Lieutenant Junior Grade was one of the top scoring aces among
Imperial Japanese Navy Air Service
The (IJNAS) was the air arm of the Imperial Japanese Navy (IJN). The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.
The Japanese military acquired its first aircraft in ...
(IJNAS) fighter pilots. He entered the
Imperial Navy in 1934 and completed
pilot training
Flight training is a course of study used when learning to pilot an aircraft. The overall purpose of primary and intermediate flight training is the acquisition and honing of basic airmanship skills.
Flight training can be conducted under a str ...
in December 1936. His first combat occurred over
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
in early 1938. He emerged as one of the top aces of the Imperial Japan during
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, credited with at least 80 aerial victories, including 14 victories in China. Subsequently, he flew
Zero
0 (zero) is a number representing an empty quantity. Adding (or subtracting) 0 to any number leaves that number unchanged; in mathematical terminology, 0 is the additive identity of the integers, rational numbers, real numbers, and compl ...
s from the aircraft carrier ''
Zuikaku'' from December 1941 to May 1942, including at the
Battle of the Coral Sea
The Battle of the Coral Sea, from 4 to 8 May 1942, was a major naval battle between the Imperial Japanese Navy (IJN) and naval and air forces of the United States and Australia. Taking place in the Pacific Theatre of World War II, the battle ...
. Iwamoto decorated his planes with
victory markings of
cherry blossom
The cherry blossom, or sakura, is the flower of trees in ''Prunus'' subgenus '' Cerasus''. ''Sakura'' usually refers to flowers of ornamental cherry trees, such as cultivars of ''Prunus serrulata'', not trees grown for their fruit (although ...
flowers, with a single or double blossom flower referring to a shot down enemy
fighter or
bomber
A bomber is a military combat aircraft that utilizes
air-to-ground weaponry to drop bombs, launch aerial torpedo, torpedoes, or deploy air-launched cruise missiles.
There are two major classifications of bomber: strategic and tactical. Strateg ...
aircraft respectively.
In late 1943, Iwamoto's air group was sent to
Rabaul, New Britain, resulting in three months of air combat against Allied air raids.
Subsequent assignments were
Truk Atoll in the
Carolines and the
Philippines
The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...
, being commissioned an ensign in October 1944. Following the evacuation of the Philippines, Iwamoto served in home defense and trained
kamikaze
, officially , were a part of the Japanese Special Attack Units of military aviators who flew suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, intending to d ...
pilots.
As a result of the Japanese use of the British naval practices, the IJNAS scoring system was based on the system the Royal Navy and the Royal Air Force (RAF) adopted from World War I until World War II. This system differed from the scoring system used by some other nations during World War II. Research by academics surnamed Izawa and Hata in 1971 estimated his score at about 80 or more than 87. In December 1993, Izawa wrote that Iwamoto was ''virtually'' the top ace of the IJNAS.
As of mid-1944, there remained only two IJNAS fighter pilots who were credited with over 100 victories. Depending on various totals cited, Tetsuzō Iwamoto or
Hiroyoshi Nishizawa was Japan's top ace. Iwamoto was known as the Chūtai leader (Flying Company, squadron of 8 to 16 fighters). Iwamoto was one of few survivors of the IJNAS from the early part of the Second World War. He fought over the
Indian and the
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
from north to south, and trained young pilots even in the last months of the war. 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.
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
is a Cities designated by government ordinance of Japan, designated city in Hokkaido, Japan. Located in the southwest of Hokkaido, it lies within the alluvial fan of the Toyohira River, a tributary of the Ishikari River. Sapporo is the capital ...
,
Hokkaidō
is the second-largest island of Japan and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by railway via the Seikan Tunnel.
The ...
,
Japan
Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
. 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
is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Shimane Prefecture is the List of Japanese prefectures by population, second-least populous prefecture of Japan at 665,205 (February 1, 2021) and has a ge ...
. 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 examination for acceptance as an Imperial Japanese naval airman 4th class, and was promoted to 3rd class 5 months later. His parents were very disappointed, for they became reliant upon Tetsuzo rather than his eldest brother, who was already studying at some university in a large city and would not return to Masuda.
In 1936, when he was a naval mechanic 2nd class and a crewman on the light aircraft carrier
Ryūjō, he studied hard and passed the difficult IJNAS exam, taken by thousands of applicants. He was enrolled in the class 34th ''Sōju-Renshūsei'' (''Sōren'' means ''flight trainee program'') for naval petty officers and sailors. He graduated as one of the select 26 young aviators of the class 34th ''Sōju-Renshūsei'' (flight trainee program) in December of that year.
On April 4, 1936, he was sent to Kasumigaura-Ku (Kasumigaura FR(AG)) as a probationer in the class 34th ''Sōju-Renshūsei'' (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 ''Sōju-Renshūsei'', 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 well-known Chitoshi Isozaki.
In December 1936. Iwamoto entered Saeki ''
Kōkūtai
A ''kōkūtai'' () was a military aviation unit in the Imperial Japanese Navy Air Service (IJNAS), similar to the Group (military aviation unit), air groups in other air arms and services of the time. Some comparable units included ''wing'' in th ...
'' (a ''Kōkūtai'' was a Naval Air Group, whether being based at land or on board a carrier) for 6 months of advanced training (termed ''extended education''), finished and next entered Omura ''Kōkūtai'' on 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 IJNAS 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
A fighter pilot or combat pilot is a Military aviation, military aviator trained to engage in air-to-air combat, Air-to-ground weaponry, air-to-ground combat and sometimes Electronic-warfare aircraft, electronic warfare while in the cockpit of ...
was recognized by all on his first air mission with the 13th Flying Group on February 25, 1938, over
Nanchang
Nanchang is the capital of Jiangxi, China. Located in the north-central part of the province and in the hinterland of Poyang Lake Plain, it is bounded on the west by the Jiuling Mountains, and on the east by Poyang Lake. Because of its strate ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
.
After combat training, on February 10, 1938, Tetsuzō 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
is the third-largest island of Japan's four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa and the other Ryukyu (''Nansei'') Islands). In the past, it has been known as , and . The historical regio ...
Japan
Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
to the airfield outside of
Nanjing
Nanjing or Nanking is the capital of Jiangsu, a province in East China. The city, which is located in the southwestern corner of the province, has 11 districts, an administrative area of , and a population of 9,423,400.
Situated in the Yang ...
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
.
His squadron on the Chinese frontline was the 13th Flying Group Fighter Squadron. This Flying Group was highly regarded and was famed as the ''Nango Fighter Squadron'', named after its former squadron leader, Mochifumi Nango, who had shown considerable courage and conspicuous leadership.
Iwamoto's first combat came on February 25, 1938, over Nanchang. His squadron's fighters escorted
bomber
A bomber is a military combat aircraft that utilizes
air-to-ground weaponry to drop bombs, launch aerial torpedo, torpedoes, or deploy air-launched cruise missiles.
There are two major classifications of bomber: strategic and tactical. Strateg ...
s
Type 96 land-based attack aircraft. Chinese fighters attacked, and the squadron's 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 secured 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
A dogfight, or dog fight, is an air combat manoeuvring, aerial battle between fighter aircraft that is conducted at close range. Modern terminology for air-to-air combat is air combat manoeuvring (ACM), which refers to tactical situations requir ...
. 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 flying at an altitude of 2000 m.
Above him, many enemy fighters were maneuvering. He found one of them coming down with landing gear 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
Anti-aircraft warfare (AAW) is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It encompasses surface-based, subsurface ( submarine-launched), and air-bas ...
started firing heavily, and he found himself in an intense
barrage of
flak
Anti-aircraft warfare (AAW) is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It encompasses surface-based, subsurface ( submarine-launched), and air-bas ...
. Rushing to escape at full throttle with a number of enemy fighters behind him, he succeeded in returning safely from the
battlefield
A battlefield, battleground, or field of battle is the location of a present or historic battle involving ground warfare. It is commonly understood to be limited to the point of contact between opposing forces, though battles may involve troop ...
. His leader Kuroiwa had already returned to the Wuhu airfield, Anhui China, waiting for his return. Kuroiwa scolded Tetsu severely for the rash attacks he made on the day.
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 landing gear painted in red and were called ''Red legs squadron'' while 2nd Chutai had gear painted in blue and were 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. Tetsuzō Iwamoto became the top IJNAS ace. His activities subsequently earned him ''Order of the Golden Kite – 5th class'' recommendation in 1940.
In September 1938, 22-year-old Iwamoto was ordered back to
Japan
Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
, where he became a member of the
Saiki Air Group and appointed to a training staff.
His flight log
:Flying Technique: Class-A of IJNAS
:Flight hours: over 8,000 hrs in March 1944
::(net hours, not tripled as with a US single-seated fighter pilot. It was very unusual among IJNAS, IJAAS fighter pilots, although it was usual over 10,000 flying hours among the multi-seated aircraft IJNAS, IJAAS veteran pilots.)
:Oceanic Transition: possible, navigating and leading his fighter chutai (without Radar)
:Instrument Flight: possible
:Night Flight: possible
::Single-seat Fighter reconnaissance and attack mission across night ocean: possible
::Night landing: possible with simple approach lighting system
::Night carrier landing: possible with approach path indicator lights
Only experienced fighter pilots in the IJNAS could execute instrument flight with their single-seat fighter aircraft on combat missions; few IJNAS officer pilots could fly on instruments.
Tactics
Single to single dogfight tactic – from losing to winning
:Quick roll (''Roll Senpō'')
:: (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.)
:Corkscrew loop (''Hineri-Komi Senpō'')
::(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 Senpō'')
::(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 fewer aircraft.
No.3 Aerial Bomb attack tactic –
:Twelve o'clock high vertical dive attack from the front top in inverted flight (''Haimen Suichoku Kōka Senpō'')
::Almost vertical diving (about 60 degree) attack because the 30 kg No. 3 Aerial Bomb needs the releasing speed over 280 knots 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.
Aerial victories claimed in his diary
(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 February 1944 the escort fighters of Martin flying boat)
*P-38 victories – 4 (Rabaul, late 1943 – 1944)
*F4U victories – 48; unconfirmed 1 (Rabaul, late 1943 – February 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, March 10 – June 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 April 1944; Battle off Formosa, 12 October 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, April 5, 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 February 5, 1944)
*Strafed Landing Craft – some hundreds (Kerama islands, Okinawa, night March 26, 1945)
*Strafed Airfields – Lae, Eastern New Guinea, January 23, 1942; Torokina, Bougainville, Solomons, night 1944)
Promotions
''from the corresponding article in the Japanese Wikipedia''
*Sailor Fourth Class (Seaman Recruit) – June 1, 1934
*Sailor Third Class (Seaman) – November 15, 1934
*Sailor Second Class (Able Seaman) – November 2, 1935
*Sailor First Class (Leading Seaman) – December 26, 1935
*Petty Officer Third Class – May 1, 1938
*Petty Officer Second Class (Petty Officer) – November 1, 1939
*Petty Officer First Class (Chief Petty Officer) – May 1, 1941
*Chief Petty Officer (regrading of Petty Officer First Class) – November 1, 1942
*Commissioned an Ensign – November 1, 1944
*Promoted to Sub-Lieutenant upon retirement – September 5, 1945
Awards
''from the corresponding article in the Japanese Wikipedia''
*
Order of the Golden Kite, Fifth Class – August 1, 1942
Post-war life
The Allied Occupation Forces searched for war criminals in the Japanese Officer Corps. Iwamoto was summoned twice for questioning to
Douglas MacArthur's Allied GHQ office in Tokyo. Although he managed to avoid being declared a war criminal, he was nevertheless
blacklisted
Blacklisting is the action of a group or authority compiling a blacklist of people, countries or other entities to be avoided or distrusted as being deemed unacceptable to those making the list; if people are on a blacklist, then they are considere ...
from public sector employment. Managers of nongovernmental businesses and local factories in his hometown also did not dare to employ him, in order to comply with the wishes of the new Allied GHQ. In general, anyone who had been an officer in the IJA or IJN was disliked by the Allied Occupation Forces.
Japanese journalists who had promoted Japanese militarism campaign during the war started a radio program of anti-militarism postwar called ''Shin-Sō wa Kō Da'' ("The Truth Is This"). The program was initiated by GHQ
and it considered people such as Iwamoto the
cat's-paws of militarism.
Iwamoto struggled to survive until the San Francisco Peace Conference was held, after which, in the spring of 1952, the Allied Occupation Forces finally left Japan.
In 1952, Iwamoto finally obtained employment at the
Masuda spinning mill of Daiwa Bōseki (since renamed to "Daiwabō" Co., Ltd, 大和紡績).
In the summer of 1953, Iwamoto developed a stomach ache. A surgeon examined him and diagnosed
enteritis
Enteritis is inflammation of the small intestine. It is most commonly caused by food or drink contaminated with pathogenic microbes,Dugdale, David C., IIII, and George F Longretc"Enteritis" MedlinePlus Medical Encyclopedia, 18 October 2008. Acces ...
. It was found later to be
appendicitis
Appendicitis is inflammation of the Appendix (anatomy), appendix. Symptoms commonly include right lower abdominal pain, nausea, vomiting, fever and anorexia (symptom), decreased appetite. However, approximately 40% of people do not have these t ...
. After a series of operations, he complained of a backache. Doctors decided to operate on him again. For reasons which are not entirely clear, the surgical team decided to remove three or four ribs without anesthesia. This led to
sepsis
Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs.
This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...
.
Iwamoto died on 20 May 1955, at the age of just 38 years old. His wife recalled his final words: "When I get well, I want to fly again."
Notes
References
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* 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)''
{{DEFAULTSORT:Iwamoto, Tetsuzo
1916 births
1955 deaths
Japanese naval aviators
Japanese World War II flying aces
Deaths from sepsis in Japan
Imperial Japanese Navy officers