Air Transportation: U.S. Army Goes Tiltrotor

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December 24, 2022: The U.S. Army has selected a tiltrotor aircraft, the V-280, to replace its 2,000 UH-60 transport helicopters. There will not be 2,000 V-280s because they cost about $25 million each, which is three times what most UH-6os cost. The V-280 is a smaller (14 ton) version of the older and larger (25 ton) MV-22 tiltrotor the Marine Corps has used since 2007. These cost $84 million each. The V-22 was developed by Boeing, an aircraft manufacturer while V-280 was developed by Bell, a helicopter manufacturer. The V-280 has the advantage of knowing all the problems the V22 had and came up with ways to avoid them. The success of that approach won’t be known until V-280s has flown a lot more hours. V-280 designers certainly appear to have avoided features responsible for V22 performance and cost problems.

While only 400 V-22s have been built so far (most of them MV-22s) total production is not expected to be more than 500. One reason for that will be the V-280, which first flew in 2017 and is expected to enter service by the end of the decade. At least four times as many V-280s will be built compared to the V-22. Most V-280s will be used by the U.S. military, mainly the army. Export sales are expected to be substantial. If sales are strong, the price per V-280 will come down to levels that justify a commercial version. This model would mean thousands of more V-280s in use by commercial firms.

Bell studied the V-22’s development and operational history to identify which items needed improvement to make the V-280 more capable and reliable. This resulted in three primary improvements. First, the V-280 airframe was built using composite materials for much of the airframe. These are lighter than metal airframe components and cheaper. Second came the engines to be used. V-280 uses engines similar to those used by the V-22. Both engines are built by Rolls Royce and have the same power ratings. Putting V-22 engines in the lighter V-280 gives it more agility and performance with less strain on the engines. Another advantage is that the V-280 operates more effectively on one engine. Changes in the design of the engine-tilting mechanism made the V-280 safe and more capable while operating on one engine. The third difference was improved electronics for flight, safety and increased usability for passengers. For example, the passenger seats wirelessly recharge the many electronic items troops carry. The V-280 is easier for troops to get in and out of. Compared to the V-22, the V-280 is more operator and user friendly.

The primary justification for the more complex and expensive tiltrotor aircraft over similar (carrying capacity) helicopters is that the tiltrotor is a much faster helicopter.

The V-280 is meant to be superior to the existing UH-60M transport helicopter. The 11 ton UH-60M can carry 14 troops, or 1.1 tons of cargo internally, or four tons slung underneath. Cruise speed is 278 kilometers an hour. Max endurance is two hours, although most sorties last 90 minutes or less. Max altitude is 5,790 meters (19,000 feet).

The 14-ton V-280 can carry 14 troops, or 1.1 tons of cargo internally, or 4.5 tons slung underneath. Cruise speed is 520 kilometers an hour (280 kilometers when carrying a slung load). Max endurance is three hours, although most sorties last about two hours. Max altitude with a full load is 1,800 meters (6,000 feet) in a hot climate, at least twice that in colder climates.

The larger V-22 was designed to replace the army CH-47F or navy/marine CH-53. The performance and reliability of the V-22 were not what the marines expected and they sought 200 CH-53K helicopters, for about $115 million each. This includes over a decade of development costs. Development took so long because the marines did not have enough cash to keep building the new V-22 while also keeping CH-53K development on schedule. Technical problems were blamed for the CH-53K delays but it was later revealed that the marines didn't want to take money away from their MV-22 program in order to keep the CH-53K program on schedule. It’s all about limited resources and aging equipment.

The CH-53K is a 34-ton helicopter with a payload of up to 15.8 tons internally or 16.3 tons externally (suspended under the helicopter. The cargo bay can hold up to six wooden pallets, five Half 463L Pallets or two Full size 463L Pallets. Three 3,000-liter (800 gallon) fuel containers can be carried for use in aerial refueling or delivery to ground forces. The 53K is also equipped to be refueled in the air. Up to 30 troops can be carried or 24 casualties on litters. The cargo load is nearly twice that of the CH-53D. Cruising speed is 310 kilometers an hour and endurance is about 2.8 hours. Combat radius is 200 kilometers and max range is 460 kilometers. Max altitude is 4.900 meters (16,000 feet).

In 2012 the marines finally retired the last of its CH-53D transport helicopters. Introduced in the late 1960s, 124 were built before production stopped in 1972. The CH-53D was to be replaced by 348 MV-22 tiltrotor aircraft, but delays in that program, and a reduction in the number of V-22s to be built, led to the CH-53K. While the CH-53K is a better cargo hauler, the MV-22 moves twice as fast and the marines have found that to be a major advantage in combat. But the MV-22 is more expensive to operate and the marines cannot afford to buy and operate all the MV-22s they need to replace older helicopters. That led to more upgrades for existing CH-53s and the need for a new model.

Periodic upgrades are the norm for military aircraft. For example, in 2013 the U.S. Navy began equipping 40 of its CH-53E transport helicopters with lightweight armor kits that provide protection from bullets and shell fragments. This feature is also available for the 53K. This CSA (Critical Systems Armor) uses lightweight materials like composites and only protects areas of the helicopter known to be critical. These modular vehicle/aircraft composite armor systems have become increasingly popular since the 1990s, for both helicopters and low flying fixed wing aircraft like American AC-130 gunships. Low-flying aircraft are vulnerable to damage from rifles and machine-guns, especially the larger caliber 12.7mm and 14.5mm models. If a bullet hits one of the crew or a vital component the aircraft can be lost, or at least forced to abort its mission.

Modern helicopters are also equipped with systems that automatically detect approaching heat-seeking missiles and deploy countermeasures. There are also systems that detect and locate the source of ground fire from automatic-weapons. Another area of constant upgrades is the cockpit where easier to use controls are always being developed as well as sensors for navigation. Military equipment not only has to deal with age but also obsolesce. That means you either evolve or die.

The complexity and low reliability of the V-22 was a major problem. Ten years after the V-22 first flew, the 300 V-22 Osprey tilt-rotor transports used by the U.S. military had spent 400,000 hours in the air. This was considered quite an achievement because the V-22 turned out to be a very complex aircraft that was very expensive to operate and, worst of all, deemed indispensable by its users. It was reliable and affordable enough to keep in service but there are still a lot of regrets over what else might have been done with all the time, effort and cash.

The marines are the primary user with 258 MV-22s in service and they are working on a number of upgrades that will result in a MV-22C model. This C version is designed to carry more weapons and operate more reliably and in just about any weather or visibility conditions that marines might encounter. Currently the MV-22C list of new techs that can be incorporated into existing and new V-22. This will probably include some of the best tech that the V-280 uses. V-22C is not expected to enter service until the 2030s. One reason for working on a C version is that some of the new technologies investigated can be adapted as upgrades for the current MV-22B. The marines also follow the upgrades SOCOM (Special Operations Command) gets for their more lavishly equipped CV-22s. The SOCOM CV-22s differ from the MV-22 in having larger fuel capacity and terrain following radar for night missions as well as electronic defenses. The marines often get called on to carry on missions similar to what SOCOM does and this makes it easier to justify the higher operating expenses of V-22s compared to traditional helicopters. This essential edge is mainly about speed.

With the growing use of special operations forces there is more need to keep these small but vital missions supplied. This has had some interesting side effects. The V-22 not only has higher operating costs but also requires more updates and modifications than conventional helicopters. Yet the V-22 has become too useful to drop, especially when it comes to supporting special operations forces or similar marine missions. An example of that is the introduction of a palletized aerial refueling system that quickly enables the MV-22B to become an aerial refueling aircraft. This VARS (V-22 Aerial Refueling System) is useful in many situations for refueling transports, fighters (F-18 and F-34), larger UAVs and, increasingly, special operations helicopters. The refueling system won’t be in wide service until 2018. VARS works by taking advantage of the V-22’s rear cargo door because that makes it easy to roll a pallet on or off. The VARS is mounted on cargo pallets and setting up (or removing) VARS in a V-22 takes only a few hours.

Accessories like VARS makes it easier for the U.S. Department of Defense to justify plans to buy 408 (or more) of the V-22s, most of them for the marines. A smaller number (51) of CV-22s were delivered to SOCOM by 2019. So far about 300 V-22s have been delivered, but the marines keep having second thoughts about buying more because of the escalating costs for maintaining them. Problems keep showing up that cost more money to deal with, especially when the V-22s are used under combat conditions in hot and dry (as in dusty) conditions.

There have been successful efforts to fix problems as they arise. In 2012 the marines began receiving the new "Block C" version of the MV-22B. This one has better weather radar, improved cabin climate control, better anti-missile defenses, and flat screen displays in the cockpit and cabin that show what external cameras see from different positions on the exterior of the aircraft (improved situational awareness). All this is important for an aircraft that takes off and lands like a helicopter, then speeds away like a fixed wing aircraft. This speed has proved to be very useful in combat, as it is more than 120 kilometers an hour faster than the helicopters the V-22 replaced. Block C helped with brownout but did not eliminate all the brownout risk.

While users of the V-22 are happy with their unique hybrid, the accountants are less pleased. Since 2009, users have been struggling to increase V-22 readiness (ready for action) rate from 50-60 percent to the 82 percent that the manufacturer had originally promised. The problem is that, despite being a wonderful feat of engineering that is now proved itself capable of serving in a combat zone, the V-22 is mechanically very complex and expensive, as well as being difficult to keep operational. The V-22 has had lots of trouble with costs and reliability even though it has been flying since 1988. Helicopters like the UH-60M and CH-47F have readiness rates of 90 percent.

Since the V-22 entered service the estimated lifetime cost of operating the aircraft has increased 64 percent to $121.5 billion.

The MV-22s used by the marines can carry 24 troops 700 kilometers (vertical take-off on a ship, level flight, landing, and return) at 390 kilometers an hour. The V-22 is mainly replacing the CH-46E helicopter, which can carry 12 troops 350 kilometers at a speed of 135 kilometers an hour. The V-22 can carry 4.5-ton external sling load 135 kilometers, while the CH-46E can carry 1.4 tons only 90 kilometers. The marines are using the faster speed of the V-22s to reach the enemy in a more timely fashion, and run more flights than a helicopter, in the same time. The V-22 also operates better at the higher altitudes encountered in Afghanistan but much of Afghanistan (and other areas popular with Islamic terrorists) is hot and dusty and that reduces V-22 reliability and increases maintenance costs. All this has made V-22s especially useful for SOCOM operations and the sort of jobs the marines see themselves getting in the near future.

 

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