Classified Project Silent Joe II

[Dynoman]

Never before published photo of the Project Silent Joe II airship and final report.

Developed by ARPA and Goodyear to investigate the use of an airship that would be able to maintain surveillance over the Ho Chi Minh trail. It would use LLLTV and infrared sensors to monitor traffic along the trail.

 

[archipeppe]

Absolutely amazing, it seems to be sorted by a Verne's novel!!
BTW what was the purpose of the rear propeller?

 

[Dynoman]

System is similar to POBAL-S which followed Silent Joe II. In the POBAL-S report the system was designed to increase maneuverability and reduce noise.

 

[Dynoman]

An interesting fact about the project, Goodyear used its N4A 'Mayflower' airship in order to conduct the tests. N4A was at the time one of Goodyears latest designs and one of the fastest non-rigid airships. You can even see the 'Skytacular' electronic sign system on the port side.

Sometimes the best place to hide something is in plain sight!

Unfortunately, the Mayflower crashed October 30, 1999, when a broken gear and drive steering system sent the airship in to a descending left turn from 600 ft AGL. Fortunately, no one was hurt.

 

[Michel Van]

a amazing project

but how hat Silence Joe II defend it self against Vietcong fighters ?

 

[Dynoman]

Michel...I think the plan was to fly at night and off the trail. Maybe high enough to remain out of effective gun range. I haven't seen any info yet on exactly how it would be deployed.

 

[sublight]

The first stealth blimp.....

 

[blackstar]

So where do we find information on this project?

 

[OM]

The first stealth blimp.....

...My thoughts exactly!

 

[Dynoman]

Obtained some additional data on the Silent Joe I airship, seperate of Silent Joe II project. Apparently the first Silent Joe was a 5,300 cu ft remotely controlled drone airship deployed over Southeast Asia carrying 'microphones and a radio transceiver,' for the purpose of detecting 'truck convoys and troop movements.' It was developed and deployed by the Range Measurement Laboratory based at Patrick AFB in Florida.

Sorry for the quality of the photo in the pdf. The information is from:
Proceedings AFCRL
Scientific Balloon Symposium
30 Sept through 3 Oct 1974
AD-A008 489

 

[Dynoman]

As a side note on balloons over Vietnam and SEA during the war, the NSA was also hard at work developing surveillance and communication technologies including this small aerostat, which was deployed near the DMZ in Dong Ha, Vietnam.

 

[Grey Havoc]

What comes around, goes around.

 

[Maverick Pilot321]

So ran into this website a couple years back and with that I also ran into the topic of Silent Joe II. interested in the topic I dug a little more into into although I cannot remember if it was this website or not, I do remember an aircraft even more bizarre than the silent Joe II project. It sucks I cant remember the name of this "project" but from what I remember it was used in conjunction with Silent Joe II as a weather monitor aircraft (or something similar) . this aircraft was not an Airship but was made in around 1967 by the U.S. Airforce and if I am correct there pictures of it next to silent Joe II as well. Truly a bizarre aircraft and if anybody has info on this it would greatly be appreciated

Sincerely
Garrett

 

[Temistocle]

Hi all, I just found there is an article about balloons in Vietnam on the "Air Classics Quarterly Review" magazine, volume 6, number 4 (winter 1979).
The title is "Balloons over Vietnam". But I have not that magazine...
There is a copy on ebay, but at too much high price for me, knowing nothing about the informations/pictures inside the article.

https://www.ebay.com/itm/Air-Classi...sh=item5d7898f6b7:g:LAYAAOSwBRFaJwCM#shpCntId

Does anybody has that magazine? Is it a good article?

 

[Dynoman]

Maverick, I'm not sure which aircraft you saw. Possibly an RC-12 with antennas mounted all over the wings and fuselage. Its definitely a 'bizarre' look for an aircraft. The RC-12 could have been used to transmit signals from the blimp to the ground in an effort to extend the range of the transmissions. Silent Joe II, however was never deployed over SEA and only conducted nine flights between 1968 and 1969. Here is a picture of Silent Joe I. It was a smaller blimp designed by Sheldahl Co.

 

[sublight_]

Georgia Institute of Technology report on their engineering work for:
Silent Joe II Acoustic and TV Sensor Evaluation Flight Test Program

 

[publiusr]

Absolutely amazing, it seems to be sorted by a Verne's novel!!

“Thus returns Hartmaan the anarchist”

Shades of the Air Wonder stories

 

[_Del_]

Maverick, I'm not sure which aircraft you saw. Possibly an RC-12 with antennas mounted all over the wings and fuselage

The Navy's Neptunes had an odd look as well. OP-2E's involved with Igloo White came with the bulbous chin radar, assorted external stores (ADSID with spindly aerials , gunpods, etc), and jet-engines.

 

[Dynoman]

Here's another picture I have of Silent Joe II. A little better clarity of the scale of the design.

 

[Nik]

Like a 'trolling' motor, would the big, slow tail-rotor be much quieter than the small 'midships' pair ??

 

[Dynoman]

The original Mayflowers motors put out a lot of noise. It was approximately 110 db. It required that the crew and passengers wear headphones or headsets to talk to each other. I believe Silent Joe II was to achieve 35 db at a particular frequency (125 Hz). The Robinson-Dadson curves were used as the standard. Whispering is about 30 db with normal conversation about 60 db. A motorcycle engine, for an engine comparison, is about 70 db.

 

[TomcatViP]

Rear mounted would also have shielded the engine noise emissions to the target during ingress. Then after the overly, the high tree top would have ensured enough protection from small arm fire. (Ho Chi Minh trail)