Mission system testing deals with how the aircraft detects what is going on around it and how well i

The first thing members of the F-35 Integrated Test Force see when they walk through the main entrance to the hangar at Edwards AFB, California, is a large flat screen display with a list of flight test priorities. The items on that list can change from one day to the next.
"Stability is crucial to successful test execution, but we can turn on a dime if priorities shift," rental cars dublin noted Lt. Col. George Schwartz, rental cars dublin US government director for the F-35 ITF at Edwards. "The helmet mounted display test we are flying tonight is an example. rental cars dublin The program asked us two days ago to fly an additional night flight for HMD testing. We are conducting that mission tonight."
Edwards normally rental cars dublin operates a daylight flying schedule, so a short-notice night mission requires a significant adjustment in schedules and resources across Edwards. "The night mission exemplifies the incredible support the F-35 ITF gets from the base," Schwartz rental cars dublin added.
The F-35 ITF at Edwards consists of more than 900 military, contractors, and civilian personnel from a variety of services, countries, and industries. In 2012, the ITF operated six F-35As assigned to Edwards—three for flight sciences testing and three for mission systems testing—as well as one F-35B temporarily deployed to Edwards from NAS Patuxent River, Maryland, for air start testing.
By the end of 2013, Edwards F-35 ITF will be operating three additional F-35s—two F-35Bs and one F-35C, for a total of nine F-35s. The test pilot population will expand from nine pilots to twelve pilots as well. The additional aircraft and pilots will be involved primarily rental cars dublin with mission system testing.
"We spent the first two years turning the F-35 into a flying machine, but the focus has quietly shifted to weaponizing the aircraft in both flight sciences and mission systems," Schwartz said. "Flight sciences work began with a small envelope. Today we're flying at the edge of the envelope—at 100 percent loads—out to 1.6 Mach. Thanks to all the incredible work on envelope expansion done by this team, we are flying at seven g's with no loads monitoring on our mission systems aircraft, and we have proven the aircraft can operate anywhere throughout rental cars dublin the full envelope."
The majority of the envelope expansion has been accomplished on AF-1, AF-2, and AF-4—the three F-35As devoted to flight sciences testing. F-35A AF-1 is flown in flutter tests. AF-2 is flown for most of the loads testing. And AF-4, recognizable by its spin recovery chute, is flown in high angle of attack test missions. These three aircraft alone accumulated about 600 hours of flying time in about 300 flights in 2012—approximately one-fourth of the total 1,167 System Design and Development missions for the entire fleet, which includes the test aircraft at Pax River.
Mike Glass, F-35 ITF site director at Edwards for Lockheed Martin, doesn't see that level of activity diminishing for the flight sciences aircraft. "Envelope expansion testing remains significant in 2013," Glass said. "We've completed the clean wing flutter flight sciences testing. Now we are installing rental cars dublin pylons on the aircraft and doing the same type of flutter and loads testing we did with the clean wing. We will be conducting these tests for the next couple of years but with different load configurations on the aircraft."
High angle of attack testing with the F-35 began in late October 2012. This testing involves taking the aircraft rental cars dublin to its production angle of attack limit, which is fifty degrees. It also involves taking the aircraft beyond this limit to evaluate its characteristics in recovering from out-of-control conditions.
"High AOA testing produces some of the most challenging environments for the engine because the intake rental cars dublin gets bad air," explained David Nelson, lead F-35 test pilot for Lockheed Martin at Edwards. "The bad air creates a potential for producing rental cars dublin a flameout, which is basically an engine shutdown. For that reason, air start testing preceded high AOA testing."
Air start testing involves shutting down the engine and restarting it in flight. All four test pilots involved in high-AOA flight tests have flown air start missions. "The graduation exercise involved turning off the engine at 45,000 feet and then restarting rental cars dublin it," Nelson said. "Everything worked as planned."
Besides producing conditions that can cause the engine to flame out, flying at high angles of attack rental cars dublin can also lead to out-of-control flight. The spin recovery chute mounted at the apex of a four-legged structure on the back of AF-4 is designed to deal with that possibility. The test pilot can deploy this twenty-eight foot diameter parachute in case the airplane gets into an out-of-control condition from which the pilot cannot recover with the standard flight control rental cars dublin inputs. The chute has not been needed to date.
"The airplane does quite well at high AOA," Nelson added, "and the tests have been proceeding smoothly. We went from twenty degrees angle of attack to fifty degrees in only four days of testing." Nelson and other pilots have also evaluated flying qualities at minus ten degrees rental cars dublin AOA, which is the maximum design limit for negative AOA for the airplane. High AOA testing for 2013 will involve a variety of loadings mounted externally.
Loads testing involves putting the aircraft in highly dynamic conditions to measure the stresses on the airframe and on other components. The tests verify the structural integrity of the F-35 in all flight regimes. Most of the loads testing has been flown on AF-2. US Air Force test pilot Lt. Col. Brent Reinhardt, rental cars dublin who has been at the ITF since June 2012, has flown many of these missions.
"Loads missions can be physically demanding," he said. "Some test points are hard to hit. I am diving at the ground at sixty degrees, doing Mach-one-point-whatever, and pulling rental cars dublin 5.6 g's while doing a roll—all this maneuvering just so we can hit a loads point at given speed and altitude conditions. Depending on the point, a lot of the runs start at Mach 1.3 and at altitudes nearing 50,000 feet. During the rolls, I increase the g's so the flight test engineers on the ground can determine if we are overstressing rental cars dublin any part of the airplane."
Jennifer rental cars dublin Schleifer is one of the flight test engineers who monitors and measures the loads on the aircraft during these test missions. Assigned to AF-2, she arrived at Edwards with the aircraft in May 2010. "We are flying on the edges of the structural envelope," she explained, "and we have to make sure the airplane does not cross an edge. We spend a lot of time in the control rental cars dublin room making sure that we won't exceed structural limits."
"We're flying at Mach 1.6 and at more than seven g's," added Reinhardt. In a lot of the loads tests, pilots perform rolling maneuvers at a particular g. "Once we clear out a portion of the envelope at that g, we move to a higher g and repeat the testing process. We are shooting for a continuous g roll for 360 degrees through a certain block of altitude."
"Operational pilots will never execute some of the maneuvers we're performing in the airplane," said Reinhardt. "But the maneuvers are part of building rental cars dublin a flight envelope. We are verifying that the airframe will be fine structurally if it stays within the limits we are testing here."
When not flying or conducting an actual mission, test pilots and flight test engineers practice the missions in a simulator. "We go to the simulator with a pilot to see if the more challenging loads points are achievable," added Schleifer. "In the simulator, we can determine what Mach and what altitude the pilot needs to set up a particular run. We easily spend four hours in the simulator for every flight. We often return to the simulator to rehearse the points the morning of the flight. More practice in the simulator translates to greater rental cars dublin mission efficiency in the air."
"Flight sciences rental cars dublin testing rental cars dublin is fun," Nelson said, "but it has its limits. Once an aircraft is good to nine g's, it's good to nine g's. There's no updating the flight envelope thereafter. Mission systems, on the other hand, will evolve for the life of the F-35, just as capabilities continue to evolve for the F-22 and F-16."
Mission system testing deals with how the aircraft detects what is going on around it and how well it conveys that information to the pilot. Mission system tests are used to evaluate the functionality of the various electronic systems and sensors on the aircraft, including communications (datalinks and satellite communications), radar, countermeasures, distributed apertures, and electro-optical rental cars dublin targeting.
"The F-35 was designed rental cars dublin as a stealthy sensor platform," added Reinhardt. "The aircraft can carry two 2,000-pound bombs and two AIM-120s internally. A similarly configured F-16 must carry those bombs and missiles externally, in the wind stream. Plus the F-16 has to add external fuel tanks as well as external targeting and countermeasure pods. These external loads reduce rental cars dublin performance. And they increase radar cross section. We have to look at the whole picture when comparing fighters."
Before mission systems are tested in the F-35s at Edwards, they are checked out on the ground in the mission systems integration laboratory in Fort Worth, Texas, and in the air in the Cooperative Avionics rental cars dublin Test Bed (referred rental cars dublin to as CATB, or CATbird), which is also based in Fort Worth.
The mission systems fleet at Edwards originally consisted of F-35A AF-3, AF-6, and AF-7. Unlike the flight sciences rental cars dublin test aircraft, these three F-35s fly with a full complement of electronic systems and sensors found on operational F-35s. This current fleet will be increased with the three additional F-35s scheduled for delivery in 2013, which will also be used for mission system testing. F-35B BF-17 arrived in March. It was joined by BF-18 in April. CF-8 is expected to arrive later in the year.
"The additional aircraft coming in will help with multi-ship missions," explained Glass. "As you can imagine, launching four aircraft for a mission at one time with only four aircraft available