Did German bombers make a different sound and why?

[GrauGeist]

I have this, but I don't know how to post it here.

That is an awesome collection of engine recordings!

Not sure how large of an audio file it would be, but if it were converted to MP3, it can be uploaded by way of the Advanced Reply, under "Manage Attachments".

Audio files acceptable to upload are: MP3, WAV and WMA

 

[Capt. Vick]

I'll try when I get a chance.

 

[N4521U]

Was it the Ital;ian bombers that went "whooooooshkah"?
or was it the VVS?

 

[KiwiBiggles]

I believe Japanese bombers tended to go 'wooof'.

 

[Capt. Vick]

Sorry guys. I can't figure out how to do it.

 

[oops]

I often hear that German bombers made a different sound to British aircraft during the blitz, my mum and others tell me the German planes made a woo woo woo sound while the British aircraft made more of a roar. Going by the amount of accounts and witnesses there seems little doubt that German aircraft actually did make this sound and I have heard a number of explanations of why this happened which include the following.

1) That the sound was caused by a large number of aircraft in formation that had engines running at different rpm's.
2) That twin engine German aircraft had each engine set at a different rpm to either frighten civilians, confuse radar or because the engines were tired and could not be synchronised correctly.
3) That the pilots themselves de-synchronised the engines while in flight to confuse the anti aircraft defences.

I would have thought that de-synchronised engines would have been a bad thing for both crew and aircraft.

My mom lived in Hull during the war. She was recently telling me that she knew when the German bombers were overhead - she heard a very low pulsing sound - she often mentions the sound they made - she is now 92 yrs.

 

[Lefa]

View: https://www.youtube.com/watch?v=aeva7zWZJAg

 

[Old Wizard]

 

[XBe02Drvr]

At a chief flight instructor seminar in the early 80s I was told of an old ex-LW pilot who was working as an instuctor/charter pilot at a large FBO in New England. He reportedly said they used to make the many small corrections to hold formation using the prop governor, as the throttle friction lock was a clunky PITA and very tiring to use, and had to be cinched down after every tiny thrust adjustment. Apparently throttle response was non-linear and the throttles subject to vibration creep if the friction lock wasn't TIGHT. Can you imagine what a formation all jockeying their prop speeds would sound like? Like wow-wow, man!
Cheers,
Wes

 

[rinkol]

At a chief flight instructor seminar in the early 80s I was told of an old ex-LW pilot who was working as an instuctor/charter pilot at a large FBO in New England. He reportedly said they used to make the many small corrections to hold formation using the prop governor, as the throttle friction lock was a clunky PITA and very tiring to use, and had to be cinched down after every tiny thrust adjustment. Apparently throttle response was non-linear and the throttles subject to vibration creep if the friction lock wasn't TIGHT. Can you imagine what a formation all jockeying their prop speeds would sound like? Like wow-wow, man!
Cheers,
Wes

This could be correct. I do recall seeing something in one of Green's books that mentioned the He111s having a distinctive sound because of the difficulty in synchronizing the engines. The other possibility would be that the German engine control systems (fuel injection and, in the case of planes with DB engines, the supercharger speed control, included feedback loops whose operation might not have been completely stable.

 

[XBe02Drvr]

This could be correct. I do recall seeing something in one of Green's books that mentioned the He111s having a distinctive sound because of the difficulty in synchronizing the engines. The other possibility would be that the German engine control systems (fuel injection and, in the case of planes with DB engines, the supercharger speed control, included feedback loops whose operation might not have been completely stable.

In a large formation nothing is stable except the leader. Everybody else is constantly jockeying to stay in position. If the prop synchronizers are a little sloppy and everybody is trying to make vernier thrust corrections with prop RPM because the throttles are clunky and the supercharger controller feedback is getting into the act, it's gotta sound downright symphonic! An orchestra without a conductor. "....and the beat goes on, la de da de dee, la de da de dah"
Cheers,
Wes

 

[XBe02Drvr]

Our engines instructor at mech school, a round engines guy dating back to 8th AF, told us that our planes had sychrophasers, while the bad guys only had synchronizers, as their bombers were a generation older technology. A synchronizer merely matches the RPM of the slave engine(s) to the master. A synchrophaser not only matches speed but also keeps the props in the same phase relationship. A stop action photo would show all props aligned evenly with each other. He said this tremendously extended the fatigue life of the airframe, especially the engine mounts, by reducing beat frequencies and harmonic vibrations. "She's only givin me good vibrations, I'm not getting any excitations; Good, good good, good vibrations!"
Cheers,
Wes