RADIO communications between plane pilots and airport dispatchers are now permanently recorded on wax cylinders by an electrical machine recently installed by the U. S. Bureau of Air Commerce at a California landing field. Reports made by pilots and orders given by dispatchers, kept on file in record form, are thus available to examiners investigating the causes of any accident to a plane.

  1. Hirudinea says: June 8, 201112:46 pm

    The origin of the “Black Box”?

  2. Jari says: June 8, 20112:45 pm

    It would be fun to change cylinders, when there’s a situation going on, as they only last 4 minutes a piece.

  3. Charlene says: June 9, 201112:24 pm

    I suspect these cylinders are closer in size and capacity to Dictaphone cylinders of the day which could hold much more than four minutes’ content. They might even have used larger cylinders and used a slower rotation rate.

  4. Jari says: June 9, 20112:37 pm

    Charlene: I stand corrected. It’s 10 minutes according to this: http://www.speechtechbl…

    On the other hand, early dictating machines had 150 grooves/inc, while music cylinders had 100/in for 2 minutes and 200/in for 4 minutes. That was to prevent secretaries listening music instead of typing the dictations on paper… I lost the link to that info, unfortunately.

  5. John says: June 9, 20114:01 pm

    Jari » The whole secretary listening to music thing is addressed here

  6. GaryM says: June 9, 20115:55 pm

    “Permanently recorded on wax cylinders” is an interesting oxymoron.

  7. Jayessell says: June 10, 20114:37 am

    With proper storage they are still usable (citation needed) but are digitalized for archival purposes.
    There’s a video of a rare cylinder falling apart in a guy’s hands.
    Our digital data of today may not reach the 30th century.

  8. Charlie says: June 10, 20117:06 am

    Jayessell: I remember seeing that. It was incredibly painful to watch:…

  9. GaryM says: June 10, 201110:23 am

    Jayessell: I know. Digital preservation is a special interest of mine. Old wax cylinders have to be handled with the greatest care to be played the one time it takes to digitize them.

    30th century? If it reaches the 21st, we’ll be doing pretty well. “What’s this? A CD? Excuse me while I put on my bearskin.”

  10. John says: June 10, 201111:13 am

    GaryM » Sorry but we already reached the 21st Century, January 1st, 2001.

  11. Toronto says: June 10, 20111:57 pm

    John: 21st Century? Great Scott!

  12. Charlene says: June 10, 20116:00 pm

    @Jari I suspect that the wax cylinders for aviation recording purposes would have been recorded at a significantly slower speed than Dictaphone, if only because accident investigators didn’t think that sound quality was important. Even in the eighties ATC recordings in Canada were recorded to tape running at some insanely low speed, which didn’t help when investigators wanted to hear background cockpit noises in incidents where the accident aircraft wasn’t equipped with a CVR.

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