Tetsuzō Iwamoto

Lieutenant Junior Grade Tetsuzō Iwamoto (岩本 徹三, Iwamoto Tetsuzō) (15 June 1916- 20 May 1955) was one of the top scoring aces among Imperial Japanese Navy Air Force (IJNAF) fighter pilots. He entered the Imperial Navy in 1934 and completed pilot training in December 1936. His first combat occurred over China in early 1938. He emerged as the top naval ace of the campaign, credited with 14 aerial victories. Subsequently he flew Zeros from the aircraft carrier Zuikaku from December 1941 to May 1942, including at the Battle of the Coral Sea.

In late 1943, Iwamoto's air group was sent to Rabaul, New Britain, resulting in three months of the hardest air combat ever for the Imperial Japanese Navy Air Force against air raids of U.S. and Allied air units.

Subsequent assignments were Truk Atoll in the Carolines and the Philippines, being commissioned an ensign in October 1944. Following evacuation of the Philippines, Iwamoto served in home defense and trained kamikaze pilots.

Like many Japanese veterans, Iwamoto was reported to have fallen into depression after the war. His diary was found after his death, with claims of 202 Allied aircraft destroyed.

As a result of the Japanese use of the British naval system, the IJNAF scoring system was based on the standard the Royal Navy, the Royal Air Force (RAF) adopted since World War I till World War II, different from the scoring system defined by U.S. Navy Air Force and U.S. Marine Air Force during World War II. Dr. Izawa and Professor Hata tried to reckon the figure at about 80 or more than 87 in their research work in Jan. 1971, Dr. Izawa wrote that Iwamoto was virtually the top ace of IJNAF, in Dec. 1993.

As of mid-1944, there remained only two IJNAF fighter pilots who were credited with over 100 victories. Depending on various totals cited, Tetsuzō Iwamoto or Hiroyoshi Nishizawa was Japan's best ace. Iwamoto was known as the Chūtai leader (Flying Company, Squadron of 8 to 16 fighters). Iwamoto was the few survived successors of the IJNAF airman's heritage, who flew over the Indian and the Pacific Ocean from north to south, showed his skilled fights against the Allied units and trained his young junior pilots even in the last months of the war.

Early life
Tetsuzo was the third son of the Iwamoto family. He was born on a border town, southern part of Karafuto 15 June 1916, later grew up in Sapporo, Hokkaidō, Japan. He enjoyed skiing in his elementary school days. When he lived in Sapporo, his father was a chief police officer.

When he was 13, his father retired and Tetsuzo moved with his family to his father's hometown, Masuda, Shimane prefecture. He studied at the Prefectural Masuda Agricultural and Forestry High School. His favorite school subjects were mathematics and geometry; in these subjects, he always scored A's on his school report.

He was an active and nimble boy. He joined a school club brass band as a trumpeter. Another hobby was growing plants and flowers. He helped local fishermen in the fishing season, going out to the sandy beach early in the morning and driving fish into the nets. He talked down to his teachers sometimes in discussions, which was very impolite for a school student in pre-war Japan. He was regarded as the most opinionated student in his school.

Starting military career
Iwamoto started his military career in 1934 after he graduated the school at 18. Following the advice from his parents to study while young, Tetsuzo left for a large city where he was supposed to take a college entrance examination. He, however, secretly applied for and passed the exam of Imperial Japanese naval airman 4th class, soon be promoted to 3rd class 5 months later. His parents were very disappointed reportedly, for they became counting on Tetsuzo rather than his eldest brother, who was already studying at some university in a large city and wouldn't come back to Masuda.

In 1936, when he was a naval mechanic 2nd class and a crewman on the light aircraft carrier Ryujo, he studied hard and passed the difficult IJNAF exam, among thousands of applicants, being enrolled in the class 34th Soju-Renshusei (Soren in short, means flight trainee program) for naval petty officers and sailors. He graduated as one of the select 26 young aviators of the class 34th Soju-Renshusei (flight trainee program) in December of that year.

On April 4, 1936, he was sent to Kasumigaura-Ku (Kasumigaura FR(AG)) as a probation for the class 34th Sojyu-Renshusei (flight trainee program), then on April 28, formally joined Kasumigaura-Ku. While his training going on November 1, 1936, he was promoted to naval mechanic 1st class. Finally on December 26, he graduated 34th class of Sojyu-Renshusei, was promoted to airman 1st class (old rank name of pre-war Japan, equivalent to senior airman).

During flight training school at the Tomobe branch of Kasumigaura-Ku (Kasumigaura FR(AG)), his fighter course instructor was the famous Chitoshi Isozaki. Isozaki was promoted to lieutenant until the end of the war and was later respected among all ranks of IJNAF Zero fighter pilots postwar Japan.

The six members of the fighter course, the class 34th Soju-Renshusei were as followed:
 * Hamada, Inao, reportedly died on his first mission of escorting bombers to Hankou, China, Feb. 18, 1938, 13th FR(AG).
 * Hatanaka, Morinosuke, survived the war.
 * Iwamoto, Tetsuzo, survived the war.
 * Iwase, Kiichi, was reported killed taking off from Buna airfield, East New Guinea, at 0615JST, August 26, 1942, 2nd FR(AG).
 * Kuwabara, Kiyomi, survived the war.
 * Yamashita, Sadao, was reported killed at Lae airfield, East New Guinea, August 27, 1942, Tainan FR(AG)
 * Yoshii, Kyouichi, reportedly died on a Port Moresby air raid, East New Guinea, March 23, 1942, 4th FR(AG)

In December 1936. Iwamoto entered Saeki Kokutai (Air Group) for 6 months of advanced training (called as extended education), finished and next entered Omura Kaigun Kokutai (Naval Air Group) at July 16, 1937. He had hard training there every day from senior pilots including Air Petty Officer 1st class Toshio Kuroiwa (rank grade was at that time), who was the IJNAF legendary dogfight master pilot. Tetsuzo Iwamoto (called Tetsu in short from his senior pilots) had to wait for his debut until February 10, 1938.

China front
Tetsuzo's ability as a fighter pilot was recognized by all on his first air mission with the 13th Flying Group on February 25, 1938 over Nanchang, China.

After combat training, on February 10, 1938, Tetsuzo Iwamoto was led by his leader APO 1/C Toshio Kuroiwa, flying for two and a quarter hours over the China Sea from Omura Airbase at Kyūshū Japan to the airfield outside of Nanjing China.

His squadron on the Chinese frontline was the 13th Flying Group Fighter Squadron. This Flying Group was the considered the best and was famed as the Nango Fighter Squadron, named after its former squadron leader, Mochifumi Nango, who showed extreme courage and conspicuous leadership. Nango had a famous samurai sword named Kotetsu with him, which became the metaphor for old IJNAF pilots' yearned for Commander Nango.

Iwamoto's first combat came on February 25, 1938 over Nanchang. The squadron fighters escorted bombers Type 96 land-based attack aircraft. Then the Chinese's tenacious air force attacked, and his squadron leader Lieutenant Takuma was lost on this mission.

Iwamoto described his first combat in his notes. During the escort mission, his squadron was intercepted by sixteen I-15s and I-16s at an altitude of 5000 meters. Iwamoto claimed 4 victories (1 probable) in the combat. He got his first victory by firing when within 50m of the enemy fighter. He first saw white smoke, then the enemy burned up and crashed. He was then at an altitude of 4000 m. When he looked back, there was an enemy fighter just behind him. He instantly made a Split S maneuver and narrowly escaped.

He got his second victory against an I-15. He saw it below him, turned and attacked from its 6 o'clock high. When it was hit, it climbed sharply and went spinning downward out of control and crashed into the ground. He kept his altitude of 4,000 m. He got an I-16 at the top of its roll in his gunsight and fired a burst, its engine burning and out of control; Tetsuzo lost sight of it before it crashed, and he reported this as probable. Another I-15 came down to him from 12 o'clock ahead. Both made a climb and were soon in a dogfight. The I-15 tried to break free of him and made a straight dive. That action made it easier for Tetsuzo to aim. He downed this I-15 on farmland near the airfield. He was down to an altitude of 2000 m.

Above him, many enemy fighters kept maneuvering. He found one of them coming down with landing gears down. He chased it to an altitude of 200 m and fired a burst. The I-16 was surprised and made a split S maneuver, but crashed at a corner of the airfield. This was his 4th victory.

Anti-aircraft guns started firing heavily, and he found himself in a terrible barrage of flak. Rushing to escape at full throttle with a number of enemy fighters behind him, he succeeded in returning safely from the battlefield. His leader Kuroiwa had already returned to the Wuhu airfield, Anhui China, waiting for his return. Kuroiwa scolded Tetsu severely for his rash attacks of the day.


 * Every rank name was the old rank name used in pre-war Japan, May 1, 1929 - May 31, 1941
 * Air Petty Officer 3rd Class Kanichi Kashimura was the famous national hero of Japan for his miraculous return safely with his Type 96 carrier fighter left wing lost in combat December 1937.
 * Air Petty Officer 1st Class Toshio Kuroiwa was the best dogfighting master pilot before the Pacific War. He was the national hero and one of the trio of IJNAF's first aerial victory over Shanghai on February 22, 1932. He finished his combat with 13 victories on the China front. He was promoted to Warrant Officer and retired IJN after the air battle settled in China October 1938, became a pilot of commercial airline Dai Nippon Koku. It was the most successful career course for a non commissioned officer pilot in peacetime Japan. He was missing off shore Malay Peninsula on an aerial transport task August 26, 1944, officially recognized as honorably died on a military mission.
 * Air Petty Officer 1st Class Sadaaki Akamatsu was another dogfight master pilot before the Pacific War. He was famous for his yo-yo tactics.

The 13th Flying Group Fighter Squadron was merged with the 12th Fighter Squadron on March 22, 1938, where Type 96 carrier fighters for 1st Chutai had gears painted in red called Red legs squadron, for 2nd Chutai in blue called Blue legs squadron.

Iwamoto was awarded the citation of flying group Cmdr Tsukahara for his extreme courage and conspicuous gallantry in action above and beyond the call of duty as a fighter pilot against intense Chinese air force on April 29, 1938. He made 82 sorties and 14 victories credited in the China front. Tetsuzo Iwamoto became the top IJNAF ace. His activities subsequently earned him Order of the Golden Kite - 5th class recommendation in 1940.

In September 1938, 22 years old Iwamoto was ordered back to Japan, where he became a member of the Saiki Air Group and appointed to a training staff.

His flight log

 * Flying Technique: Class-A of IJNAF
 * Flght hours: over 8,000hrs on March 1944
 * (net hours, not tripled as U.S.A. single-seated fighter pilot. It was very unusual among IJNAF, IJAAF fighter pilots, although it was usual over 10,000 flying hours among the multi-seated aircraft IJNAF, IJAAF veteran pilots.)
 * Oceanic Transition: possible, navigating and leading his fighter chutai (without Radar)
 * Instrument Flight: possible
 * Night Flight: possible
 * Single-seat Fighter renaissance and attack mission across night ocean: possible
 * Night landing: possible with simple approach lighting system
 * Night carrier landing: possible with approach path indicator lights


 * Note that only experienced ranked fighter pilots in IJNAF could do instrument flight with their single-seated fighter aircraft on their combat mission, few IJNAF officer pilots could do instrument flight even to their best.

His tactics
Single to single dogfight tactic - from losing to winning
 * Quick roll (Roll Sempoh)
 * (up and down quick roll tactic, skidding sideway (sudden decelerate) within 1/2 quick roll to forward the opponent aircraft on one's tail and get tail shot position of it. Cmdr Takeo SHIBATA promoted, his men developed and taught him. )
 * Coke-screw loop (Hineri-Komi Sempoh)
 * (short-cut or twist-in loop tactic, skidding loop. Lieutenant Isamu MOCHIZUKI's special, Section leader and Warrant Officer Toshio KUROIWA trained him. )
 * Yo-yo turn (Suichoku-Senkai Kasoku Sempoh)
 * (Lt. JG Sadaaki AKAMATSU's special at China front. )

Formation tactics -
 * Two groups linked formation attack
 * one section plays offence, zooming and diving formation attack, another section plays defense, positioned on the higher altitude to cover and support the offence section.
 * Keeping his groups underneath thick clouds to hide his formation and waiting until the small number of opponent aircraft group coming down, then diving and zooming attack with all in formation.
 * Attacking the opponent groups after their mission over and on the way to the waiting circle, in a group to fly back across the distance range over the sea. This tactics was taken when his group had much less number of aircraft.

No.3 Areal Bomb attack tactic -
 * Twelve o'clock high vertical dive attack from the front top in inverted flight (Haimen Suichoku Kohka Sempoh)
 * Almost vertical diving (about 60 degree) attack because the 30kg No.3 Areal Bomb needs the releasing speed over 280knot/h to work timer correctly for 1st small explosion.
 * Inverted flight at the starting point because Zero Fighter could not keep steep angle while diving due to its excellent flight stability.

China Front, Feb.1938 - Sep.1938

 * 14 victories:
 * I-15, I-16 (citation as the IJNAF top ace)

World War II, Pacific Front and Indian Front, 8 December 1941 - 15 August 1945

 * 228 aerial victories:
 * victories - 202
 * shared victories - 26


 * unconfirmed - 27
 * damaged - 2
 * destroyed on the ground - 2

Aircraft types he confronted
(World War II, 8 December 1941 - July 1942, April 1943 - 15 August 1945, Allied U.S. Army, Navy, Marine, Royal Navy, Australia, New Zealand)
 * F4F victories - 7 (Coral Sea, 8 May 1942;  Rabaul, late 1943 - 10AM 19 Feb.1944 the escort fighters of Martin flying boat)
 * P-38 victories - 4 (Rabaul, late 1943-1944)
 * F4U victories - 48; unconfirmed 1 (Rabaul, late 1943 - Feb. 1944; Mobara-airbase outskirts of Tokyo, Japan, February 16, 1945; Operation Kikusui (Imperial Chrysanthemum on the Water - divine wind), Okinawa, March 10 - June 24, 1945). This is more than 1 in 4 of all F4U air-to-air losses during the Second World War.
 * P-39 victories - 2 (Rabaul, late 1943)
 * P-40 victory - 1 (Rabaul, late 1943)
 * F6F victories - 29 (Rabaul, late 1943 - Feb. 1944; Truk 28–29 April 1944; Operation Kikusui,  Okinawa, Mar.10-Jun.15 1945)
 * P-47 victory -  1 (Rabaul, late 1943 - 1944)
 * P-51 victory - 1 (Rabaul, AM 19 February 1944, the Allied 2nd air-raid of the day, recognized as the latest-style escort fighters)
 * British "Spitfire" (= Hurricane) - 4; burned on the ground 2 (Indian Ocean, 9 April 1942)


 * SBD victories - 48;  unconfirmed  7 (Coral Sea, 8 May 1942; Rabaul, late 1943 - February 1944; Truk 28, 29 Apr.1944; Battle off Formosa, 12 Oct. 1944)
 * SBD w/No.3 Aerial Bomb victories - 30 (Rabaul, late 1943 - 1944)
 * TBF victories - 5;  unconfirmed 19 (Rabaul, late 1943 - 1110 19 February 1944,  the Allied 6th and the 3rd final air-raid of the day to Rabaul)
 * SB2C victories - 5 (Rabaul, late 1943 - 1944)
 * B-25 victories - 8 (Rabaul, late 1943 - 0900 19 February 1944, the Allied 4th air-raid of the day)
 * B-26 victories - 2 (Rabaul, late 1943 - 1944)
 * B-24 victories - 6; w/No.3 Aerial Bomb victories(SH) 24, damaged 2 (Truk, 6 March - June 1944, confirmed by ground members)
 * B-29 victory - 1 (Kagoshima, Kyushu, Japan, April 1945)


 * PBY5A flying boat victory - (SH) 1 (Indian Sea, 5 April 1942)
 * Martin Mariner flying boat victory - (SH) 1 (Rabaul, 10AM 19 February 1944, interlude between Allied air-raids of the day, escorted by 12 F4Fs)


 * Strafed Destroyers - 3     (Rapopo Rabaul, Night 5 February 1944)
 * Strafed Landing Craft - some hundreds (Kerama islands, Okinawa, night 26 March 1945)
 * Strafed Airfields - Lae, Eastern New Guinea, 23 January 1942; Torokina, Bougainville, Solomons, night 1944)

Promotions
from the corresponding article in the Japanese Wikipedia
 * Sailor Fourth Class (Seaman Recruit) - 1 June 1934
 * Sailor Third Class (Seaman) - 15 November 1934
 * Sailor Second Class (Able Seaman) - 2 November 1935
 * Sailor First Class (Leading Seaman) - 26 December 1935
 * Petty Officer Third Class - 1 May 1938
 * Petty Officer Second Class (Petty Officer) - 1 November 1939
 * Petty Officer First Class (Chief Petty Officer) - 1 May 1941
 * Chief Petty Officer (regrading of Petty Officer First Class) - 1 November 1942
 * Commissioned an Ensign - 1 November 1944
 * Promoted to Sub-Lieutenant upon retirement - 5 September 1945

Awards
from the corresponding article in the Japanese Wikipedia
 * Order of the Golden Kite, Fifth Class - 1 August 1942
 * Order of the Rising Sun, Green Paulownia Leaves Medal - Seventh Class - 1 August 1942

Postwar
Postwar tales of friendships between Allied pilots and IJNAF aces were not the case for Iwamoto. Allied Occupation Forces searched for war criminals in the Japanese Officer Corps. He was summoned twice to Douglas MacArthur's Allied GHQ office in Tokyo. Though he avoided being declared a war criminal, he was blacklisted for public sector employment. Managers of nongovernmental businesses and local factories in his hometown also didn't dare to employ him to comply with the wishes of the new Allied GHQ. Those who had been officers in the IJA or IJN were disliked by the Allied Occupation Forces.

Japanese journalists who had promoted and heavily exaggerated the militarism campaign during WW2 started a radio program of anti-militarism postwar called ""Shin-Jitsu wa Kou da (The Truth Is This)"". People like Iwamoto were considered the cat's-paws of militarism there.

Iwamoto had a hard time until the San Francisco Peace Conference was held and the Allied Occupation Forces left Japan in the spring of 1952. In 1952, he finally got employment at the spinning mill, Masuda factory of Daiwa Bouseki (now renamed as "Daiwabo" Co., Ltd, 大和紡績 ). However, in the summer 1953, he got a stomachache. A surgeon examined him and diagnosed enteritis. It was found later to be appendicitis. After a series of operations, he complained of a backache. They decided to operate on him again. With cause unknown, they removed three or four ribs without anesthesia. This led to sepsis  (septicemia, blood poisoning).

His wife recalled his words, "When I get well, I want to fly again." The Zero Fighter ace died on 20 May 1955.

Movie

 * Nippon Eiga-sha, Feb.16, 1944, Nippon News No.194 Solomon no Gekisen Nankai-Kessenjo (means, Southern Ocean Battle Fields of Solomon)
 * Nippon Eiga-sha, Feb.2, 1944, Nippon News No.192 Rabaul (means, Fortress Rabaul)