Gliders Carrying Main Battle Tanks?

Gliders Carrying Main Battle Tanks? by MaJor E. C. Parrish 111 It’s an emotional issue and, as a pair of United States Military Academy engineers have determined, one well worth facing.

As his senior-year Capstone project, Cadet George Joseph Kopser conducted a preliminary design study of a glider to insert two-tank teams on drop zones. When he briefed his concept to the prestigious American Institute of Aeronautics and Astronautics’ Minta Mrutin Student Competition, he won the oral-presentation contest. Jet-towed gliders clearly intrigued aerospace engineers attending the event, hosted by the Massachusetts Institute of Technology.

“You could‘ve head a pin drop,” Kopser said ‘The idea’s so mdical nobody’s considered it, but it makes sense. I used ARMOR’S article (“It’s Time to Consider Glider Delivery of the M1 Abrams.“ September-October 1992) as my operational concept. The judges thought it was great approach, and they said the design I presented might very well work and certainly is worthy of further study.” His instructor, Colonel Kip P.

Nygrar, agrees:

“We certainly can build the glider using available materials, and we can tow it with today’s jet transports,” Nygren said. “Joe’s idea, a joined-wing design,* is a clever approach. It’ll have tremendous strength, shorten the wingspan to just 20 feet more than a C-130’s. and weigh less than a conventional wing with as much surface area.” (*Julian Wolkovitch invented the pined-wing aircraft, for which he received a patent on June 24,1974.) The question is, should we build it? According to Nygren, that decision is best left to forcedevelopment experts.

“This concept will give them the op portunity to re-look the whole process of airborne deployment and resupply. They’ll need to answer some questions. ‘What do we want to move by air?’ ‘How long do we want it in place?’ ‘How much need is there to produce an mor force on the ground in a hurry’?” ble each cargo jet’s load. “Essentially, the C-5-glider combination is another airplane,” N y p said. “The combination could carry as much as two C-5s at a lot less cost. The big question is: what extra capability, above and beyond that which we have now, does the glider give us?”

And there are m e good mswers. But theoretically, gliders could dou- ‘If we load the glider with tanks, we can fill up the C-5 with support vehicles and supplies,” Kopser said. “Mer initial deployment, gliders nearly double the loads we can carry into a theater by air, not to mention, they’re the best possible resupply vehicles for paratroopers until we get a That’s because properly designed gliders can land heavy loads on un-prepatxi airships and drop zones, something the Air Force’s cargo planes can’t do; and that defines the issue.

Here’s the problem: currently, if we deploy the 82d Airborne Division or special operations forces, they must go to war without main battle tanks. in hours of commitment, but U.S. tanks may not anive for weeks. That’s a long time for the 82d to be a “line in the sand” as in Operation DESERT SHIELD, and it p.ecludes using tanks at all in special operations. (See “The 82d -me in Saudi Arabia” by CPT Sean Comgan on Page 32.) Seaborne transports are too slow for contingency operations, and geography limits their debarkation points. Plus, if the target nation is hostile, we might have to force a seaport as well support base going.”

Today, paratroopers an attack with-One battle precedent for glider-borne tank delivery was an unsuccessful one. The British 6th Airborne carried American-made M22 Locust light tanks in their Hamilcar gliders when they assaulted across the Rhine in 1945. Undergunned a d lightly armored. the Locusts were outdassed. The author‘s concept involves transport of the M-1 series in large, C-5A-towed gliders of a ”joined-wing’ design. PMO: ~.borpl sorirg MUSOW SeptemLwOcfober 1993 ‘1 j 5 : 0 4 0 - : p i , 7 2 6 1 FRONT VIEW

CG-140 GLIDER”

19.24 ft 100.08 ft.

SIDE VIEW

a Three-view Sketch of a Joined-Wing Glider Design as an airhead just to get tanks on the ground.

Because unfriendly nations are unlikely to host U.S. tank units, forward-deployed armor historically is in the “wrong place at the right time” for contingencies. And, as the U.S. closes strategic overseas posts, the chance of using pre-positioned tanks grows even slimmer.

Transporting tanks by cargo jets is only one M1 Abrams at time, and runway requirements preclude delivering that tank to paratroopen unless there are sophisticated airports. Yet, our post-cold war, potential adversaries arm themselves with main battle tanks, meaning our patatroopers must be ready to fight them. Like it or not, light infantry can’t move as fast and doesn’t pack as much punch as armor, which puts our toughest soldiers at a severe disadvantage. Though disadvantages are great for h a and movie heroics, big guns and tough armor are more practical when lives depend on the outcome. impratid. A C-5 G d ~ y can any And, just because our paratroopers are Bradley Fighting Vehicles and Ar-great warriors, that’s no excuse f a mored Gun Systems, using superior employing them to fight tanks without cunning, concentrated fires, and care-theirownmainbattletanks,especially ful tactics, can defeat main battle if we could provide them. tanks, so the story goes. “light armor.”

The currently correct solution lies in History says, ‘hot so.”

Tow Force and C-5 Excess Thrust @ 25,000 ft U ’ 0 160 260 300 460 500 6bO 700 800 900 Velocity (KTS) ~ m e point is, while Bradleys and the AGS have useful, “tank-destroyer“ places in our war-fighting mix, they are not tanks, and history indicates they cannot fight tanks on equal terms. They are also at a disadvantage.

The British army discovered the folly of such halfway measures during its March 1945 Rhine crossing.’ Thinking to defeat German tanks with “superior cunning, concentrated fires, and careful tactics,” the 6th Airborne Division flew in several U.S.-built M22 Locust light tanks aboard Hamilcar gliders.

Admittedly, the Locust was a 1941 design and obsolete by 1945; but it qualifies as a light tank going against heavy armor. Its thin skin warded off only small-arms fire, and its 37-mm gun and .3O-caliber machine gun hardly dented German tanks. predictably, it lost a lot more tank fights than it won.

The point is, while Bradleys and the AGS have useful, “tankdestroyer” places in our war-fighting mix, they are not tanks, and history indicates they cannot fight tanks on equal terms. They are also at a disadvantage.

So, experience shows the “light armor“ solution is no solution at all. If we try to fight real tanks with “almost tanks,” we’re likely to have the same problems and suffer needless casualties.

No, we need main battle tanks fight real tanks.

Hence, the M1 Abrams continues to be the best weapon to kill enemy tanks, as well as just about anything else on the ground. Main battle tanks offer devastating long-range firepower, all-weather mobility, and protection; and they do so in ways no other weapons system can. So logically, we must give our paratroopers main battle tanks, and there’s just one way to do that -jet-towed gliders much like the one our West Point engineers designed.

“There are some very good reasons to explore gliders again,” Kopser Mission Specifications for the M1 A1 Glider Delivery System Payload: Two combat-loaded MlAl Abrams tanks including crews Crew: Two pilots with safety and suMval equipment Range: 60 nautical miles from release point at 25.000 feet above ground level Altitude: 25,000 feet (Corresponding to the C-5s cruise altitude) In-tow Cruise Sped: 450 knots at 25,000 feet Powerplant: AuxiliIlly-power units Pressurization: 5,000 f t cabin at 30,000 R. Certification Base: Federal Aviation Regulation 25 and Military Specifications &d. “Gliders could perform better than parachutes. They’re more efficient for heavy loads because parachutes scatter forces over huge areas; and modem technology lets us overcome the World War 11 problems of structure, control, and nighttime navigation.”

“In fact, global positioning systems give us the ability to pinpoint a spot anyplace on earth, set up a software-only, instrument-landing system for that point, and put down the glider right where we want it,” Nygren agreed. “A computer in the cockpit could pick release points, glide speeds and angles, headings, and everything else. From an engineer’s point of view, the system is elegant and the software is simple.”

And jet engines mean tank-carrying gliders could fly.

‘The big problem is initial accelem-tin,” Kopser said. “The C-5 has plenty of power to tow this glider at approximately its best-range airspeed. We’re eager to get good data on C-141s and C-l7s, too; either plane probably could do it with the same load, and certainly could with only one tank, or maybe with one tank and a mechanized-artillery piece or a recovery vehicle. But takeoff is a problem we’ll have to research more.” So flying isn’t the problem. Takeoff is. “I think the best way to solve it will be some kind of JATO (Jet Assisted Takeoff), maybe with disposable rockets you can jettison after you get to cruise altitude,” Nygren said. That’s precisely the solution the Germans used. They blasted their biggest glider, the Gigant, into the sky with rockets behind a monstrous tow plane, the Heinkel 11 1Z. The Zwilling was two He 11 1 bombers joined at the wing with a fifth engine added at the junction. Of come the Zwilling itself was clumsy in the air, and the combination was very slow?

“Well, speed won’t be a problem with jets,” Nygren said. “Even with the increased load of a glider, they’ll still fly at or near best-range airspeeds. Increased power settings will degrade their range, but air-to-air refueling extends range as far as we need it.”

One big problem with World War 11 glider operations was the rapid obstruction of landing zones. Once a glider landed on skids, it stayed put, usually directly in the approach path of following gliders. If the glider landed on tactical wheels, soldiers inside could shove it out of the way, but the wheels extended the landing run, endangering the glider. The only way pilots could brake was to shove the control wheel forward and drag the nose in the dirt.

‘‘This glider will weigh between 25 and 35 tons and carry a 140-ton load,” Kopser said. “Though the belly needs to be tough enough for a wheels-up landing, we want to land on the gear if at all possible, and we’ve made that the best option in most cases. I’ve designed the glider to land at 75 knots airspeed, which means wheelsdown landings will require about a 2,130-foot roll on a hard-surface runway and less on soft surfaces. Historically, wheels-up landings require anywhere from ‘15 to ‘13 that distance. If we land wheelsdown, one of the Mls aboard can hook up to the glider and tow it off the landing zone. If we land wheels-up, that technique still should work. Besides, computers can gener-Author’s Note The author would like to thank Colonel Kip P. Nygren and Second Lieutenant George J. Kopser for their help in preparing this article. Colonel Nygren is a graduate of the U.S. Military Academy. He holds two M.S. degrees, one in Aeronautics and Astronautics and one in Industrial Engineering, both from Stanford University, and a Ph.D. in Aerospace Engineering from Georgia Tech. He has been on the USMA faculty more than nine years and currently is a Tenured Associate Professor there in the Department of Civil and Mechanical Engineering.

Second Lieutenant Kopser received a B.S. in Aerospace Engineering and his Armor commission from the U.S. Military Academy in 1993. Upon graduation from the Armor Officer Basic Course, he will be assigned to the 3d ACR at Fort Bliss, Texas. ate precision landing points anywhere on earth. We can land these gliders in formation a couple hundred meters apart, and they won’t get in each others’ way.”

One option is to extend the landing gear only slightly beneath the glider. Twelve inches ground clearance is more than enough for takeoff and landing on prepared surfaces and provides wheels for tow-away operations on tactical surfaces.

Are recovery operations a problem? “Nope, they’re a challenge, and there are plenty of options to examine.’’ Nygren said. “Joe’s designed this glider for easy disassembly. You can stow the wings inside the glider, tow the glider to an Wield, and insert the whole thing inside a C-5 for redeployment.

“Or, you could do an airborne snatch. The glider will weigh ‘16 its loaded weight after it discharges its tanks. It could cany in a couple of JATO rockets. The crew could attach them and blast out of the landing zone as a recovery jet approaches, possibly the very same airplane that delivered the glider in the first place. Remember, those rockets were powerful enough to propel the glider and two tanks into the air from a runway. They’ll be powerful enough to lift an empty glider from a tactical landing zone. Once airborne, the glider deploys a towing cable, and the recovery jet hooks up for a normal tow. For training, say at Sicily Drop Zone on Fort Bragg, the rockets might take the glider high enough for self recovery to Pope Air Force Base.”

What if the Air Force says it doesn’t have a suitable towing aircraft? ‘That’s just not SO,’’ Kopser said.

“The C-5 definitely can tow this glider. I expect my analysis will show the (2-141 can’ and the (2-17 will be able to also.”

And Nygren agrees.

“In World War 11, we towed gliders with just about anything powerful enough to do the job. DC-3s towed some pretty heavy loads, and even P-38 Lightning fighters towed Waco gliders on occasion.”

These two aerospace engineers have completed a preliminary design. “Joe’s purpose was to determine if Nygren said. “The bottom line is, it can. I think the need is there; and if it is, we should get to work on this glider.” this tank-cwing glider can Work,” Notes ‘Fitzsimons. Bernard (4). The Illurrrorsd Encyclopedia of 20th Century Wmpons and WorJore, V. 16. Columbia House, New Yo&. ’Mrazek. James B., The Glicicr Wor. St. 1978. p ~ .

1757-1760.

Martin’s Press. New Yo&, 1975, pp. 35-36. Major E. C. Parrish Ill is a Distinguished Military Graduate of Pennsylvania State University and holds an M.A. in journalism from the University of Missouri-Columbia. His 18 years of military service include combat in Grenada and Iraq, company command in the 160th Special Operations Aviation Regiment (Airborne), and assignment to the 1st Battalion (Ranger), 75th Infantry. A graduate of the Command and General Staff College and Armor Officer Advanced Course, he is assigned to HQ, U.S. Army Recruiting Command, Fort Knox, Ky. Additionally, has has authored seven magazine articles supporting the President’s 50th Anniversary of WWII

Commemorative Committee. He is a previous contributor to ARMOR.