As I stepped off the C-2 Greyhound, I was immediately welcomed aboard the USS Dwight D. Eisenhower by a blast of hot exhaust pouring out of two Pratt & Whitney F135 engines. Chained to the deck while hot refueling and accompanied by a swarm of colored shirts, two Lockheed-Martin F-35C Lightning IIs from Air Test and Evaluation Squadron 23 (VX-23) were already well established into the day’s testing when our COD (Carrier Onboard Delivery) trapped aboard the Mighty Ike.
The pair of JSFs and approximately 200 members of the F-35 Patuxent River Integrated Test Force (ITF) deployed aboard the Eisenhower during the first two weeks of October for the Developmental Test Phase II, otherwise known as DT-II. Following the first round of testing aboard the Nimitz last November, DT-II further expanded the testing on the aircraft’s flight envelope and aircraft carrier integration.
DT-II marks yet another major milestone as the F-35C marches towards initial operational capability (IOC) for the Navy, expected in 2018. Though it is the last variant expected to reach IOC, getting the aircraft to that point takes more effort relative to a solely land-based version like the USAF’s F-35A.
“Essentially what we’re doing is sea trials for the aircraft… we’re testing the handling qualities of the aircraft in, around, and behind the ship, especially on approach” says U.S. Navy Commander Ryan “Flopper” Murphy, director of test and evaluation for the F-35 Naval Variants. “We’re focusing on the basics of getting the aircraft operating around the ship: launching it, recovering it, and maintaining it.”
Commander Christian “Wilson” Sewell, F-35C test pilot and government flight test director for the Patuxent River-based ITF, elaborates:
“The whole point of this developmental testing is we need to get a jet to the fleet that can take off and land reliably on the boat, with an easy workload and good handling qualities. The way we do that is through our developmental test I, II, and III periods… We’re expanding the envelope a little bit to include the aircraft launch and recovery bulletins. We’re testing multiple wind-over-deck scenarios, and during this period we’re focusing on high-wind (around 40 knots) coming across the landing area on the carrier. What we’ve seen is the handling qualities are all Level 1 – what we call low workload – even in a high-wind scenario. We’ve also seen minimal touchdown dispersion, so we’re reliable about putting the jet right where we want to on deck.”
Some of the last test points being tested during DT-II were also some of the most hazardous to plane and pilot. For example, the aircraft was subjected to several minimum energy catapult shots utilizing both afterburner and mil power.
“This is a key test for us, because we’re doing what test pilots go to school for,” explains Rear Admiral John Haley, Commander Naval Air Force Atlantic. “Theoretically we know what the airplane is supposed to do because of all the work the flight test engineers have done. While it sounds pretty simple, it’s probably one of the things that creates the most pucker factor for a pilot because you’re exploring the bottom edge of the envelope – ‘speed is life, more is better’ – and now we’re purposely reducing the speed to validate the reality with the theoretical engineering data.”
Tom Briggs, F-35 Air Vehicle Lead Engineering Department Head for the Pax River ITF, explains the process:
“We were shooting the aircraft off the front of the boat at a gradually slower amount of energy until we found a level of sink that was deemed unacceptable. We then add 15 knots worth and we give that data to the fleet. We anchor that test point, so that even with inevitable wind and weight variations, the fleet guys are good to go.”
By establishing the bottom of the flight envelope, “we were going where a fleet jet should theoretically never go,” adds Sewell. “Barring a failure or other event, a fleet jet should never get to where we were the past few days.”
Though not visible thanks to the jet’s internal weapons carriage capability, the F-35s carried inert stores during DT-II, in contrast to the first DT-I test period where the aircraft flew with empty weapons bays. Each aircraft carried a 2000lb GBU-31 JDAM and two AIM-120 AMRAAMs, adding almost 2700 pounds to the aircraft’s gross weight, resulting in some 55,000 and 60,000 pound catapult launches.
Building on DT-II’s success with internal stores, the F-35C will fly with external loadouts during the third and final evolution of the developmental test program, slated for late summer of 2016. The land-based testing of the F-35C with external stores is already underway to prepare for the next phase, as the Patuxent River ITF recently completed the first external weapons release over an Atlantic weapons range, separately dropping four inert GBU-12s.
Based on the proven success of the first two phases of carrier-borne testing, following DT-III the aircraft will be deemed suitable for fleet operations. “It will be our last planned opportunity to go to the ship prior to IOC for the Navy,” says Sewell.
Though the F-35 ITF team consisted of approximately 200 personnel, the testing force consisted of all several thousand people, says Briggs. “It’s not just two aircraft and a ship, or two hundred people from Pax River. It’s thousands of people on this ship that worked together to make this happen.”
Despite the threat of a major hurricane churning in the western Atlantic, and other foul weather delaying the arrival of the jets onboard the Mighty Ike the F-35C DT-II phase was successfully completed ahead of schedule. “We’re done with flight testing sooner than expected,” says Murphy. “It’s a testament to the aircraft, and to the entire team that works on it.”
The F-35 program continues to make huge strides with its respective services, with the USMC recently declaring IOC and the USAF anticipated to follow suit in 2016. Though the Navy is slated to be the last of the services to reach IOC, the fleet aviators will know that their jet will be fully capable of operating off the carrier thanks to the intense testing done by VX-23 and the F-35 ITF.
FighterSweep would like to thank the following for their support: Sylvia Pierson, F-35 Naval Variants/JPO PA; Joe DellaVedova, JPO/PA; RADM John Haley, COMNAVAIRLANT; Capt Stephen Koehler, CVN69/CO; CDR Mike Kafka, NAVAIRLANT/PAO; LCDR Rebecca Rebarich, CVN69/PAO; MCC Leah Stiles, NAVAIRLANT/PA; CDR Christian Sewell, F35 ITF; and CDR Ryan Murphy, F35 ITF.