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Mark 41 Zuni warhed?

Magii

Member
While reading Volume 4 of the history of China Lake Naval Ordinance Station I came across a reference to the Helicopter Trap Weapon, a Zuni derivative that was used to clear helicopter landing zones.

The strange thing is that the warhead used was listed as the Mark 41 Mod 0, with a continuous-rod warhead setup.

None of the Zuni warheads I am aware of use continuous-rod warheads and the Mark 41 Mod 0 is listed in OP 2210 as a Mark 32 ATAP warhead with Mk 188 fuse on the Mk 16 motor. Mark 32 ATAP warhead uses a plastic fragmentation liner and is not continuous-rod. Mk 24 HE-GP head is just a thick steel body. Mk.63 HE-FRAG I am unsure of, as only NAVAIR 11-75A describes it and I have not seen any cutaway drawings. Additionally, Mark 63 entered service in ~1971, so I'm unsure if it was available in the early 1960s


So, is the Mk.41 Mod 0 head an experimental warhead design that never went anywhere? Does anyone have any good pictures of cutaway Zuni warheads?


OP 2626 Zuni

NAVAIR 11-75A-92 Aircraft Rocket Systems

History of China Lake Part 4
 
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Googling Helicopter Trap Weapon, I found a discussion about it. It was designed to remove helicopter traps from landing zones. They experimented dropping 500 Lb. parachute retarded bombs from helicopters and eventually went to the Zuni warheads retarded by parachutes.

From this conversation: http://popasmoke.com/notam/forum/vietnam-1962-1975/squadron-forums/hml-167/465-helicopter-bomb


This discussion:
"I was in HML-267 (LtCol P. P. Upschulte) in the late summer/early Fall of '68 when I answered the call for volunteers to become the Project Officer for the HTW Project. I was shortly transferred to MAWTU at MCAS El Toro and began a series of trips to China Lake for training. Maj Jon Robson and Maj Bob?? Peterson were stationed at China Lake and had been working with the HTW for some time. Our team of 2 departed for RVN in Jan '69 to install the circuitry on all gunbirds, teach the weapon specifics in classes, then take some pilots out for practice drops -- on selected missions. Warrant Officer Harry Minch was the Ordnance guy who learned about and did all the in-country wiring installations. I flew with every in-country Marine Huey squadron over the next 3 months on these training/practice/actual missions. I remember LtCol Miller as the CO HML-167 at MMAF. He also had Maj Jay Davis and Capt John Henry Key in his command, Marines I had served with in earlier VMO tours. Jay Davis was my Flight Leader the night of 25 Sept '66 when Phil Ducat was blown out of the sky on a night medevac by our own artillery, out by the Razorback. John Henry gave me my PQM check in VMO-1. He was not flying in 167 at the time because he was recovering from his terrible wounds when he was shot down.
Anyway, I had a rough time trying to convincingly teach HTW to the Huey gunship pilots. I had been Flight Instructor for a lot of them in HML-267 and preached that they stay above 1500' if at all possible until they had damned good reason to be lower. The HTW was a parachute-retarded weapon (operative word is retarded!), best delivered S&L from 700' AGL at 80 knots to deliver one or two sticks of 4. IF (big IF) all went well, the chutes would all deploy, the weapons would not drift TOO much and the bombs would land vertically on the fuze in the nose and detonate.
The "bomb" was an old Zuni warhead with a 3/8" continuous steel rod wound back and forth. Zuni had been designed as an air-to-air weapon with a proximity fuze. When the fuze detonated, the rod expanded outward, still continuous (to a point), at a slight angle, to eventually impact the enemy aircraft and damage hell out of his fuselage wings, etc. The parachute was an Army idea to make it go in vertically. The expanding steel rod came off in an ever-expanding circle, angling upward as it expanded. Intent was to clear elephant grass, small trees, punji stakes, grenades wired up in trees, etc (e.g., Helicopter Traps!)
On 1 actual recon insert mission, we actually cleared elephant grass from an LZ, exposing big-assed rocks which would have wreaked havoc if the Frogs had landed there. But the HTW had lots of drawbacks as well. Delivery profile notwithstanding, chute failures could actually put pieces of the expanding rod through the chin bubble on the delivering Huey. The bomb went in at an angle and detonated, sending the steel rod right out in front of the Huey flight path. In addition, the expanding rod had torn Hell out of the circle of pine 2x2's around the drop zone in China Lake. We dropped 2 sticks of 4 into a grove of ironwood trees up near Khe Sanh. All 8 dropped and detonated successfully, However, when we circled back to get BDA, we were unable to tell where they had detonated."

Another blurb here:
https://books.google.com/books?id=O...AQ#v=onepage&q=Helicopter Trap weapon&f=false
 

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Googling Helicopter Trap Weapon, I found a discussion about it. It was designed to remove helicopter traps from landing zones. They experimented dropping 500 Lb. parachute retarded bombs from helicopters and eventually went to the Zuni warheads retarded by parachutes.

From this conversation: http://popasmoke.com/notam/forum/vietnam-1962-1975/squadron-forums/hml-167/465-helicopter-bomb


This discussion:
"I was in HML-267 (LtCol P. P. Upschulte) in the late summer/early Fall of '68 when I answered the call for volunteers to become the Project Officer for the HTW Project. I was shortly transferred to MAWTU at MCAS El Toro and began a series of trips to China Lake for training. Maj Jon Robson and Maj Bob?? Peterson were stationed at China Lake and had been working with the HTW for some time. Our team of 2 departed for RVN in Jan '69 to install the circuitry on all gunbirds, teach the weapon specifics in classes, then take some pilots out for practice drops -- on selected missions. Warrant Officer Harry Minch was the Ordnance guy who learned about and did all the in-country wiring installations. I flew with every in-country Marine Huey squadron over the next 3 months on these training/practice/actual missions. I remember LtCol Miller as the CO HML-167 at MMAF. He also had Maj Jay Davis and Capt John Henry Key in his command, Marines I had served with in earlier VMO tours. Jay Davis was my Flight Leader the night of 25 Sept '66 when Phil Ducat was blown out of the sky on a night medevac by our own artillery, out by the Razorback. John Henry gave me my PQM check in VMO-1. He was not flying in 167 at the time because he was recovering from his terrible wounds when he was shot down.
Anyway, I had a rough time trying to convincingly teach HTW to the Huey gunship pilots. I had been Flight Instructor for a lot of them in HML-267 and preached that they stay above 1500' if at all possible until they had damned good reason to be lower. The HTW was a parachute-retarded weapon (operative word is retarded!), best delivered S&L from 700' AGL at 80 knots to deliver one or two sticks of 4. IF (big IF) all went well, the chutes would all deploy, the weapons would not drift TOO much and the bombs would land vertically on the fuze in the nose and detonate.
The "bomb" was an old Zuni warhead with a 3/8" continuous steel rod wound back and forth. Zuni had been designed as an air-to-air weapon with a proximity fuze. When the fuze detonated, the rod expanded outward, still continuous (to a point), at a slight angle, to eventually impact the enemy aircraft and damage hell out of his fuselage wings, etc. The parachute was an Army idea to make it go in vertically. The expanding steel rod came off in an ever-expanding circle, angling upward as it expanded. Intent was to clear elephant grass, small trees, punji stakes, grenades wired up in trees, etc (e.g., Helicopter Traps!)
On 1 actual recon insert mission, we actually cleared elephant grass from an LZ, exposing big-assed rocks which would have wreaked havoc if the Frogs had landed there. But the HTW had lots of drawbacks as well. Delivery profile notwithstanding, chute failures could actually put pieces of the expanding rod through the chin bubble on the delivering Huey. The bomb went in at an angle and detonated, sending the steel rod right out in front of the Huey flight path. In addition, the expanding rod had torn Hell out of the circle of pine 2x2's around the drop zone in China Lake. We dropped 2 sticks of 4 into a grove of ironwood trees up near Khe Sanh. All 8 dropped and detonated successfully, However, when we circled back to get BDA, we were unable to tell where they had detonated."

Another blurb here:
https://books.google.com/books?id=O...AQ#v=onepage&q=Helicopter Trap weapon&f=false
Thanks, but I'm trying to figure out what the Mark 41 warhead was.
 
It was a CRW (Continuous Rod Warhead) air-to-air warhead for the Zuni. Designated the Mk. 115, there were 11,000 of them made for use in NAM.

The Zuni began production in 1957. It was originally designed by China Lake for Air-to-air use, but was then only used for air-to-ground use. The Mk. 41 warheads were probably in storage since the air-to-air function was cancelled, so they reworked them for the MK. 115 system.
 

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Looks like it uses either a mechanical impact fuze (M111 series) or a mech time fuze (M144/145, etc.). Interesting use of a Zuni CROW.
 
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Thank you for that Hazord, I did not realise that the HECR concept was created in Mexico.
As you know each alternate rod is welded at the opposite end so that when the detonating wave hits the inside of the warhead it expands as a hoop and eventually breaks up in a very distinctive manner.
A typical section end break is shown in the famous photo of Nikita Kruschev with the wing of Francis Gary Powers' U2 aircraft which the Russians at the time claimed that they shot down (see Tom Hanks film 'Bridge of Spies'). It was not believed that they had a missile which could reach that altitude.
 
"New" Mexico.
The city of Socorro is home to New Mexico Technical University, which has long had a strong explosives program and has farmed out to do a large number of government projects (25 miles from White Sands Missile Range). A number of different government contractors have also had offices on campus, and utilize facilities for different purposes. On campus at an Aerojet facility in 1991 I worked the first incident involving the then new TOW IIB missile, Lot #1, which had armed on the assembly line. While the political aspects of the incident played out we were given a tour of the facility, quite impressive.
 
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