Japanese Airborne Radars

[Brady]

I am seeking some clarity on this subject, Below are two sources, Combined Fleet, and A book I have on the Subject:

Japanese Radar and Related Weapons of World War II, by Yasuzo Nakagawa

IJN Set's:

1) When was the first use of the H-6

2) What was the type commonly seen on Kates and Jill's ?

Presumably the N-6 or the FM-3 ?

Photographic evidence suggests that these aircraft had them earlier than the reference indicates, or perhaps it was an H-6 ?

IJA sets:

3) Any idea on when these sets were introduced, and what Planes used them ? Referring to the Taki-1 set's shown below.







Thanks

[fontessa]

Hello Brady,

FM-3.jpg

Above “single engine 3 seat aircraft” seems to be “twin engine 3 seat aircraft”.
FM-3 was to be used for Land Based Patrol Airclaft 東海 Tokai = East Sea LORNA. However, it seems that the H-6 was used for LORNA in time.
Upper figure shows the illustration of 901st Naval Air Group LORNA stationed at Shanghai in 1945. She wears one submarine kill mark, but I couldn’t confirm it in the related record. We can see side antenna near the partially missing white ring (Randolt Ring) for checking the distance between planes during formation flight. Lower figure shows Yagi-antenna on the right wing of maybe another LORNA. What should be noted in LORNA is that she had MAD 三式一号探知機 Type3 Mark1 Detector for the first time in the world.

東海1.jpg

東海2.jpg

fontessa

[Brady]

Below you can some images from a couple different books:

The first Shows us the Marking that radar equipped planes carried, although it would seam that not all planes equipped carried the marking.

From Japanese Naval Aircraft Camouflage and Markings, Thorpe



The Second Image Shows a pair of Jake's, one Clearly Sporting the Marking for radar, the Second Appears to have radar.

From Famous Airplanes of the World series # 47



The Question is, When at what type are we looking at ?

It would seam it's pretty clear that in 44/45 we can see several types of Japanese Navy Planes Patrol and Attack equipped with surface search radar and even Night Fighters equipped with air intercept radar.

But in late 42 and 43 it's a bit more vague, various References state that Large Flying Boats, Emily's had Radar I know at times, but the Mavis ?

And when did the Emily's first get the Radar set's presumably the H-6 ?

Radar Equipped Betty's and Irving's:



Francis:



Jill:




So Far I have:

Jake's

Betty's

Nell's

Emily's

Lorna's

Jill's

Kate's

Frances's

Equipped with Surface Search Radars at one point or another, but no real entry dates for the set's on those types, and While Not all were equipped with sets certainly this is understood, it would be helpful to have some idea as to when the IOC occurred


As far as the IJA set's are concerned I have really no clues for Surface Search set's apart from perhaps the Ki 67

[fontessa]

Hello Brady,

When was the first use of the H-6

But in late 42 and 43 it's a bit more vague, various References state that Large Flying Boats, Emily's had Radar I know at times, but the Mavis ?
And when did the Emily's first get the Radar set's presumably the H-6 ?

The H-6 prototype was installed on the three Mavis of 851st Naval Air Group sent to Solomon at the end of December 1942. This was the first actual battle use. Since then, Maivis other than 851st Naval Air Group have also been equipped with H-6. Unfortunately I couldn’t find the photo of Mavis equipped with H-6. The first picture is the Emy equipped wieh H-6. She was high-ranking officers transporter 敷島 Shikishima modified from prototype 4. I think half-wavelength dipole transmitting and receiving antennas on both sides. The front antenna on the nose looks like a two-element common transmission / reception antenna consisting of a radiator and a reflector. However, it seems that the front antenna was not put into actual battle. At least I haven't seen their photo. I guess that this might have been attached to the prototype for experimentation. If you look closely at the photo, you can see that the port side element of the radiator was missing. If it was actually used, it wouldn't have been left unattended. The second picture shows the Emily at Negishi Air Base after the end of the war. The nose antenna was not clear. It is a part of color firm taken by US Navy.
https://www.youtube.com/watch?v=O5bWhEpfMlc&t=23s
Four Emily were gathered there, and one of them, Takuma Naval Air Group T-31 was shipped to US for the investigation by US Navy. The third picture is T-31 before shipping to the US. It's sad to have the US Military Mark, but it's easy to see that she doesn't have a nose antenna. She was returned to Japan in 1979 and was stored at 船の科学館 Museum of Maritime Science. Her repairs including repainting were based on the Museum’s examination. Then she was moved to 海上自衛隊鹿屋基地歴博物館 Maritime Self Defense Force Kanoya Air Base Historical Museum in 2004. The fourth picture is T-31 there. Side antennas were omitted.

2式大艇1.jpg

2式大艇2.jpg

2式大艇3.jpg

2式大艇4.jpg

.
fontessa

[Brady]

Thanks!

So Mavis by the End of 42, and Emily’s Presumably at the same time?

[fontessa]

Hello Brady,

So Mavis by the End of 42, and Emily’s Presumably at the same time?

I don't have any confirmation. .. ..
The H-6 was rushed to Maivis because they suffered enormous losses. Therefore, I think that the equipment for Maivis, which was inferior in performance including bulletproof performance, was prioritized. I don't know when the installation on Emily started.

fontessa

[fontessa]

Hello Brady,

You may not be interested in FD-2 because it was not a Searchm Rader. It was an Approach to Enemy Rader. The research of it began at the end of 1943, and the prototype was completed in May 1944. Although practical experiments were conducted, FD-2 was not adopted due to its poor performance, and the research was finally abandoned. The below picture shows the nose of Irving. There were four six-element Yagi antennas. Two red transmitting antennas for isosensitivity method and two orange receiving antennas also for isosensitivity method. In principle, it was the same as the Luftwaffe Liechtenstein Radar. The difference was that they have been successfully put into practical use.

月光 (Yokosuka).jpg

月光 (FD-2).jpg

LiechtensteinRadar.jpg

fontessa

[Brady]

Your Timing is Good Because I have been looking at the J1N this past week, So what your saying is that No Gekko's J1N1-S were equipped with radar, the FD-2 set's that is and used Operationally, or that some were but the set's performance was not very good ?

There are many Photo's, it seams, of J1N1-S aircraft that have been built to mount the FD-2 but had not actually been fitted with them.

What was the Date of the First Set's to equip these Planes ?

...........................

While were Talking about the J1N1:

This Suggests that the J1N1-R and -S could carry two 300 l Drop tanks, But Not the J1N1-C ?

This also Suggests that they all could carry a Couple of Bombs, Presumably on the wings? Is this Also true of the J1N1-C ?





The Green Indicates what Appears to be a Bomb Sight ?




Above Images from FAoW # 57

[Brady]

P1Y1, When were they equipped with radar, I see a lot of images of them with Radar.

[fontessa]

Hello Brady,

Your Timing is Good Because I have been looking at the J1N this past week, So what your saying is that No Gekko's J1N1-S were equipped with radar, the FD-2 set's that is and used Operationally, or that some were but the set's performance was not very good ?

Japanese Wiki says there was no battle result. But I found one example.
On 25 May 1945, 502 B-29s raid Tokyo. 302nd Naval Air Group stationed Atsugi intersepted them by 26 intersepters including 8 Gekkos and shot down 16 B-29s. On the same day Yokosuka Naval Air Group dispatched 2 Gekkos. One of them, J1N1-Sa ヨ-101 Yo-101 equipped with FD-2 shot down 5 B-25s. Due to this achievement, her crew ENS 黒島四朗 Kurosima Shiro (Observer / Captain) and Senior Flight Sergeant 倉本十三 Kuramoto Juzo (Pilot) were promoted specially to LTJD and Master Flight Sergeant respectively. The 1st picture shows J1N1-Sa ヨ-101 Yo-101 with the crew and mechanics.

What was the Date of the First Set's to equip these Planes ?

I found very interesting phot. The 2nd picture shows J1N1-Sa wih H-6 radar. She was captured in Tinian in July 1944. She seems to have been belonged to 321st Naval Air Group, the 1st Naval Night Fighter Grou. According to 321st Naval Air Group War Diary five 2式陸偵(夜戦) Type2 Land-based Reconnaissance Plane (Night Fighter) J1N1-S. I guess they were equipped with H-6 radar and it was the first usage of the radar for J1N1-S. The 3rd picuture shows her. Note she had one Yagi-antena. As mentioned at Emily, the H-6 prototype on board flying boats had antennas for transmission and reception to prevent interference between the transmission and reception signals. The mass-produced H-6 was able to share the transmitting and receiving antennas. (This was technically more difficult) As you can see from the fact that they were carrying H-6 radar, they were used for maritime patrols, even though they was called as Nnight Fighter.

This Suggests that the J1N1-R and -S could carry two 300 l Drop tanks, But Not the J1N1-C ?

Do you mean Prototyep (J1N1) with J1N1-C ? If so, the answer is No. The data seat you attached says only J1N1-R after No.27 could carry 300l drop tanks.

This also Suggests that they all could carry a Couple of Bombs, Presumably on the wings? Is this Also true of the J1N1-C ?

The data seat you attached says J1N1-C could carry tow 60kg bombs. I think they were suspended on the wings.


About 13試双発陸上戦闘機 Type13 Trial Land Based Twin-engine Fighter (J1N1)
Around from 1936 some Air Forces intended to develop twin-engine fighters for escorting long-range bombing operations.
Luftwaffe: Bf-110 (2 Crew)
Japanese Navy: J1N1 (2 Crew)
Japanese Army: Ki-45 (2 Crew)
French Air Force: Potez 631 (3 Crew)
Royal Air Force: Westland Whirlwind (1 Crew)
US Army: Bell YFM Airacud (5 Crew)
The Lockheed XP-38 (1 Crew) was intended as a high-altitude interceptor equipped with twin engines with exhaust turbine supercharger.
These were expected to have the same air combat performance as agile single-engine interceptors, but of course that was not possible and they were not put into practical use in the end. It is well known that the first three models found their way into night interceptor fighters.
The following was required for J1N1.
--Maximum speed: 280 knots (about 519km / h)
--Climbing power: 6 minutes to 6,000m
--Cruising power: Regular 1,300 nautical miles (about 2,408 km), overload 2,000 nautical miles (about 3,704 km)
--Armed: Fixed nose 20mm x 1, 7.7mm x 2, rear remote-controlled power swivel 7.7mm x 4
--Other: Must have the same turning performance as Type12 Trial Carrier Based Fighter (later Zeek). Have the same navigation and communication capabilities as land-based attack aircraft.
The figure below is a conceptual diagram of CINI. The first prototype flew on March 26, 1941, but of course it could not achieve the same turning performance as A6M1 (Later ) Zeek, and the A6M1 showed excellent performances as escorting long-range bombing operations, so the J1N1 was rejected.
However, its performance as a reconnaissance aircraft was superior to that of the C5M, so J1N1 was decided to be adopted as a Type 2 Land-based Rreconnaissance Aircraft (J1N1-C) on 6 July 1942. J1N1 survived for the time being and took on reconnaissance missions, but as the U.S. military's strength increased, damage continued to occur in forced reconnaissance, and reconnaissance missions came to be entrusted to the faster D4Y1-C or Type100 Heaquarters Reconnaissance Aircraft Ki-46 borrowed from Army. It was the use as a Night Interceptor Fighter that saved the J1N1-C that was about to be dismissed. The IJN Air Force was suffering from B-17s air raid on Rabaul, which was difficult to intercept with Zeek. 251st Air Group Commanding Officer CDR Kozono Yasuna 小園安名 proposed to Navy Air Depo in November 1942 to add to add a 20mm connon firing upwards and downwards at a 30-degree angle to J1N1-C, but initially the person in charge of Navy Air Depo laughed, "It's not worth experimenting". As a result of several subsequent negotiations, the remaining J1N1-C were modified in May 1943. These modified J1N1-C KAI shot down 9 B-17s until July. Again J1N1 survived by being adopted as Type “C” Fightert 月光 Moonlight (J1N1-R) on 23 August - Type “C” Fighter meand Night Fighter.
The 4th picture shows J1N1. The 5th picture shows J1N1 - R and J1N1 - S. Not the differences in cockpit shapes.

月光_ヨ-101.jpg

月光_テニアン.jpg

月光_H6レーダ.jpg

13試双発陸上戦闘機.jpg

月光 (夜戦).jpg

fontessa

[Brady]

Again that’s extremely helpful and fascinating, it’s interesting that they would equip them with the H6 radar and use them for surface search missions, The reference above does note that it could be used for air search though, so perhaps it was a set capable of searching for planes and ships?


so none of the J1N1, Built before the 27th built R, could use wingmounted drop tanks?



“Type100 Heaquarters Reconnaissance Aircraft Ki-46 borrowed from Army.”

This is also very intriguing, do you mean the IJN used them operationally, with their own crews, that some of the units were at least partially equipped with them, or that they merely used the information gleaned from IJA sorties ?

if they did employ them operationally, the IJN, Did they have a different nomenclature for them, or like the KI 67 did they merrily use the army nomenclature?

[fontessa]

Hello Brady,

About Ki-45 Kai 2式複座戦闘機 Type2 Two - seat Fighter
Prototype Ki-45 rolled out in December 1939. After a review at the Institute of Aeronautical Technology, she was taken to the Akeno Army Airplane School (fighter pilot training, which also conducted tactical research). Her evaluation was harsh because she had so many glitches that she was cursed, saying, "Don't bring this trash again!" Her maker Kawasaki Airplane replaced her design chief at with Doi Takeo. He had just finished working on the K-48 and was a very talented engineer who was later involved in the development of the Ki-61 Tony, Ki-100 Tony and Ki-102 Randy. He adopted a policy of scaling down the Ki-48 regardless of the Ki-45. This was successful and the Ki-45 Kai was successful and was adopted as 2式複座戦闘機 Type2 Two - seat Fighter 屠龍 (Dragon Slayer) in February 1942.
There were many armed variations. As for raders, 10 modified Ki-45 Kai with Taki-4 (Taki-2?) radaer in transparent nose housing were producted before August 1944, but it seems that the performance was insufficient and this modification was not formalized. The number of Ki-45 Kai production was 1,693 The 1st picture shows Ki-45. The 2 picture shows Ki-45 Kai with Taki-4 (Taki-2?) radar.

Ki-45.jpg

Ki-45 Kai.jpg

Potez 631
The pote631 was the forerunner of this type of twin-engine fighter, first flying in February 1937 and deployed from 1939. In terms of performance, it could not compete with single-engine fighters and was removed from daytime combat missions in 1940. Total 215 aircraft was produced.
The 3rd picture is Potez 631.

Potez 631.jpg

Westland Whirlwind
In February 1937, a traial was ordered based on specification 37/35. The first prototype flew in October 1938 and was deployed in June 1940. However, due to frequent problems with the Periglin engines, production was discontinued with 112 aircraft.
The 4th picture is Westland Whirlwind.

Westland Whirlwind.jpg

Bell YFM Airacud
Do you know it? It was Bell's first design in response to the 1936 traial order. It was a strange idea to set up a turret in front of the propulsion engine nacelle and shoot spree 37mm canons. As seen on P-39 Airacobra, Bell seems to have been fascinated to the 37mm canon. As for Airacobra, the engine was moved behind the cockpit to set the 37mm cannon on the nose, and the propeller was driven by the extension shaft. United States has made this with ease. It was a technological capability that Japan could not match. But Airacud was not adopted because it was naturally sluggish and couldn't even do somersault.
The 5th picture is Bell YFM Airacud.

BellAiracuda.jpg

fontessa

[fontessa]

Hello Brady,

The reference above does note that it could be used for air search though, so perhaps it was a set capable of searching for planes and ships?

Because of Insufficient resolution, H-6 couldn’t find airplane. FD-2 was developed to search airplane.

so none of the J1N1, Built before the 27th built R, could use wingmounted drop tanks?

The J1N1, built before the 27 couldn’t couldn’t hang on drop tanks.

“Type100 Heaquarters Reconnaissance Aircraft Ki-46 borrowed from Army.”

This is also very intriguing, do you mean the IJN used them operationally, with their own crews, that some of the units were at least partially equipped with them, or that they merely used the information gleaned from IJA sorties ?

if they did employ them operationally, the IJN, Did they have a different nomenclature for them, or like the KI 67 did they merrily use the army nomenclature?

IJN procured Ki-46s through a regular route with the consent of the IJA. IJN did not seem to give them the original Navy name. The piture below shows Ki-46 in Naval Air Unit. 151st Naval Air Group used both D4Y1-C and Ki-46.

100式司令部偵察機_海軍部隊.jpg

fontessa

[Brady]

It's always Fun to learn something New, Thanks !

Did the IJN use all the different model of the Ki-46 or just the two shown above, any idea s to the quantity's procured ?

[fontessa]

Hello Brady,

The Green Indicates what Appears to be a Bomb Sight ?

It was 97式偏流測定器 Type97 Drift Measuring Instrument.
I guess only J1Ni-R was equipped with it, but J1N1-S was not.
D4Y1-C was also equipped with it.

97式偏流測定器.jpg

fontessa