Murphy's Law: Brownout

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March 29, 2016: V-22 Osprey tilt-rotor transports are being defeated by high costs and too much dust. The U.S. Department of Defense wants to buy 408 of the V-22, most of them as MV-22s for the marines. A smaller number of CV-22s are going to SOCOM. So far 220 V-22s have been built but the marines are 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. This is not unique to the V-22, just worse. For example AH-64 Apache helicopter gunships suffered 17 accidents during the month long advance on Baghdad in 2003. Most of these accidents were caused by brownout. When a helicopter is close to the ground, and there’s a lot of dust around, the air pushed down by the rotors causes a cloud of brown dust, or brownout. The problem is particularly common, and severe, in Iraq, and Afghanistan. It was a new experience for many pilots, and many became so disoriented that they ran into the ground, or turned the wrong way and had their rotors hit something. Most of the accidents did not destroy the helicopter, or kill anyone. But in all cases, the gunship was out of action for days, weeks, or even months, as repairs were made. With the V-22 brownout is more serious because it was eventually discovered that too much dust (sand was stopped by filters) jammed up the turbine engines and there was no easy way to keep the dust out. Many engines had to be replaced or required expensive repairs and more time-consuming maintenance. At least four serious accidents (heavy damage and or fatalities among those on board) were definitely linked to brownout and another six were probable brownout losses.

Until recently the marines downplayed the role of brownout but eventually the truth got out. Partly this was due to the limitations put on how long pilots could operate under brownout conditions. First it was limited to 60 seconds and then to 35 seconds. This was not attributed to the risk of hitting the ground but must V-22 crews knew it was about engine failure too. It was also noted that many accidents involving brownout were blamed on “pilot error” yet none of the pilots involved were punished. It was also noted that even 35 seconds in brownout conditions caused problems with the engines and that meant there were a lot of situations where V-22s could not be used at all if there was risk of brownout.

When there is no brownout to deal with the V-22 works great. In 2012 the marines began receiving the new "Block C" version of the MV-22. 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 replaces. Block C helped with brownout but did not eliminate all the brownout risk.

The SOCOM (Special Operations Command) CV-22 differs from the MV-22 in having larger fuel capacity and terrain following radar for night missions as well as electronic defenses. SOCOM has also had brownout problems but less so because of their terrain following radar. Since it entered service in 2007 V-22s have flown over 200,000 hours.

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 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.

Since the V-22 entered service the estimated lifetime cost of operating the aircraft has increased 64 percent to $121.5 billion. Although the major user (the U.S. Marine Corps) has had an excellent safety and reliability record, despite the brownout problem, the MV-22s are very expensive compared to the helicopters they replaced. This is especially true when it comes to operating and maintenance expenses. In response to this, the marines are seeking to buy 200 CH-53K helicopters. These are slower (315 kilometers an hour) but carry more, are more reliable, and cheaper to operate.

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 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 a 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 reduced V-22 reliability in increases maintenance costs.

 

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