Republic-Ford JB-2 "Loon" ...

[Mark Allen M]

A little Loony today ...

"The Loon was the U.S. Navy's copy of the German V-1. The U.S. Army Air Forces' copy was designated JB-2. Intended for launching from ships against ground targets, the Loon had a pulse jet engine, a range of 150 miles, and was tracked by radar and controlled by radio. All Loons built were used in tests after the war. None were fired in combat.

The Loon was developed by the Army Air Forces (AAF) beginning in 1944. As with the V-1, the AAF intended the JB-2 to be a ground-launched missile used against ground targets. The AAF started flight tests in October 1944. The Navy developed interest in the AAF program shortly thereafter, intending to launch the missile from escort carriers with guidance from either shipboard or airborne radar.

Formally, the Navy's project was initiated under the Bureau of Aeronautics in April 1945 and at that time the missile was designated the Loon. (Initially, the Navy also designated the Loon as KGW-1 then in 1946 redesignated it as KUW-1.) The Bureau of Aeronautics received some JB-2s from the AAF, and in June 1945 contracted with Republic Aviation for 151 missiles. The XM-1 system (using a slotted tube powder catapult) was selected for the launching system.

The Loon was 27 feet long and had a wing span of 18 feet. It carried a 2,100 pound warhead and weighed 5,020 pounds with the warhead and fully fuelled. Powered by a PJ 31-1 pulse jet which developed a gross thrust of 850 to 900 pounds at a specific impulse of about 1,100 pounds per second, the Loon had a 180 gallon tank and could use any gasoline-type fuel. Control surfaces on the airframe consisted of a rudder and elevators. The Loon was tracked by radar to the target and was controlled by radio. Stabilization was provided by 3 air-driven position and rate gyros. An aneroid unit and magnetic compass controlled altitude and course through the gyro system.

In late 1945, tests of the XM-1 system using dummy Loons were conducted at Point Mugu Naval Base in California. Several operational tests of the missile took place at this base in early 1946. Directives were then issued in March 1946 to develop a launching capability from submarines. Submarine launchings started in February 1947 from the U.S.S. Cusk (SS-348). Several months later, the U.S.S. Carbonero (SS-337) joined the tests and acted as the control and tracking station. Based on the successful results of these tests, the Navy directed in August 1947 that submarine launchings continue through 1949 to develop terminal guidance procedures and tactical concepts for the Regulus, a submarine-launched guided missile with a range of 500 miles that was then under development.

In late 1948, directives were issued to develop a launching capability from surface vessels as well. The U.S.S. Norton Sound (AV-11) was selected as the platform, and four successful launchings from her took place in 1949 and 1950. The Loon project was cancelled after the last of these.

With a maximum range of 150 miles, the Loon was launched at a minimum speed of 220 m.p.h. It climbed at a rate of 500 to 1,000 feet per minute to the altitude set on its altimeter. The optimum altitude in flight was between 2,000 and 4,000 feet, and the optimum speed in flight 400 m.p.h.

The Loon was one of the first guided missiles built by the U.S. Navy. Knowledge gained from its testing onboard submarines and surface ships led to the subsequent development of more advanced guided missiles, and eventually the sea launched cruise missiles which are still deployed by the fleet today."






Loon missile launch from the USS Cusk off NAS Point Mugu c 1948

Below is a series of photos showing the USS Cusk (SS-348) launching another 'Loon' Missile from the deck. 'Unsuccessfully'.
The skipper of the boat submerged and prevented a lot of damage.












Army Air Forces Fair 021 V-1 Flying Bomb (Republic JB-2 Loon V1 US version)


B-17 Flying Fortress with two JB-2 bombs

[Mark Allen M]

Moving pictures of a 'Loon'

https://www.youtube.com/watch?v=dX69Lx0emu4

[Chris Brame]

Another cool photo set! Did we reverse engineer it from a captured V-1, or did we swipe the plans? And what improvements did we make to the German design, if any?

[Clifford Bossie]

Great stuff as always Mark! Thank you.

Wonder where the B-17 is? Could be White Sands (Holloman), or Eglin.

[sandiego89]

Another cool photo set! Did we reverse engineer it from a captured V-1, or did we swipe the plans? And what improvements did we make to the German design, if any?

I wondered the same thing. Looks like a bit of espionage but mostly reverse engineering from crashed examples. Wiki page on the Loon looks pretty good, and cites: U.S. Air Force Tactical Missiles, (2009), George Mindling, Robert Bolton, which states:

"The JB-2 was different from the V-1 in only the smallest details....Wingspan 2.5 inches wider...length extended less than 2 feet...wing area 60.7 square feet vs 55 for the V-1...gross weight of Loon 5,025 vs 4858 for the V-1....

https://books.google.com/books?id=P5WMD ... les,+(2009),+George+Mindling,+Robert+Bolton&source=bl&ots=TM2LlL3SyQ&sig=nBY3JSEW9NgTfU9qB2YxOybpITA&hl=en&sa=X&ved=0CCwQ6AEwAmoVChMIm8vPl4bRyAIVAaQeCh3Gewyx#v=onepage&q=U.S.%20Air%20Force%20Tactical%20Missiles%2C%20(2009)%2C%20George%20Mindling%2C%20Robert%20Bolton&f=false

Wiki also mentions that: "One of the few visible differences between the JB-2 and the V-1 was the shape of the forward pulsejet support pylon — the original V-1 had its support pylon slightly swept back at nearly the same angle on both its leading and trailing edges, while the JB-2's pylon had a vertical leading edge and sharply swept-forward trailing edge.>

Sounds like the engine and guidance system was a reverse engineered copy.

[wendovertom]

Actually some of the very initial testing took place in Wendover, Utah. It would not surprise me to find that the B-17 photo is over the Utah Test and training range (UTTR). The launch pad and bunker house are still here in Wendover and can be toured on the rare occasion (they are still on USAF controlled property). The City tore out the launch rails in the 80's for the scrap metal value Not a lot of concern for history back then. I will dig up the photos I have and post them.


Tom P.

[Jerry O'Neill]

New England Air Museum's JB-2 Loon. The center section is believed to be German as it had original markings found under the paint during restoration.

[wendovertom]

Here are a couple from June 7,1946 in Wendover - well the first is from that date for sure.






Tom P.

[Clifford Bossie]

There was quite a bit of Loon testing at Holloman. For a time the base was the Holloman Air Development Center.

A JB-2 at the Holloman launch facility:



Much of that facility is still present at Holloman:



(Neither of these photos are mine)

In reality the JB-17 shot could be anywhere, but my guess is Eglin like this one:



I really like the Loon shots aboard the subs. I have just been researching GUPPY conversions and though the Loon carriers are not such they do fit into that time period.

[Mark Allen M]

More 'Loon-acy' ... Launch of a Loon missile from USS CUSK (SS-348), off Point Mugu, California Sep 12, 1948

[Mark Allen M]

More shots off of Pt. Mugu




USS CARBONERO (SS-337) Launches a loon derby LTV-N-2 #995, while operating at the sea test range off Point Mugu, California, 2 December 1950.

Last edited by Mark Allen M on Tue Oct 20, 2015 7:51 pm, edited 1 time in total.

[Mark Allen M]

[Mark Allen M]

USS CARBONERO (SS-337) Launches a loon derby LTV-N-2 #950, while operating at the sea test range off Point Mugu, California, 16 December 1950.

Last edited by Mark Allen M on Tue Oct 20, 2015 7:52 pm, edited 1 time in total.

[Mark Allen M]

Still more shots off Pt. Mugu







Lots of stuff going on at Pt. Mugu back then, and still today.


CTV-N-2 No. 23 ("Gorgon") missile. Under the wing of a PB4Y-2 aircraft, at the Naval Air Materiel Test Center, Point Mugu, California, 17 January 1950


"Loon" LTV-N-2 No. 227 S/L 374 Missile. Checked out using electronic text equipment, at the Naval Air Materiel Test Center, Point Mugu, California, 16 January 1950.


XAAM-N-2 ("Sparrow") missile. On the wing launcher of a Grumman F6F-5 "Hellcat" aircraft (BuNo 72933), 13 January 1950. Taken at the Naval Air Materiel Test Center, Point Mugu, California. Note radar of instrumentation pod beneath the "Hellcat".


Aircraft returned from the war zone (Pacific) for repair, NAS, Point Mugu.



NAS Point Mugu, close to Camarillo CA and not too far from me.

[Pogmusic]

The B-17 in the picture was over Eglin AFB. It is flying south over Hurlburt Field, Santa Rosa Sound, and then Santa Rosa Island. All of these are still Eglin AFB property. In fact, there was a JB-2 launch ramp built just off the nose of the B-17 out of the picture. I use to play on it in the 1970's.