The USAAF didn't like the night... or it did?????

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Staff Sergeant
Oct 19, 2021
Done a bit more digging and turned up the rest of the US 1945 reports.

Vol 1 - Japanese radar development.
In para 5.1 on IJN warning radars (p11), it notes that the Type 11 was developed between April 1941 and March 1942. "The Japanese report that the first No.11 set was installed ar Rabaul."

It goes on "Set No.12 appeared at the end of 1942; it was later adapted for shipborne use also." This latter set was named No.21. So at first sight the timescale seems a bit at odds with having prototype on Ise in May / June 1942 that I referred to in my last post. But then on p32 it notes "Type 21 - Lookout for aircraft and surface crafts - Completed June, 1942, wave length 1.5 meters .... Range: from battleship to battleship 20km, from battleship to aircraft 50km."

Vol 2 - Japanese Army radars.

Vol 3 - Japanese Navy radars.

And a paper on Japanese Airborne Radar.

All these are attached below.


  • A-short-survey-of-japanese-radar-Volume-1.pdf
    4.2 MB · Views: 22
  • A-short-survey-of-japanese-radar-Volume-2.pdf
    11.3 MB · Views: 17
  • A-short-survey-of-japanese-radar-Volume-3.pdf
    9.4 MB · Views: 23
  • Reports-of-the-U.S.-Naval-Technical-Mission-to-Japan-1945-1946.-Series-E-02-Japanese-Airborne-...pdf
    2.6 MB · Views: 17

Geoffrey Sinclair

Senior Airman
Sep 30, 2021
Do you have a source for that?

The reason I ask is that Parshall & Tully devoted Appendix 8 in "Shattered Sword" to the question of whether the Japanese had radar at Midway and followed up on the reports from a couple of Japanese officers interrogated at the end of the war that Hiryu had radar during Operation C in the IO. Those contradicted statements from other officers. Then John Prados in "Combined Fleet Decoded" made reference to Hiryu's post Op C action report that said she had some new form of detection gear that had a blind spot at the rear.
As you note, the source is John Prados, he provides the citation that presumably Parshall and Tully followed up on and discovered went missing sometime between 1995 and 2005. Parshall and Tully have done a good job and are most probably right. The following is the small holes in what they present. Mainly as Japanese can be a very difficult language to translate. Both Prados and Parshall and Tully provide excepts, not the full section of the report.

The Short Survey of Japanese Radars notes Detectors was the name for early warning sets. The quote talks about search installations which Parshall and Tully define as exclusively non electronic. Next is "many times when the first warning was the splash of bombs", I am trying to remember when the carrier force was actually bombed before April 1942.

"install AA search radar or sound equipment" radar is not a Japanese term in 1942, not British then either, as far as the RAAF was concerned its units were called radio stations until end 1942, then RDF, then Radar from 1 September 1943.

Parshall and Tully state it was many weeks of dockyard work to install one of the then Japanese naval radars and state Kaga had far too small superstructure for a set, yet looking at the diagrams Hiryu's superstructure is larger, but is it really so much that Kaga is "far too small"? They are assuming the entire system was in the superstructure and takes weeks to install. Looking at Shokaku, which did get a search radar, its superstructure was not enlarged to do so.

It leaves an unlikely possibility Hiryu had an experimental installation in the Indian Ocean, removed or not working at Midway, given the quality issues the Japanese electronics industry had. In any case detecting the incoming is one thing, the IJN did not have the controlled intercept system, relying on the ships to signal or use their guns to show where the enemy aircraft were.

On another note Australian War Memorial - AJRP

Reluctant Poster

Staff Sergeant
Dec 6, 2006
Gen LeMay reinvented night area bombing with the B-29 missions in the Pacific. (no offense to Bomber Command).
Night bombing was being practiced by the 20th AF before LeMay showed up. From Craven and Cate:

In fact LeMay put an end to night bombing:


The concept of stripping B-29s of protection for use on night raids was also developed before LeMay arrived:



Senior Airman
Aug 6, 2017
The USAAF over the ETO could have happily moved to night bombing once the blind bombing aids became available, but… their major secondary mission once the P-51 came into service was to force the Luftwaffe to come up and fight over the Reich to be defeated in detail.

33k in the air

Staff Sergeant
Jan 31, 2021
The USAAF over the ETO could have happily moved to night bombing once the blind bombing aids became available, but… their major secondary mission once the P-51 came into service was to force the Luftwaffe to come up and fight over the Reich to be defeated in detail.

Changing to nighttime bombing would have required retraining all the heavy bomber crews in the ETO — operating at night is a very different thing from operating in the daytime. It would have also required a complete retooling of the training procedures back in the United States. Both of these would have entailed a lot of effort and organizational change.

(On the plus side, it probably would have extended the bombing range of the B-24 and B-17 since the one to two hours of time spent assembling into formations could now be used to cruise toward targets, and the crew size could be reduced since the waist gunners wouldn't really be needed at night.)

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