|
...flights took before daybreak from Al Minhad Air Base, United Arab Emirates. The pilots navigated their Block 40 F-16Cs though darkness using their inertial navigation systems that Global Positioning Satellites updated every two seconds. The planes carried LANTIRN (Low-Altitude Navigation and Targeting Infrared for Night) pods that clearly showed the ground terrain and their targets on cockpit displays. Upon reaching their targets, the pilots accurately dropped their loads of anti-tank and anti-personnel mines despite bad weather and being shot at by anti-aircraft artillery (AAA) and surface-to-air missiles (SAMs). At dawn, three hours later, all eight planes landed back at Al Minhad. The power of their F-16s' navigation and weapon guidance systems gave the 421st their motto, "We own the night." (1)
The F-16's capability for night operations stands in stark contrast to the Air Force's limited ability twenty-four years earlier to strike targets in North Vietnam at night or in bad weather. During Operation Rolling Thunder in 1965 through 1968, pilots in the 388th TFW and the 355th TFW flew F-105 Thunderchiefs from Korat and Takhli Royal Thai Air Force Bases in Thailand. The annual cycle of northern monsoon weather over North Vietnam's Red River valley during late winter through early spring often prevented F-105 pilots from putting bombs on significant targets around Hanoi. If an F-105 pilot couldn't see his target, he could not hit it accurately.
The Air Force tried hard, with only limited success, to overcome this technical deficiency during the Vietnam War. Their efforts during Rolling Thunder highlighted the need for the targeting and weapon guidance systems for bombing at night and in bad weather that today's Air Force employs. This article tells the story of the Air Force's first-generation all-weather systems and the men who used them for attacking targets in North Vietnam.
The Navy's A-6A Flew Night and Bad-Weather Missions
A-6A Intruders from VA-75, the "Sunday Punchers" on the carrier USS Independence (CVA-62), flew their first combat mission against North Vietnam on July 1, 1965. The new Intruders gave the Navy a night and all-weather strike capability that was lacking in USAF fighter-bombers. (2)
The Navy learned from their experiences during the Korean War that their attack aircraft needed the capability to hit ground targets in darkness and bad weather. In 1956, the Navy sought bids for such a plane and selected Grumman to produce it. Grumman's A-6 was subsonic, with a maximum speed of 560 knots, but it could carry a large load of conventional bombs over long distances. It had a capacity for twenty-eight 500-pound bombs and a fuel load that allowed it to reach targets over 1,000 miles away with time to locate its target and drop its bombs before returning home. (3)
The Intruder's avionics system--DIANE (digital integrated attack and navigational equipment)--provided its night and all-weather attack capability. The key components of DIANE were the APQ-92 search radar, APQ-122 tracking radar for terrain mapping and target location, the APN-141 radar altimeter, the APN-153 Doppler radar, the ANS-31 inertial navigation system, and the ASQ-61 ballistic computer. (4) The A-6 carried a crew of two, a pilot and, to his right, a bombardier-navigator who operated DIANE's controls for automatically passing steering and bombing instructions to the pilot's displays. (5)
In the fall of 1965 and into the spring of 1966, as the seasonal monsoons obscured the Hanoi area, the two squadrons of Navy's A-6As--when they weren't grounded by their early reliability and supportability problems--were the only planes that could consistently strike targets in this region. The Navy's capability for attacking targets at night and in bad weather with the A-6A in 1965 gave rise two years later to the Air Force's attempts to use its F-105s for similar missions.
The F-105--A Nuclear Bomber in a Conventional War
During the late 1950s, while the Navy was developing the A-6A to deliver conventional bombs in bad weather, the Air Force was developing the F-105 to drop nuclear bombs on targets behind the Iron Curtain. Built by Grumman's Long Island neighbor, Republic Aviation, the F-105 was a supersonic fighter-bomber with an internal bomb bay for carrying a single weapon with provisions for carrying two more nuclear bombs on wing pylons. The Mach 2 F-105D had a much simpler bombing system than the Navy's A-6A. Republic's "Thunderstick-Fire-Control" system included the ASG-19 ground-mapping radar, the APN-131 Doppler navigator, and analog toss-bomb and air-data computers. The ground-mapping radar had a terrain avoidance mode and a means for setting terrain avoidance distances to help the pilot deliver a nuclear weapon at night and in bad weather. (6)
During their training, F-105 pilots needed to achieve certain bombing accuracy scores to be qualified to sit on nuclear alert. For example, between October and December 1961, F-105 pilots in the 53d TFS from the 36th TFW at Bitburg AB, Germany, trained in their new Thunderchiefs by dropping practice bombs on the desert weapons range in Libya. When the 53d pilots used the system's two radar delivery modes, called Blind Target Identification Point (BTIP) and Blind Laydown (BLD), they achieved circular error averages (CEAs) respectively of 1,313 feet and 884 feet. (7) These CEAs were essentially the best scores the system could produce since they were achieved under ideal weather conditions and with no enemy defenses with which to contend. Considering the large blast radius of a nuclear weapon, these average distances from an aiming point were sufficient to ensure the destruction of a target. However, four years later, when the Air Force used these F-105 radar delivery modes with conventional bombs dropped from hostile skies over North Vietnam, the CEAs were usually worse and their 750-pound and 3,000-pound bombs seldom damaged their intended target.
Pathfinders
During the Vietnam War the Air Force employed radar systems, the primary technology then available, for their fighter-bombers to bomb at night and in bad weather. They tried two general methods for using radar, some based on a planes' internal radar that displayed a target's return on the cockpit radarscope, while other methods employed external ground radar that guided planes over targets.
The first uses of radar to allow bombing North Vietnam in bad weather were the "pathfinder" missions where EB-66B Destroyers led single-seat F-105Ds above the weather. F-105s flew in formations of four, eight, or twelve aircraft alongside a B-66 at altitudes usually above 15,000 feet. Also called synchronous radar bombing and buddy bombing, this method required the EB-66 navigator to use his K-5 radar bombing navigation system to detect the target and send a signal tone to the F-105s to drop their bombs. (8)
On December 24, 1965, President Lyndon B. Johnson imposed a 36-day halt to the Rolling Thunder bombing of North Vietnam. Despite this restriction, the 355th TFW, based at Takhli, Thailand since November 3, 1965, began flying these pathfinder missions on January 1, 1966. This technique was their primary means of contending with the 1965-1966 northeast monsoons that frequently obscured their targets across North Vietnam. The 355th wing history for the period described this radar bombing technique.
So that weather would not be a factor in the lack of missions into North Vietnam, a new technique was developed using the buddy system radar type bombing, with a B-66B Destroyer aircraft. The Destroyer would guide a flight of four F-105 aircraft into a target. At a certain predestined point and signal on the Destroyer radar, the navigator would give the signal to the flight to make their weapon release. The wing flew practice missions in the southern Pan Handle of North Vietnam to test the feasibility and accuracy of this method of delivery. These test flights proved that the technique was practical and could be used effectively against certain targets.
Wing pilots also flew practice missions against targets in Laos. (9)
On December 8, 1965, the 333d TFS from Seymour Johnson AFB, North Carolina, arrived at Takhli with its 25 experienced F-105 pilots to become the second of the three squadrons to form the 355th TFW. (10) Capt. Robert D. Gobble, one of the 333d pilots who flew these early pathfinder missions, recalled, "The B-66 would alert us by radio that the tone would start in say 10 seconds and, as briefed prior to flight, when the tone stopped, the Thud's would release their bombs. The tone was over the UHF radio on the B-66 frequency [also] briefed prior to flight. If any one of the 105's radio was out, then they were briefed to drop when the flight lead dropped." (11)
After their experiments in January, the 355th began using B-66 pathfinder bombing. On February 1, 1966, EB-66 pilot Capt. Jerry S. Grimes from the 41 TRS at Takhli led twenty of the 355th's F-105s on the first official pathfinder-bombing raid over North Vietnam. Their target was a port facility near Vinh in the southern panhandle of North Vietnam. "On the initial run-in, they had two flights of F-105s with them. Upon completion of the first drop, they returned to the IP [Initial Point] and guided three more flights to the target. Not one round of flak was observed during the entire mission." The 20 F-105s dropped 60 bombs on the target. (12) An Air Force report, ignoring the January practice missions, officially acknowledged those flown in February.
The resumption of air strikes in February saw the introduction of another method of synchronous bombing to increase all-weather capabilities. The B-66 pathfinder aircraft, using synchronous radar bombing procedures, led the fighters on their bomb runs.... A total of 82 radar strikes were flown in February, dropping approximately 95 percent of all bombs delivered on North Vietnam by the Air Force during the month. (13)
Some F-105 pilots derisively began calling them "12 O'clock High" missions, reminiscent of the World War II B-17 formation bombing raids over Germany depicted in the Gregory Peck film of the same name. They were hardly the roving missions that fighter pilots like to do. (14)
F-105 Radar Bombing Experiments
Early in February 1966, the 355th TFW experimented with using the F-105's own radar and bombing computer as a means of hitting targets through bad weather. As reported in the wing history, the 333d TFS launched several flights "... against coastal North Vietnam targets using radar toss bombing techniques. The results of these trials were inconclusive and this technique was discontinued." (15) Bob Gobble flew one of these "inconclusive" missions, his 42d, on February 11, 1966, as the lead of "Healey" flight.
I was #3 and lead aborted so I took lead on a TBC [toss bomb computer] drop on the coast of [North Vietnam]. It was a flight of three as #2 aborted also. I tried to drop using the TBC and radar but my TBC was bad and we came around for another pass. I called the pickle on radar but #2 set his switches wrong and we got an early release. (16)
Gobble described how this F-105 bombing technique should have worked. "The Thud system allowed you to fly straight ahead level until you got in range to loft the bombs by pulling up or you could remain level and the bombs would come off at the right time since the pickle button was held down all the time from target designation. Wingmen dropped manual when lead's bombs came off." (17) This radar bombing technique, tried and abandoned in February 1966, would become a major program in the spring of 1967.
Continued Pathfinder Bombing
Bad weather over North Vietnam during March 1966, forced the continued use of pathfinder bombing.
This technique continued to be the mainstay of USAF efforts in North Vietnam during March. Bad weather, limiting visual strikes in many areas, placed heavy requirements on the all-weather capability of the radar pathfinder aircraft. During the month, 80 percent of all bombing operations in North Vietnam utilized this technique. (18)
On April 1, 1966, under Rolling Thunder 50, President Johnson authorized more targets for attack in North Vietnam. At the same time, the Air Force and Navy agreed to change the seven "route packages" in North Vietnam from a weekly "time share" basis between the two services into permanent assignments of each service to specific route packages. The Air Force got Route Packages 1, 5, and 6A while the Navy took on Packages 2, 3, 4, and 6B. The Marines flying from Da Nang AB, South Vietnam, shared targets in Route Package 1 with the Air Force. (19) However, weather continued to hinder Air Force planes from attacking many of the newly authorized targets and F-105s still depended on pathfinder missions into the southern areas of North Vietnam. It was too dangerous for unarmed EB-66s to escort bombing missions...
NOTE: All illustrations and photos
have been removed from this article.
More articles from Air Power History
"Always above": Major Edward 'Mick' Mannock in World War I., March 22, 2006
The Wings of Change: The Army Air Force Experience in Texas during Wor..., March 22, 2006
Waging Modern War: Bosnia, Kosovo, and the Future of Combat., March 22, 2006
First Flight: The Wright Brothers and the Invention of the Airplane.(B..., March 22, 2006
A War of a Different Kind: Military Force and America's Search for Hom..., March 22, 2006
Looking for additional articles?
Search our database of over 3 million articles.
Looking for more in-depth information on this industry?
Search our complete database of Industry & Market reports by text, subject, publication
name or publication date.
About Goliath
Whether you're looking for sales prospects, competitive information, company
analysis or best practices in managing your organization,
Goliath can help you meet your business needs.
Our extensive business information databases empower business
professionals with both the breadth and depth of credible,
authoritative information they need to support their business
goals. Whether it be strategic planning, sales prospecting,
company research or defining management best practices -
Goliath is your leading source for accurate information.
|
