Article

Block III Apache helicopter tests nearly complete at YPG
Mark Schauer
September 5, 2012
Though the Apache helicopter has long been known for its lethal air-to-surface missiles, the aircraft's pilots also count on its 30 millimeter M230 chain gun to take the fight to the enemy. Tests of the software that ensures its accuracy have been part of the Block III Apache testing conducted at YPG for over three years. Accomplishing these tests safely and accurately takes the efforts of a variety of support personnel, including workers who reload the aircraft's chain gun, as seen in the lower photo.(Photos by Mark Schauer)

A primary responsibility of Yuma Proving Ground is to support developmental testing designed to assess improvements to existing weapons systems, even on platforms considered the most lethal of their kind, such as the AH-64D Apache Longbow attack helicopter. Having been involved in Apache testing for over 30 years, the Air Combat Systems Test Directorate boasts a huge amount of institutional knowledge and experience.

This knowledge has been brought to bear across the extensive Apache Block III improvements to the long-serving airframe that have been taking place at the proving ground since 2009. The latest version of the Apache boasts a wide array of upgrades, from a new engine and transmission to instrumented flight capability normally associated with large airplanes. More excitingly, the gunner aboard the updated Apache is able to control an armed, fully functional unmanned aerial system (UAS) from the cockpit.

Survivability is a critical component of any attack helicopter, and the Apache has been designed as a heavily-armored fortress. It has proven to be a robust aircraft with a remarkable ability to return to friendly territory and land safely even when severely damaged by enemy fire. Yet the Apache is no lumbering behemoth: its primary defensive strategies are stealth and evasion, and the aircraft is particularly adept at low-altitude flying as a means of escaping radar detection. It has always been identified with state-of-the-art sensors and precision guidance systems, as well as lethal air-to-surface missiles.

The aircraft's M230 30 millimeter chain gun in a turret below the cockpit is another deadly part of its arsenal, capable of firing hundreds of rounds per minute. As the aircraft reacts to the powerful gun's recoil during firing, however, the gun's pointing angle moves. Without sophisticated software that corrects the aim point of the gun, the rounds would be thrown off target as the aircraft bends. To prevent this, YPG testers have recently conducted over 25 test flights in which the fire control and targeting systems were put through their paces against a variety of stationary targets from multiple angles that simulate actual combat conditions.

"The purpose of this subtest is to take a random sampling of multiple aircraft and characterize the shift of individual turret and air frames fired at various angles," said Pat Franklin, test officer. "Each airframe has a slightly different variation, and characterizing these differences allows designers to find a best-fit software for the entire fleet."

To accomplish this type of testing, YPG evaluators use a massive target 70 feet tall and 30 feet wide and covered with thick armor plating. The chain gun's 30 millimeter bullets pepper the black and white checkerboard pattern painted onto it as the aircraft fires from different angles and elevations, sometimes from a stationary hover, sometimes at high speed while approaching the target, but always with test officers and support personnel watching a live video feed and gathering real-time data in a mission control room.

It is necessary to refuel the aircraft and reload the chain gun during a long day of testing, and while ground crews perform these tasks, other workers rapidly lower the target with a large winch and counterweight and touch up the chipped paint, making the target ready to go without any degradation to the uniformity of test data across multiple tests.

Though the final gun accuracy performance testing later this summer will conclude the Block III testing, YPG testers expect an extensive new round of updates to the venerable attack helicopter to take place within the next two to three years, all of which will require careful evaluation prior to fielding it to troops.

"This is the greatest place in the world for our purposes," said Dan Girardin, Boeing Flight Test Engineer. "The support here is always perfect, the weather is ideal, and the facility has all the capabilities we need for testing." YPG Outpost