Radar Ignites Flash Bulbs in Aircraft (Apr, 1948)

Wow, I’ve never heard about this effect.

Radar Ignites Flash Bulbs in Aircraft

Flashbulbs and aircraft like liquor and automobiles, don’t mix.

Enroute from Los Angeles to New York, fire broke out in the baggage compartment of a DC-6. The pilot tried for an emergency landing but just missed the strip and crashed in Bryce Canyon, Utah. All 52 persons aboard were killed. Flashbulbs ignited by radar were given as the probable cause of the tragedy last October. The completeness of the plane’s destruction is shown in the top photo.

Tests conducted by the Air Materiel Command at Wright Field, have proved that such could have been the cause as the picture at the left shows.

The test board shown contains flashbulbs being exposed to radar. The light patch at top left shows a bulb being ignited. Burned out and exploded bulbs are scattered throughout the rack. Wire and foil filled bulbs are both highly susceptible.

7 comments
  1. Charlene says: February 22, 20119:30 am

    I’ve read the accident report for this crash (United Flight 608, if you’re interested) and I’ve never heard about this effect either. The plane crashed because of a design flaw – fuel was sucked into the cabin heater during transfer.

  2. Pardik says: February 22, 201110:26 am

    Doesn’t DC-6 have an all-metal fuselage? If so, it could only be a single flashbulb close to the window? I’ve heard of anecdotal accidents that happened when someone walked past military radar with his pants pockets full of flashbulbs.

  3. Charlene says: February 22, 20111:30 pm

    The accident report. The relevant paragraph:

    “The investigation clearly established that the origin of the fire in this instance was not in either of the baggage compartments. The Board has been cognizant of the public concern over the possibility of a fire being started in flight as a result of discharge of photo flash bulbs carried in passenger baggage and this subject was given careful study during the investigation. As a result of tests conducted by the Air Forces and by General Electric Corporation it has become apparent that the inadvertent discharge in flight of such bulbs in an aircraft interior is highly improbable and that, if discharged by any means, the amount and rate of heat dissipated is insufficient to ignite even the most highly inflammable materials normally carried in baggage or express.”

    So this article is wrong, and directly contradicts the findings of the investigators.

  4. C.H. says: February 22, 20114:02 pm

    Flashbulbs can in fact go off with radar or any other source of electromagnetic fields or static electricity. Now Imagine trying to pass flashbulbs in your pockets through airport security then have your cell phone ring….

  5. rick s. says: February 22, 20115:54 pm

    I spent four years in the Navy as a photographer’s mate back in the early 50s at the Navy base in Norfolk, VA. The photo lab where I worked was right next to the radar training school which was also located at the base. We stored flashbulbs there and carried them around all the time. Huge military radar transmitters were all over that base and we never had any of our flashbulbs fire on their own as a result of all that close-in radar activity. The radar used to set off those bulbs in the test must have been right on top of the array or as others have said here, that article is just plain bogus.

    Rick

  6. Anton says: February 22, 20116:05 pm

    It doesn’t say in the test what type of radar, antenna distance, and duration in main beam or side lobes set off the flashbulbs. Illuminator type weapons radars constantly aimed at an object a few feet away can cause paint to peal, plastic melt, and burn wood in a period of about a half minute. Plastic type flashbulbs will certainly ignite at such a high power concentrations but they have to be close to the antenna or transmiting tube. However, ASR and ARSR type pulse radar used in air traffic control do not pose such dangers to flashbulbs (or chocolate bars) aboard aircraft because of how they work scanning the sky unless your plane was fastened to the rotating antenna.

  7. Kosher Ham says: February 22, 201110:06 pm

    on a similar note, a blasting cap hooked up to wires can be very easily triggered by a radio transmitter if the wires are near the resonant frequency.

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