Adrian,

Interesting.  The cylinder shaped piece hanging down from the hub on a cable(?) at the end of the tow line looks to be a standard tow release mechanism.  The whole thing looks jury rigged to me.  Probalby done by the same man who ordered the nylon tow line with the communications wire inside the line..... 

The hub seems to have a large black blob on it where the photograph was doctored to hide something?  The nylon line stretched  up to 30%+ and tried to untwist under load.  Thus the feathjered prop being tied so securely.

Charles 

Silent Ones, WWII Invasion Glider Test & Experiment

The hub seems to have a large black blob on it where the photograph was doctored to hide something?

 
Yes , I noticed the square white block on the P-47’s side of the cylinder. The text identifies the cylinder as the explosive link (text attached). IMPACT is enjoyable reading, but from a technical standpoint, it is noted for errors and embellishment.
 
Project MX-548’s final report should tell the story. -Adrian

[image]local://upfiles/4170/20466ABE6D23435A925D383446DBAD60.jpg[/image]

Attached Image(s)

ORIGINAL: GLIDERMAN1

Somewhere I have seen images on the internet, made I think in late 1940's, in the desert(?).  A B-17 is snatching aircraft but it apparntly did not use the winch system that had been developed by All American and tested at CCAAF, Wilmington Ohio.     
   

That's the one.

Same system as done at CCAAF April-May 1945 with B-17 #43-37881 tow target and light loads, picture in Silent Ones, as described on the web site, no winch.  They definately did not snatch an airplane with this system.

Charles Day

Silent Ones, WWII Invasion Glider Test & Experiment

The whole thing looks jury rigged to me. Probalby done by the same man who ordered the nylon tow line with the communications wire inside the line.....

 
Charles - Dismissing the Muroc tests as "jury rigged" would be a miscalculation. MX project tests were typically methodic. These tests were done to explore the feasibility of recovering downed aircraft in remote forward combat areas for return to rear repair centers. The crude appearance of the P-47 photo likely reflects simulated field conditions. The test report would seem to fall within the scope of your research. –Adrian

"The crude appearance of the P-47 photo likely reflects simulated field conditions. The test report would seem to fall within the scope of your research."

Adrian,

Everything done by Wright Field was typically methodic. They had to work with standard stuff that would be available in the field, so they "jury rigged" the steel cable around the hub and around the prop., nothing more, nothing less.

This would be a side trip for my research which primarily revolves around the Glider Branch. I would guess that after the Glider Branch established that the tow and snatch of a fighter was feasible by using the BT-13 and the Stinson the information was turned over to another branch who took it to Muroc because Wright Field was too crowded to mess with the runway time it would take for these tests--the same reason the gliders were moved to CCAAF.  However, since the aircraft with installed pickup winches and the pilots were assigned to Glider Branch, CCAAF, they would have gone out to Muroc to fly the snatches.

Charles

 

Silent Ones, WWII Invasion Glider Test & Experiment

The whole thing looks jury rigged to me. Probalby done by the same man who ordered the nylon tow line with the communications wire inside the line.....

 
Charles – Your analogy of the Muroc tests and "the same man who ordered the nylon tow line………" seemed to position the term "jury rigged" as one of derision. The two events had little in common, with the Muroc test showing some promise.
 
In any case, attached are some early shots of what appears to be an All American Aviation, Stinson SR "dash ten charlie" snatching an unknown sailplane. No date or location is provided. Those with remaining interest might like to see them. -Adrian

[image]local://upfiles/4170/A09DD52398F842E2A8CB87E956AA5202.jpg[/image]

[image]local://upfiles/4170/B63967095C3A463CAE9CED685C9A6C75.jpg[/image]

Attached Image(s)

I like the fixed perspective of the two photos from a technical perspective, framing the glider climbing well inside the SR-10 climb path. 

Despite looking, I have never found any documentation on the physics of snatch pickup.  I am revisiting a graduate class term project I did, modeling some non-linear dynamics for an engineering conference paper that I've just been accepted.

Adrian,I know what you are saying but I won't give in. The wire in the towline showed promise too or the Army would not have ordered thousands of feet of it. 

The pictured All-American Stinson is NX-2311.  The glider is a Schweizer but I don't  know the number without  looking through a bunch of stuff.  They also picked up a Piper with the prop removed.  These snatches were the original snatch sales job by Richard duPont.  He flew the glider and the Piper. 

NX-2311 is the plane in the Postal Museum in D.C.  It is represented there as being the plane used for the first human snatch. But NASM archives records prove that NX-2311 was never renumbered to 43-7280 (which did the first human snatch) and never left All-American ownership during WWII.    

Charles 

Silent Ones, WWII Invasion Glider Test & Experiment

wanted to add concerning the Piper snatch.

You will read that the engine was removed from the Piper for the snatch.  The engine was not removed, the propellor was. In Silent Ones WWII Invasion Gldier Test & Experiment, I used a starboard side photo showing the tow release and the engine w/o the prop. 

Charles

Silent Ones, WWII Invasion Glider Test & Experiment

It is an extremely interesting discussion. On the margin it would not be a bad thing to add that the snatch technique is much older than WWII though not for the gliders of course. In Europe snatch was used in various armed forces at least since early 1920s if not sooner. In Europe mainly the French and Poles used snatch technique in their liaison aircraft or so-called army cooperation aircraft. The French and Polish Air Force manuals of early 1920s describe the snatch very well.

Does anybody know who is world "father", inventor and pioneer of the snatch? Somebody from the USA or Europe?

Best regards

Greg

Interesting question Greg.  The "father" depends on your definition of snatch pickup; there is no undisputed first.

Richard Chichester du Pont was the clear leader in taking All American Aviation into a decade+ of continuous postal air pickup contracts in US Appalachia, and grew it into the culminating 500+ operational Allied cargo glider snatch pickups of WWII.   He was an innovator and could inject du Pont engineering when he bought controlling interest from Dr. Lytle Adams.  Adams had been unsuccessful since the late '20's to make a completely different pickup technique commercially viable.

I'd have to look up the barnstormer's name and years, but he could fly at shows such that an assistant on the ground could grab the towline, attach an object to it, and release it into tow.  Probably more than one pilot could do that maneuver.

I suspect that snatch pickup was likely an independent fancy of nearly every early barnstormer that had some mastery of aerobatics.  This is not likely to be unequivocally documented.  Even Otto Lilienthal had enough flying time that he could have grabbed something or intentionally kicked a clod of dirt or such off the ground on the spur of the moment.

Technically I invented a marinized concept of heavy cargo glider snatch pickup in 2005, and then went looking for previous military accomplishment to see what had been done before.  Had to go back a bit further than expected, and found more operations than expected.  Still researching them, see my new thread later tonight.

Depends on your definition, I favor duPont.