The Mustangs of Iwo

April 1, 2013

Any pilot who has flown a single-engine airplane beyond sight of land has experienced the syndrome: enhanced hearing and a pessimistic anticipation of trouble. But imagine a 1,500-mile combat mission over the Pacific Ocean, with the only landfall occupied by people who cut off the heads of captured airmen—or worse.

Such was the world of the airmen flying the Mustangs of Iwo Jima.

From Guam, a glance at the map showed the way to Japan: the Bonin Islands, midway between the Mariana Islands and Honshu, some 750 statute miles south of Tokyo. They put the home islands within range of the long-legged North American P-51D Mustang. With the Bonins in American hands, fighters could escort B-29s anywhere over southern Japan.

In February 1945 at Iwo Jima, the largest of the Bonin Islands boasted three airfields. The fields had been taken by three Marine Corps divisions at the cost of 4,554 American lives.

Seventh Air Force VII Fighter Command was ready to move to Iwo as soon as facilities were readied. Planning for very long-range (VLR) escort missions had begun the previous summer, as Brig. Gen. Ernest M. Moore prepared his “Sunsetters” for the challenging mission.

Moore was typical of the young flying generals in the Army Air Forces. A 37-year-old West Pointer, he had been in the Pacific since 1939. Having assumed leadership of VII Fighter Command in May 1944, he led from the front and landed the first Mustang on Iwo Jima on March 6. Behind him were three squadrons from the 15th Fighter Group. Eleven days later the first element of the 21st Fighter Group landed. Most of the pilots were new, averaging fewer than 300 flight hours.

Iwo Jima was crammed with airplanes: two P-61 night-fighter squadrons, Navy and Marine Corps strike aircraft, and air-sea rescue airplanes. But the P-51s were the most numerous and strategically the most important.

Other than flying local patrols and occasionally striking other islands in the Bonins, pilots on Iwo had precious little diversion. Some didn’t mind: The 72nd Fighter Squadron’s Capt. Harry C. Crim Jr. said, “Iwo was perhaps the most hostile ground environment an airman could find himself in. Nature provided an active volcano (Mount Suribachi), and man provided the war.”

There was literally no place to go, not much to do, and precious little to see. However, the Army fliers found ways to spend their idle time.

One primary diversion was commerce with the eminently “negotiable” Navy Seabees. Engaged in expanding Airfields No. 1 and 2 (No. 3’s expansion was never completed), the sailors’ motto seemed to be, “We’ll do anything for whiskey.”

When the airmen discovered the Seabees had an ice machine but no booze, the law of supply and demand took over. The 21st Fighter Group traded 15 bottles of whiskey for the ice machine, installation included. Dug in, sandbagged, and camouflaged, the precious device escaped detection by the irate Navy commander until Moore became island commander. After that, the fliers had no worries.

Crim, an aggressive Floridian, was one of the Sunsetters’ most experienced pilots, with 2,200 flight hours. He had flown 50 P-38 missions in the Mediterranean, enduring sand, flies, and disease while losing 50 pounds. Consequently, he became “an Iwo booster.” He believed that being able to concentrate 100 percent on combat training, without serious diversions, was one of the island’s strong points. He helped his pilots devote their attention to flying and fighting, thus preventing their going “rock happy.”

But there was unexpected drama. The 21st FG had been ashore barely a week on March 27, 1945, when eight dawn-patrol pilots were walking to the airfield. They were suddenly overcome by some 350 Japanese who poured out of underground caves and tunnels. The pilots were instantly and unexpectedly embroiled in a vicious infantry war.

After five hours of fighting, all the Japanese were dead or captured, but VII Fighter Command had suffered 44 killed and nearly 100 wounded. Crim replaced the wounded commanding officer of the 531st Fighter Squadron, and the next day the group flew its first mission, strafing Haha Jima.

The Mustang

Thirty years after the war, Moore wrote, “I don’t believe there is any question about the P-51 being the best prop fighter of World War II. It was our top air fighter and, hence, best for escort missions and equal to the [P]-47 as an attacker against ground targets.” Squadron and group COs described the sleek North American as “perfect for these missions.”

Neither the 15th nor the 21st had much time for P-51 checkouts before leaving for Iwo. In the 21st, the more senior pilots averaged perhaps 20 hours “in type” before landing at the advanced base. Most pilots were newly out of operational training and averaged merely five to 10 Mustang hours.

In the Pacific—the largest theater of war in history—the Mustang’s long legs made the difference. In Europe the usual drop tank was 110-gallon capacity, but VLR missions produced 165-gallon “drops.” Fully loaded, two such tanks added a ton to the Mustang’s 10,100-pound “clean” combat weight, but they allowed an hour or more of loitering over Japan instead of 20 or 30 minutes on internal fuel.

With such heavy loads, the Mustangs needed a long takeoff run even at sea level. Airfield No. 1 had 5,000- and 3,900-foot runways; No. 2 had 5,200 and 4,400 feet. Originally the strips were barely 2,000 feet long, and that was often inadequate for B-29 emergencies. The hazards also extended to the local area: The 531st Fighter Squadron’s flight line coffee tent was wiped out three times before it was moved to the upwind side of the runway.

The standard tour for a Sunsetter P-51 pilot was 15 VLRs—about 105 hours of flight time—plus local ground attacks and standing patrols. Moore restricted pilots to three long-range missions a week but few logged more than six in a month. Moore managed to fly about 20 hours a month though he was prohibited from combat.

When Col. Bryan B. Harper’s 506th Fighter Group arrived in mid-May, it lifted some of the burden off the first two groups. The 506th alternated with the others in launching two-group missions to the home islands, so one group could ease pilot strain and catch up on deferred maintenance.

The universal comment from Sunsetter pilots was, “Maintenance on Iwo was tops.” If a flier wanted a new carburetor, he needed only mention it. Many crew chiefs kept their aircraft waxed for extra speed, though some joked it was because there was nothing better to do. The mechanics conscientiously changed spark plugs after every VLR to avoid later fouling, as prolonged low-RPM cruising could burn up the plugs.

Lt. Harve Phipps of the 72nd Fighter Squadron recalled, “The squadron had been in the VII from the beginning and the [ground crews] were not rotated very often. They were experienced, and we had practically no aborts because of [bad] maintenance.” Pilots deeply appreciated such diligence: The last thing they wanted to worry about was engine failure 600 saltwater miles from home.

A far greater concern than mechanical failure was the North Pacific weather. Three to five fronts usually moved south daily from the Japanese coast, and that made mission planning difficult. High, dense cloud formations often were a factor.

Mustangs seldom penetrated a front but tried to fly between the thunderheads.

When possible, they remained in the clear to avoid major turbulence, as the 85-gallon fuselage tank became a critical factor.

In rough weather, “the -51 with the fuselage tank full didn’t fly like anything resembling an airplane,” Crim said. Before entering weather, standard procedure was to run the tank down to 40 gallons to put the center of gravity on the near side of controllability. Even then it was no fun flying a P-51 in turbulence. When the drop tanks were partially empty, the gas sloshed from front to back, creating a roller-coaster sensation. It was almost impossible to fly straight and level visually, far less so on instruments.

From late April to late June, 830 P-51 strike sorties were dispatched but fewer than half reached their targets. Four missions were completely spoiled by heavy clouds, and the Mustangs were grounded for 10 days in early May because of the bad weather.

The worst weather problem occurred on June 1 when the Sunsetters launched 148 Mustangs only to encounter a solid front from sea level to 23,000 feet.

B-29 weather airplanes with fighter pilots aboard preceded each strike and reported the front thin enough to penetrate. But the Mustangs hit a severe thunderhead and had no option but to make an immediate turn out of “the soup.”

Flying completely blind in extreme turbulence, several P-51s collided and others fell prey to violent winds. Twenty-seven fighters were lost, along with all but three of their pilots. The 506th Group, which had been operational for only two weeks, lost 15 aircraft and 12 pilots. Eventually, 27 Mustangs broke through to escort the bombers over Osaka.

On another mission, a lone 21st FG pilot stuck it out through the weather to find himself the sole escort for about 400 B-29s.

Navigating the Pacific

Flying single-engine fighters on 1,500-mile round-trips over a vast ocean with minimal navigation aids required a confidence born of experience. It was a task none of the Mustangs, and few of the pilots, were equipped to attempt on their own. The standard P-51D had a magnetic and gyro compass plus a radio compass—the latter of limited range. Voice communication was available on one VHF four-channel radio, and that was all.

“You lose your radio or dynamotor and you have to time-and-distance 600 nautical miles to a spot in the ocean less than four miles in diameter,” said Crim. “Coming back, if your radio worked you could get a steer for the last 100 miles from radar, if it was working. That’s why you didn’t want to be alone.”

Fortunately, help was available. Six B-29 navigation airplanes in three pairs led about 100 Mustangs on each mission to a designated point off the Japanese coast, circling while the fighters flew inland. When the Mustangs began to return to the rendezvous point, the first pair of B-29s waited until about half had arrived, then set course for Iwo. The other two pairs of bombers departed the coast at 10-minute intervals to allow latecomers to latch on to one navigation group or another. The last B-29 to depart transmitted the Morse Code letters for U and D on the “Uncle-Dog” radio frequency so that stragglers could home in.

Six islands, or islet groups, strewn along the watery path aided visual navigation—but they were often hidden beneath a cloud deck. Consequently, Uncle Dog and accurate dead reckoning were essential.

The bare statistics of what was involved in one VLR mission did not begin to tell the story. In round numbers, nearly 100 Mustangs took off with 57,000 gallons of high-octane fuel and some 230,000 rounds of .50-caliber ammunition. The round-trip distance was equal to halfway across North America, from Los Angeles to Little Rock, Ark. Except for the time spent over Japan, the entire mission was flown above water. Seven-hour sorties were routine; eight hours were not unknown.

Contrary to the procedure in Europe, VII Fighter Command Mustangs did not escort specific bomber boxes but guarded a stream of B-29s as much as 200 miles long. One fighter group was assigned target cover from the initial point to the target; another provided withdrawal support.

Usually flying 2,000 feet above the bombers, the three “TarCAP” squadrons flew two on one side of the bomber stream and one on the other, with four-airplane flights about half-a-mile apart. The three squadrons were staggered line astern, flying in the same direction as the Superforts that were approaching the drop point.

Flak was the most common resistance, but 90-degree course changes with slight altitude variation allowed the fighters to remain under anti-aircraft fire for nearly an hour with little damage.

“Finding enemy aircraft was difficult,” Crim recalled. “They weren’t interested in tangling with us, and the only aggression I saw was when they thought they had us at a great disadvantage. Some of the pilots were skillful, but there weren’t enough of them to make much difference.”

The first VLR escort, a Tokyo mission on April 7, was an exceptional occasion. It featured beautiful weather and plenty of “bandits.” The 15th and 21st Fighter Groups escorted 107 B-29s and encountered stiff opposition during the 15 minutes over the target. Pilots estimated 75 to 100 Japanese fighters were seen and claimed 21 downed while only losing two Mustangs.

The 15th saw the most combat that day, returning with claims of 17 destroyed and one probable. Maj. James B. Tapp was the belle of the brawl, bagging four aircraft. Crim headed the 21st’s score column with two of the group’s four kills. Tapp and Crim became two of Iwo’s four aces, with Tapp being first to achieve that distinction on April 12.

Nothing else over Japan had the Mustang’s speed, and nothing could match its acceleration or high-altitude performance. The Mitsubishi Zero was some 80 mph slower, and could only hope to outturn or outclimb it at low-to-medium altitudes. Among the fastest enemy fighters, the Nakajima Frank gave away 40 mph to the P-51, but it climbed and turned better. Still, a Mustang using combat flaps could stay with a Frank long enough for a kill if the P-51’s speed was not excessive.

Few pilots fired their guns at airborne bandits on more than five missions; top gun Maj. Robert W. Moore of the 15th Fighter Group had 11 kills in seven engagements. A handful of others added to previous records, most notably Col. John W. Mitchell, who took over the 15th FG that summer. Having led the Yamamoto interception in 1943, Mitchell downed three airplanes over Japan to run his total to 11. He also commanded an F-86 wing in Korea, adding four MiGs to his World War II tally.

Sunsetters Sunset

Always fuel conscious, the Mustang pilots “coasted in” at a fairly high power, hoping to keep their spark plugs clean and the aircraft in fighting trim. They wanted the fuselage tank to contain less than 40 gallons because in a steep turn, shifting fuel weight could cause control reversal, and the aircraft would try to snap roll. As a rule, the P-51s escorted and fought using the fuselage tank; they would jettison the “drops” for a dogfight. When the fuselage tank ran dry it was time to think about heading home, as the internal wing tanks only provided a bare margin for return.

To some pilots, the 20 to 60 minutes over Japan were just the thing to shake off the lethargy of the long northward flight. Phipps said, “I think the combat break midway in the mission served to stimulate you enough that you didn’t get bored.

The main problem was the cramped space for the time involved.”

For the return flight, Crim explained, “We dropped our tanks, shot up all our ammo, and tested the relief tube.” Then it was a matter of managing fuel for the 750-mile flight home. Cruising at 40 gallons per hour could burn up a set of plugs but the hardy Merlin engines did not seem to mind.

In addition to bomber escort, the Sunsetters flew an increasing proportion of strike missions. Their primary targets were Japanese airfields or industrial facilities, and they were often loaded with five-inch high-velocity aerial rockets. Six HVARs added about 700 pounds to takeoff weight but they packed a tremendous punch—equal to a destroyer’s broadside—and were effective against shipping and reinforced buildings.

The Sunsetters’ last aerial combat occurred near Tokyo on Aug. 10, when the 15th and 506th FGs claimed seven kills. In all, Iwo’s Mustangs were credited with 206 Japanese airplanes shot down between April and August 1945—75 percent of the Pacific P-51 aerial victories. The 15th FG led with 111 kills; the 21st notched 71; and the 506th got 24.

At war’s end Crim prepared to return to college as a sophomore—and an ace. He asserted, “I fought the Germans for patriotism and the Japanese for fun. Next time, I’m fighting for money!”

Barrett Tillman is a professional author and speaker who has flown a variety of historic aircraft and has received six writing awards for history and literature. His most recent article for Air Force Magazine, “The Forgotten Fifteenth,” appeared in September 2012.