SBD Dauntless Dive Bomber – A Pilot’s Perspective
The Battle of Midway has been described as the turning point of World War II in the Pacific. Sources differ, but Gordon Prange’s “Miracle at Midway” says Japanese losses were about 2,500 casualties, 4 carriers (Akagi, Kaga, Soryu, Hiryu), 1 heavy cruiser (Mikuma), and 332 aircraft. The U.S. lost 307 men, 1 aircraft carrier (Yorktown), 1 destroyer (Hammann), and 147 aircraft.
American planes from Midway Atoll and three carriers (Enterprise and Hornet, in addition to Yorktown) attacked the Japanese carriers.
Many U.S. Navy, Marine Corps and Army Air Forces planes were involved, but the carrier-based SBD Dauntless dive-bombers were the only American planes to score significant hits. They were credited with sinking all four Japanese carriers and the Mikuma.
SBD pilot Norman “Dusty” Kleiss flew from the Enterprise. On the morning of June 4, 1942, he joined 31 other SBDs of Scouting Squadron 6 (VS-6) in one of several American attacks on the Japanese carriers. His bomb struck the Kaga’s flight deck, starting major fires that led to its sinking. Later that day, Kleiss and 23 other SBDs attacked the Hiryu. Kleiss scored a direct hit. He flew two more missions over the next two days, making a direct hit on the Mikuma. He was the only dive-bomber pilot during the battle to score three direct hits on Japanese ships. He was awarded the Navy Cross for his actions. Lieutenant Junior Grade Kleiss rose to the grade of Captain before retiring from the Navy.
SBDs used a dive angle of about 70 degrees, virtually straight down, which provided two great advantages:
First, with an angle that steep, it was difficult for Japanese gunners to score hits. Guns on the carriers had to be elevated to high angles, making tracking and leading much more difficult. Barrage fire (shooting at a predetermined spot) forced an aircraft to fly through the anti-aircraft (AA) fire, but because of the high dive angle, they quickly traversed the area. Attacks by Japanese Zeros also were complicated by the high dive angles.
Second, high dive angles significantly enhanced bombing accuracy. Shallow “glide bombing” often resulted in short hits and made the attacking aircraft more vulnerable. “Hurling yourself at the ground,” as dive-bomber pilots often described the act, required a lot of training.
Let’s fly through one of these maneuvers under enemy fire — virtually, of course.
The SBD pilot generally approached his target at altitudes ranging from 15,000 to 20,000 feet, cruising at about 150 knots (one knot equals one nautical mile per hour). Just before pushover, he would increase engine RPM to “high” and select “low blower” on the supercharger. Since his pullout would be at low altitude, he wouldn’t need the power provided by “high blower.”
As the target began to disappear under the aircraft’s nose and passed under his feet, the pilot pushed the stick well forward to begin his steep dive. As he did so, he rose a bit in his seat and loose items in the cockpit floated.
He deployed the SBD’s “dive flaps” — perforated devices on the rear of the wing that added significant drag to keep the airspeed from exceeding pre-planned limits. Without the dive flaps, pullout altitudes were higher, increasing exposure to enemy fire and reducing accuracy.
Typical bomb-release (or “pickle”) altitudes were 2,000 to 2,500 feet above the target, but could be lower if more “g’s” were used during pullout. Release airspeeds were generally between 240 and 250 knots indicated airspeed (KIAS).
Pulling the throttle to idle, the pilot would lean forward in the straps and divide his attention between the altimeter (rapidly decreasing) and the bomb-sight in the forward windshield. He tried to ignore the AA, and his rear gunner kept an eye peeled for enemy fighters.
Because the Japanese carriers were probably maneuvering by now, the pilot tried to roll to keep his ground track aligned with his target. He typically picked a specific spot on the ship, such as the large red “Rising Sun” painted on the decks of Japanese carriers. At the designated altitude, with his “pipper” on the target, the pilot reached for the bomb release lever on his left and pulled.
He immediately began his recovery by pulling the stick hard back, raising the dive flaps and pushing the throttle forward to full military power.
The recovery altitude in a 70-degree dive at 240 knots IAS, using a 4g recovery (see below for a description of “g” forces), was about 1,100 feet. Bomb fragments flew out to about 500 feet. If the pilot released at 2,000 feet and immediately began a 4g recovery, he “bottomed out” at about 900 feet, safely recovering above the bomb fragments. But if he “pressed,” or delivered the bomb at a lower altitude, he stood a good chance of flying through fragments of his own bomb.
“Dusty” Kleiss, in his book “Never Call Me a Hero,” said he rarely used a 4g pullout in a high-threat area. He often used 7, 8, or even 9gs, significantly reducing his pullout altitude. But during a pullout at 9g’s, a 200-pound pilot would weigh about 1,800 pounds, and every part of his body — arms, legs, head — would weigh an equivalent of nine times its normal weight. His blood would rush toward his lower extremities. When flow of the blood passed his eyes, he would begin to black out. A gray curtain would seem to descend over his eyes. He would still be conscious, but temporarily blind.
To prevent this, Kleiss used a technique that today we call an “anti-g straining maneuver,” or AGSM, which is similar to a breathing method known as valsalva. He would take a big breath, hold it, and strain or grunt to help prevent the blood from continuing its downward flow. He would then quickly release the breath, draw another, and grunt once again. Once the pullout was completed, he would discontinue this AGSM.
But now the pilot was in the middle of a fight for his life, with AA from every enemy ship in range aimed at his aircraft. He began “jinking” to prevent enemy gunners from tracking him. He made a hard turn in one direction, held it for a few seconds, then turned hard in another direction. Perhaps he leveled off for a few seconds, then began a steep climb, making sure to not lose airspeed. Once clear of the ship-borne guns, our SBD pilot and his gunner kept a sharp eye out for Zeros.
Now they had to navigate to their carrier. Later versions of the SBD, beginning with the SBD-3, were equipped with the YE-ZB homing system. It consisted of a high-frequency transmitter attached to a carrier’s antenna array, and a coded receiver on the aircraft. The carrier would transmit a Morse code signal based on 30-degree arcs around the ship. Once the SBD crew received the signal, they knew where they were relative to the ship, and could home on the transmitter. If the system was inoperative, or the carrier had turned off the transmitter — enemy aircraft could also receive the signal — the crew used “dead reckoning,” a combination of time, distance and heading, to navigate home.
Many aircraft in World War II ran out of fuel trying to reach their carriers and were forced to ditch.
(One g is what we feel standing on the ground. Elevated g’s occur whenever an object undergoes some form of acceleration. In a tightly turning aircraft, for instance, positive g forces cause a pilot to be pressed down into his or her seat with a force corresponding to the number of g’s. At 2 g’s, a pilot weighs twice as much as normal.)