History Friday: Analyzing The Okinawa Kamikaze Strikes & Japanese/US Planning For Operation Olympic

This column has visited established narratives of Pacific war many times to try and validate their worth by “opening the hood” of the “Narrative Car” to see what makes them run. Today’s column does that with the Japanese Kamikaze campaign at Okinawa and rival Invasion of Japan planning in the form of the Japanese “Ketsu-Go Six“ plan — predominantly take from Japanese Monograph No. 85 and various American “Sphinx Project” reports and the Pacific Theater War Plans for Operation Olympic. Then the column will analyze them via operational realities that are generally missing from even the best end of the Pacific War books like Richard B. Frank’s “Downfall: The End of the Imperial Japanese Empire.”

The genesis of this column began when I recently read THE ULTIMATE BATTLE, OKINAWA 1945 — The Last Epic Struggle of World War II by Bill Sloan. He made a comment to the effect that the Imperial Japanese high command planned during operation TEN-GO the Kamikaze plan used during the American Invasion of Okinawa — to include 4,085 aircraft for suicide operations.

When I checked my copy of VICTORY IN THE PACIFIC 1945 by Samuel Eliot Morison for details, I found his table of TEN-GO attackers listed only 1465 planes as making suicide attacks (and 1,900 other Japanese aircraft sorties identified by US Navy radar plots).

Using that comparison, only 35.8% of the planned attack force actually reached the American fleet and made attacks.

However, I have read elsewhere that only half the aerial Kamikazes launched from Kyushu actually found targets and those that did not returned to base to try again.

So American military countermeasures against Kyushu airfields stopped 1155 of the planned 4,085 TEN-GO suicide aircraft sorties before they were launched, leaving 2930 (approximate) to make suicide attacks.

Of those 2930, there were 1465 that were successfully engaged by American defenses or attacked ships, leaving a further 1465 to return to base.

The problem with that thought is that no two sources seem to agree on the total number of Japanese sorties launched. Other authoritative sources I looked showed the following:

o US Strategic Bombing Survey (USSBS) gives around 1,900 Kamikaze sorties & 3,000 conventional sorties

o Takushiro Hattori’s “Dai Toa Senso Zenshi” (The Complete History of the Great East Asia War, 1953) lists 2,571 kamikaze sorties between 3 March – 16 August.

o Richard B. Frank’s “Downfall” gives 1 unnamed source as 2,940 Kamikaze missions and another as giving 3,106 kamikaze missions flown from between October 1944 – August, 1945. The unnamed source 1 listed 1,162 missions & 1,264 missions, respectively, flown during April, 1945.

Okinawa Kamikaze Campaign Analysis —
Richard B. Frank’s “3,106 kamikaze missions flown” during that period would include the Philippines suicide missions as well as Okinawa. And half of between 2,571 Kamikaze (via Takushiro Hattori) and 2,940 Kamikaze missions (via Richard B. Frank) finding and engaging American naval ships or air defenses at Okinawa is roughly the 1465 Samuel Elliot Morison mentions in VICTORY IN THE PACIFIC 1945.

The numbers seem to agree within 10-15%. Given the destruction of Japanese records by American fire bombing and the mass record purge between the August cease fire and the formal surrender and occupation that looks good enough.

Since THE ULTIMATE BATTLE, OKINAWA 1945 says only 570 operational aircraft of all types were left in Kyushu when the last TEN-GO strikes ended. This suggests that of the 1465 Kamikaze missions that did not find a target at Okinawa, that 895 of them —

1) The returned flights were suffering rather high operational attrition, or
2) They were destroyed on the ground after landing and before being
hidden again,
3) They ran to Honshu or Korea (unlikely based on Ultra reports of the time),
4) Some combination of #’s 1, 2 or 3.

The reason I mention this is we are looking at a 895 out of 2930 of 30.6% Kamikaze rate of loss for just taking off!

A lot of authors keep harping on the fact that shorter flight times and an invasion fleet off the coast mean that this rate will be far lower. The problem with that thought are several fold.

First, the mass use of smoke over landing beaches by the American fleet means that a lot of navigation land marks are going to be eliminated for untrained pilots. Even trained pilots in WW2 had a hard time telling ship size over 5,000 feet, unless they were long flight time patrol bomber pilots and/or trained observers, and even those guys made mistakes as Midway makes clear. Low flight time Kamikaze pilots are going to go for the first clear target they find, as opposed to transports.

Second, the American air forces plans for a large scale use of defoliant plus napalm was going to result in huge forest/grass fire smoke plumes that were going to blanket Kyushu making navigation even with radio and radar direction hard to accomplish.

See these Southern California and Central American satellite fire smoke plume photos —

The photos at this link
http://www.goes-r.gov/users/comet/npoess/multispectral_topics/fire_wx/print.htm

The photos at this link
http://capita.wustl.edu/central-america/reports/jgr/smokeimpactjgrdoc.htm

And the video at this link:

Pole Creek Fire Sunset Smoke Plume Sept. 18th 2012 NFS FAIL
http://www.youtube.com/watch?v=T9GDPWJhdBU

Third, the Japanese did not intend to provide the Kyushu Kamikazes much fuel for loitering. That had a number of very vexing implications for those low flight time pilots in terms of target choice, given poor weather and confusing air combat disorienting them and making them lose their escorts, in addition to smoke. Effectively by the second or third day of the battle, I expect that the 30% operational losses for the Okinawa Kamikaze pilots who missed a target will be on the low side for Kyushu.

Fourth, the Japanese low flight hour Kamikaze pilots were going to have a “target fixation problem.” Richard O’Neill’s book “Suicide Squads: Axis and Allied Special Attack Weapons of World War II: their Development and their Missions” estimated that 300+ Kamikaze attacks (or more than 15% of all attacks at Okinawa) were made during April 1945 alone at Okinawa radar Picket Station No. 1. ‘Suicide Squads’ includes a description in the book of how USS Bush met her end — a group of 40(!) aircraft began to circle overhead, with groups of 1, 2, or 3 peeling off for individual attack runs on Bush; and even after it became obvious that Bush was severely damaged, the Kamikazes continued to concentrate on her.

The scary number for the Americans in the Invasion of Japan was the 5% of 10,000 Kamikaze pilots who would be instructors. Those guys would get though unless killed and would know enough to pick transports and not picket ships or gunboats. Thankfully, had the A-bomb failed to cancel the invasion, many of those instructors would have been in wooden biplanes with limited lethality.

Where Ketsu-Go Six Becomes Fantasy –
The last and biggest problem for the Japanese Ketsu-Go Six plan would have been the huge issue of command coordination. There were three big and interrelated reasons that the Japanese Ketsu-Go Six Kamikaze coordination plans were going to fall apart like their aerial plans for the “Decisive Battles” from Midway to the Marianas, through to Leyte. They consisted of the following:

1) Communications,
2) Maintenance, and
3) Flawed operational planning amounting to wishful thinking.

First, the Japanese had problems with both their land line and radio communications for Ketsu-Go Six arising from the lessons the USAAF learned in it’s European transportation bombing campaigns in Italy, the Normandy campaign and by tactical air forces over 1945 Germany. The Japanese railways in Kyushu (and elsewhere in Japan) co-located the telephone and telegraph lines on the railway right-of-ways similar to those of Europe. Most of that right-of-way they were buried and effectively immune to air power. However, that changed at the bridges. This was where these land lines were vulnerable to being cut when a major bridge went down, or a major tunnel was closed by bombing or bombing induced land slides.

As a part of the transportation campaign, the General Kenney’s Far Eastern Air Forces was going to systematically attack the Kyushu railway bridges and tunnels with Azon/Razon bombs radio guided bombs by B-24 and B-32 heavy bombers, via low level skip-bombing by A-20/B-25/A-26 medium and via dive bombing by USMC Helldivers of Marine Air Wing One and Two. This was going to utterly dislocate Japanese land line telephone and telegraph communications. At best, the Japanese were going to have several isolated telephone networks with “patches” consisting of the following;

a. Short distance tactical telephone wired across river gaps through
bridge debris with human operator repeating nodes,
b. Short range directional radio similar to ‘a’ above (more on that later),
c. Motorcycle couriers,
d. Pony express, and
e. Just plain human runners between land line networks.

This would push the Japanese heavily into using radio communications from the planned — and secure — land lines in the weeks before the Ketsu-Go Six operation, revealing many locations that hosted suicide unit base areas to intensive US photo reconnaissance targeting efforts. In fact, the historic October 1945 hurricane that wrecked a portion of the American invasion fleet at Okinawa also struck Kyushu. It would have destroyed many of the “patches” and showed to Ultra a much more detailed footprint of Japanese suicide and land defenses, and how those units communicated under pressure.

Hold that thought.

This takes us to our next Japanese communications issues American radio jamming. Both the US Navy and the US Army had developed jamming capabilities and doctrine for using it called “Radio Counter Measures” or “RCM”.

The US Navy doctrine was built around fleet actions during the Central Pacific Campaign and the twin shocks of the German Fritz-X/HS-293 radio guided bombs in 1943 and surprise Japanese deployment of low frequency aerial radar for night torpedo bombers in Oct 1944 off Formosa, which the US Navy’s capital ship TDY radio jammers for the Fritz-X/HS-293 threat could not defeat.

USN RCM doctrine — first fully implemented at Iwo Jima in February 1945 — called for the isolation of the landing target via destruction of radio transmitters at the target and the jamming of both Japanese and American radio frequencies during the assault. The Japanese radar and radio frequencies would be jammed at the target by ships usually LCI(R) gunboats — and TBM single engine torpedo bombers outfitted to deal with Japanese amplitude modulated (AM) band tactical radios.

The Navy’s 4-engine patrol bombers would fly race track pattern directional jamming between the landing target and known by Ultra code breaking and direction finding Japanese radio receivers during a short period prior to and after the assault, to deny the Japanese intelligence of our amphibious traffic.

Meanwhile, a radio/radar feint with a naval bombardment deception unit would happen elsewhere during this period with simulated amphibious traffic, jamming and low level barrage balloons with radar corner reflectors to draw Japanese attention. This happened at Chichi Jima during the Iwo Jima campaign using elements of Pacific “Beach Jumper” deception units.

Japanese aerial radio was left alone to allow naval radio direction finders to vector CAP fighters onto incoming Japanese aircraft formations.

Japanese aerial radar was jammed whenever possible and F6F(N)5 Hellcat night fighters were being fitted with radio frequency direction finding (RF/DF) gear hunt those radar planes at war’s end.

The intent of this USN doctrine was not to completely fool the Japanese, but to delay their effective reaction long enough for the landing force to get the initial beach head secured.

American Army and in particular USAAF strategic bombing Air Forces developed a jamming capability aimed at German ground control intercept (GCI) radar/fighter communications and gun laying/search light radars. Early on — before long range escort fighters The USAAF was very interested in using British night fighter channel jamming capabilities to spoof/deny German day fighters “good radar dope” to vector onto American bomber streams.

Later, as they realized that ground observers with telephones in France could warn Germany of incoming bombing streams and that the answer to defending fighters was long-range escort fighters. They redirected interest from GCI link jamming to stopping German radar directed flak via active jammers on bombers and window/rope drops. Fighter GCI link jamming was replaced by using radio direction finding to vector American escorts on assembling German fighter formations for similar reasons to the USN in the Pacific.

This is the RCM template that the 20th Air Force brought with it to the Marianas in Oct 1944 and only got to partially implement prior to war’s end. And what the experienced European Theater RCM officers of the Eighth and Ninth Air Forces were bringing Olympic/Majestic.

Please note that both American Naval & USAAF fighters had very high frequency (VHF) band frequency modulated (FM) voice radios while Japanese aircraft used medium and low frequency AM radios. American jammers could use AM band jamming wave forms on the VHF frequencies leaving the FM radios still usable, if shorter ranged.

The USAAF deployed a whole family of jammers aimed at German AM band tank radios that left American FM tank radios unaffected. These jammers were used during American counterattacks in the Battle of the Bulge.

Meanwhile, the Pacific Signal Corps units had taken the information of Japanese aerial radars to heart and developed a family of ground based jammers to blanket port and anchorage areas filled with amphibious shipping with electronic jamming “smoke” to go with the real smoke from both the CWS’s and USN’s smoke generators.

The Japanese planned an Air-Surface-Subsurface suicide combined arms defense of Kyushu built around radio-radar coordination. A coordination they would not have in the face of a RCM buzz saw that was lined up for Kyushu.

In terms of maintenance, the Japanese were executing a “hide and strike” plan that put many if not most engines, explosives and radios for their suicide units in underground, dark, wet environments with hydrocarbon fuels heavily blended with alcohol.

This was asking for a great deal of trouble as aircraft have to be run continually or they develop faults that can only be cured by a lot of skilled maintenance and test flights.

Japanese suicide aircraft were in many cases reconditioned obsolete models with “doubtful” stocks spares parts. By which I mean they would be old, ill-stored and built with poor tolerances that required mechanics to machine them to proper fit prior to use. The upshot was that the part machined to fit on one aircraft often could not be salvaged and made to fit on another.

This problem was endemic in the Japanese aircraft industry of the time and was the biggest reason for the superb Japanese air power performance in the first few months of the Pacific War, when operating from at-start bases & ships filled with stocks of machined parts with skilled mechanics. Which then fell apart in the Solomons & New Guinea campaigns after those stocks were used up, newer aircraft models were introduced without the years of pre-war tweaking to build up the mechanic knowledge base to maintain them, and the large numbers of the pre-war skilled mechanics were stranded on by-passed islands.

Asking ill-trained mechanics to operate equipment not conditioned for long term exposure to damp environments in a low light cramped environment is not conducive to high levels of operational readiness.

This leaves aside the problems of support equipment like generators and radios, which the US Naval and USAAF technical intelligence investigators found were inoperative when they looked inside many of these Japanese cave facilities in October-November 1945.

Finally, this takes us to the Operational planning style of the Japanese that retreated increasingly into fantasy as the war progressed.

The Imperial Japanese Military liked big, complicated operational plans with lots of moving parts, where everybody got a piece of the action. This worked with the consensus style of Japanese leadership in that it let the various military factions participate with the least amount of political friction. When there was a lot of time to plan and collect intelligence. There were highly trained forces that had long lead times to execute rehearsals of the plan, and most importantly an unprepared foe. This style worked. It was the “Short Victorious War” planning style.

When the Imperial Japanese faced a prepared foe with anything approaching equal capabilities, they got locked in a war of attrition. Then, when they went for the “Big Plan” decisive battles, they got their heads handed to them as the command consensus could not adapt to the changing realities fast enough and started to believe in fantasy in order to cope.

Retreat into fantasy is the best way to describe Ketsu-Go Six’s operational assumptions.

At Kyushu, the Imperial Japanese would be facing a prepared American foe with superior capabilities that was reading their communications in real time and had a template of the Imperial Japanese fighting style to apply it’s overwhelming force upon.

True, the Japanese had successfully hidden a huge number of Kamikaze in Kyushu, Shokaku, Western Honshu, Korea and Formosa.

True they had hidden the fuel for them.

What was not true, and assumed to be so, was that the Japanese would have the ability to coordinate large numbers of them, with disparate flying characteristics, over a wide area to achieve large, hourly, time-on-target pulses of 300 Kamikaze at a time off individual landing beaches. Which -is- what the plan assumed.

One of the Defense Technical Information Center (DTIC) Far Eastern Air Technical Intelligence reports I read spoke of a cave hanger with 13 ‘modern fighters’ investigated in Oct-Nov 1945. It went into detail about how well hidden the hanger was to include a description of the light rails with hand mine cars filled with vegetation constructed in front of the hanger entrance to hide it from the air.

Then the report spoke to the practical reality of this cave as a working hanger.

o There was one string of electrical lights run by generator, for which there was limited fuel. Most work was done by torch or candle light.
o The cave floor was mud save for a wooden walk way.
o There were no vehicles to move the airplanes, only draft animals and people.
o There was no room to stage operational aircraft at the back of the cave past inoperative aircraft closer to the cave mouth.

So come the day, if the facility was to get out seven aircraft, and the seventh operational plane was number 13 at the back of the cave. The entire cave had to be cleared of planes to get that plane airborne…by hand. And all the planes had to be placed back in the cave — or pulled away some distance from it and camouflaged before day light or roving American fighter-bombers would pounce and napalm and fragmentation bomb the whole area, then seed it with tamper fuzed M-83 butterfly-bombs. The modern term of art for the tamper fuzed M-83 is air delivered scatterable mine. This points out the most effective way the American military planned to beat the Japanese Kamikaze. The way to stop a human Kamikaze was to use a non-human, cheap and easily manufactured Kamikaze of its own…a land mine.

This facility would have been expected to handle further aircraft staged from elsewhere after the original planes were gone while American intelligence would be busy correlating pilot reports, radar plots and signals intelligence to steer day and night air patrols and photo intelligence flights looking for it.

A single plane crashing on take-off or landing would be a smoking beacon drawing American fighter-bombers and medium bombers for miles around to come look.

Now multiply that example 100 times and you see after the first couple of days the Kyushu suicide campaign would have been a continual and irregular stream of planes over several weeks and not a 10-day orgy of coordinated Kamikaze strike pulses Ketsu-Go 6 assumed.

Sometime during this period– between 3 and 7 days after the Japanese Kamikaze plan kicks off is my guess — the American military would start orbiting B-29 and US Navy patrol bomber jamming platforms over Kyushu to blot out Japanese radio communications to stop coordinated aerial Kamikaze strikes. However the fighter pilots complained, because it would reduce ship loss/damage rates by keeping the Kamikaze numbers low at any one time. Thus preventing the Naval/USMC/USAAF CAP from becoming overwhelmed and letting the Naval ships outside the smoke screens concentrate automatic weapons fire on a few leakers at a time rather than coordinated waves that covered Okha/Baka suicide rocket-bomb launches.

The American military would have taken a lot of losses from the close-in bombardment gun boats manning the smoke line for the transports on all the various beaches. I think something on the order of Picket Station No. 1. multiplied by at least four in the first 3-to-7 days, and the instructor pilots would get hits on the transports, closest CVEs and the old BBs no matter what we did.

In the end, however, the Japanese Ketsu-Go Six Kamikaze plan would have been a failure, like every other decisive battle plan they had after Dec. 7th 1941.

Notes and Sources:

1. Richard B. Frank’s “Downfall: The End of the Imperial Japanese Empire.” Penguin Books, New York, ©1999 ISBN: 9780141001463

2. Japanese Monograph No. 85 – Preparations for Operations in Defense of Tbe Homeland, July 1944 – July 1945, copy obtained on line at Hyperwar WW2 archive.

3. Kuehl, Daniel T., Lt Col, “The Radar Eye Blinded: The USAF and Electronic Warfare, 1945-1955” AFIT/CI, Wright-Patterson AFB OR 45433-6583, 1992, AD-A265 494 pages 31 – 41 (48 thru 58 of the 295 page Dissertation)

4. Morison, Samuel Eliot, History of United States naval operations in World War II, v. 14., Victory in the Pacific : 1945, Little, Brown, Boston, 1960. OCLC Number: 7649498

5. O’Neill, Richard, “Suicide Squads: Axis and Allied Special Attack Weapons of World War II: their Development and their Missions” St. Martin’s Press, New York ©1981.

6. Price, Alfred , The History of US Electronic Warfare. Volume 1- “The Years of Innovation-Beginnings to 1946”, The Association of Old Crows; ©January 1, 1984, ASIN: B000H48XLW

7. Project Sphinx, 14th Supplimental and Final Report — Defoliation and Burning. A Joint Report by special Projects Division, Chemical Warfare Service, Camp Detrick Maryland, and Armored Medical Research Laboritory, Fort Knox, Kentucky. 15 September 1945

8. Sloan, Bill, “THE ULTIMATE BATTLE, OKINAWA 1945 — The Last Epic Struggle of World War II,” Simon & Schuster, New York, ©2007 ISBN: 9780743292467

9. Spangler, S.B. Capt., USN, AIR TECHNICAL INTELLIGENCE REVIEW, REPORT No. F-IR-44-RE, DATE: 15 JUNE 1946, “UNDERGROUND INSTALLATIONS NEAR YOKOSUKA NAVAL AIR STATION,” AIR TECHNICAL INTELLIGENCE GROUP, ADVANCED ECHELON FEAF, HEADQUARTERS AIR MATERIEL COMMAND WRIGHT FIELD, DAYTON, OHIO

10. Streetly, Martin. Confound & Destroy. London: Macdonald and Jane’s (Publishing) Company Ltd., ©1978. ISBN 0-354-01180-4.

11. Summary TECHNICAL REPORT OF DIVISION 15, NDRC, VOLUME 1, RADIO COUNTERMEASURES, 1946, Ch 14 & 15, Office of Scientific Research and Developement, Wash DC

12. Takushiro Hattori, “Dai Toa Senso Zenshi” (The Complete History of the Great East Asia War), ToÌ„kyoÌ„ : Hara ShoÌ„bo, ©1965 ISBN: 9784562001279

13. United States Strategic Bombing Survey, “Japanese Air Power,” Military Analysis Division, July 1946, See pages 21 – 25

Internet links Consulted–

14. Smoke background

a. The photos at this link
http://www.goes-r.gov/users/comet/npoess/multispectral_topics/fire_wx/print.htm

b. The photos at this link
http://capita.wustl.edu/central-america/reports/jgr/smokeimpactjgrdoc.htm

c. And the video at this link:

Pole Creek Fire Sunset Smoke Plume Sept. 18th 2012 NFS FAIL

15. B-29 Jammer planes over Japan

http://en.wikipedia.org/wiki/330th_Bombardment_Group_(VH)#Miscellaneous_missions

“Radar jamming missions[edit]Early in the war, it was identified that although the Japanese had sophisticated radar, it was not used effectively. The job of the 330th BG Radar Countermeasures Section (RCM) was to ensure that this was the case. The dramatic fall in 330th BG losses to zero in July and August 1945 was due, no doubt, to luck, but also to the work of this section. The RCM participated in all BG missions from 4 May 1945 till 15 August 1945. They searched for Japanese radar, spot jammed individual Japanese radar units and barrage jammed target areas with specially equipped B-29s called “Porcupines”. Locating Japanese radar required specialized electronic equipment which was installed in these aircraft. The equipment included; a) a tuner-analyzer to measure the radar frequencies and strength and presumably the pulse width and pulse repetition frequency and b) four to five transmitters producing static noise, in effect drowning out Japanese radar signals.
.
They could determine whether the signals were emitted by gun laying radar or radar-directed searchlights or air-to-air radar carried by Japanese fighters. The radar countermeasures observer also noticed the coincidence of enemy signals with enemy action and the weather. What was not observed was just as important. The Japanese night fighters had no airborne radar. In a few cases, they were observed to have air-to-surface vessel (ASV) type radar. The Japanese radar operated on 75 and 200 megahertz bands but no 540-megahertz band radar was observed. The latter was the frequency of German Wurzburg radar which produced devastating results for the 8th Air Force in the European theater.
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On BG missions from 4 to 25 May 1945, radar signal analyzers were carried, but no radar jamming was permitted. Only “chaff” was used during this period. Due to the concentration of gun-laying radar around Tokyo, jamming was requested but it was denied. The 20th Air Force lost the largest number of B-29s over Tokyo on 2526 May 1945. On all subsequent missions, either spot jamming or barrage jamming of enemy radar signals was done. The “chaff” consisted of spools of foil packaged in breakout containers and each spool gave the impression on enemy radar of a B-29. B-29 gunners stated that searchlight beams sometimes followed the chaff as it floated down. A variation on the foils were packets of “straws” -straw shaped strips coated with aluminium- packed 20 to a packet and dropped by the Navigator; these gave the impression on enemy radar of 20 B-29s.
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Further reports stated that the foils falling across bare electric power and communication lines shorted them out, further complicating Japanese existence.”