New details have emerged about plans for the “mix” of F-35B and F-35C Lightning II Joint Strike Fighters (JSF) that the U. S. Marine Corps will operate. At the same time, some in Washington are questioning whether the short takeoff/vertical landing (STOVL) F-35B version may be in jeopardy.

Gen. James F. “Tamer” Amos, commandant of the Marine Corps, defends the F-35B, but acknowledges that its future is less clear than it once was. With their emphasis on ship-to-shore operations, the Marines have an enormous stake in STOVL, but in Washington some question whether the F-35B is worth the investment.

Doubts arose about the viability of the F-35B before Britain dropped its plans for the STOVL version. Still, a major defense downsizing in the United Kingdom sharply reduces the number of the STOVL aircraft on order. Britain once wanted 150 F-35Bs, reduced the number to 138, and subsequently shifted to the F-35C carrier-based model in an economy move that also involves redesign of the first of two 65,000-ton Queen Elizabeth-class carriers.

The only other committed user, Italy, wants 22 F-35Bs for its navy aircraft carriers, and 40 more for its air force. Observers in both Washington and Rome, however, are wondering whether the 40 air force aircraft will be built. If not, overall purchases of the STOVL F-35B would be cut in half at a time when questions about cost persist.

Curiously, Amos – chosen, some say, for his patrician and gentlemanly manner, especially when testifying on Capitol Hill – has been transformed into something of an attack dog for the F-35B. He recently made several appearances to speak on behalf of the STOVL fighter, including a speech at an industry dinner. He testified before the Senate Armed Services Committee that the long troubling issue of the weight of the F-35B is “getting under control” and that the number of test flights so far in 2011 is “140 percent of where we expected to be” in the program.

But Amos also confessed: “I’d like to see it farther along in the test program, but we are where we are. This is a complicated airplane, and we’re going to work our way through the issues.”

That was before it was announced that the Marines will also purchase F-35C JSFs, optimized for carrier operations.

JSF Fighter Mix

As expected, it has been decided that Marines will not attempt to fly the short takeoff vertical landing or STOVL F-35B version on large carriers. The STOVL B model JSFs are not designed for catapult launch and would require their own, tailored, specific launch-and-recovery operations. The STOVL aircraft also have different range and ordnance-carrying capabilities than the carrier version. What will happen is that carrier-capable F-35Cs will appear on decks alongside F/A-18E/F Super Hornets, and some of the “C models” will belong to Marine squadrons.

For the past few years the Marine Corps focus – and its top priority – has been STOVL operations from land and from assault ship decks, and the Corps long planned to acquire only the F-35B model, to continue the long tradition begun with early versions of the AV-8B Harrier II. Several successive Marine Corps commandants have characterized the STOVL F-35B as a linchpin of the Marine Corps’ unique amphibious warfare mission. Until recently, Marines weren’t expected to operate the carrier-based (and non-STOVL) F-35C at all.

That has changed, in part because of restructuring of the JSF program. In fact, as now planned, the proportion of Marine aviators who will fly strike fighters from aircraft carriers will actually increase when the F-35C enters the fleet. Marines currently have a commitment to provide three F/A-18C/D Hornet equipped carrier-capable squadrons to the fleet, but soon will be expected to contribute five, using the F-35C.

Under an inter-service memorandum of understanding signed by the Navy and Marines, the Marine Corps will now acquire 80 F-35C models. Marine pilots serving aboard carriers will fly the same C version as their Navy compatriots. Following several restructurings of the program, the first Navy F-35C carrier squadron is set to stand up in December 2015, with the first Marine F-35C squadron following a year later.

The Navy has eleven carriers and ten carrier air wings (CVWs) with 44 strike fighters in each CVW, broken down into squadrons of 10 to 12 aircraft each. Eventually, each CVW will have two Super Hornet squadrons (one of single-seat F/A-18Es and one of two-seat F/A-18Fs) and two F-35C squadrons. The Navy will then have 35 carrier-capable strike fighter squadrons along with the Marines’ five. The Navy has long said it would buy 680 JSFs, but had not previously disclosed the mix: now the service will use 260 F-35Cs while the Marines will operate 80 more, with the remaining 340 aircraft being STOVL F-35Bs; and even split between the two variants. The Navy recently increased its planned purchase of Super Hornets from 471 to 556, and has 418 in inventory today.

The first squadron to operate the F-35B will be the fleet readiness squadron (FRS), or training unit, VMFAT-501 “Warlords,” part of the Air Force’s 33rd Fighter Wing at Eglin Air Force Base, Florida, and commanded by Lt. Col. James Wellons. The FRS – as well as the wing, which will train JSF pilots of all service branches – has seen two reschedulings as they wait to receive their first aircraft. “Warlords” flight instructors began flying sorties in F-16 Fighting Falcons in late March, beginning a familiarization process in preparation for the transition to the Department of Defense’s fifth-generation fighter, the F-35 Lightning II.

Flight tests of all JSF versions were briefly interrupted when the entire fleet was grounded as a safety precaution after an Air Force F-35A experienced a dual generator failure and oil leak during a March 9 flight at Edwards Air Force Base, California. In late March, most but not all JSFs were returned to test flying duties, including four STOVL F-35Bs. A fifth F-35B and two other JSFs remain temporarily grounded during an investigation.

Whatever happens next, the F-35B won’t be going away soon. Said Amos: “STOVL is still our primary purpose.”