One of the most challenging missions of Operation Desert Storm in 1991 was flown on Jan. 27 after Iraqi troops opened the taps on the oil terminal delivery pipes at Al Ahmadi, in Kuwait, causing a disastrous, spreading oil spill that threatened to pollute the entire Persian Gulf.
Reconnaissance on Jan. 25 revealed that Saddam’s troops were extending a campaign of sabotaging Kuwait’s oil well-heads to the Al Ahmadi oil terminal, where a million barrels of oil were released from tankers. A pipeline to the Sea Island loading terminal was also left open, spilling more than 11 million barrels. The end result of this campaign was a major environmental disaster four times worse than any previous oil spill. After studying Kuwaiti blueprints of the terminal, a plan was devised to ignite and burn off the oil-stream and ‘surgically’ attack the manifold structures ashore, cutting off the leak.
As explained by Peter E. Davies in his book F-111 & EF-111 Units in Combat, five GBU-15-capable F-111Fs at Taif were prepared for this task (nicknamed the ‘duck mission’, as one of its aims was to preserve cormorant colonies) on Jan. 26, but Gen Schwarzkopf’s doubts about the possible extent of the damage they might trigger off, combined with poor weather, delayed takeoff until the following day. By that time oil had been released into the sea at 1.2 million barrels per day for at least three days.
The first batches of F-111Fs to deploy to Taif included eight that were adapted to launch the GBU-15 data-linked glide-bomb. Seventy-one GBU-15s were dropped, all from F-111Fs, in attacks from the first night of Desert Storm onwards, but the most notable were the GBU-15(V)-2/Bs (a Mk 84 warhead with IIR guidance and the original long-chord wings) delivered during the Al Ahmadi mission.
The Rockwell-built weapon was developed at the Air Force Development Test Center at Eglin AFB from 1974, and the TV-guided GBU-15(V)1/B test programme was completed in November 1983. The weapon duly entered service with the 493rd TFS at Lakenheath just weeks later. Trials of the imaging infra-red GBU-15(V)-2/B were finished by February 1985. Development then passed to Air Force Logistics Command, and from 1999 the GBU-15 also received a GPS add-on. The 12 ft 10 in GBU-15 weighed 3640 lbs (3655 lbs for the IIR version) and used a Mk 84 warhead with 945 lbs of Tritonal explosive, or a BLU-109 penetrating warhead with 535 lbs of Tritonal (as the GBU-15(V)31 TV and GBU-15(V)32/B IIR guided versions, both using the later, narrow-chord wings). Its 4 ft 11 in span wings gave it a range of up to 15 miles — further than LGBs.
Either a TV sensor or an IIR guidance section similar to the Hughes-built one used on the AGM-65D Maverick could be attached, depending on whether the mission was during day or night and in good or poor visibility conditions. In direct mode, the pilot located the target using the weapon’s camera imagery on his cockpit display — TV for a daylight mission or an infra-red imaging view at night or in poor visibility. He locked the weapon on target using cross-hairs on the display and released the bomb, which then guided to the target. In automatic mode the bomb was dropped from a loft manoeuvre, the weapon then following a programmed trajectory to the target. Course corrections were provided automatically in flight via the Hughes AN/AXQ-14 data link pod (hung beneath the F-111F’s rear fuselage) to the bomb’s autopilot, which steered it by using the tail-wings.
On Night One of Desert Storm several F-111Fs sortied with two GBU-15s each, dropping one bomb ahead of a follow-up strike on the same HAS target by another aircraft with a GBU-24. The main infra-red version supplied to the 48th TFW(P) was particularly effective against `soft’ targets, or to damage a hardened target sufficiently for a GBU-10 or GBU-24 to finish it off. The GBU-15s dropped during the Gulf War scored a 98 per cent success rate.
At Lakenheath a select group of 493rd TFS ‘Freedom Squadron’ crews had gained experience with the weapon, which they normally delivered as a pair. One F-111F would launch the GBU-15 at high speed to give it maximum glide range while the WSO in the second ‘buddy’ aircraft used the AN/AXQ-14 data-link pod imagery on his video display and a small toggle ‘joystick’ to guide it home. This group of 493rd TFS personnel provided the crews for the Al Ahmadi strike on Jan. 27.
Four aircraft operated as buddy pairs, each with one jet as the GBU-15 launcher and the second flying more than 50 miles off-shore to guide the weapon through data link. Capts Rick `Spanky’ Walker and Ken Theurer, in F-111F 72-1446 (`Charger 34′), made the first supersonic drop eight miles from the target at 15,000 ft and then turned away to avoid heavy AAA, while the guiding F-111F, 65 miles away, linked to the infra-red sensing bomb. Contact with the weapon was lost soon afterwards so a second GBU-15 was launched, also at supersonic speed, by Maj Sammy Samson and Capt Steve Williams from F-111F 70-1452 (`Charger 35′). Its signal was picked up by WSO Capt Brad Seipel and pilot Capt Mike Russell from 50 miles distance in ‘Charger 32’ (70-2414).
Seipel, who had flown in the lead F-111F attacking Saddam’s Tikrit palace on Night One of the war, guided the bomb to a direct hit on one of the manifold structures and then picked up and directed a second bomb from Samson’s aircraft for a hit on the other manifold building three miles away. It took a day for the oil in the pipelines to burn out, but the spillage was almost stopped. A second data-link aircraft (70-2408 ‘Charger 31′) was flown by Capt Ben Snyder and Maj Jim Gentleman and a fifth jet, 70-2404 `Charger 33’, crewed by Capts John Taylor and Seth Bretscher, had to abort the mission with technical problems.
Craig `Quizmo’ Brown, who completed 26 Desert Storm missions with the 494th TFS, later learned that most of the Canadian Armed Forces’ CF-18 detachment (from Nos 439 and 416 Sqns) was airborne to provide cover for this risky, but vital, operation.
F-111 & EF-111 Units in Combat is published by Osprey Publishing and is available to order here.
Photo credit: U.S. Air Force, U.S. Navy