By Jack Woodul
As Veteran Viet Nam Attack Pilots, our dive bombing dive angle and release heights varied with the threat environment. Napalm and Snakeye retarded bombs were limited to permissive environments, with delivery altitudes of 100-300-ft AGL (above ground level). Initially, our air wing attacks against major targets in North Viet Nam, which were heavily defended with both optically aimed and radar controlled flak, used a 60 degree high-dive delivery from some 12,000-15,000-ft, with a release altitude of around 6,500-ft. Anti aircraft hits were common, so dive bombing runs were not the canned, predictable, stable flight paths of peacetime, predicated on an accurate dive angle and release altitude. Getting shot at accurately tended to disrupt stability, so my bomb run often involved getting as steep as I could and pressing the attack to as low an altitude as I could; then, pulling as many g’s as I could (7 g’s was standard) until the nose was above the horizon, maintaining enough energy to maneuver vertically and horizontally to escape tracking fire. This tactic evolved with the advent of surface-to-air missiles (SAM) to ingress at 3,500-ft AGL, which was supposed to be above the light weapon envelope and below the SAM envelope. The bomb run involved popping up to some 12,000-ft, then diving at 45 degrees and releasing at an altitude of some 4,500-ft. I can tell you that a heavily-laden A-4 Skyhawk was uncomfortably slow and sluggish at roll-in, vulnerable to both flak and SAM. Later tactics reverted to steep dive angle and higher release, the better see and avoid SAMs. The same Stuka technique of steep dive angle and low release got good results. But the lower the release, the better chance Uncle Gomer had to perforate you some.
Peace-time bomb patterns were mostly canned, 450-knot, 30-degree dive angle, 2500-ft release altitude, practiced over and over again until the groove was automatic. Errors of dive angle, airspeed could be recognized and compensated for in other ways. In combat, maneuvering in the dive made this skill very necessary to compensate to get hits. Air Force Thud (F-105 Thunderchief) pilot friends agree with me that, when in a tight, get as steep as you can and press the target as long as you can; then, pickle and pull like crazy.
There was a peace time bomb delivery tactic called “Low and Slow.” The A-4 was flown at 180 knots and half flaps to deliver both bombs and rockets. It was fun and accurate, but the Bad Guys would have blown us out of the sky in North Viet Nam. Some staff puke Navy captain visited our air wing and advocated the use of Low and Slow to win the war. We didn’t have to be told not to talk to him.
I found an intriguing 1951 article by Major Jack Bolt, then of VMF-311 but later and F-86 exchange pilot and the only USMC ace of the Korean War. He noted that Douglas SBD dive bombers from World War II typically dived at 70 degrees and 240 knots and seldom took anti-aircraft hits (AA). But F9F Panthers and other jets usually bombed at 30 degrees and more than 400 knots, but frequently took AA hits. In order to be nose-level at 2,000-ft the SBD dropped at 2,400-ft; the Panthers at 3,200-ft with attendant diminished accuracy. However, “own blast” concerns had many jets recovering at 3,000-ft to avoid the fragmentation pattern. What to do?
Bolt recommended delayed-action bombs (up to five minutes) in order to concentrate a flight onto and off the target as fast as possible. Recommended procedure was a 35-40-degree dive, drop 1,800-ft above target elevation, with simultaneous 100-percent power, retract speed brake, and a 5 g pull.
Apparently, it wasn’t widely adopted owing to increasing AA, but I thought it interesting that the “Slow But Deadly” of Battle of Midway fame influenced jet tactics, however briefly.