HIRO FLYING BOATS

 

Posted By: Clint Muse <clint@musec.freeserve.co.uk>

Date: Friday, 2 February 2001, at 5:09 p.m.

In Thorpe's Japanese Naval Air Force Camouflage and Markings there is a photo of an Hiro H1H3 of the Yokusuka Ku during 1940-41 according to the caption. Is anyone aware whether any type of Hiro Boat remained in use, presumably in the training role, if at all, after Pearl Harbor? Personally, I was surprised that the photo caption the aircraft as in use at this late date.

Some references on various Hiro(sho?) flying boats

Posted By: Charles Metz <c-metz@uchicago.edu>

Date: Monday, 5 February 2001, at 4:05 p.m. In Response To: Hiro Flying Boats (Clint Muse)

FWIW, I'm appending a short list of references on the H1H and some other Hiro (Hirosho?) flying boats. According to my database, the book by Mikesh and Abe lists the H1H1, H3H1 and H4H as "Hirosho" aircraft but the H1H3 as an Aichi product, with the H2H1 listed under both manufacturers. The book by Nozawa, Abe and Hashimoto, on the other hand, lists the H1H, H2H, H3H and H4H under "Yokosuka (Hirosho)."

Baker: 'Nippon's Naval Air Force: Japanese Navy Aircraft Colours & Markings in the Pacific War ... and Before' (privately published [Australia], 1989; 126 pages; approximate value US$30 [out of print]) -- H4H markings profile (p. 31)

Mikesh and Abe: 'Japanese Aircraft 1910-1941' (Putnam Aeronautical series [unnumbered]; Naval Institute Press [USA], 1990; 293 pages; US$55) -- H1H1, H2H1, H3H1 and H4H

Nohara: 'Imperial Japanese Navy Warplane [sic]' (Illustrated Warplane History series, No. 5; Green Arrow [Japan], 1996; in Japanese; 263 pages; US$35) -- H1H, H2H, H3H and H4H

Nozawa, Abe and Hashimoto: 'Encyclopedia of Japanese Aircraft 1900-1945. Vol. 3: Kawanishi, Yokosuka (Hirosho)' (Encyclopedia of Japanese Aircraft series, No. 3; Shuppan-Kyodo Publishers [Japan], 1966; in Japanese; 179 pages; approximate value US$30 [out of print]) -- H1H, H2H, H3H and H4H

------: 'I.J.N. Flying Boats' (Model Art Special Issue series, No. 541; Model Art [Japan], 1999; in Japanese; 200 pages; US$27.95) -- H1H2, H2H1, H3H1, H3K2 and H4H1, including multiview drawings [H1H2 (p. 32), H2H1 (p. 34), H3H1 (p. 36), H4H1 (p. 39)] and marking profiles [H1H2 (p. 10), H2H1 (p. 10), H4H1 (p. 11)]

Posted By: Jim Broshot <jbroshot@socket.net>

Date: Monday, 5 February 2001, at 10:29 p.m. In Response To: Some references on various Hiro(sho?) flying boats (Charles Metz)

Wasn't "Hiro" the Hiro Naval Arsenal - No. 11 Naval Air Depot at Hiro?

Posted By: Mike Goodwin <Mike.Goodwin@iname.com>

Date: Monday, 5 February 2001, at 5:57 a.m. In Response To: Hiro Flying Boats (Clint Muse)

This message board seems to have broadened its scope from floatplanes to seaplanes! I am grateful for that, because it gives me the excuse to ask a couple of questions about Hiro flying boats.

What happened to Hiro? They seem to have stopped producing aircraft before 1941, and their inline aero-engines also seem to have been phased out of service soon after. But there is mention of an Hiro H10H flying boat. Was this built? It is consistently listed in the references, but I have found few details as to what it was actually for. It was designed to a 14-shi specification; did

Hiro still exist as an aircraft producer at that time?

Posted By: Allan Alsleben <Wildcat42@AOL.com>

Date: Monday, 5 February 2001, at 9:24 a.m. In Response To: Re: Hiro Flying Boats (Mike Goodwin)

This is a shot, and only that because I could be wrong again. Hiro must have been a small company, secondly, their aircraft were mostly underpowered. The aviation in Japan was a competitive field and had to meet stringent requirements. With the likes of Aichi, Mitsubishi and others, it was probably most difficult. Because there is little interest of aircraft that saw service in China, most of the material I have is in storage, and most probably will stay there. Hiro's aircraft were used mostly for testing and never got beyond that with the exception of the H4H series. Really, this is a new field to venture into, and would take much time to get the needed answers. When I say new, I'm referring to myself. Most of the information I have on Naval participation comes from IJA monographs, since the Sino-China affair was basically Army, and there is tons of paper that deal with it. So, the upshot is to weed out that which I deem unusable just to get to the naval stuff. I'm not really into the industry itself, but the naval operations and the aircraft that were used.

That's how I view it.........

Posted By: Mike Goodwin <Mike.Goodwin@iname.com>

Date: Monday, 5 February 2001, at 1:07 p.m. In Response To: Re: Hiro Flying Boats (Allan Alsleben)

 

Thank you for your reply. All information is welcome, however long it takes to come to light! I know what it is like to have all your references in storage, mine were for ten years until I upgraded my house a couple of years ago.

I know very little about Hiro, but I believe that the reason they faded from view might be more to do with the fact that they were an IJNAF arsenal (like Yokosuka), rather than a private industrial company. I am guessing that aircraft and aeroengine development there was wound down for some logistical reason, maybe it was all transferred to Yokosuka, or sold off to Aichi when they decided to get into aeroengine development with the Atsuta.

Whatever happened to Hiro, they seem to have faded comfortably into obscurity as aircraft developers during the end of the 1930s, but suddenly reappear in the form of the H10H project. This is mentioned by all the main references I have found, but with no details as to what it was for or what it looked like. I doubt any were built, but even that is not confirmed!

If none was built, they certainly wouldn't have seen service in China, but I will still look out for postings from you, as the whole aspect of Hiro hardware is obscure and interesting to me!

Posted By: William Blado <wblad@msn.com>

Date: Monday, 5 February 2001, at 8:45 p.m. In Response To: Re: Hiro Flying Boats (Allan Alsleben)

Hiro was not a private, commercial aircraft manufacturer, like Mitsubishi, Aichi, etc. Rather, it was the Japanese Navy's in-house factory. The closest American counterpart would be the US Naval Aircraft Factory.

Hirosho (Hiro Naval Arsenal) (Hiro Kaigun Kosho) was established on 1 Aug, 1920, under the name Aircraft Department, Hiro Branch Arsenal, Kure Naval Arsenal, as the navy's first real aircraft repair and manufacturing factory. At that time, two Naval aircraft factories were operating at Yokosuka and Sasebo, but space was very limited. To increase production capability for the Navy, the Kure Naval Arsenal expanded by establishing the Hiro Branch Arsenal three miles southwest of Kure. This new factory, known by its acronym Hirosho, was completed in October 1921, and licensed production of the F.5 Flying boats was begun. On 1 April,

1923, the Hiro Branch Arsenal was upgraded to the Hiro Naval Arsenal to which the Aircraft Department belonged.

Hiro's products were the following:

Navy F.5 Flying boat. Twin-engine biplane flying boat. All wooden construction with fabric covered wings, tail and control surfaces. Ten built by Yokosuka Arsenal, ten by Hiro Arsenal, forty by Aichi.

Experimental R-3 Flying boat. Twin-engine shoulder-wing monoplane flying boat. All-metal construction with cantilever wing and stressed skin. One built in 1927.

Navy Type 15 Flying boat (H1H1 to 3).Twin engine biplane flying boat. Wood construction with fabric-covered wing. Approximately twenty built by Hirosh and Yokosho in 1927-32 and forty-five by Aichi in 1927-34.

Navy Type 89 Flying-boat (H2H1).Twin-engine biplane flying boat. Hull of all-metal semi monocoque construction, metal structured wings and tail surfaces with fabric covering. Approximately thirteen built from 1930 by Hirosho and Kawanishi, and four from 1931 by Aichi.

Navy Type 90-1 Flying-boat (H3H1). Three-engine monoplane flying boat. All metal stressed skin construction. One built in 1931.

Navy Type 91 Flying boat (H4H1 and 2). Twin-engine monoplane flying boat with two-step hull. All metal stressed skin construction. Hiro built about thirty from 1932, Kawanishi built five in 1933, four in 1934, one in 1935, four in 1936, and three in 1937.

Navy Type 92 Carrier Attack Aircraft (B3Y1). Single-engine biplane carrier-borne attack bomber (Hiro version had a four-bladed propeller). Approximately thirty built were built by the Hiro Arsenal.

Navy Type 95 Land-Attack Aircraft (G2H1) (Navy Experimental 7-Shi Attack Aircraft). Twin-engine land-based mid-wing monoplane bomber. All metal stressed skin construction. Hirosho built six from 1933 and Mitsubishi built two from 1936.

Thus Hirosho closed its impressive history of all-metal aircraft development. Its refinement of the technology, with improvements, was passed on to Mitsubishi which led to its success with the 9-Shi Single-seat Fighter (A5M) and the 8-Shi Special Reconnaissance Aircraft (G3M), and brought Japanese aeronautical engineering capability to Western levels. The new technology spread to all other Japanese aircraft manufacturers, for both the Army and the Navy. From 1935, the navy continued to expand its aircraft repair and supply facilities and branch arsenals of Hirosho were established at Ohita and Maizuru. From 1 Oct, 1941, all aircraft departments of Naval arsenals became Naval Air Arsenals. These were

different to the former Air Arsenals which had already been renamed Naval Air Technical Arsenals. With this reorganization, Hirosho became the 11th Naval Air Arsenal.

Hirosho began augmenting production of aircraft types developed by other manufacturers in an effort to supplement the build up of the war effort.

Among these types were:

Nakajima Navy Type 97 Carrier Attack Aircraft (Kate).

Aichi Navy Type 0 Three-seat Reconnaissance Seaplane (Jake).

Aichi Navy Carrier Bomber Suisei (Judy).

Also, various Navy engines from commercial manufacturers. No other aircraft after the Type 95 Attack Aircraft (G2H) of the mid-1930s was identified as a Hirosho designed aircraft, since the function of new aircraft development was transferred to Kugisho.

The last aircraft with Hiro code H was the H10H1, 14-Shi Medium Flying boat, but this was not completed because of higher wartime priorities.

Source for most of the above:

"Japanese Aircraft 1910-1941," by Robert C. Mikesh & Shorzoe Abe.

All errors are my own.

Posted By: Clint Muse <clint@musec.freeserve.co.uk>

Date: Saturday, 3 February 2001, at 4:46 a.m. In Response To: Re: Hiro Flying Boats (Jeff McGuire)

As far as I know no code name was assigned to any of the various models of Hiro Flying Boats or at least Francillion lists none. I don't believe however, that this necessarily rules out their use in the training role in small numbers.

Posted By: Allan Alsleben Wildcat42@AOL.com

Date: Saturday, 3 February 2001, at 8:55 a.m In Response To: Re: Hiro Flying Boats (Clint Muse)

I've been attempting to put together what the IJN had in inventory Pre-war and it is far from complete, but at the time of hostilities with the Allies, Tsuchiura Ku had 3 on hand. After that, they disappeared, or at least I don't know what happened to them. They were used briefly during the China conflict on coastal patrol, but before I can I can go any further, I'll need to dig a lot deeper as I'm only halfway through aircraft usage in aircraft types used by the Japanese Navy during the China affair.

Posted By: Allan Alsleben <Wildcat42@AOL.com>

Date: Saturday, 3 February 2001, at 6:14 p.m. In Response To: Re: Hiro Flying Boats & Tsuchiura Ku (Clint Muse)

The Hiro was known as the Type 90 (1930) Model 1. She operated out of Tsingtao (Also known as Tsingtao Ku), for coastal work and observation. When Kamikawa Maru brought in her "Alfs" and "Daves" to Shanghai that eliminated this type and sent by to Sasebo. That was about early 1938. However, the Shanghai Base Force also had 3, but were discarded, date not given. These monographs that deal with China are tantalizingly vague. They give you bits and pieces then BOOM...... gone. The only Order of Battle one gets, is at the beginning of an Operation, which the Navy cooperates, or when the Navy issues a new fleet order, which usually around the middle of each November (i.e.: November 15th, 1938)and lists the Fleet Order, which would be the 2nd and 3^rd Fleet. But as far as being around in 1st or 2nd Line service, I don't think so. Another good example is the E10A1 and E11A1. Built in very limited numbers, and did serve on Light Cruisers for a very short time, before being replaced by the E7K2 model "Alf" or the Type 94 Model I which I prefer to list them as. Since your posting on the Dutch Board, I've been going over all reference material to see if other aircraft types were also in service, and I'm still looking.

Posted By: Clint Muse <clint@musec.freeserve.co.uk>

Date: Sunday, 4 February 2001, at 8:15 a.m. In Response To: Re: Hiro Flying Boats & Tsuchiura Ku (Allan Alsleben)

Thanks for the clarification. I found your remarks concerning the E10A and E11A interesting also. I had assumed that the E11A remained in service as of 07.12.41 as Francillion states that production did not end until 1940.In addition the not invariably reliable Combat Aircraft of World War Two states that both types were in service at the outset of the Pacific War. Also as you say the E10A may have been in service aboard light cruisers attached to the destroyer divisions, this at least being the case on Leo Niehorster's site. I take it that you are at least somewhat skeptical whether these aircraft were in service at that time?

 

Posted By: Allan Alsleben <Wildcat42@AOL.com>

Date: Sunday, 4 February 2001, at 9:11 a.m. In Response To: Re: Aichi Flying Boats (Clint Muse)

Indeed, These two Aichi aircraft were in inventory and used towards the end of 1942. The E10A1 was the Type 96 and the E11A1 was the Type 98, both night reconnaissance types. The E11A1 was embarked aboard Ashigara briefly in 1941 and Agano in December of 1942 as well. At various times, both were used aboard Flagships of the old light cruisers, the last one being Isuzu.

Both of these little aircraft's had a longer service career than the Hiro boats and the same is true with the Type 99 (H5Y) Yokosuka flying boat. Although not as successful as the Type 97 Kawanishi (H6K), it was used locally for Anti-Submarine work and mail plane from the Yokosuka District and Sasebo as well.

The Navy General Staff were very critical of the types they felt they needed, and for that reason, production was limited to these lesser known aircraft until it was settled on the specific one they felt would provide the most service.

Since there has little or no requests for these lesser-known aircraft, I've not put together much information on the subject, and I've only begun to put these lesser knowns into a separate file for references. And the other reason is the lack of evidence on these lesser types in regard to usage.

If you wish, allow me some time (A month or so) to put something together on these lesser types and the reason they weren't used or were used sparingly. Please be mindful that many were used only locally, but tracking them down is going to be very difficult.

Posted By: William Blado <wblad@msn.com>

Date: Saturday, 3 February 2001, at 9:31 p.m. In Response To: Re: Hiro Flying Boats & Tsuchiura Ku (Allan Alsleben)

The Type 90 Flying Boat was also designated H3H1. I believe the original question was about the H1H1 through H1H3, also known as Navy Type 15-1 and 15-2 (respectively) Flying Boat. Mikesh & Abe states that these "were the main naval flying boat until about 1938." No mention of their service after this date is given, but second-line/trainig use is possible though it's strictly conjectural.

 

Posted By: Allan Alsleben <Wildcat42@AOL.com>

Date: Sunday, 4 February 2001, at 12:22 a.m. In Response To: Re: Hiro Flying Boats & Tsuchiura Ku (William Blado)

The one I'm referring to is the H3H1 Type 90 Model 1, which is a three engine monoplane Flying boat. The others were the Type 89 twin engine Flying Boat (H2H-1) and the one after that is the Type 15 twin engine Bi-plane (H1H 1 thru 3).

I have no information on the Type 15 or the Type 89 by Hiro although they might have seen some service in China, but more likely in the training role. Neither were in inventory in December 1941 as far as I know.

Posted By: William Blado <wblad@msn.com>

Date: Sunday, 4 February 2001, at 11:16 a.m. In Response To: Re: Hiro Flying Boats & Tsuchiura Ku (Allan Alsleben)

The H3H1 Type 90 three-engine monoplane was a one-of-a-kind aircraft. It was basically a three-engine redesign of the twin-engine Hiro Experimental R-3 Flying Boat. It was considered unsatisfactory and only one was built. That one aircraft, however, received several modifications in an attempt to make it acceptable to the navy and with each modification a new dash number was assigned until the final configuration became the Type 90-1-14 Flying Boat. It became a flying test-bed before being retired from service.

The point of my post was that the original question was about the twin-engine biplane Type 15 Flying Boat, which evolved from the British F.5 Felixstowe, which in turn had evolved from the Curtiss America. One of these variants was known as the H1H3, and I thought you might have confused it with the H3H1, which is the Type 90 you described.

I hope I haven't confused things too much. These threads tend to take on a life of their own and sometimes the original question becomes lost.

 

Posted By: William Blado <wblad@msn.com>

Date: Sunday, 4 February 2001, at 3:02 p.m. In Response To: Re: Hiro Flying Boats & Tsuchiura Ku (Allan Alsleben)

The Hiro H4H1 (and 2) Navy Type 91 Flying Boat was twin-engine monoplane flying boat with two-step hull, all metal stressed skin construction with a wing having a Wagner/Rohrbach box-spar. It had an enclosed cockpit, twin-rudders, and the two engines were mounted on struts on top of the wing. Overall, the H4H had a much more modern appearance than its precedors.

Mikesh&Abe states: "During the entire Sino-Japanese Conflict, these flying-boats were very active although used in small numbers. They patrolled along the coast of China, and served as transports for mail and cargo between the home islands of Japan and across the East China Sea to the mainland. This brought about the claim that the Type 91 Flying-boats were the first Japanese flying-boats to be used in a war zone."

Hiro built about thirty from 1932, Kawanishi built five in 1933, four in 1934, one in 1935, four in 1936, and three in 1937, for an approximate total of forty-seven.

Posted By: Allan Alsleben <Wildcat42@AOL.com>

Date: Sunday, 4 February 2001, at 5:45 p.m. In Response To: Re: Hiro Flying Boats & Tsuchiura Ku (William Blado)

That's what I've got also except that when Kamikawa Maru appeared at Shanghai, they gradually disappeared from the scene. Only Amoy Base Force had 3 in 1939, but those would soon by supplanted by the Type 99 Carrier Bomber.

To know my knowledge, H1H-3 never saw service in China, at least it was never listed with any coastal operation of note.

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