Vow to 'Support Ground Troops' Rings Hollow

For sheer sophistry, deception and delusion, it is hard to top the status report "100 Years of Marine Corps Aviation" that appeared as an advertising supplement arriving in this former Marine's Washington Post newspaper on 2 May 2012. My view is that Marine aviation is now broken, riven by exploding costs, starkly troubled development programs and, above all, the triumph of technical wants over tactical needs.

The Marine Corps could have had superior flying machines at dramatically less cost to acquire and maintain. There is an old aphorism about "pride goeth before the fall" that certainly applies. The country cannot afford these habits and the junior Marines at the "pointy end" deserve better for tactical support.

The eight-page supplement was dominated by breathless paeans to the Marines' two dominant aircraft modernization programs, the V-22 tilt-rotor, a troop hauler which takes off and lands like a helicopter but flies like a turboprop airliner, and the F-35B, a jet that will similarly be capable of short take-offs and vertical landings but fly to the battlefield at supersonic speed.

Neither machine will deliver on its heady promises.

Consider first the V-22, now equipping Marine squadrons after a troubled development program spanning two decades, the usual cost overruns, two failed operational tests, belated fixes and missed performance requirements.

Two photographs showing head on and side view of the V-22 aircraft

This airplane, nearly as big as the CH-53E heavy lift helicopter, was ostensibly intended to replace the venerable CH-46. The V-22's troop cabin is markedly smaller than that of the CH-46. The cabin is not only cramped, it lacks windows for the troops to orient themselves as the V-22 comes in for landing. And the V-22 descends into the landing zone very carefully, lest controllability be lost and the aircraft careen wildly into the ground. The aircraft descends at a rate of about 800 feet per minute, or roughly 9 miles per hour (slower than the driving speed limit in a school zone), on a flight path that is predictable to enemy gunners. The V-22 has never been tested against the kind of rocket propelled grenades likely to be launched in droves.

The term "sitting duck" does a disservice to the agile avian; the V-22 is more like a very slow clay pigeon.

The prop wash from the V-22's rotors is fierce, kicking up a cloud of dust, rocks, branches and whatnot. The debris cloud is greater than for a standard helicopter. This is because the V-22's "disk loading" is higher (the amount of air pushed through its rotors in helicopter mode). If the enemy has not divined the location of V-22s landing, a quick scan for sudden dust clouds billowing up will be sufficient to give the game away.

Marine officials have compared the V-22 to the aged CH-46 helicopter, a smaller, lighter, obsolete helicopter that saw service in the Vietnam war.

Photograph of a CH-46 Helicopter

The match-up stacks the deck. They are contrasting the V-22 with a helicopter that has 1/6 the power, 1/3 the weight and represents 40 year old technology.

They have not judged their acquisition against available, modern combat helicopters. The CH-53E helicopter now operated by the Navy and Marines is a revealing comparison for its relative size, power and span of rotor disk.

Photograph of a CH-53E helicopter

Here's some salient data:





2 engines x 6,150 = 12,300 HP

3 engines x 4,148 =

12,474 HP

Same installed power

Empty weight

33,140 lb

33,235 lb

Same empty weight

Maximum hover weight

47,500 lb

69,750 lb

On a hot day

Useful load

14,360 lb

36,500 lb

Helicopter carries 2 1/2 times as much

Cruise speed

240 knots

150 knots

Tilt rotor is 1.6 times faster

The tilt rotor's greater speed does not make up for less payload (speed x payload = ton-miles/hour). Using the metric of ton-miles/hour, the CH-53E has a 55% advantage at 50 NM and a 25% advantage at 400 NM.

The CH-53E's lower acquisition costs ($40 million each) puts the productivity comparison even more against the V-22 ($80 million each). In terms of ton-miles per hour per million dollars, the CH-53E has a 2 to 1 productivity advantage at both 50 NM and 400 NM.

The dollar figures are a few years old. The V-22 now costs $116 million apiece and the CH-53K (yes, K, indicating the CH-53E has been supplanted with a K version) has a sticker price of $133 million. The CH-53E option may be overtaken, but the $80 million-versus-$40 million cost comparison applies to other state-of-the-art helicopters that would do the job advantageously in terms of ton-miles per hour per million dollars. Suffice to say, Defense Department costs are out of control.

Why does the tilt rotor carry less? The V-22 has two rotors, each of 38 foot diameter, placed at the end of the V-22's stubby wings. The CH-53E has one large 79 foot diameter rotor.

Rotor size determines hover power needs. And large rotors act on a larger air mass, requiring less velocity change. In other words, large rotors need much less power to do the same job.

"Disk loading" bears some brief discussion. The term refers to the weight of the tilt-rotor or helicopter divided by the rotor disk area. The higher the disk loading, the more power is required. With 2,270 sq ft of combined disk -- 50% less than the CH-53E -- and the same power as the CH-53E, the tilt rotor has a disk loading of 21 pounds per square feet at maximum hover weight. With its 4,900 sq ft rotor, at maximum weight the CH-53E has a disk loading of 14 pounds per square foot.

This is a graph showing the correlation between disk loading and hover lift efficiency

This explains the ability of the CH-53E to carry a larger payload for the same power.

I have long thought the Marines should have seriously considered an all-CH-53E helicopter fleet. The CH-53E could have been armored to better protect the crew and troops, and a chin-turret mounting a machine gun would have provided suppressive fire during final descent. The helicopter has so much carrying capacity that the added weight of these features could easily be accommodated. The Marines could have modernized their helicopter squadrons at half the price of the V-22 effort, sooner, and they would have had a fast, armored, armed machine with tremendous capability in light of the V-22s many limitations.

Photograph of an AV-8B Airplane

The Marines covet the F-35B as a replacement for the AV-8B Harrier jump jet. Like the AV-8B, the F-35B will feature vectored thrust for short take off and vertical landing (STOVL). Think of vectored thrust as a small rotor inside the fuselage. The Harrier engine has a disk loading of 1,500 lbs per square foot. As such, it needs a lot of thrust and fuel to hover: 21,550 lbs of thrust and 13,000 lbs per hour fuel flow -- about a 30,00 horsepower equivalent.

The F-35B will require 50,000 hp to hover. It will feature a powerful, thirsty engine.

This is a photograph of a F-35B Fighter Jet

As in the case of the AV-8B, the F-35B in the STOVL mode will be severely limited as far as carrying useful ordnance for close air support.

A critic of the AV-8B as a close air support platform quipped that wrapping a hot gas turbine engine with non-self-sealing fuel tanks is an obscenity. The airplane is terribly vulnerable to enemy ground fire, as evidenced by loss of 10% of the AV-8B force in the first Gulf War to eject Iraqi forces from Kuwait.

The AV-8Bs operated conventionally from a paved runway in Saudi Arabia to maximize the plane's payload, but survivability was terrible.

Photo of an A-10 Airplane

Air Force A-10 jets, however, proved not only survivable but highly capable of supporting ground operations. The airplane's 30mm cannon proved devastating against enemy tanks (and just about any other target caught in the open). With armor and four main wing spars (as opposed to the usual two), the A-10 proved itself capable of taking incredible damage and remaining flyable. One grateful A-10 pilot returned to base with three of his four wing spars severed.

The AV-8B cannot carry the A-10's 30 mm gun. As for other ordnance, I recall a typical radio transmission from an AV-8B pilot to troops on the ground: "I've got 5 minutes of gas; where do you want these bombs?"At the end of Gulf War, a Marine Corps after action report judged a single A-10 as roughly equivalent to having 12 or more AV-8Bs.

Expect F-35B pilots to radio, "I've got three minutes of gas ..." and, with fewer bombs carried internally rather than slung under the wings, the F-35B pilots will have less ordnance to disburse.

The Air Force, unwilling to support troops in contact, promptly retired more than half its A-10 force after the Gulf War. Hundreds of these tough, effective airplanes are mothballed in the American desert. Instead of investing billions of dollars in the delicate F-35B, the Marines could seek to operate about 300 A-10s at the cost of painting "U.S. Marines" on the sides of these superb "mudfighters".

The Marines have pursued technological wants in lieu of tactical needs. They have got, and will have, flying machines of marginal tactical utility at huge expense in dollars, time to acquire, and credibility.

As a former Marine, I find current trends in Marine aviation dismaying, for they reflect a myopic technical enthusiasm without regard to relevant performance in the unforgiving arena of the battlefield.