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Anyone have info on ADSID Igloo White sensors?

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As part of the ongoing F-4 packs I'm doing, I'm putting together a 25th TFS pack - this unit flew the first D-model F-4s with tapelights in SEA, and all aircraft had a distinctive fuselage spine antenna offset to one side (and later had the LORAN towelrack antenna added as well). These birds specialized in supporting the Igloo White program and deploting various seismic/acoustic sensors. I'd like to add some of these, but photos are scarce and dimensions even more so. Any help would be appreciated.



Mike D.

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The ADSID, or Air Delivered Seismic Intrusion Detector, was a family of sensors

that were released from aircraft as the name implies, and fielded in

versions I, II and III. Sensors dropped in each area of operations were

factory-built with a fixed-frequency on which they transmitted. For any of

the area-designated frequencies, they had to be ordered by unique FSN

(Federal Stock Number) to match the assigned frequency channels.


Nomenclature Model Variant Type Length Weight

ADSID I (N) - - - - - - normal - seismic - 31.00 ins - 26.0 lbs

ADSID I (S) - MA-36 - short - seismic - 20.10 ins - 13.7 lbs

ACOUSID II - TC-415 - ****** - seismic-acoustic - 53.14 ins - 38.8 lbs

ACOUSID III - MA-31 - ****** - seismic-acoustic - 47.63 ins - 37.2 lbs

ADSID III (N)- MA-33 - normal - seismic - 37.66 ins - 37.2 lbs

ADSID III (S)- MA-37 - short - acoustic - 20.10 ins - 13.7 lbs

MODS 81 mm - mortar - ****** - seismic - 33.00 ins - 9.6 lbs


It is estimated that some 36,000 ADSID and ACOUSID sensors were produced by

just one of the contributing manufacturers involved.

Sensor design consisted of a series of common modules, using the latest

Integrated-Circuit chip technology of the time to keep costs down. The

electronics design centered on a concept of interchangeable subsystem circuit

boards - 'Common Modules'.


Common Modules were cylindrical, sealed in hard foam potting compound, and

connected to each other with circular connectors around the outer circumference

at the ends of the cylinders. As with the GSID, the same adjustments - Gain,

Code, Real-Time, Inhibit, and Disable - could be programmed into the ADSID


A 'Common Module' existed for each of the following functions; Transmitter,

Encoder, Command decoder, and Command receiver.

RF alarm messages were modulated with a combination of 19kHz, 25kHz and

32kHz pulses, which provided up to 27 codes (IDs) on a single radio channel.

The transmitter radiated two watts power on one of 40 channels in the 160-175

MHz-band FM/VHF radio spectrum.



If switched to the RT (Real Time) mode, the sensor would transmit alarms at a

maximum rate of 1.4 per second. If the sensor alarmed constantly in the RT mode,

minimum battery life was at least 48 hours.

If switched to the INH (Inhibit) mode, the sensor would transmit alarms at a

maximum rate of one every ten seconds. Minimum battery life in this mode was

45 days.

In spite of rocks, trees, rice paddies and other inhospitable impact sites, 80%

of the ADSIDs were found to be operational after air delivery.




The ADSID III shown in the photograph above is typical of the devices dropped

from U.S. aircraft along roads, rivers, and jungle trails in Southeast Asia.

They were dropped in sequential 'strings' along a predetermined target line

in a series of from 4, up to 10, 12, 15 or sometimes more, depending on the

priority of the target area. With their flexible spring-steel antennas, they

were designed to bury in the ground and blend into the surrounding foliage by

resembling tree branches and plants. All devices transmitted alarm data for only

a short distance. They were continuously monitored twenty-four hours a day by

U.S. Air Force crewmen flying unarmed, propeller - driven electronic surveillance

aircraft orbiting overhead at 20,000ft.


Initially, Navy OP-2E Neptune aircraft performed sensor air deliveries at very

slow speeds from altitudes as low as 500 feet, making them easy targets for enemy

gunfire. The pilots of VO-67 at Nakhon Phanom AB knowingly expected that they would

incur as high as an 85% casualty rate from such operations, but volunteered to

fly them anyway, and many crewmen were lost.

During later operations, sensors were hand-dropped from CH-3 Jolly Green Giant

helicopters by personnel of the 21st SOS Dust Devils (Special Operations Squadron)

and later, delivered by Air Force F-4D Phantom-IIs.




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Thanks KB,

That's more than I had found for dimensions. The photo I had found. I had a feeling that you'd have something on 'em. Thanks again,


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BINGO!! Outstanding!! Exactly what I needed - I can't guarantee I'll do every one, but several at any rate. No one else will probably ever fly a mission dropping them anyway...


Thanks again, owe you a favor!



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Write them into a Recon mission. Must drop them at the target area, or something like that. Looks to be a great new add-on.

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Thanks Storm, but the historical stuff seems to be about as popular as the make-believe stuff for the Third Wire series. I'm just trying to get the USAF F-4 variants done with at least one markings/decal package each before I take a break. The 25th TFS birds were sort of distinctive, so I guess they deserve a separate pack - they received the LORAN "towelrack" in 1971 or so as well.



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SUU-42 or -42/A Flare (or sensor...) dispenser - for F-4 or AC-130...



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