Donivanp
Captain
Just stumbled on to this thread, great stuff from all.
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I'm pretty sure the radio operator had a feed of the microphones on the sonobuoys, it's not like he was stuck watching a needle move on the radio set. I believe there are a few recordings of these attacks in the National Archives, including one of the sinking of the Japanese submarine I-52 in June 1944. The recordings were taken on a strange "wire" format. I've never managed to find a digital copy of any of these recordings, which is a shame.
Update: I found the recording online, it's very interesting. You can hear I-52's propeller beat and the explosion of the Mark 24 later on, plus some of the radio traffic between the Avengers that sank her. Files are here, down at the bottom below the more general training audio files:
Sonobuoy2 | Historic Naval Ships Association
Great thread with good info. Couple of things I will belatedly add. Sono-buoys were used extensively by multi-engined aircraft during WW2. I cannot recall any issues with turning circles. The deployment patterns allowed adequate air space for faster aircraft such as Liberators and lumbering giants like Sunderlands to operate effectively. As well as aiding the aircraft to position itself effectively to launch a FIDO at a submerged submarine that it would otherwise be unable to locate there was another major benefit. Assuming no evidence of a successful sinking the SBs allowed the aircraft to try to track the submarine and assess its likely path. Another aircraft could then be called in or surface escorts could then be vectored to a meeting point with a view to a sonar search and a hunt to exhaustion/destruction. The spare SB was useful as it could be dropped along the estimated path to help confirm the escape direction.
Came across this old thread and maybe I can add a bit to the good information it already contains.
Sonobuoys
The signal level was a factor but so was the character. The main sound heard was usually described as a "swishing" from the propellers. A "beats per minute" calculation could be done to give an indication of the U-boat speed and changes in speed. The sound was created by the cavitation (air bubbles forming and collapsing around the blades) but this faded with the increase in pressure at greater depths making it hard to track a deep U-boat.
In trials in benign conditions there are reports of tannoy announcements being picked up. Various mechanical noises of differing authenticity were reported in numerous accounts but analysis of after-action reports frequently concluded it was operator imagination.
Check this site out if you want to hear real and training sonobuoy recordings. (subsequently seen someone else already posted the sound files)
Historic Naval Sound and Video
Ultimately the non-directional sonobuoys were not great successes in WW2 despite 150,000+ being made. They were more of a prototype and results were weak. Post-war developments turned it into a key tool in ASW.
Aircraft types using sonobuoys
From US and RN carriers the Avenger was by far the major user. Possibly the only one in the Atlantic for the USN?
Both the USN and Coastal Command used sonobuoys on B-24s so the issue of flying a large multi-engine patrol plane was not just a post-war challenge. There are reports of B-24s laying a pattern beneath cloud cover at 500 feet. Initial instructions to the crew basically placed the bulk of the decision-making on the first pilot. He was clearly overburdened and revised doctrine passed more of the sonobuoy aspects to the operator leaving the pilot free to concentrate of flying, a busy enough task at low level and in poor visibility. Sonobuoys were fitted in land-based aircraft such as Lancasters and Halifaxes but the B-24's dominated. Catalinas and Cansos also featured.
Incredibly the old sturdy Swordfish biplane carried sonobuoys along with radar, rockets and/or depth charges operating from RN CVEs. With the open cockpit, even with good headphones, it must have been very difficult. Just to add to the fun the operator's seat faced forwards but the receiver was placed behind so he had to twist round to alter the tuning dial. All in bracing Atlantic weather.
Weapon use
All forces used sonobuoy information as adequate tracking information to justify launching a Mark-24 (often in pairs) close to a buoy returning a good sound. With its homing ability there was thought to be sufficient chance of a hit. The USN did use sonobuoy information to drop depth charges but the RN always felt the accuracy was far too weak to make that effective. All aircraft would look to track a U-boat and home in close by surface escorts to commence an ASDIC search and, if necessary, continue a hunt to exhaustion.
Sonobuoys
The signal level was a factor but so was the character. The main sound heard was usually described as a "swishing" from the propellers. A "beats per minute" calculation could be done to give an indication of the U-boat speed and changes in speed. The sound was created by the cavitation (air bubbles forming and collapsing around the blades) but this faded with the increase in pressure at greater depths making it hard to track a deep U-boat.
In trials in benign conditions there are reports of tannoy announcements being picked up. Various mechanical noises of differing authenticity were reported in numerous accounts but analysis of after-action reports frequently concluded it was operator imagination.
Check this site out if you want to hear real and training sonobuoy recordings. (subsequently seen someone else already posted the sound files)
Historic Naval Sound and Video
Ultimately the non-directional sonobuoys were not great successes in WW2 despite 150,000+ being made. They were more of a prototype and results were weak. Post-war developments turned it into a key tool in ASW.
Aircraft types using sonobuoys
From US and RN carriers the Avenger was by far the major user. Possibly the only one in the Atlantic for the USN?
Both the USN and Coastal Command used sonobuoys on B-24s so the issue of flying a large multi-engine patrol plane was not just a post-war challenge. There are reports of B-24s laying a pattern beneath cloud cover at 500 feet. Initial instructions to the crew basically placed the bulk of the decision-making on the first pilot. He was clearly overburdened and revised doctrine passed more of the sonobuoy aspects to the operator leaving the pilot free to concentrate of flying, a busy enough task at low level and in poor visibility. Sonobuoys were fitted in land-based aircraft such as Lancasters and Halifaxes but the B-24's dominated. Catalinas and Cansos also featured.
Incredibly the old sturdy Swordfish biplane carried sonobuoys along with radar, rockets and/or depth charges operating from RN CVEs. With the open cockpit, even with good headphones, it must have been very difficult. Just to add to the fun the operator's seat faced forwards but the receiver was placed behind so he had to twist round to alter the tuning dial. All in bracing Atlantic weather.
Weapon use
All forces used sonobuoy information as adequate tracking information to justify launching a Mark-24 (often in pairs) close to a buoy returning a good sound. With its homing ability there was thought to be sufficient chance of a hit. The USN did use sonobuoy information to drop depth charges but the RN always felt the accuracy was far too weak to make that effective. All aircraft would look to track a U-boat and home in close by surface escorts to commence an ASDIC search and, if necessary, continue a hunt to exhaustion.
pararaftanr2
Airman
- 82
- Nov 20, 2013
The camera in question is the US Navy Aircraft Torpedo Camera Type 1. It was a panoramic still camera, and could be mounted outboard under the port wing on the Avenger. It's purpose was to provide images of an aircraft's approach to the launching of it's torpedo. Images of the kit, the camera and an example in service below:
cammerjeff
Staff Sergeant
Great Find, thanks for posting it!
Thumpalumpacus
Captain
What a great thread.
Given the loadout the Avengers could carry, I'd think a better unofficial nickname for the plane than "Turkey" would be "Mule". Those things were loaded down!
Given the loadout the Avengers could carry, I'd think a better unofficial nickname for the plane than "Turkey" would be "Mule". Those things were loaded down!
- Thread starter
- #29
Conslaw
Senior Airman
Yes, and yet, the generation that was set to follow the TBF/TBM sent the loadings to ludicrous mode. The Douglas Skyraider could carry an 8,000 lb load, and the Martin Mauler over 10,000. (Note, I didn't say anything about distance or from a carrier.)
Thumpalumpacus
Captain
Oh, absolutely. But in 1943-44? A Fido, a couple of depth-charges, six or eight sonos, and 8 rockets is as much asskick as they could put on one single-engine airframe ... and then launch from a CVE?
- Thread starter
- #31
Conslaw
Senior Airman
The -3 got more flexibility. Radar was standard. The wings were plumbed for droptanks and rocket stubs. This means the -3 could substitute droptanks for the removable long range tank that was sometimes carried in the fuselage. The extra horsepower helped make up for the extra drag of external stores.
