On the wire

By lex, on April 11th, 2007

The four-ship typically comes in level at release altitude. For a 45 degree dive bombing pattern that’d be around 5000′ above ground level (AGL). Aligned with the attack heading, the lead will push it up to the planned release airspeed – typically around 450 knots calibrated airspeed – and the savvier wingmen will ensure that their jets are trimmed out in yaw as they attain release speed: Even modern jets get “bent,” and what is trimmed for level flight at 300 knots won’t always work at 450, while uncorrected yaw is a source of bombing inaccuracy. Once over the target, dash one will call, “Lead’s breaking,” on the aux radio, followed by his wingmen every four seconds or so thereafter, 2, 3, 4.

A four-g climbing turn to downwind at military power, targeting 10,000′ AGL and 350 knots – just enough to keep a little g on the jet. Each pilot will strive to maintain about a 3nm arc around the target – a 30 degree angle of bank turn and the target down there just above his left shoulder. Quickly through the stores management system, ensure that the SIM mode is de-selected – no bombs come off in SIM – the proper stores are selected for release on the digital multi-function display, the target designator control is assigned to the HUD (for a visual release), air-to-ground master mode is selected, stores multiple and programs are properly set (with correct fuzing option) and finally that the Master Arm switch is set to “Arm” just as he approaches the roll-in. If they don’t do each of these steps in sequence, the bomb won’t come off, the jet goes through “dry” and this we label buffoonery. It makes no sense to fight your way into a target just to go through dry because you boogered up the switchology.

The wingmen chase the jets ahead of them in the bombing pattern using a combination of lead, pure and lag pursuit while jockeying the throttles to ensure that they 1) not hit anyone, 2) keep sight of everyone, 3) get themselves in a position to make their own attack runs with a clear lane of fire.

With thirty degrees to go before final attack heading, the lead will run his throttles back up to mil, increase the g by levering aft on the stick before unloading to swiftly overbank the jet and pull the nose down almost to the target, calling “One’s in.” The armament data line is displaced by a calculated angular distance – the “aim off distance” or AOD – from the jet’s flight path, typically four to six degrees for low drag ordnance. Another unloaded roll – loaded rolls take longer and displace the jet away from the target – back upright to get the wings underneath him, then (assuming good alignment and no crosswinds) bunt the jet to a g-loading conforming to the cosine of the dive angle, or 0.9 g in a 45 degree dive. Now he’s on the wire. Now he’s on “government time.”

Throttle back a bit – supersonic release of conventional ordnance is considered bad form – and the altimeter unwinds like a clock in a science fiction movie while the pilot designates the target (if using the “Auto” mode, or constantly computed release point) or else aligns the bomb fall line on the target while waiting for the constantly computed impact point cross to come up in the HUD. Although the bomb release button (or “pickle”) is always hot with an armed jet in CCIP, the impact point is underneath the fuselage and out of the HUD field of view until just before release altitude, so waiting for the aiming cross to emerge from below the nose takes a degree of patience bordering on faith which can nevertheless be worth waiting for: CCIP gives great hits.

The airframe starts to howl as the speed builds up.

Auto releases are more appropriate to the exotic weapons, and offer other flexibilities as well which are beyond the scope of this post. In an Auto release, the target is designated using an aiming diamond in the HUD, which presents wind-corrected attack steering and a release cue that marches down towards the velocity vector (a representation of aircraft flight path). Weapons computers are smart enough to handle various g-loadings with a degree of relative aplomb, but for optimal accuracy a stable, non-accelerating delivery platform is desired.

The windscreen fills with dirt at a rate which can at first be alarming. Weapons release comes quickly, at about 5000′ AGL: Final attack tracking time from designation to release is ideally no more than 4-5 seconds. Any more than that and you’ll be showing a little more thigh to hostile ground gunners than is deemed appropriate to a fully explored career – and then it’s time to execute the dive recovery. No point in following a dumb bomb into the turf with a smart pilot. You’ll typically hit long anyway.

A four to five g pull back up to the horizon and then 30-40 degrees or so above the horizon by 3000′ AGL to avoid your own frag pattern, with the throttles coming back up to the mil stops again. “One’s off.” That should be close, looked like a good run.

“Two’s in.”

You’re not supposed to spot your own hits. You do it anyway. There’s a column of smoke northeast of the bullseye a bit. Not bad. You find dash-four in the pattern – there he is approaching the abeam position – and work your way back into the downwind for another hack. Five more bombs to go.

The target controller calls on the UHF, prime freq: “One your hit was 25 feet at two o’clock.” Not quite a shack hit, but not bad either, not for a first bomb. Put you in the running for one of three bets with your wingmen, “first hit, best hit, CEP.”

“Two’s off.”

“Three’s in.”

CEP is short for “circular error probable,” the mathematical calculation of the radius wherein 50% of your bombs should land. The smaller the radius, the better the bomber. Everything’s a competition.

“Three’s off.”

“Four’s in.”

Check your gas, go through the switchology once again – you never want to go through dry. Laugh to yourself a little that you get paid for this. Plan to aim 12 feet at eight o’clock on the next go around. You can do better than a 25 foot miss.

“Four’s off.”

Your turn: Time to get back on the wire, go back on government time..

“One’s in.”

If you’re really lucky, you’ll get to do it again tonight.

 

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