C-17 Undergoes Upgrades to Extend Life in Pacific


The last C-17 to ever roll off a Boeing production line was delivered to the Air Force in September, but that doesn’t mean the Globemaster will fade into retirement anytime soon as service officials expect the airlifter’s mission set to expand as the U.S. military pivots its focus to the Pacific region.

In service since the early 90’s, the Air Force’s C-17 fleet is engineered to carry heavy payloads such as equipment and armored vehicles, and deliver or air-drop battlefield supplies, said Col. Glen Downing, Chief, Mobility Division.

The Air Force has 222 aircraft in its fleet with the first 152 lagging behind the 70 most recently delivered aircraft. In order to upgrade the first group of C-17s, the Air Force has launched a modernization program to add the latest electronics, radios and avionics and standardize the entire fleet.

Downing explained that the Air Force will need to rely more heavily on the C-17 in the Pacific because the C-130s have limitations in the Pacific when it comes to flying greater distances.

“There is a range challenge there. Moving stuff with C-130s in the Pacific is limiting. It can be tough to come from the U.S. and get where you want to go,” Downing said.

At a length of 174-feet and a height of 55-feet, the four-engine C-17 is larger than a C-130, but smaller than the service’s hulking C-5 aircraft which must land on a large concrete runway. Engineered with four Pratt & Whitney F117-PW-100 turbofan engines, C-17s can fly up to altitudes of 45,000 feet and reach speeds up to 450 knots, Downing explained.

“In many ways you get the capability of a C-5 as far as what you can carry combined with the performance capability of a C-130.” said Downing.

Downing emphasized the aircraft’s austere or “short field” landing capability, praising its recent performance in Afghanistan. The plane is engineered to land on a short field because thrust from the motor blows over flaps when the aircraft comes into land, providing additional lift at slower speeds, Downing explained.

The Air Force’s 222 C-17 aircraft are designed to fly for 30,000-flight hours or reach 30-years of service. The last ten aircraft cost $225 million each, said Maj. John Vinson, Program Element Monitor, C-17.

The 70 most recent C-17s were engineered with all of the latest technological gear including electronics, radios and avionics that will now be installed on the first 152 over time, Vinson explained.

“We’re going back and retrofitting the early aircraft and adding modifications to these aircraft. The goal is to get a common configuration that is going to lead to efficiencies in scheduling and an ability to maintain the aircraft,” Vinson explained.

The Air Force plans to spend somewhere between $150 and $200 million per year on these modifications through 2018, service officials said.

Many of the modifications, which are slated to finish up by the end of fiscal year 2015, involve the addition of communications technology such as radios, antennas for Satcom, weather radar, combat lighting for night vision and something called the Formation Flying System – a technology which allows planes to fly in formation in bad weather or obscured conditions.

“I can fly in formation in close proximity to another airplane without being able to see that airplane. You get a display which shows you the formation – you can tell how far they (other planes) are away from you. It also gives you cueing information on your instruments,” Downing explained.

The modifications are being performed at Boeing Support Systems, San Antonio, Texas, and Warner Robins Air Logistics Center, Ga.
All C-17s since the delivery of aircraft number 71 have been built with an Extended Range Retrofit, an additional fuel tank on the center wing section of the aircraft designed to increase fuel capacity by 9,600 gallons and add up to 600 nautical miles of range to the aircraft, Vinson said.

Another of the ongoing improvements to some of the older aircraft is a survivability initiative called “On-Board Inert Gas Generating System II,” a method of lowering the fuel tank oxygen content to reduce the change for combustion should it be hit, for example, by small arms fire.

“Vapor from fuel is what is dangerous. Nitrogen fills the air portion of the fuel tank so you don’t have that vapor. So you can shoot it with small arms and you are not going to ignite the fuel,” Vinson said.

The C-17 modernization effort is also integrating a new glass cockpit display called a Heads Up Display which improves the flight instrumentation showing altitude, terrain maps and what’s called “attitude” or position of the plane in relation to the ground, Vinson explained.

Certain C-17s are also getting upgraded with a survivability system called Large Aircraft Counter Measures – a high-tech laser jammer designed to detect incoming heat-seeking missiles and jam their flight path, throwing them off course. While many of today’s C-17s are already equipped with this system, there are some airplanes that this is being retrofitted on to.

Thus far, 159 C-17s are equipped with some version of the technology with the remainder slated to be finished by 2017, Vinson said.

One analyst said the C-17 modernization effort may even need to extend beyond its current plan.

“The next step may be a broader service life extension program for the C-17. The fundamental issue is every couple of decades there’s a new strategic airlifter built. Right now, there is nothing in sight so it is important to make the existing force last and make sure it is sustainable,” said Richard Aboulafia, Vice President of analysis at the Teal Group, a Virginia-based consultancy.

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