Just Cause Sheridan's

[Talyn]

Operation JUST CAUSE, he U.S. invasion of Panama began on December 20, 1989, at 12:46 a.m. local time. The operation involved 27,684 U.S. troops and over 300 aircraft, including C-130 Hercules tactical transports flown by the 317th Tactical Airlift Wing (which was equipped with the Adverse Weather Aerial Delivery System or AWADS) and 314th Tactical Airlift Wing, AC-130 Spectre gunships, OA-37B Dragonfly observation and attack aircraft, C-141 Starlifter and C-5 Galaxy strategic transports, F-117A Nighthawk stealth ground-attack aircraft flown by the 37th Tactical Fighter Wing, and AH-64 Apache attack helicopters. The invasion was the first combat deployment for the AH-64, the HMMWV, and the F-117A.

Panamanian radar units were jammed by two EF-111As electronic warfare aircraft of the 390th ECS, 366th TFW.

https://www.jcs.mil/Portals/36/Documents/History/Monographs/Just_Cause.pdf

But, it was the only instance of the M-551 Sheridan Armored Reconnaissance/Airborne Assault Vehicle (AR/AAV) being used exactly as it was designed: as an airdropped light tank.

Crewed by the 3rd Battalion of the 73rd Armor Regiment, 82nd Airborne, the 10 M-551A1s that were hurled to the earth from speeding C-141 Starlifters on 20 December 1989, were the only air drop into combat of the vehicle.

Just Cause Sheridans

Following up on the recent mention of the anniversary of Just Cause here on the blog, I would be remiss to point out something super interesting in that 1989 intervention. It was the only instance …

laststandonzombieisland.com

One was damaged and another destroyed when their chutes failed to deploy properly (an 80 percent success rate!), but the use in Panama of the eight functional survivors was “considered highly successful.”

 

[Cedric]

The 82d should have air landed Sheridans for Urgent Fury on Grenada. The Cubans had BTR-60s (I think). But mainly accurate fire from their main guns would have been preferable to taking out the gun emplacements in Richmond Hill Prison rather than calling in A-7 Corsairs resulting in collateral damage. But maybe this was asking too much from an operation suffering from many coordination problems.

 

[Ascout]

An "80% success rate" is pretty abysmal and in a rational world, even as uncertain a one as airborne operations, should be enough to dismiss the concept in all but the most desperate of efforts. Ironically, the success rate for most SWIMEX's would be lucky to be 90%. A commander just cannot plan/commence an operation sustaining those kind of losses just getting to the battlefield. The vehicle already had an ostensibly well-concealed operational risk in operation due to the weapon system's many shortcomings. As the GAO/Congressional investigation concluded, the M551/Shillelagh should have been canceled no later than 1966. My personal history with the vehicle, which is pretty extensive, is consistent with that view.

 

[KillerFord1977]

An "80% success rate" is pretty abysmal and in a rational world, even as uncertain a one as airborne operations, should be enough to dismiss the concept in all but the most desperate of efforts. Ironically, the success rate for most SWIMEX's would be lucky to be 90%. A commander just cannot plan/commence an operation sustaining those kind of losses just getting to the battlefield. The vehicle already had an ostensibly well-concealed operational risk in operation due to the weapon system's many shortcomings. As the GAO/Congressional investigation concluded, the M551/Shillelagh should have been canceled no later than 1966. My personal history with the vehicle, which is pretty extensive, is consistent with that view.

If I’m not mistaken, the 80% rate was due to 2 of the 10 vehicles being damaged/out of action due to para drop failures, not the vehicle itself.

 

[Ascout]

If I’m not mistaken, the 80% rate was due to 2 of the 10 vehicles being damaged/out of action due to para drop failures, not the vehicle itself.

Could well be the case. As the commander of an operation like this the precise nature of the failure is irrelevant. Real world, the expectation of "all singing, all dancing" airdrop & swimable unique & complex weapon platform still means "I'm two vehicles down without a shot being fired" owing to the nature of the operation. A platoon, or two, of your main combat vehicle rendered combat ineffective by losses before ever engaging the enemy. It was an expensive lesson.

 

[Talyn]

Reading the posted info & links is fundamental.

 

[KillerFord1977]

Could well be the case. As the commander of an operation like this the precise nature of the failure is irrelevant. Real world, the expectation of "all singing, all dancing" airdrop & swimable unique & complex weapon platform still means "I'm two vehicles down without a shot being fired" owing to the nature of the operation. A platoon, or two, of your main combat vehicle rendered combat ineffective by losses before ever engaging the enemy. It was an expensive lesson.

You harped on the Sheridan, yet in this case, the Sheridan performed. The riggers did not.
Your comments dont reflect the situation regardless of your experience

 

[negolien]

My grandparents were in Gamboa at the time working for the canal company. He was an engineer on a dredge there till he retired. I spent some time there in 84. It was pretty fantastic

 

[Cedric]

Could well be the case. As the commander of an operation like this the precise nature of the failure is irrelevant. Real world, the expectation of "all singing, all dancing" airdrop & swimable unique & complex weapon platform still means "I'm two vehicles down without a shot being fired" owing to the nature of the operation. A platoon, or two, of your main combat vehicle rendered combat ineffective by losses before ever engaging the enemy. It was an expensive lesson.

Two vehicles is a section, not one or two platoons.

 

[Cedric]

An "80% success rate" is pretty abysmal and in a rational world, even as uncertain a one as airborne operations, should be enough to dismiss the concept in all but the most desperate of efforts. Ironically, the success rate for most SWIMEX's would be lucky to be 90%. A commander just cannot plan/commence an operation sustaining those kind of losses just getting to the battlefield. The vehicle already had an ostensibly well-concealed operational risk in operation due to the weapon system's many shortcomings. As the GAO/Congressional investigation concluded, the M551/Shillelagh should have been canceled no later than 1966. My personal history with the vehicle, which is pretty extensive, is consistent with that view.

It's rare that any unit goes into combat at 90+ readiness. Think of any ground or air or amphibious operation, and many factors contribute to a reduced readiness rate: maintenance, not enough landing craft or aircraft, or what have you. My experience has been an 80% success rate was pretty damn good when crossing the LD. And it certainly wasn't abysmal. Example, in WWII the 8th tank battalion of the 4th Armored Division started its 100 mile march to Bastogne with 32 out of a normal complement of 52 tanks due to previous combat losses and maintenance. That's 60%. Nevertheless, they were committed to combat. As a side note, in a testament to crew training and the Sherman's reliability, all 32 made it to their initial attack positions.

 

[Ascout]

Two vehicles is a section, not one or two platoons.

I was referring to the strength represented by 10 M551's (one-two platoons worth, depending on the time frame, theater, OOB). And this was, as has been pointed out, a "special operation", not a standing line unit with a certain number of deadlined vehicles & other readiness stats. When the force package was being organized, the usual "readiness" standards did not apply, as they hadn't in some other early such operations...there was a learning curve. The Ad hoc approach had been unsatisfying.
When you function as a sort of Ready Reaction unit (and I have) the designated gear better start at 100%.

 

[Cedric]

I was referring to the strength represented by 10 M551's (one-two platoons worth, depending on the time frame, theater, OOB). And this was, as has been pointed out, a "special operation", not a standing line unit with a certain number of deadlined vehicles & other readiness stats. When the force package was being organized, the usual "readiness" standards did not apply, as they hadn't in some other early such operations...there was a learning curve. The Ad hoc approach had been unsatisfying.
When you function as a sort of Ready Reaction unit (and I have) the designated gear better start at 100%.

It was the 73d Armor; a line unit. Each platoon has five Sheridans, unlike a cav platoon in a cav regiment in Europe at the time which had six plus three other vehicles. A special operation is irrelevant when it comes to readiness. Whether we airdrop, come across the beach, or maneuver to the LD, 80% is not abysmal. Regardless, I would wager heads would roll if the unit had said, "hey, this is a special op, readiness standards don't apply."

 

[Ascout]

It was the 73d Armor; a line unit. Each platoon has five Sheridans, unlike a cav platoon in a cav regiment in Europe at the time which had six plus three other vehicles. A special operation is irrelevant when it comes to readiness. Whether we airdrop, come across the beach, or maneuver to the LD, 80% is not abysmal. Regardless, I would wager heads would roll if the unit had said, "hey, this is a special op, readiness standards don't apply."

Apart from Vietnam, I've never served in a "Regular Army" line unit like one in Germany or CONUS. And VN was an experience unlike anything later. There was no applicable "readiness" or "deadline" in the usual sense or every one of our vehicles would have been deadlined (three years of continuous combat ops does that..not one of our 551s had intact swim gear, claimed by the jungle). I have more time in Test & Eval Cmd. operating vehicles.
I realize that Airborne anticipates losses/injuries during a major jump but this sort of outcome illustrates why the "air droppable" requirement (itself a knee-jerk copy of a Soviet requirement) was poorly considered. The "swim" requirement was an even more poorly considered last minute add-on based on murky intel reports relayed by the Brits at the 4th Tripartite Conference.
If you anticipate bringing a Sheridan ashore without an airfield, line up some old CH-54's and fly them ashore or beg the Navy to bring you ashore, more-or-less ready to fight.

 

[Cedric]

Apart from Vietnam, I've never served in a "Regular Army" line unit like one in Germany or CONUS. And VN was an experience unlike anything later. There was no applicable "readiness" or "deadline" in the usual sense or every one of our vehicles would have been deadlined (three years of continuous combat ops does that..not one of our 551s had intact swim gear, claimed by the jungle). I have more time in Test & Eval Cmd. operating vehicles.
I realize that Airborne anticipates losses/injuries during a major jump but this sort of outcome illustrates why the "air droppable" requirement (itself a knee-jerk copy of a Soviet requirement) was poorly considered. The "swim" requirement was an even more poorly considered last minute add-on based on murky intel reports relayed by the Brits at the 4th Tripartite Conference.
If you anticipate bringing a Sheridan ashore without an airfield, line up some old CH-54's and fly them ashore or beg the Navy to bring you ashore, more-or-less ready to fight.

I will agree that the swim requirement for any armored vehicle should have gone the way of the dodo a long time ago.

 

[Ascout]

I will agree that the swim requirement for any armored vehicle should have gone the way of the dodo a long time ago.

Done by the book, what is the prep time to unwrap a parachute-delivered M551, assemble the crew and the ammo and get underway ready to shoot?

 

[Cedric]

Done by the book, what is the prep time to unwrap a parachute-delivered M551, assemble the crew and the ammo and get underway ready to shoot?

I have no idea. The closest I got to an airborne Sheridan was an NCO transferred in to my platoon from 73d Armor.

 

[Talyn]

I believe four Sheridan's were successfully delivered by C-130 Hercules using the Low Altitude Parachute Extraction System (LAPES) maneuver in the 1989 Panama invasion,...

with the remaining 10 being conventionally airdropped by C-141s, with two being lost in that manner.

Either way gravity is a constant when the rigging works, or doesn't.

 

[Ascout]

I believe four Sheridan's were successfully delivered by C-130 Hercules using the Low Altitude Parachute Extraction System (LAPES) maneuver in the 1989 Panama invasion,...

View attachment 101030
View attachment 101031



with the remaining 10 being conventionally airdropped by C-141s, with two being lost in that manner.

Either way gravity is a constant when the rigging works, or doesn't.

...or the pilot miscalculates. I believe that was the cause of the LAPES crash that killed everybody ~1986 when the C-130 broke it's back dropping an M551.

 

[Talyn]

...or the pilot miscalculates. I believe that was the cause of the LAPES crash that killed everybody ~1986 when the C-130 broke it's back dropping an M551.

That crash plus there was one when the 130 came in too fast and low enough to scrape it belly on the ground (compared to the pics above) when dumping the M511 out the back. It survived the drop but the rest of the vid didn't show what happened to the 130.