F-15 AAR

[kcdusk]

Hypothetical scenario of a Russian Tarantul making a getaway out of a no fire zone. F-15 is scrambled to intercept & engage.

 

This was a random encounter I put together to use the aircraft movement rules for the first time, compare radars of plane v ship and then see how the F-15 (one of my favourite aircraft, along with the Tornado) goes about attacking a target.

 

This is my second time using H4.1 rules.

 

The Boat started at a range of 100nm miles moving east at 20 kts. The F-15 had to take off and chase it down from the West. I figured this would give me a chance to see the F-15 accelerate, gain altitude, use movement and detection in tactical turns and see how long it took in game time to play out.

 

The F-15 accelerated from 0kts at 0.1x2.0 (loaded aircraft)x493kts (probably should have used afterburner speed rather than F-15 cruising speed) = 100 kts per hour in the first 15 second and up to 200 kts at the end of the 30 second game turn.

 

The F-15 accelerated up to 400kts at the end of the next 30 second turn and climbed to 2000m. Once at its cruising speed of 493 kts the F-15 settled on an altitude of 5000m (it just seemed a nice height). This equated to medium altitude.

 

The boat continued to run away at 20kts. After 6 minutes the range between the two units was 71nm, and I checked detection ranges for the first time.

 

The boat didn’t have ESM, so that was easy. The F-15 used its ESM and was easily within range and had a 90% chance of detecting the boats radar, which it did. The successful ESM meant the F-15 had a range, direction (bearing) (rule 4.2.2.3) and it knew the radar type of the boat.

 

Radar LOS from the F-15 to the small boat was 106nm. Oddly, working from the boat back to the F-15 gave a range of 96nm ( I assumed the range going the other way would be the same, oh well). But the F-15 radar range to a small target is 25nm so at this point the F-15 cannot see the boat on its radar. Due to the F-15 having LD/SD capability it can look down 2 altitudes and “see” a target on the water from its medium altitude.

 

At the 12.00 minute mark the F-15 had closed to within 21.7nm so I took the game “backwards” 30 seconds. This meant the range was 23.8nm, which was within the 25nm range of the F-15 radar. Having picked the small boat up, the F-15 decelerated by 20% of its max speed to 394kts (3.3.2.1). There was a 60% chance of picking the boat up on radar in the engagement turn (or 90% in the tactical turn).

 

The F-15 carried a (single?) GBU-28 guided missile, which has a range of 5.0nm. I considered having the F-15 do a “flyover” (permission to buzz the tower?) and visually sight the boat, but figured knowing the radar type would identify nationality of boat it had picked up on its radar.

 

At the 18 minute mark the range was down to 3.8nm and the F-15 fired. I prepared for all sorts of complicated maths, only to find all I had to do was compare 3G missile v 3G ECM on table 6-5 and I found I had an 85% chance of hitting.

 

What was the boat doing during all of this? Well the boats radar, as far as I could tell, was type SS so it could only “see” contacts up to low altitude, and the F-15 was above this so went undetected. And without ESM the boat didn’t know there was a radar operating in the area. So as far as I can tell the boat is unaware of the approaching doom from above. I should have done the flyover to try the “visual sighting rules” and allow the boat to use its 76mm but ran out of time at work.

 

Even without the flyover, I considered having the boats 76mm gun try and shoot the inbound missile down just to see how those rules worked, but ran out of time. I rolled the dice (< 85%) and the ship took a hit (61 damage points). I ruled the boat didn’t get a chance to try and engage the missile because it couldn’t see the F-15. Maybe when the missile got closer and below medium height the boats radar would have picked it up but by then, given the speed of the missile, I could see it impacting without the boat having time to react.

 

I was looking forward to working out damage and critical hits because I didn’t do that in my last AAR (sub v sub). But the Tarantul only had 27 hit points and the missile inflicted 61 damage points so the show was all over.

 

Any comments or discussion is welcome. I’m already looking forward to my next AAR. For my next AAR I hope to have two closer matched opponents and a bit meatier scenario. Happy reading.

 

 

 

My own comments.

 

I don’t think I used the acceleration and climbing rules very well / at all. This is something I will need to cover again. 3.3.4 gives an Altitude Change Table (page 3-7) where high performance (F-15) aircraft can climb 1000m per phase. Is this 1000m rate of climb per tactical turn or engagement turn?

 

It goes on to say “aircraft climbing at more than 50% of maximum rate cannot accelerate at the same time. I think in my AAR above, I had the F-15 climbing at 1000 per 15 second movement phase in an engagement turn, and accelerating at 100kts per hour, so that might have all been wrong (I was accelerating and climbing. Overall wouldn’t affect the game because the F-15 had enough time to do both, just not the way I worked it).

 

I will use a different ship (maybe even a USA ship) and work my way through the rules of engaging an incoming missile.

 

I used the Tarantul because I had recently read about Somalian pirates boarding cape size vessals. And the Tarantul is some kind of patrol boat I think. In the end it was a poor choice because it had no air radar, no ESM (this is very important because ESM range is often further than radar or even radar LOS ranges so ESM is often the first sign of “something is out there” and the Tarantul took the missile and sunk without me being able to use the CH rules (the CH rules seem easy enough to use, but I will have more comments in the next AAR about them).

[CV32]

Some comments:

 

1. The Tarantul I (Project 1241) class is a early generation fast attack craft/missile boat. Not exactly the kind of vessel the Somalian pirates are operating (though I'm sure they'd like to). That said, even if you do go with the Tarantul I, did you consider the operation of the AK-630 air defense gun or the SA-N-5 Grail? Anyhow, maybe something like the Iranian Boghammar would be more appropriate?

 

2. The GBU-28 Paveway III is a laser guided bomb (LGB), a "bunker buster" nicknamed "Deep Throat". (You may recall it was rushed into service for Desert Storm, having been manufactured from old 8 inch artillery gun barrels). It can be carried by an F-15E Strike Eagle, but requires a laser designator (typically the AAQ-14 LANTIRN targeting pod). It is not the ideal weapon for attacking missile boats by any means. (Other issues pop up here, like the ineffectiveness of most ECM against a laser guided weapon). I'd suggest an AGM-65F Maverick launched by a Navy F/A-18?

[kneecaps]

Wow...Harpoon 4 paper rules sounds really fun! (do you need a board, or hex paper or something like that?)

 

Wouldn't an F-15 have been visually sighted/heard by the Tarantul? If I see an F-15 coming i'm reaching straight for the nearest MANPAD to at least take a pot-shot!

 

I imagine an LGB to be a decent option against a large ship, but Mavericks are certainly the way to go for a small mobile target.

[pmaidhof]

Wow...Harpoon 4 paper rules sounds really fun! (do you need a board, or hex paper or something like that?)

 

Kneecaps,

 

H4 paper rules are currently 4.1 with development to a H5 standard in the works and which is supposed to tie in all the systems of the Admiralty Trilogy (WWI's Fear God and Dread Not, WWII's Command at Sea, and modern day Harpoon).

 

I believe the intent is to play via miniatures/counters. I have a number of 1/2400 and 1/6000 ships. Space quickly becomes a glaring issue. Therefore, most of my solo H4 gaming has been using pencil/graph paper/ruler/eraser/calculator combo.

 

There is no map board or hex board included within the game. Scale is variable but usually 1cm=nm, 1"=nm, or 2"=nm. As you can see the ship models will be hopelessly out of scale, but still nice to look at given the models, a blue sheet to delpoy them on and above all else...time.

[kcdusk]

I am playing H4.1 with pen and paper only. Its part of why, each turn, i try and list distance between contacts. I'm not graphing/moving minatures. This is working well for me while hte encounters are small. Even the examples in the book kinda use this, with only a few pics that show relative positions in the examples.

 

(gulp!) i didnt realise the GBU-28 Paveway III was "Deep Throat". I guess i took my biggest hammer to the grape eh?

 

Work calls ...

[kcdusk]

OK, a bit more time to respond.

 

I "ruled" the boat didnt hear the F-15 coming because it was too far away (5 miles) when it fired, and the missile would have hit soon after that. I dont know how realistic this is, but it made it easier for me.

 

GBU-28 (Deep throat) only does 61 points of damage, whereas the smaller GBU-10 does 72. Odd.

 

What is the "GCS Rating" in Annex G4 guided air ordinance used for?

[noxious]

OK, a bit more time to respond.

 

I "ruled" the boat didnt hear the F-15 coming because it was too far away (5 miles) when it fired, and the missile would have hit soon after that. I dont know how realistic this is, but it made it easier for me.

 

GBU-28 (Deep throat) only does 61 points of damage, whereas the smaller GBU-10 does 72. Odd.

 

What is the "GCS Rating" in Annex G4 guided air ordinance used for?

 

GCS is Ground Combat System, a set of rules for ground warfare in Harpoon. The rules are in South Atlantic War, 2nd edition supplement.

[TonyE]

I hope to play with the takeoff and climb to altitude section of the rules tomorrow. What I do know is that an F-15 doing 100kts is one quickly approaching the ground for a crash (under stall speed).

[kcdusk]

Yea, 100kts isnt fast. But its what i worked out its "acceleration" to be. So it went 100kts to 200kts to 300 kts each 15 seconds i think. I was essentially playing it "from take off" and accelerating up to 493kts which was its cruise speed from memory.

 

I should have used its "full mil" or even "afterburn" speed to work its acceleration out, but didnt have those details with me at the time.

 

Maybe post up how you go tony ... :-)

 

thanks noxious.

[CV32]

GBU-28 (Deep throat) only does 61 points of damage, whereas the smaller GBU-10 does 72. Odd.

 

The GBU-28 (BLU-113 warhead) contains considerably less explosive content (supposedly less than 650 lb in the original version), much of its weight being dedicated to the thick bomb case for better penetration of buried or protected targets. (The new GBU-28B/C uses an improved BLU-122 warhead).

 

The GBU-10 (Mk 84 warhead), meanwhile, contains about 950 lb of explosive and a relatively thin walled bomb case for better blast effect.

[TonyE]

My interpretation of a loaded (assume Load2) F-15E takeoff roll using military power.

 

F-15E uses Turbofans and has a cruise range of 2400nm. Given High altitude and cruise that equates to 17,525 seconds of endurance in a clean configuration (3.3.6.2).

 

3.3.4 Aircraft climbing more than 50% of maximum rate cannot accelerate at the same time.

3.3.4 Climb rate for loaded high performance aircraft is 500.

 

I understand both 3.3.4 stipulations to be per 15 second movement phase since the earlier 3.3 rules apply per movement phase, not per 30 second engagement turn.

 

Acceleration at V/Low Military power is 0.1 (10%) * 2.0 (Loaded ATA) * 660 kts (military top speed) = 132kts per 15 second movement phase.

 

At this point I'm lost (didn't make it very far did I?). I can't find an specific guidance for taking off from a land base.

 

So I jump right into 3.3.4.2 which says the plane will be moving at 25% of its maximum speed, altitude 100m. That means the F-15 is doing 165kts @ 100m. Fuel usage, military power uses 4x fuel per second compared to cruise; then consider Load2 @ VLow means we use 3.33x fuel per second; fuel usage is 13.3x base consumption. So we used 200 seconds of fuel in our first 15 seconds leaving 17,325 seconds of fuel.

0:15 165kts @ 100m 17,325s

 

Now we accelerate for 15 seconds

165kts + 132kts = 287kts @ 100m

0:30 287kts @ 100m 17,125s

 

Next we start a gentle climb and continue acceleration

287kts + 132kts = 419kts

climb rate 250m/15s -> 350m

0:45 419kts @ 350m 16,925s

 

Continue climb and accelerate to 493kts

419kts + 74kts = 493kts

climb rate 250m/15s -> 500m

1:00 493kts @ 500m 16,725s

 

Reduce throttle to Cruise, max out climb

climb rate 500m/15s -> 1000m

fuel usage Load2 @ VLow 3.33x, 3.33 * 15 = 50 seconds of fuel

1:15 493kts @ 1000m 16,675s

 

Continue climb

1:30 493kts @ 1500m 16,625s

 

Continue climb

1:45 493kts @ 2000m 16,575s

 

Continue climb into Medium altitude band

fuel usage Load2 @ Med 2.5x, 2.5 * 15 = 37.5 seconds of fuel. This is cheating, our movement phase starts in Low and should use Low's fuel burn modifier but since we're only 1m away, I cheat and use the Medium band fuel burn rate for Load2 Turbofan.

2:00 493kts @ 2500m 16,537.5s

 

 

 

Well, that's my uneducated run thru takeoff and climb with no turns. imho going thru the fuel usage calculations really shows how important fuel management is to the entire mission process. Imagine going into afterburner at 12x or 24x rate depending upon your plane!

[kcdusk]

hehe. From the altitude table at 3.3.4 you used a climb rate of 500m, which looks to be correct. Making my climb rate of 1000m that i used wrong. Oh well, thats why i'm here.

 

Wow, good write up. Nothing like getting into mission planning by-the-second! Myself, if i do this again i might cheat a bit and do my calcs in 3 min turns to save time. I wouldnt feel too bad tony about rounding your altitude up by 1m just to get a more favourable calculation :-)

 

Some good info there too CV32. I'm definatley not a gear head, so much of the equipment is still a mystery to me. Just numbers and performance on a page rather than knowing the gears "personality".

[pmaidhof]

I would never discourage someone from doing the math olympics required to conduct mission planning from take-off to target and back because some day curiosity may eventually get to you, or you may be involved in a campaign or MBX that you will have to. I felt the need when I first started solo'ing H4 feeling that not too I would be missing soemthing. What I missed was getting to the point that I really wanted to in the first place, putting "ordnance on target."

 

When conducting the actions described above, it would certainly be ok to pixy dust the mission planning to presume that the aircraft is on station with the fuel and the loadout you intended in developing the scenario and conduct the actions from just beyond detection. Gets to the battle portion sooner.

 

Should you really want to do the mission planning, there is a mission planning spreadsheet on the Clash of Arms website here. where you can plug in all the numbers, determining if the mission is possible, or whether you would need to foresake ordance for "yet another" drop tank.

 

To Tony's question about the procedure for taking off a land airbase despite it not being discussed, I'd go with 3.3.5.4.2 Fly Off.

 

At the end of the launch movement phase, either the first or second, the aircraft is at 165kts (25% FMP) and 100m altitude.

 

There are "Official Rules Changes" revised Aircraft Climb Rates found in Naval SitRep #26 April 2004 explained that the ones in H4.1 based upon further research are "too restrictive". For this discussion, at full military power, the turbo fanned F-15E will climb 250m per phase (250m x2 Low Altitude= 500. 500/2 fully loaded=250m).

 

I will not get into Tony's acceleration and fuel consumption math as he is the smart guy here, and the NY Jets game will start soon.