F-15A Single-seat all-weather air-superiority fighter version, 384 built in 1972–1979[109] F-15B Two-seat training version, formerly designated TF-15A, 61 built in 1972–1979[109] F-15C Improved single-seat all-weather air-superiority fighter version, 483 built in 1979–1985.[109] The last 43 F-15Cs were upgraded with AN/APG-70 radar and later the AN/APG-63(V)1 radar. F-15D Two-seat training version, 92 built in 1979–1985.[109] F-15J Single-seat all-weather air-superiority fighter version for the Japan Air Self-Defense Force 139 built under license in Japan by Mitsubishi Heavy Industries in 1981–1997, two built in St. Louis.[109] F-15DJ Two-seat training version for the Japan Air Self-Defense Force. 12 built in St. Louis, and 25 built under license in Japan by Mitsubishi in the period 1981–1997.[109] F-15N Sea Eagle The F-15N was a carrier-capable variant proposed in the early 1970s to the U.S. Navy as an alternative to the heavier and, at the time, considered to be "riskier" technology program, the Grumman F-14 Tomcat. It did not have a long range radar or the long range missiles used by the F-14. The F-15N-PHX was another proposed naval version capable of carrying the AIM-54 Phoenix missile, but with an enhanced version of the AN/APG-63 radar on the F-15A. These featured folding wingtips, reinforced landing gear and a stronger tailhook for shipboard operation.[110][111] F-15E Strike Eagle Two-seat all-weather multirole strike version, fitted with conformal fuel tanks. It was developed into the F-15I, F-15S, F-15K, F-15SG, F-15SA, and other variants. Over 400 F-15E and derivative variants produced since 1985; still in production. F-15SE Silent Eagle In March 2009 Boeing unveiled the F-15SE, a Proposed F-15E variant with a reduced radar cross-section via changes such as replacing conformal fuel tanks with conformal weapons bays and canting the twin vertical tails 15 degrees outward, which would reduce their radar signature while providing a slight boost to lift to help offset the loss of conformal fuel tanks.[112][113] F-15 2040C Proposed upgrade to the F-15C, allowing it to supplement the F-22 in the air superiority role. The 2040C concept is an evolution of the Silent Eagle proposed to South Korea and Israel, with some low-observable improvements but mostly a focus on the latest air capabilities and lethality. Proposal includes infra-red search and track, doubling the number of weapon stations, with quad racks for a maximum of 16 air-to-air missiles, Passive/Active Warning Survivability System, conformal fuel tanks, upgraded APG-63(v)3 AESA and a "Talon HATE" communications pod allowing data transfer with the F-22.[114][115]