ON 29 MAY 1942

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Warrant Officer Susumu Ito, the pilot of a Japanese Yokosuka E14Y1, Navy Type 0 "Glen" float plane was catapulted off the forward deck of Japanese submarine I-21 located about 35 nautical miles north east of Sydney, at 3:45am on Friday morning, 29 May 1942. Ito and his navigator/gunner, Enlisted Man Iwasaki, were tasked with carrying out a reconnaissance flight over Sydney Harbour to gain intelligence for a midget Submarine attack on Sydney Harbour scheduled for the evening of 31 May 1942. Submarine I-21 was one of five Japanese submarines positioned off Sydney ready to launch 3 midget submarines the following night.


glen03.jpg (15916 bytes)

Yokosuka E14Y1, Navy Type 0 "Glen"


Twenty Five minutes after being launched, they had reached South Head at about 500 metres. Ito dropped down to 300 metres to allow Iwasaki to sketch the submarine boom net and locate its opening. Ito flew along the Eastern Channel, still at 300 metres, towards Garden Island Naval Base.

The "Glen" floatplane, burning navigation lights, circled twice over Sydney Harbour. They spotted USS Chicago, four destroyers and a hospital ship. He dropped right down to 30 metres and flew between USS Chicago and the Sydney Harbour Bridge. Ito stated that he was caught three times by searchlights. Each time this happened he climbed to 700 metres into the low cloud cover.

The War Diary for USS SELFRIDGE of 29 May 1942 shows the following ships moored nearby in Sydney Harbour:-

USS SELFRIDGE - moored starboard side to USS DOBBIN at buoy No. 5, Man-of-War Anchorage
USS BLACK HAWK - War Diary of USS BLACK HAWK actually shows her leaving Sydney on 29 May with USS PARROT
USS PARROT - War Diary for USS BLACK HAWK actually shows USS PARROT leaving Sydney on 29 May
Netherlands Cruiser TROMP

Ito dropped down to a lower altitude again at about 4:20 a.m. to allow Iwasaki to sketch the position of HMAS Canberra anchored adjacent to Farm Cove. He flew down low over HMAS Canberra and then flew low towards Sydney Harbour Bridge. He was so low he could look up at the bridge. He pulled up and flew over the top of the bridge and flew westwards for about 3 kilometres towards Cockatoo Island where he could see the welding flashes from men working in the dock area.

Ito looked towards the south and spotted the airfield runway lights at Mascot Airfield about 8 kilometres south of Sydney Harbour. Ito turned around and flew back towards the Sydney Harbour Bridge flying over Kirribilli, Cremorne Point and Taronga Park Zoo. He flew back up into the low cloud cover to avoid the search lights.

It was initially thought by those who spotted the Japanese floatplane, that it was an American aircraft, but eventually some Airacobras from the 41st Pursuit Squadron, of the 35th Fighter (Pursuit) Group, USAAF were sent up to intercept the floatplane. Another unidentified plane was also reported in the Newcastle area. Neither could be found.


Photo:- US Navy Photo #:80-G-5885

The Japanese "Glen" Float Plane was misidentified as a
Curtiss SOC-1 Seagull Scout Observation floatplane


At about 5am he flew over North Head out to sea to rendezvous with submarine I-21. Due to the cloud cover blocking out the moon, he was unable to find the submarine. He decided to fly back towards Sydney to allow him to get his bearings to make another approach towards the position of I-21. He flew north east from the Macquarie lighthouse.

Ito had an arrangement with the Commanding Officer of I-21, Commander Matsumura, that if he became lost, he would send a very brief radio message and the submarine would turn on a light for a short period. Ito sent his short radio message and the submarine flashed a small lamp 2 or 3 times. Ito, despite being 10 miles away, managed to see the small lamp being flashed from the deck of I-21.

The seas had been very bad when the float plane was launched and Ito warned Commander Matsumura, that he would probably crash when he landed after his reconnaissance flight over Sydney. He requested that a rescue crew be on standby in case the floatplane crashed on landing.

Ito and Iwasaki unbuckled their parachutes, and Ito pushed back the canopy so they could make a quick exit if the inevitable was to occur. Ito lowered his aircraft into the darkness not being able to judge the height of the waves. He throttled back to almost a stalling speed, and he then let the aircraft fall onto the rough seas. It hit a wave which collapsed the struts wrecking the integrity of the float assembly.

The "Glen" nosed into a second wave and was flipped over on its back. Ito managed to scramble from the cockpit and started to grope around looking for Iwasaki. He could not find him and then he lost his hold on the aircraft which started to drift away from him.

Submarine I-21 came in close and a crew member threw a line to Ito who grabbed it and was soon pulled onto the deck of the submarine. Ito told them that he had lost Iwasaki, but they told him that they had already rescued him.

Submarine I-21 then attempted to sink Ito's overturned floatplane. They started to shoot at the floats with a small gun on the submarine and a pistol. They then approached the aircraft and tried to break the floats with a large hammer. They eventually opened up a sizeable hole in one of the two floats. By this time it was getting light and the sun was starting to rise. They could see Allied ships approaching Sydney Harbour.

After some more frantic work with the hammer, the floatplane finally sank in about 200 metres of water about 35 miles north east of Sydney. Ito did not go below until he saw his aircraft finally sink. Submarine I-21 then submerged as soon as possible.

Ito apologised for losing his aircraft and then reported on what they had seen over Sydney. The following is from a translated copy of an original Japanese document:-

(a) One U.S. Battleship at 400 east of Garden Island. One large Transport Ship (U.S.) at 900 North of Garden Island. Several destroyers on the west side of the same island. (Those have wharfing lights on). Cockatoo Island has no enemy vessels around it. However at the dockyard, there are 2 light cruisers and a destroyer.

(b) No detection made on the defensive of the enemy, but seeing the frequent passage of the enemy vessels (in nighttime too) it is presumed that there must be an opening for sea passage. No recognition of enemy patrol boats.

(c) There is no control on land / lighting inside the harbour, the lights at Barrenjoey light-house are ON.

(d) There is a frequent passage of merchant ships in and out of the harbour and those ships have their lights ON. However, there may be false wharfing lights ON.


Ito's Aircraft refound in 1994

In 1994, Philip Dulhunty and his team rediscovered the submerged remains of Ito Susumu's "Glen" floatplane near Norah Head. It only took them two days to locate it!

Philip was a gunner at George's Head during WWII and spotted Ito's aircraft flying over Sydney that night. In 1997 Philip Dulhunty visited Ito Susumu in Japan. Philip was also the owner and pilot of his own seaplane, so he had something in common with Ito. Prior to his visit, Philip had arranged for Ito to become an honorary member of the Seaplane Pilot's Association of Australia.

Philip plotted the direction and distance advised by Ito giving a location near Norah Head. The other input to their search was information supplied by amateur spear-fisherman George Davis, who had found the submerged aircraft in the 1950s. George had last dived the location in the early 1970s. After seeing an article written by Philip about Ito, George contacted Philip and told him his story. George had sent some parts to the RAAF Museum at Point Cook but they were unable to identify it.

Philip and a team of divers located the wreckage which consisted mainly of the engine and a few bits of metal. One of the cylinders had come adrift from the rest of the engine and this was brought to the surface. Philip contacted the Australian War Memorial and informed them of the find and sought assistance with the preservation and restoration of the aircraft's remains. The AWM advised they were not interested in taking on the job due to lack of funds!

Similarly the Heritage Branch of the NSW Government were less than enthusiastic, and advised of the high costs involved and their doubt suggesting that it may have been one of the several Wirraways out of Williamtown which crashed in the area. George Davis was very familiar with Wirraways and said that the wreckage at Norah Head was nothing like a Wirraway.

The team of divers raised the engine and other parts to the surface to inspect it and then attached buoys and towed it to a new location and lowered it to a less turbulent location on the seabed.



NOTE:- I had originally shown this reconnaissance flight over Sydney happening on the evening of 30 May 1942, as documented in the book "Hitting Home - The Japanese Attack on Sydney 1942" by David Jenkins.

Information from a number of other sources has since convinced me that this event happened on the evening of 29 May 1942 (See information below).

A few ships in Sydney Harbour noted an "Air Raid Warning Yellow" in their War Diaries for the 29 May 1942. For example HMAS BUNGAREE has the following entry:-

29 May     0740K    Air Raid Warning Yellow
                0825K    All Clear

K Time is UTC + 10 hours which is Eastern Australian Standard Time.

The War Diary for No. 2 Volunteer Air Observer Corps Centre Sydney makes no mention on either 29 1942 of any unidentified aircraft sightings. And the War Diary for No 1 Fighter Sector Headquarters (Sydney) makes no mention of an Air Raid Alert.

The book "World War II Sea War, Vol 6: The Allies Halt the Axis Advance" shows that the Recce flight over Sydney happened on the morning of 29 May 1942.

In his book "Never a Dull Moment", ex WWII Heavy Anti-aircraft Gunner Philip Dulhunty, describes his visit to meet Ito Susumu in March 1993. He quotes Ito's description in part as follows:-

"At precisely 2:45am on the morning of the 29 May, when the mother submarine was at a suitable angle, my plane was catapulted out to begin the flight, at a height of 500 metres to the Port of Sydney."

The following is an entry from the Operations Record Book for A.C.H. Sydney, Eastern Area Headquarters RAAF:-

29 May 1942

"UNIDENTIFIED AIRCRAFT. At 0600K, the Controller, FIGHTER SECTOR HEADQUARTERS, reported by telephone that two unidentified single engine float planes were over Sydney 0440K. Aircraft flew north towards Rathmines and returned, circling out to sea between Rathmines and Sydney. A force of 41st Pursuit Squadron aircraft was ordered out to intercept by No. 1 F.S. HQ."

AM 29 May 1942 - Yellow warning issued by FIGHTER SECTOR HEADQUARTERS at 0507K/29. All clear received at 0825K/29. One aircraft similar type to Curtiss float plane sighted over Sydney Harbour by personnel of "U.S.S. CHICAGO" at approximately 0420K/29 but not reported or challenged. At 0430K/29 WOOLLAHRA A/A reported unidentified aircraft over Sydney corresponding to report and identified as "Curtiss F.P." At 0245K/29 RATHMINES A/A reported one plane flying south. At 0243K/29 two aircraft reported by observers in RATHMINES flying north. At 0430K/29 two unidentified aircraft still flying around at sea, but last plot showed them going inland. Aircraft still unidentified.

The 41st Pursuit Squadron was attached to the 35th Fighter (Pursuit) Group, USAAF.

The RAAF Air Power Development Centre web page also indicates this happened on 29 May 1942.

A translated copy of an original Japanese document was provided to me by Duncan John Perryman, Director of Strategic & Historical Studies at the Sea Power Centre - Australia. It shows the following entry:-

"I-21 after arriving in the bad weather from Auckland on 28th in teh evening at off Sydney Heads, despatched he aircraft for pre-attack reconnaissance on 29th at 0247 hrs."



"Hitting Home - The Japanese Attack on Sydney 1942"
by David Jenkins

AWM78 Reports of Proceedings, HMA Ships and Establishments, HMAS BUNGAREE

"World War II Sea War, Vol 6: The Allies Halt the Axis Advance"

"Never a Dull Moment"
by Philip Dulhunty



I'd like to thank John Perryman for his assistance with this web page.


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This page first produced 26 March 2017

This page last updated 14 January 2020