|Photo courtesy Naval Air Systems Command
A small software tweak is improving the operational performance of the V-22 Osprey tiltrotor, according to tests performed by the Naval Air Systems Command (NAVAIR).
NAVAIR said a test team from the V-22 Joint Program Office spent about six weeks in Logan, Utah, confirming that a small software change will result in more lift capability for the Osprey. The actual change, which is barely observable to the eye, calls for the V-22 rotors to be tilted about four degrees outward. This change reduces the air flow from the rotors over the wings, which allows the V-22 to carry more weight and achieve greater overall performance in hover mode, according to NAVAIR.
The flight control computer software, which was designed as a collaborative effort between the Navy, Bell-Boeing and BAE, is loaded on each aircraft and functional tests are performed in accordance with technical directive instructions, according to a V-22 program official.
Improving the performance of the aircraft was the goal of the study. Over the years, hardware has been added to the aircraft increasing its weight. The program recognized the need to increase hover performance and contracted Bell-Boeing to conduct a design trade study, according to program officials.
“We did see the performance gain from the software change that we expected,” said Trevor Strand, V-22 flight test engineer. “It gives the pilot more options. He can either carry more fuel, more troops, go to higher altitudes, or some combination of the three.”
V-22 program officials are still analyzing the data gathered from these tests, but said "preliminary results are positive for significant increases in hover performance. A concrete conclusion can be made when all data is analyzed."
Strand led the 30-person integrated test team during the off-site test at the Logan-Cache Airport during July and August. The team flew 25 test flights in 31 days. This effort was the result of about two years of work by NAVAIR engineers to improve the hover performance of the V-22.
The software change that was measured and confirmed in Logan has already been implemented into some MV-22s. The plan is to upgrade all 152 V-22s by the end of the year, NAVAIR said. The test team is currently updating performance documentation for V-22 operators.
“We don’t like to do all of our hover performance testing at sea level because the proprotor is not working at its maximum limits,” Strand said. “We don’t want to max out the engines at a very high altitude like 9,000 feet either so the ideal location is somewhere in between.”
At about 4,400 feet in elevation, Logan provided an ideal test location including the required wind conditions. “It was one of the most successful off-sites that we’ve ever had,” Strand said.