Defend sky over Japan -Desperate War of Japan in the Pacific

1. Defend sky

Desperate War of Japan in the Pacific
This page contains kanji.

Fighters over Tokyo

Intelligence of IJA had estimated how US would product B-29 correct. They could do from sources of foreign newspapers and correspondences. US publicized area of the production factories. A team of IJA intelligence officers, they were not from IJA cadet academy, calculated the B-29 production number but order number. But most of IJA and IJN HQ could not evaluate importance of B-29's stragitic bombing to Japan mainlad. They looked in Phillipnes rather than Mariana with traditional view. They worried which direction US would select Palau, Biak and Mariana. Onlly intelligence section of IJA and IJN evaluated it correct. Hori, IJA intelligence officer, said, 'IJA's war plans were dogmatic' in a book. If Japan thought value of B-29 and intention of US President, the direction of US attack would be obvious.

IJA Sentai and Aircraft of Defence Sky of Tokyo
Sentai No 47th 53rd 18th 70th 244th Independent 17th

Position Narimasu Mito Kashiwa Kashiwa Chofu Chofu

Aircraft Nick name 鐘馗屠龍飛燕鐘馗飛燕司偵

Designation Ki-44 Ki-45kai Ki-61 Ki-44 Ki-61 Ki-45

Code name Tojo Nick Tony Tojo Tony Dinah

Joint HQ of IJA and IJN was afraid of Tokyo raid of USN carriers attack in February 1944. So IJA withdrew 1st sentai of Oscar and 70th sentai of Tojo which were 70 aircraft total. IJA established the 10th Air Wing on 8 March 1944. Yoshida was its division commander. Yoshida requested General Tojo aviation fuel and wiress radios on 8 April. IJA Fighters fought air combat without radios in 1944! The 10th Air Wing had 5 sentai and 1 independent chutai on 1 November 1944. The table shows their positions and aircraft. All the number of working aircart were 160. The aircraft actioned air combats against carriers aircraft on 16 February 1945 and lost 37 aircraft. IJA ordered 47th and 244th sentai no combat. The next day other sentai lost 16 aircraft. Commander Yoshida was to move Manchuria on 8 March.

Radar over Tokyo

Land radars

IJA Tachi 2	IJA Tachi 18	IJN Type 11

As for anti air ground weapon, Watanabe writes that there were 61 radars near Tokyo including shooting radars that could detect altitude of targets. While Hattori writes 38 IJA radars and he did not refer shooting radars. The photos show them. Tachi 2 was an anti air shooting radar. Tachi 18 was an anti air warning radar. 400 of Tachi 18 were built in 1944. But I am doubtful that a lot of operators were trained.

Pulse width of landed radars
Type Wave length[m] Power Pulse width

IJA Tachi 6 4.4, 4.2, 3.9, 3.8 50kW 10 - 70us

IJA Tachi 7 3 50kW -

IJA Tachi1 8 3.2, 3.1, 2.9, 2.8 50kW -

IJN Type 11 3 40kW 10 - 30us

It was very windy on 9 March 1945. The day is known well as Tokyo Big Raid among people of Tokyo. Radars of IJA did not work well because of the wind speed of 20-30 m/s. At a glance I find the frame of IJA radar was less rigid than IJN radar. A single pole of Tachi18 supports force of the antenna. Though wave length of IJA and IJN land radars almost were the same, pulse width of IJA was bigger twice. I think echo signal of IJA was vague.

Flak over Tokyo

Flak rentai
Rentai 7cm 8cm 12cm Search
light

111st 54 12 6 36

112nd 48 6 0 18

113rd 36 24 8 26

114th 30 30 19 19

115th 24 42 6 38

116th 48 12 60 39

117th 36 12 0 18

118th 28 6 0 12

Total 304 144 99 206

As for flaks, Watanabe writes that there were 7cm (318), 8cm (186) and 12cm (26). Search lights were 251. While Hattori writes how each flak rentai was equipped as follows. The 115th flak rentai had main roll on the Tokyo raid. The flak shot 2 B-29. All of the flaks dissipated 12,000 shells.
Gunzo, p2-9, No70

IJA radar of Hachijyo Island missed detection of the big raid. The 10th Wing commander Kondo ordered intercpt at full length at 0015. The 53rd sentai flew almost 37 fighters. Twin-engine fighters actioned combat 15 times. A single-engine fighters actioned 33 times. B-29s did saving action of escaping in smokes or decending rapid each time. This suggests fighters were very effective to interrupt release of bombs at targets. It shows how importatnt to warn early. If radars find B-29s early and detect flying altitude, fighters could intercept a stream line of B-29s in effective manner.

Otherwise IJN how actioned? IJN alerted at 2206. IJN Chichijima of Ogasawara Islands reported enemies flying to the north at 2210. IJN flew 4 twin-engine night fighters till 0334. After all, information from IJN Ogasawara was in vain. Watanabe writes that IJN did not flew other night fighters because of conflict with flying area of IJA. A B-29 already had bombed Tokyo at night on 29th Nov 1944. B-29s had released firebombs of 411t using radar sight only on 25th Feb. Why IJN could not cooperate with IJA?

A pathfinder of 29th BG of 314th BW released bombs at 5,000ft at 0008 on 10 March. Though 24 B-29s took off Guam per a minute, It took an hour that all of them released bombs. A pathfinder of 497th BG of 73rd BW released at 7,500 ft at 0014. 29 B-29s of 497BG released at 2,000 ft. 51 B-29s of 505th BG of 313rd BW and 500th BG of 73rd BW crossed Ara River and released at target 2.
Watanabe p.230
Kerr, p157-165
Hachijo-Nojima HF Radar

Airfields in Kyushu and Taiwan


Airfields	TG.38 location

Japan had to defend herself because war front came near Japan main land. So IJA and IJN built a lot of airfields there. Japan fought the biggest air battle in Okinawa 1945. The area of Kyushu and Taiwan were 37,437 km² and 34,507km² each. Prince of Wales Island of Canada is 33,339 km². And Okinawa is 1,206km² only. One map shows airfields of Japan in Kyushu and Taiwan. Another shows location of TG.38 on 8 May 1945. Japan got the locations of 4 TF groups by reconnaissance. USN selected Okinawa for Taiwan to campaign. USN thought USN could make air cover, though Okinawa was within a range of Japanese aircraft. USN thought ground battle in Taiwan was tough because Taiwan is bigger than Okinawa 30 folds. And P-51 and P-47 had a combat range of 960km and 600km in Europe. But P-47 raided Kanoya in the south of Kyushu, and Itatsuke in the north of Kyushu from Iejima. P-47 also bombarded Omura in the north of Kyushu. P-47 had to flew 630km to Kanoya on 29 June, 740km to Omura on 20 June and 827km to Itatsuke on 23 June. Could P-47 fly at cruising speed and altitude because of weak air defense of Japan?
Gunzo, p42 No65
Gunzo, p152 No90
Gunzo, p43 No89

2. Night fighters

WWI
A UK Morane Parasol shot down LZ 37, a flying boat at night on 7 August 1915 for the first time in history^[3][4][7]. Othewise a German DFW C.V shot down UK bombers on 10 February 1917^[5][6][7].

UK at WWII
A Blenheim scored a Dornier Do 17 on the night of 2/3 July 1940, which was equipped with AI Mk 3^[8][9][10].

Iwamoto's memory

Iwamoto was a IJN ace pilot.

No aircraft came home on 23rd Mar 1945. They patrolled Okinawa. An aircraft telegrammed fighter's tailing. A shitei(Ki-46) reported quite a few warships off Kerama Islands, which flew from Taiwan to Kanoya. Iwamoto, an IJN fighter pilot of 303rd Kokutai reconnoitered Okinawa at night^[11]. He wrote the action in Japanese as follows. US Marined landed Okinawa mainland on 1 April 1945.

Stars twinkles in the sky of no moon. Riding on a Zero-sen, I finished idle running. I turned on a light of wing to informing ready. I see a light of indicating lantern far forward. Seeing a signal of command post, lever full opened I took off softly. I saw no lights below in dark. Turnning around Kagoshima Airfield once with a big circle, I get 3,000m high. I fly for Okinawa on intended course directioning. I see purple bright exhaust flame in the dark sky. 30min later, I see Yaku-shima on the left, maybe. I see dotted islands forward. Up to 4,000m high, I turn on a recieiver. I hear enemy telegrams in English slightly. An hour later, Watching night fighters, up to 6,000m high, I use oxygen. I hear English intense. I see shadow of Amami-oshima on left at the back, maybe. I hear English more intense. In case of preparing intecept, flying up higher, I see a shadow of aircraft on right. Watching at the back, I gained 8,000m high. Coming near Iejima, I looked back. A night fighter chases me far some hudred meters. Diving to Iejima I lost it. Pulling up at 5,000m high, I turn around Ie-sima. I get to Okinawa-honto in a while. I fly south along the west sea side. I see a dim light far south. I fly with zero boost. Looking down Kerama Islands, big transports are lifting. I see a lot of daihatsu on the sea. I sent a wireless message. On course of returning at 500m high, I see fling aircraft for Okinawa to attack enemy near Akuseki-shima. I finished my mission of 4 hours flight^[12].

Was the US night fighter F6F-5N?

131st kokutai

Iwakawa base^[13]

The 131st kokutai was equipped with carrier bomber Suisei and Zero. It advanced at Kanoya in the end of March 1945. The kokutai refused sucide attack. It repeated attacks to airfields and warships at night. Ido, a crew of recon told a story, "We took of at 2 or 3 am and flew at 300m height. After a while, P-61 chases us. We were always shot whenever we flew to Okinawa. Comming near Okinawa, search lights catch us at once. Flaks burst very near. Invading over Naka airfild, we decended slow and released a 250 kg bomb. Passing the Nakasugusu Bay, We came back at dawn^[17]." The 131 kokutai had actioned 81 times since 1st April. All the sorites were 630 and lost 40 aircraft and 80 crews in the Okinawa Battle^[15]. 131 kokutai began to move secret Iwakawa Base off 30 km Kanoya on 13 May and finished the deploy in 10 days. 131 kokutai actioned again on 25 May. IJN ordered retreat and destroy of the Kanoya Air Base on 30 July 1945^[16].

Kasa-no-hara Air Base

A Betty detected enemy TF by a radar at night on 17th Mar 1945. A radar in Tanegashima also confirmed the enemy. But a 6F6-5N was trailing the Betty. The 6F6 shot it at dawn of 5:40 am over the Kasa-no-hara Air Base of Kyushu and lead F4Us. The 301st and 721st koukutai lost 34 aircraft and were destroyed 8 aircraft on the ground^[18]. This shows F4U took off aircraft carriers before dawn and could flow at night, as well as IJN actionedat Pearl Harbor Operation.

The tail gunner of the betty could not find the 6F6-5N. How far did it chase?

IJN night fighters development

IJN planned night fighters in 1944 & 1945
Date	Name
1944Jun05	Denko, Kyokko, Suisei^[14], Saiun-kai
1944Sep01	Suisei(D4Y2-S), Saiun-kai(C6N3)
1944Sep10	Suisei
1945Jan15	Ki-46
1945Mar24	Ginga(P1Y1)

IJN worried about intercepting B-17s at night at Rabaul in 1943. A IJN night fighter, J1N1-S shot down 2 B-17s on 21 May 1943 at first. IJN planned to develope higher performance night fighters than J1N1-S in 1943. They were Denko (S1A1) and Kyokko (P1Y2-S). IJN stopped producting J1N1-S in October 1944^[1]. The both planned night fighters were not in time of intercepting B-29. IJN gave up developing them in September 1944. The table shows how IJN worried developing night fighters and confused^[2].

While IJA adopted Ki-45 and Ki-102 as night fighters. The production of Ki-45 and Ki-102 were 1,704 and 215. Kawasaki made a trial of Ki-102 in March 1944. Japan should stop developing IJN night fighters since then. Air raids of B-29s at night destroyed Japanese cities which flew at low altitude. Instead of productioning new IJA Ki-102 and developing IJN night fighters, I think Japan had better continue old Ki-45 much as night fighters. And IJA and IJN should cooperate and develop airborne radar with desperate effort. IJN airborne PPI rader made a trial test and showed its image in the sky in August 1945 for the first time. It was late more than 5 years than UK. Japan knew Germany and Britain fought severe at night. But Japanese military governers had ignored watching on European air battle.

IJN air crews dosed with drug

An IJN medical doctors dosed air crews with drug at night action. The drug was a kind of awakening drug, methamphetamine. The doctor told them that an injection would work to see far at night. Methamphetamine was a drug synthesized by Nagai at University of Tokyo in 1893^[19]. An Irving (Gekko) of Yokosuka Kokutai shot 4 B-29s at one night on 25 May 1945. They dropped near Kumagaya, Sumida and Choushi. The last dropped off Chiba into the sea. But the pair of crews worried illness for 40 years after the Pacific War. They were Kurotori Shirou ( 黒鳥四朗 ) and Kuramoto Jyuzou ( 倉本一三 )^[20].

After the Pacific War, Dai Nippon Pharmacy sold it and named hiropon. It said, "Hirou ga pon to toreru." The abuse of it destoryed lifes of famous writers, 太宰治, 田中英光, 坂口安吾 and 織田作之助. Soon Japan regulated it by 覚醒剤取締法 in 1951. Once Chinese emperors or bureaucrats enjoyed opium in Qing Dynasty, it declined China. A few modern Japanese governers depended drug. Matsuoka Yousuke usually dosed cocaine. He was an importand diplomat, when Japan walked out League of Nations and tied Tripartite Pact. Prime Minister Abe Shinzo depended on a kind of drug to sleep well in his late short duty. A site writes JFK was dependent of Amphetamine and hydrocortisone^[21]. If it is true, I found why JFK choiced wrong Vietnum option. If he read Vietnumese history himself, the knowledge helped his option. US famous inherited lawmakers sometimes use a kind of drug. Are they tired of their work? If medical doctors dose them, it permits by law. Even if our leaders are dependent of drug, govern system usually works well, someone else does their work actually. Actually Japan and Thailand eacaped Western colonization, though Shougun was not smart. All most commons always work their brains to continue their daily life. Laboring harder, we always sleepy at night.

[1] Gekko ( Irving )
[2] Syowa 20 nendo no Kaigun Sentoki Seisan Keikaku
[3] The Zeppelin Raiders
[4] Zeppelin Raids
[5] DFW C.V
[6] World Aviation in 1917
[7] Yakan, p15
[8] Yakan, p68-69
[9] Blenheim
[10] Nightfighting
[11] Ki-46
[12] Iwamoto p.357-361
[13] Iwakawa Kichi
[14] Suisei (Judy)
[15] Omoi, p162
[16] Ebina, p418-419
[17] Watanabe, p369-370
[18] Watanabe, p.341-342
[19] Yakubutsu jyouhou ron
[20] Omoi, p24
[21] ＪＦＫ no yamai
[22] Ahen