauge "OPT" mode

[jeffy]

While flying the Mig I noticed a small lever on the top left corner of the fuel gauge what if you put it in opt will it like a fmc generate me an optimum altitude and engine rpm or whatever, so can a mig 29 expert tell me what the hell is it

[TerrorMango]

Not a MiG-29 expert in any way but according to the manual:

On the front panel of the ISTR4 indicator there is a switch "T-R" [9], to select information about remaining
fuel base on direct in-tank measurement or based on flow-measuring calculations of STR system; a switch
"TAC. – OPT." [2], change estimated distance indication: for max fuel conservative flight modes "OPT"
or for actual flight mode fuel consumption.
The ISTR4 scale provides fuel readings in hundreds of kilograms. The estimated distance in EN cockpit
in nautical miles

So in TAC, is hows you flight distance for regular flight "TAC" or for very conservative flight "OPT".

So when in OPT, the distance is greater than in TAC, but you'll have to adjust your way of flying to conserve fuel. I am unaware of which parameters actually constitutes this though in terms of speed, RPM etc.

[AeriaGloria]

My video here goes through least fuel consumption speeds for each altitude 

 

1 hour ago, TerrorMango said:

Not a MiG-29 expert in any way but according to the manual:

On the front panel of the ISTR4 indicator there is a switch "T-R" [9], to select information about remaining
fuel base on direct in-tank measurement or based on flow-measuring calculations of STR system; a switch
"TAC. – OPT." [2], change estimated distance indication: for max fuel conservative flight modes "OPT"
or for actual flight mode fuel consumption.
The ISTR4 scale provides fuel readings in hundreds of kilograms. The estimated distance in EN cockpit
in nautical miles

So in TAC, is hows you flight distance for regular flight "TAC" or for very conservative flight "OPT".

So when in OPT, the distance is greater than in TAC, but you'll have to adjust your way of flying to conserve fuel. I am unaware of which parameters actually constitutes this though in terms of speed, RPM etc.

 

2 hours ago, jeffy said:

While flying the Mig I noticed a small lever on the top left corner of the fuel gauge what if you put it in opt will it like a fmc generate me an optimum altitude and engine rpm or whatever, so can a mig 29 expert tell me what the hell is it

 

[jeffy]

5 hours ago, AeriaGloria said:

My video here goes through least fuel consumption speeds for each altitude 

 

 

 

Thanks very intresting

 

[Nealius]

The real-world Luftwaffe manual has much more understandable wording for explaning this system:

In TAC the remaining flight distance is calculated based on current fuel flow and ADC data. In OPT the remaining flight distance shows the max possible range "with an optimized calculated fuel flow." I believe this would be referenced through charts, however my manual is incomplete and missing said charts.

[AeriaGloria]

3 minutes ago, Nealius said:

The real-world Luftwaffe manual has much more understandable wording for explaning this system:

In TAC the remaining flight distance is calculated based on current fuel flow and ADC data. In OPT the remaining flight distance shows the max possible range "with an optimized calculated fuel flow." I believe this would be referenced through charts, however my manual is incomplete and missing said charts.

The chart is in my video above There really aren’t many for Fulcrum “fuel flow per speed and altitude” charts, though there are more for “fuel used for climb/descent with xx payload”

[Nealius]

I'll check out your vid when I have time. Typically I avoid videos since I need written text and ctrl+F capability to find the info I'm looking for; also cellular data consumption 

Edited 5 hours ago by Nealius

[AeriaGloria]

Take screenshots. I make all my videos with the intention that people can take screenshots to save all the info 

1 hour ago, Nealius said:

I'll check out your vid when I have time. Typically I avoid videos since I need written text and ctrl+F capability to find the info I'm looking for; also cellular data consumption 

 

[IvanK]

Rule of thumb when hurting on gas and trying to get home:

Max range at any Altitude set 4 deg Alpha power as required to maintain level flight (nil wind)

Max endurance at any Altitude set 5-6 deg Alpha power as required to maintain level flight.

For Max performance in both be at Optimum altitude/ Which will vary as a function of Drag Index and weight but be in the 30,000's roughly.

Edited 3 hours ago by IvanK

[AeriaGloria]

1 hour ago, IvanK said:

Rule of thumb when hurting on gas and trying to get home:

Max range at any Altitude set 4 deg Alpha power as required to maintain level flight (nil wind)

Max endurance at any Altitude set 5-6 deg Alpha power as required to maintain level flight.

For Max performance in both be at Optimum altitude/ Which will vary as a function of Drag Index and weight but be in the 30,000's roughly.

Manual mentions 4-7 degrees as optimal AOA. If I follow the maximum range speeds I end up with 4 degrees AOA down low and 6-7 up high