Tank drag

I got the jet loaded with three tanks, 4 97s, 2 9s, 2 120s. The jet hardly climbs with mil power to 26000. About 800fpm. Is this right? Hardly capable of deep strike if so.

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Three tanks is not used for such missions. With a more realistic 4x CBU, 2 radar 2 heat 2 bag loadout that doesn't sound too far off in performance. With 10,000 lbs. of JP8 you can go 500 miles round trip and any honest deep strike would throw an AAR in there and probably pare down to 2 cans CBU. The TER and interference on the 4-can loadout is a stiff DI penalty. The optimum cruise altitude will increase over time as the GW reduces.

Operation Opera was done with 600 gallon tanks with a significant low level segment and planned to the last drop of fuel. If flight profile is optimized for fuel economy the F-16 will absolutely surprise you.

https://www.youtube.com/watch?v=PeHc4vbQrNY

I'm sure the real F16 can do deep strike missions. I was asking if our F16 and the drag values for the tanks were correct. Currently with the load out I have, I would require refueling going to and from to go from Al Minhad? to Iran, patrol for 40 minutes, then RTB. It seems odd.

Also this isn't doing a "deep strike" into Iran. This is on the shore of Iran. So again, I ask does this still seem right for the DCS jet?

3 Tanks + TERs and 4 CBUs is going to be A LOT of drag and weight. If you're going a long way I'd take 2 tanks and 2 bombs (probs MK84) or if they have to be CBUs only take 2 of them.

Operation Opera was done with 600 gallon tanks with a significant low level segment and planned to the last drop of fuel. If flight profile is optimized for fuel economy the F-16 will absolutely surprise you.

No 600G tanks in 1981. Photos from Pre mission clearly show 2 x 370 tanks and 1 x 300G tank and they were all jettisoned before the target. Note that the A had better range.

No 600G tanks in 1981. Photos from Pre mission clearly show 2 x 370 tanks and 1 x 300G tank and they were all jettisoned before the target. Note that the A had better range.

Thanks

Also this isn't doing a "deep strike" into Iran.

Israel literally made a deep strike to Iraq. Alone their return back to Israel was 600 miles, after they have bombed the Iraq nuclear plant.

https://en.wikipedia.org/wiki/Operation_Opera#Attack

That is about 2200 km in total route, where they dropped their fuel tanks after about 450 km after take-off. And they did fly below the radar at very low altitude up to the attack in Iraq airspace, and from there they RTB at low altitude to avoid SAM's etc and then they took altitude to 40'000 ft for return of home (600 nm range).

And considering that they did that by loading each F-16 with a two Mk-84 (2000 lbs each) with three fuel tanks, that is heavy load, compare that to your four Mk-82 with 500 lbs each. So they had even heavier loadout than you have.

Two AIM-120 is only 340 lbs each, and two AIM-9 is 190 lbs each. In total such A-A loadout is about 1800 lbs in total.

So with four Mk.82 and A-A loadout you get about total weight of two Mk.84 bombs (4000 lbs).

One could try to find out the speeds and altitudes to calculate what was the result of that actual deep strike mission, where F-16's couldn't carry any A-A armaments because the range.

Israel literally made a deep strike to Iraq. Alone their return back to Israel was 600 miles, after they have bombed the Iraq nuclear plant.

 

 

https://en.wikipedia.org/wiki/Operation_Opera#Attack

 

That is about 2200 km in total route, where they dropped their fuel tanks after about 450 km after take-off. And they did fly below the radar at very low altitude up to the attack in Iraq airspace, and from there they RTB at low altitude to avoid SAM's etc and then they took altitude to 40'000 ft for return of home (600 nm range).

 

And considering that they did that by loading each F-16 with a two Mk-84 (2000 lbs each) with three fuel tanks, that is heavy load, compare that to your four Mk-82 with 500 lbs each. So they had even heavier loadout than you have.

 

Two AIM-120 is only 340 lbs each, and two AIM-9 is 190 lbs each. In total such A-A loadout is about 1800 lbs in total.

 

So with four Mk.82 and A-A loadout you get about total weight of two Mk.84 bombs (4000 lbs).

 

One could try to find out the speeds and altitudes to calculate what was the result of that actual deep strike mission, where F-16's couldn't carry any A-A armaments because the range.

Weight is only one part of the equation, drag is the other. A single Mk-84 on a pylon is MUCH less draggy then a TER with 2 CBU-97s. Also you mention him taking Mk-82s? OP said he was taking CBU-97s which on its own is much draggier then a Mk-82.

Drag is much more important than weight. MK84 is slick compared to 2 Mk82 on a TER. The 2x CBU on a TER load is possibly the draggiest choice outside of LAU-88 Mavericks.

One can do an equivalence between dragless weight and weightless drag and touch find it takes quite a lot of induced drag from pure weight to equal most external stores. As for the original question someone can run the numbers and find what the mission range would be . I'm guessing it's more than 500nm but not by much.

EDIT: OK let's see how this load goes. Assuming B 120s and M 9s takeoff GW is 42700 lbs., DI about 280. Optimum cruise 26300. Takeoff to climb speed takes about 400 lbs. Gunna take you 89.4nm on a 340/M0.79 MIL schedule burning 1700 lbs.

So let's say you get to altitude with about 40,000 lbs. GW. That gives about 12.1 lbs/nm outbound. Let's say you want 2000 lbs. at recovery so you have 12000 to burn. We at 2100 lbs for takeoff and climb which gave 90nm of distance. On the way back let's make some assumptions, DI down to 200 GW less by 6000 lbs. of gas and 4000 lbs. of stores. Now we're at 37kft cruise. Max range descent and getting 8.3lb/nm. Max range descent gives 50nm taking about 200 lbs.

So we can graph the inbound fuel slope and outbound fuel slope and where they cross is the turn around point. And wouldn't you know it on my drawing that happens at about 505nm and 6,100 lbs. fuel.

Tank drag

Israel literally made a deep strike to Iraq. Alone their return back to Israel was 600 miles, after they have bombed the Iraq nuclear plant.

 

 

 

 

 

 

https://en.wikipedia.org/wiki/Operation_Opera#Attack

 

 

 

That is about 2200 km in total route, where they dropped their fuel tanks after about 450 km after take-off. And they did fly below the radar at very low altitude up to the attack in Iraq airspace, and from there they RTB at low altitude to avoid SAM's etc and then they took altitude to 40'000 ft for return of home (600 nm range).

 

 

 

And considering that they did that by loading each F-16 with a two Mk-84 (2000 lbs each) with three fuel tanks, that is heavy load, compare that to your four Mk-82 with 500 lbs each. So they had even heavier loadout than you have.

 

 

 

Two AIM-120 is only 340 lbs each, and two AIM-9 is 190 lbs each. In total such A-A loadout is about 1800 lbs in total.

 

 

 

So with four Mk.82 and A-A loadout you get about total weight of two Mk.84 bombs (4000 lbs).

 

 

 

One could try to find out the speeds and altitudes to calculate what was the result of that actual deep strike mission, where F-16's couldn't carry any A-A armaments because the range.

Again, I’m not denying it’s not possible in the real world. What I’m questioning is it doesn’t seem possible in DCS. The drag values seem to be a bit too much. My whole climb to 26k (intended to climb higher) was mil power climb and by the time I was on the Iran shore my bags were empty. That wasn’t anything close in distance to this mission you all keep referencing.

Something doesn’t seem right. I don’t know.

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Well let's check. 2 120B 2 9M 4 CBU97 2 FT370 1 FT300, full fuel and guns taking off from Anapa +15C SLT straight out.

I started MAXAB takeoff at 14,000 lbs exactly and accelerated to climb speed at 13,617 which spot on the 380 lbs. expected.

Next MIL climb through 26,300. In this it's clear that performance is lower than expected as altitude increases. I was unable to achieve 26kft by 90nm keeping to the MIL schedule. In the end I cheated and pitched up not exceeding LDmax AOA. Fuel remaining ~12klbs so it took 1,600 lbs. which is in line with expected.

Next is cruise which at 25kft should be 420 KTAS 5100 pph with a maximum possible of 517 KTAS at 7200 ppb in MIL. Neither of which is possible in DCS as MIL is about 5500 pph and gives only about 420 KTAS. Instead I set 5100 pph and cruise at LDmax AOA of ~6.8.

Slightly before 500nm radius all three bags are empty. Jettison CBUs and TERs and turn around and start new MIL climb 365/0.82 up to new cruising altitude 35kft. Fuel is 7000 pounds at this point, oddly more than calculated but there have been a few deviations from plan.

Doing about 470KTAS I figure I'm a 34klb DI 200 but it doesn't line up with the charts. I think I should be burning 4kpph and not 3 but oh well I'm 4.5 AOA back and if all goes well I'll be 3klb of fuel at top of descent 50nm from the airfield.

50nm to go top of descent and 3440 lbs in the tanks. Beginning max range idle descent at 230 KIAS. I calculated descent from 25kft instead of 35kft so I ended up 10kft over the airfield, small detail. In any case I showed up with 3300 lbs remaining.

So apart from the insufficient performance at altitude which I can't explain and the unusually low fuel burn on the outbound cruise leg (which gave me 1000 lb extra) everything went as expected. I was able to cart that draggy and heavy load out 500nm and turn around to land with ample fuel reserve.

Tank drag

Okay, so it sounds like for my mission I have to incorporate a refueling stop then even though the patrol area isn’t 500 miles away. Because by the time I get to my patrol area I’m already at about 6000lbs. The problem is I know for certain that there will be extensive maneuvering from ground attack as well as possible AA combat and waiting for relief flight before RTB.

Thanks for putting in the time to verify the sim.

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Frederf, did your test mission have zero wind?

Yes, default DCS day/weather except changed SLT to +15C.

Just did a quick math. Drag index and weight with such payload make max altitude of level flight nearly 26.5k feet. Assuming that I was not precise in calculations and you have spent some fuel, altitude can be greater. Also, please, keep in mind that flight model is still being refined and some discrepancies with the real behaviour can occur.

Good to know thx

The Israeli attack is out of context since it was done in another bird than the one we have in DCS. F-16 was much lighter back then.