The U.S. Marine Corps is preparing for its first and only operational testing (OT) period for the Lockheed Martin F-35B before declaring initial operational capability for the fighter as early as July.

The trials—set for May 18-29—are the first shipboard operational tests for any of the three F-35 variants. Six -F-35Bs from VMFA-121 and VMFAT-501 are slated to participate in the trials off the Atlantic coast on the USS Wasp, according to Maj. Paul Greenberg, a Marine Corps spokesman. This will be the first time six of the single-engine, stealthy aircraft have been deployed to sea on the same ship simultaneously. 

Operators will assess the ability of the fighter to function not only on takeoff and landing but also in navigating around the deck and in the belly of the ship, where maintenance operations take place. The trials largely focus on validating that users can maintain a relevant operations tempo at sea with the short-takeoff-and-vertical-landing F35B. “The desired aircraft-ready-for-training rate of the F-35B aircraft during OT-1 is 100%,” Greenberg says.

“This exercise will evaluate the full spectrum of F-35B measures of suitability and effectiveness to the maximum extent possible,” he notes. “Specifically, the trial will assess the integration of the F-35B while operating across the array of flight operations, maintenance operations and logistical supply chain support while embarked at sea.” The Wasp, an amphibious assault ship, was also used for the F-35B’s first developmental testing sea trials; the first F-35B vertical landing took place on its deck in October 2011.

During the trials, the Marines plan to execute numerous day and night short takeoffs and landings and conduct “standard” day and night extended-range operations, Greenberg says. Also part of the testing will be an assessment of the aircraft-to-ship network communications interoperability as well as the efficacy of the landing signals officer’s launch-and-recovery software.

Though Greenberg says operators will assess day and night weapons loading, no live-fire testing is slated; most live-fire activities are handled for the program by the test force at Edwards AFB, California.

The F-35Bs will be expected to fly in both optimal and inclement weather: “Only extreme weather conditions will halt operations during OT-1,” Greenberg says.

The six aircraft used in the OT-1 trials will operate with the 2B software package, which was not originally intended for operational use. However, delays earlier in the program prompted the Marine Corps to prioritize 2B, which allows for use with limited weapons, with no external weapons stations approved. Marine Corps officials say the aircraft will provide better capability than the F-18s and AV-8Bs they are intended to replace.

The Marines will also use the -Automatic Logistic Information System Standard Operating Unit Version 1 (ALIS SOU V1); this is not the hardware with which they plan to declare initial operational capability (IOC) and eventually deploy. An updated hardware unit, the ALIS SOU V2, is slated for delivery for VMFA-121 by early June. This hardware is smaller and designed to be deployable on the small-deck ships on which the F-35B will operate. The SOU V2 is required for IOC.

Though operating with the 2B software, the operational test team will not be able to fly with the software patch designed by engineers to improve ship-to-ship “sight picture” sharing. As part of the F-35’s so-called data-fusion attribute, the aircraft are required to share targeting data among themselves using their Multifunction Advanced Datalinks, which can operate covertly to preserve multiple aircrafts’ stealthy characteristics in high threat environments.

In fact, the OT series is more geared to demonstrating sortie generation and maintenance tempo. Ship-to-ship targeting is not expected during the trials.

Test pilots at Edwards had reported problems with targets on the cockpit display associated with more than one symbol, a sign the system had not fully “fused” the data collected on that target from multiple F-35s. In some other cases, wingmen are not seeing the same objects other pilots are in multi-ship formations.

Program officials opted earlier this year to move forward to develop the software patch to correct the deficiency; they created the code in 22 days, according to Joe Dellavedova, F-35 spokesman for the F-35 Joint Program Office.

Marine Corps officials say they are confident the 2B package will be sufficient for IOC in July; F-35 test officials hope to have the patch ready for the Marine Corps IOC, however.

The F-35B is slated for its first deployment to MCAS Iwakuni, Japan, in 2017. Separate ship trials are slated for the F-35C on an aircraft carrier this fall.

As the squadrons ready the aircraft, Marine Corps and Navy officials are also preparing the USS Wasp for the trials and laying the groundwork for the aircraft-to-ship integration that will be key to that first deployment in 2017 as well as those to follow. 

As fifth-generation aircraft, the -F-35s feature an array of sensors and data links that will require more attention and offer more capability than the F-18s and AV-8B Harriers the Marines have been using, according to Marine Corps Maj. Gen. Robert Walsh, Navy director of expeditionary warfare.

The services also need to figure out the requirements for operating the aircraft with carriers and other ships in the fleet, he says. It will be a learning process, says Rear Adm. -Peter Fanta, director of surface warfare. “We will not be able to bring that data completely aboard on that first deployment,” he said during the roundtable. “We will learn where the gaps are.”

“What are the C5I [command, control, communications, computers, collaboration] requirements for the -F-35B? Because they are not going to be how we operated the Harrier,” Walsh said April 9, during a media roundtable. “What is the requirement for the F-35 to be able to disseminate data across the battlefield? What pipes need to be there?”

The learning curve needed to codify the integration is likely to prompt frustration by some. “There will be disappointment,” he says, because there will be a desire to capture more of that data and information.

Just preparing the JSFs and big-deck amphibious ships for the first deployment in fiscal 2018 will be difficult enough, the admirals say. “It’s a real challenge,” Walsh says.

The LHD 1 USS Wasp has already been modified with a reinforced flight deck and a new heat-resistant material to better withstand the exhaust from the F135 engines powering F-35B short takeoffs and vertical landings. The LHA 6 USS America will undergo similar work.

“In the America, the very time-consuming piece is going inside the ship and dropping lighting and ventilation and piping wiring and everything down far enough so you can install new material and weld it in place and then restore all that stuff,” Rear Adm. David Gale, program executive officer for ships, said during the roundtable.

About a dozen modifications are needed for the ships to house the -F-35Bs, he says. 

This article was originally published on April 16.