Help with VREST Cruise & Bingo

[Zaneboy]

I'm having difficulties understanding/trusting the VREST CRUS & BNGO pages.

Are pages fully functional?

 

 

1. Is it normal that the bingo page always shows 2000 & 2250 pounds of remaining fuel? Can't these values be changed or simply matched with the bingo knob on the fuel panel?

 

2. Very often my OPCR CALT would show 40k+ altitude. Is this correct? Can the harrier even fly decently at that altitude? Also, the higher I climb, the higher that value becomes. Theoretically I can never reach this alt if it keeps increasing.

 

3. Are the RNG values correct? Often/always it shows a really low value.

 

 

Thnx!

Edited November 15, 2019 by Zaneboy

[Ramsay]

I'm having difficulties understanding/trusting the VREST CRUS & BNGO pages.

Are pages fully functional?

 

NO, the biggest recent change AFAIK is that DI (drag index) now changes with loadout and effects the calculations that are implemented.

 

1. Is it normal that the bingo page always shows 2000 & 2250 pounds of remaining fuel? Can't these values be changed or simply matched with the bingo knob on the fuel panel?

The values are place holders.

 

• ABNG = "Altitude Bingo" i.e. if you stay at your current altitude

• OBNG = "Optimum Bingo" i.e. if you climb/descend to the optimum altitude.

 

• RFUL = "Remaining Fuel" when you reach the selected waypoint

 

If they (2000 & 2250) were working, they would be calculated values and not be set/effected by the bingo knob on the fuel panel.

 

2. Very often my OPCR CALT would show 40k+ altitude. Is this correct?

Yes, for a "clean" Harrier.

Can the harrier even fly decently at that altitude?

The optimum cruise altitude for a "clean" Harrier is between 37,000 ft and 45,000 ft depending on weight, in DCS it's more like 35,000 ft - 42,000 ft but pretty close.

 

 

Also, the higher I climb, the higher that value becomes. Theoretically I can never reach this alt if it keeps increasing.

As you climb, you are burning fuel and getting lighter, hence the Optimum Cruise altitude increases, as you get closer to the "optimum" altitude the increase slows and you can reach it (it's better to be 2,000 ft too low, than 2000 ft too high). IIRC it helps to set the flaps to "Cruise" and keep AoA ~8° (high AoA increases drag).

 

3. Are the RNG values correct? Often/always it shows a really low value.

 

They are correct on the "Cruise" page

 

• RNG = "Range" (Distance) to selected waypoint

 

For OPCR (Optimum Cruise)

 

• MRNG = "Max Range"

• RFUL = "Remaining Fuel" at selected waypoint

 

are working.

 

Note: The "Bingo" page, "RNG = 20 NM" is a place holder.

 

Also note the fuel/distance calculations are to the selected waypoint i.e. they don't take the route into account.

Edited November 16, 2019 by Ramsay
Add example flight plan

[Zaneboy]

Thanks for your reply, really helpful. So if I'm reading it correct, the bingo page should not be used due to placeholders whereas the cruise page can be used?

[Ramsay]

Thanks for your reply, really helpful. So if I'm reading it correct, the bingo page should not be used due to placeholders whereas the cruise page can be used?

Most of the figures in the Optimum Cruise column (OPCR) are working including max range if you fly at the optimum altitude and speed.

 

Altitude Cruise (ACR = Optimum cruise at existing altitude) is not complete with waypoint remaining fuel (RFUL) and max range (MRNG) being place holders (2000 lb, 250 NM) and the suggested CAS and MACH being incorrect i.e. 0.8 mach may be optimum @ 37,000 ft, but at 8,000 ft the optimum cruise air speed is ~0.5 mach / 290 CAS (the ACR column shows 0.8 mach / 450 CAS).

Edited November 16, 2019 by Ramsay