Scenario: An F-15 approaching and firing on, a French Tourville class destroyer.

 

I had no expectations for how this might play out. The only reason for choosing a Tourville was because it was a Destroyer and I’d get to see how effectively a randomly picked destroyers radar and air-defences worked.

 

Detection ranges

The Tourvilles Air Search radar is able to pick up a medium sized target (F-15) at 146nm (low altitude and above). Radar LOS is 96nm.

 

The F-15 is flying at 650kts and medium height. Radar LOS to the Tourville is 106nm. The F-15 radar range is 70nm.

 

The F-15 flies at medium altitude with its search radar on, since it is not worried about being picked up by the Tourville or the Tourvilles defences (more on that later). The F-15 will detect the Tourvillie at a range of 70nm. The Tourville has 2G ESM and detects the F-15 search radar at 129nm.

 

 

Intermeadiate turns

Flying at 650kts the F-15 (33nm/3min) closes in on the destroyer.

 

0:00 range 129nm and Tourville detects the F-15

 

0:03 range 96nm

 

0:06 range 63nm and the F-15 detects the Tourville.

 

0:09 range 30nm.

 

0:10:5 range 15nm and in range of the GBU-15 (max range is actually 12nm, so not quite in range yet. Also, the EO (electro-homing, page 5-4) GBU-15 needs visual line of site, so time to work that out.

 

 

Page 4-15 visual line of site.

Air to surface table and the Tourville is a small target so the F-15 can pick it up at 14.0nm – ie the ship is visually detected before the F-15 gets within its 12nm firing range.

 

0:11 range is 12nm. The F-15 fires both of its GBU-15’s. While I don’t plot it out, the F-15 breaks away from the Tourville, staying within the 14nm visual sighting range but not getting closer than 5nm of the Tourville. Reason being the Tourvilles only air protection is a single barrel 20mm gun with a long range of 1.1nm. So the F-15 wont take any fire. Understanding this now, I should have picked a target with better defences. As it is, the 20mm can be used against the inbound missiles.

 

 

OK. Correction called for. Page 6-16 details that the 12nm range is if weapons are released at high altitude. Weapons released at medium halve their range. So I’m assuming the same as above but released at 6nm and the F-15 still veering away at no more than 30degrees.

 

 

Second correction. The operator can only control 1 weapon at a time, so the F-15 can only fire a single GBU.

 

 

The Pointy End Outcome

The Tourville waits until the GBU enters its 20mm short range band and fires at a range of 0.6nm with a 20% chance of hitting --> it misses and the GBU is free to see if it hits the Tourville.

 

Which “to hit” table to use gets a bit confusing. I thought to use the Antiship missile table at 6-5 giving a 40% chance of scoring a hit. However, the GBU is EO and therefore a PGM meaning I use the table on 6-12 which gives an 85% chance of hitting and there is no adjustment for the Tourvilles Jaming and Decoying devices. Please let me know if I have interpreted this wrong or used the wrong table.

 

Assuming the Precision Guided Munition table is the correct one to use, the to hit chance is 85% and the GBU (die roll) hits!

 

The GBU-15 hits the Tourville (164 damage points before sinking) and inflicts 72 damage points which has the following results.

 

1. The Tourvilles top speed is reduced from 32kts to 24kts.

 

2. Critical hits calculation is 72 / (164 – 72) = 70% and the D6 roll is 6! Meaning 9 critical hit rolls. Summarising the 9 rolls sees 3 x weapon hits, a sensor hit, 2 x flooding results, an engineering hit, a bridge hit and a rudder hit.

 

I did not follow through with the weapons or sensor hits.

 

The Flooding results mean a breach has been made in the hull and water is coming in. In this case, there is both major and sever flooding which will result in more damage being taken over time and the threat of sinking if the flooding is not able to be brought under control.

 

The engineering hit means the ships maximum speed is reduced to 8kts and a minor fire starts.

 

The bridge is hit, the main control centre is damaged.

 

The rudder hit means the ship is unable to issue new orders or change course for at least 30 minutes.

 

Before determining further damage done by the two flooding results and the minor fire in the engine room (and trying to stem the flooding and put the fire out!), its easy to see that while the Tourville had 164 damage points and suffered a hit doing 72 points, the Tourville is effectively out of action loosing weapons systems, sensors, a much reduced operating speed and cannot change direction for at least another 30 minutes! The F-15 still has a remaining GBU and the Tourville is now a floating target!

 

I have to say, I don’t know if the Tourville is a typical example of a “Destroyer”. Maybe I’ve been influenced too much by childhood memories of world war II movies where destroyers were bristling with guns and just looked … fearsome. But in this admittedly simple example, the Tourville was always going to suffer a catastrophic fate.

 

 

Time to reverse the roles and have a French Super Entard attack an American Destroyer (Spruance) and see what differences there may be.

 

 

 

PS: I did go back and determine flooding and fire damage.

 

The fire was extinguished in 30 minutes. The flooding was stopped in 2 and a half hours. By that time total damage to the Tourville was 140 damage points. The tourville would be dead in the water at 148 damage points. So the flooding was literally stopped just in time.

A French Super Entard is flying at High altitude (so missiles are able to be fired at maximum range per page 6-16) and 500kts with its search radar on. Its surface search radar is able to detect the Spruence Class Destroyer (medium size) at 85nm. Radar LOS is 244nm.

 

The Spruence class radar is able to detect the small Super Entard at 112nm and the Radar LOS is 232nm. The Spruence ESM picks up the direction and radar type of the Entard at a range of 313nm.

 

This encounter will begin with the range at 112nm which is the range the Spruence picks up the Entard.

 

Tactical Turns

0:00 Range 112nm. Super Entard @ 500kts.

0:03 Range 87nm.

0:06 Range 62nm and the Super Entard picks up the Spruence Class destroyer on radar, exactly where it was expected to be.

 

The Super Entard is armed with 2 x AM39 Exocets. The Exocet begins its journey as an inertial projectile. The missile flies towards a set point where its target is expected to be. Once near its target, in this case the Spruence. Terminal guidance kicks in near the target and has a good chance of locking on. Once locked on the exocet is an active radar homing missile (I assume all of this from the I/TARH description of the missile).

 

The exocet has a maximum range of 38nm and is surface skimming. This is clearly a much better weapon system than the GBU-15 used by the F-15. The exocet has a much longer range and is more difficult for a ship to engage with anti missile defences (surface skimming capability).

 

0:09 Range 37nm. The Super Entard fires both of its Exocets. Each exocet flies at 613kts and impact with the Spruence is expected to be about 3 minutes 30 seconds later.

 

First line of defence

The Spruence class has two lines of defence against the incoming exocets.

The first line of defence is the Sea Sparrow (question: can the sea sparrow engage an antiship missile?). The sea sparrow has a range of 12.0nm. I am not sure if it is able to engage the incoming exocet. I cannot see why it cant so I have to assume it can.

 

The Spruence fires 4 sea sparrows, 2 at each incoming exocet. The sea sparrows roar off at 2640kts!

 

The Air to air attack resolution table is used to determine how successful the sea sparrows are. The exocet doesn’t have an ata rating – therefore I will use 0.5.

The calculation then is sea sparrow ata 5.0 subtract exocet 0.5 = 4.5.

Minus an additional 1.0 for a sea skimming target being engaged by a sea skimmer capable anti air missile = 3.5. Therefore there is a 65% chance for each sea sparrow to hit an incoming exocet.

 

The two die rolls against the first exocet are 99 and 8 (hit, exocet destroyed).

The two die rolls against the second exocet are 53 (hit, exocet destroyed)

 

The Spruence has 8 sea sparrow launchers and has a ROF of 15 – I think the 15 ROF for a magazine of 8 is to show how quickly the system can fire the 8 missiles! Only 4 sea sparrows were fired in this example, and with a 65% chance of each missile finding its target (the very capable exocet in this example), it looks safe to say the Spruence is a much better ship defensively than the French Tourville.

 

Second line of defence

The Spruence’s second line of defence would have been a single barrelled 127mm gun which looks to be capable of engaging air targets. Its range is 5.2nm and short range (2.6nm) chances of a hit are 35% . The exocet is a surface skimmer which halves the hit chance to 17%. With two inbound exocets, the 127mm gun could have only engaged a single exocet and even then had a small chance (17%) of hitting it.

 

Exocets chances

If an exocet had managed to make it through both layers of protection, its chance to hit the Spruence would have been;

 

Question: would the Spruences 2nd generation decoys be any use against the exocet which is a radar homing missile? I didn’t think so but it appears so. The Antiship missile table on page 6-5 gives J, D and J&D so maybe the decoys do work?

 

Medium target size, 2nd generation missile and 2nd gen decoys gives a to hit chance of 62%.

 

If the exocet had hit the Spruence, 33 damage points would have been inflicted (Spruence can take 183 damage points before sinking). Worst case critical hits would be 33/(183-33) = 0.2 and a 6 would see 3 critical hits.

 

 

Summary

There were a few surprised and contrasts in this exercise for me.

1) the exocet is difficult to shoot down and has much longer range than the GBU (providing some protection for the delivering aircraft).

2) The GBU did more than twice as much damage than the exocet. Perhaps the GBU was not fit for purpose being easier to shoot down, however packing a heavier punch

3) The Spruence as expected seemed a much better ship defensively than the Tourville

The first line of defence is the Sea Sparrow (question: can the sea sparrow engage an antiship missile?). The sea sparrow has a range of 12.0nm. I am not sure if it is able to engage the incoming exocet. I cannot see why it cant so I have to assume it can.

 

Yes, the Seasparrow can engage incoming missiles. That is its primary purpose (that and knocking down offending aircraft).

 

The Spruence fires 4 sea sparrows, 2 at each incoming exocet. The sea sparrows roar off at 2640kts!

 

Keep in mind that you have only a single Mk 91 fire control director for those SARH guided Seasparrows. Which would mean, in effect, that you could only engage one target at a time. Fortunately the SPG-60 gun fire director is also capable of tackling a second target for the Seasparrow.

 

The Air to air attack resolution table is used to determine how successful the sea sparrows are. The exocet doesn’t have an ata rating – therefore I will use 0.5. The calculation then is sea sparrow ata 5.0 subtract exocet 0.5 = 4.5. Minus an additional 1.0 for a sea skimming target being engaged by a sea skimmer capable anti air missile = 3.5. Therefore there is a 65% chance for each sea sparrow to hit an incoming exocet.

 

Did you consider the Vsmall target modifier?

 

Also, do not forget that when engaging non-maneuvering airborne targets (such as your Exocets), the Seasparrow will gain a 50% percent range increase. (See Rule 5.3.5)

 

The Spruence has 8 sea sparrow launchers and has a ROF of 15 – I think the 15 ROF for a magazine of 8 is to show how quickly the system can fire the 8 missiles!

 

Yes, a high rate of fire but always limited to the number of ready to fire missiles and the number of available fire control directors.

 

The Spruence’s second line of defence would have been a single barrelled 127mm gun which looks to be capable of engaging air targets. Its range is 5.2nm and short range (2.6nm) chances of a hit are 35% . The exocet is a surface skimmer which halves the hit chance to 17%. With two inbound exocets, the 127mm gun could have only engaged a single exocet and even then had a small chance (17%) of hitting it.

 

Don't forget the Vsmall target modifier and crossing target modifier.

 

Question: would the Spruences 2nd generation decoys be any use against the exocet which is a radar homing missile? I didn’t think so but it appears so. The Antiship missile table on page 6-5 gives J, D and J&D so maybe the decoys do work?

 

Absolutely. This is their intended purpose.

 

The GBU did more than twice as much damage than the exocet. Perhaps the GBU was not fit for purpose being easier to shoot down, however packing a heavier punch

 

Although capable of attacking a ship, this is not the primary role of the GBU-15. It is designed to hit point targets on land.

Thanks for the commets CV32 - some items there for me to follow up on.

HMAS Adelaide, a small Australian frigate was steaming along in open waters west of Japan, suspects a Russian T-22 Backfire was out there somewhere, stalking her.

 

 

The Captain of Adelaide had a choice to make re activating his radar. If he activated his air search radar, he was likely to detect the large aircraft anywhere out to 300 nautical miles away (in actual fact, the radar LOS reduced detection range to 232nm). However, turning on his search radar also meant his ship possibly would be picked up by the searching aircrafts ESM and allow the bomber to home in on his signal.

 

 

It was an easy decision to make, keep the radar off and make the plane find him. Even if his ship had been able to locate the bomber, he had no weapons able to bring the aircraft down. Instead he would continue on blind, and allow his own passive ESM to detect the planes surface search radar. And hope he wasn’t able to be located in the vast ocean.

 

 

The Captain of the Adelaide, not being familiar with his Russian foe, was not aware the Backfire had a simple radar warning receiver (RWR) which was only able to detect fire control radars. If the Adelaide had activated its search radar, it would not have given his position away.

 

 

After hours of searching, the Tu-22 had come across many contacts requiring at least a limited amount of investigation. This used up valuable fuel as the Backfire trekked across the sky, and less fuel translated to less time on station searching.

 

A new contact appeared on the radar, bearing 270 degrees at a range of 100nm, and the Tu-22 turned to investigate.

 

For many minutes now, Adelaides ESM had detected a PNA Beat Down class search radar and knew the Backfire must be getting close. The bearing of the signal changed markedly. Was this a change of direction in the Tu-22 grid search pattern? Or was the Backfire onto something?

 

 

The Captain of the Adelaide had another decision to make. If he had been “made’, he needed to activate his radar in order to identify incoming missiles and engage them as best he could. However if he had not been found, activating his radar may just give his position away. By not activating his radar it could mean any incoming missiles were first seen as they crossed his ships hand railing!

 

 

The Tu-22 closed on the so far unidentified target. Range was inside 81 nautical miles, well within range of its AS-4 Kitchen guided missile. However the contact was not giving off any radar emissions to identify it by. It could be a fishing boat? Or a whale? Or a “blind” warship whose Captain was either stupid, or very smart?

 

The Blackjack was now 40nm from its contact. The Adelaide didn’t know this, relying on passive ESM meant only transmitter type and bearing was known. The Blackjack knew it had passed within the 70nm mark because that was its weapons shortest engagement range.

 

 

The Tu-22 was relying on the contact activating a radar and identifying itself one way or the other, or the Tu-22 had to get within 14 miles to identify the contact via visual means. The Bombers pilot was not happy, he had no way to engage the target if it was hostile as he was too close. And getting within 14 miles of a warship left himself open to counter attack.

 

 

The Backfire closed within 14nm and the pilot was thankful for the cloudless day and smooth seas allowing him uninterrupted views. The contact was a ship, its wake clearly visible, and it took only a few more moments to positively identify the ship as the Adelaide. Its target had been found! An alarm suddenly blared inside the cockpit of the Blackjack.

 

 

The Adelaide had spotted the Backfire barely a minute earlier. Immediately the Adelaides air search radar went active, and painted the Blackjack causing its radar warning receiver to sound.

 

 

Aboard the Adelaide three SM1MR Block III anti air missiles were dispatched, streaking from their launch mechanism at a rate of 1650kts they would take little more than a minute to reach the Backfire even at its high altitude.

 

 

The Backfire turned to run, knowing it was hopelessly outpaced.

 

 

 

SM1MR Block III ata rating 4.0 subtract Backfire 0.5 = 3.5.

 

Further modifiers

 

Attacker is below the target by more than one level, +1.0 defender (2.5)

 

3G J verse 2G missile +2.0 defender (0.5)

 

3G D verse 2G missile +2.0 defender (-1.5)

 

Final result of –1.5 means 15% chance of a missile hitting the Backfire.

 

Die rolls are 13, 87 and 18. The Backfire is shot down with the first missile. An outcome I didn’t see coming.

Good and explanatory piece of text, thanks

Very interesting. Good job.

 

Doesn't the Tu-22MR version have an ESM?

I'm not certain that the MR variant is in service [or even made it past prototype stage] but my sources claim the following sensor layout

 

NII-17 Shompol SLAR

Tangazh ELINT

Osen IR

A-359Z (Down Beat) SS Radar

SPO-23 3rd Gen. RWR

PRS-4 Kripton (Box Tail) Tail Warning Radar

SPS-171/172 Sorbtsiya DECM

Avtomat Series RWR

'Several' A-70M Cameras

'Several' A/E-10 Cameras

 

Nice package in that bird. If they ever got around to deploying the jamming version of the Backfire (Tu-22MP) then we'd have a new ball game.

 

Later

D

A-10 Thunderbolt/Warhog verse ground targets

An American A-10 thunderbolt descended from high altitude after spotting a convoy of vehicles clearly visible from the dust they were kicking up across the desert floor, and made ready to do a fly over in order to positively identify the potential target.

 

Mistakes, blue-on-blue fire, had happened before. So while none of these vehicles were transmitting the identify friend or foe electronic beep expected from friendlies, no chances were taken.

 

Passing overhead at 340kts, the pilot confirmed a convoy of Russian armoured personnel carriers, light and heavy tanks and a single AAA half track.

 

The vehicles scattered across the desert sand floor as the A-10 performed its flyover. Each vehicle hoping to distance itself from the others in the hope it wouldn’t be targeted as part of the larger group. Overhead, the warthog wheeled around to make its first “hot” pass.

 

Random chance saw the A-10 straighten up, slow to 300kts and have 3 heavy tanks aligned roughly 10 miles along its flight path. They were slow moving, small sized targets.

 

When the first tank was at 4 miles, an AGM-65 was released. With an 85% chance of hitting, 25 seconds later the single missile ploughed into the sand near the tank, not close enough to do any damage.

 

Undeterred, the A-10 fired a second AGM-65, this time at the 3rd tank in line, and watched as that tank was hit square and centre, disappearing in a cloud of dust.

 

Rising to medium altitude, the A-10 circled and readied for another pass. It still had 4 x AGM-65’s left, and even the 30mm gun in its nose could wreak havoc against the tanks weak top armour presented from its firing position overhead.

 

For its second pass chance had a medium tank and a heavy tank in the A-10s next attack run. First AGM-65 away … its scores! Second AGM-65 away … and another hit! 3 out of 4 AGM-65s having found their mark. The precision-guided bombs were as accurate as advertised.

 

Unbeknown to the A-10, a 23mm anti air gun opened up during its last attack run but sent its sausage sized bullets far, far wide.

 

On its 3rd run, the last two Maverik-65’s were released, hitting a small APC and just managing a hit against a large tank. The APC would be vaporised, the large tank was not hit flush but was expected to be found destroyed after the dust cleared.

 

Again, the Russian 23mm AAA opened up at long range but was not able to hit the nimble A-10. However this time as every 5th tracer passed close by, the Warthogs crew knew they were now being fired upon.

 

Having expended all of its 6 Mavericks, for 5 confirmed kills. The A-10 considered a gun run verse heading for home (not pushing its luck verse the anti air gun). It had been a successful day - but the flyboys were not done yet. They wanted to try their own 30mm gun against ground targets!

 

The Warthog wheeled around and found itself on a strafing run at low altitude with a lone heavy tank in its sights. The aircraft bombing table on page 6-12 shows the warthogs internal cannon has a 60% chance of hitting a small target (heavy tank). The A-10 looses air speed from its own cannon recoil, the 30mm ammunition arcing down and finding their target. The cannon has a damage rating of “12” while the heavy tank can sustain “8” damage points (from page 6-20 General attack table), hence the A-10 destroys a heavy tank before turning for home. Despite having 30mm ammunition left over the A-10 heads for home rather than risking a lucky strike by the lone Russian AA gun.