The U.S. AIM-174B (air-launched SM-6) has been reported to achieve ranges exceeding 400 km, dramatically greater than the ~240 km range of its ship-launched parent missile. This leap in performance is rooted in launch physics: the advantage of altitude, forward velocity, and trajectory freedom when firing from an aircraft. The same principles explain why Russian and Chinese long-range air-to-air missiles advertise extreme reach.
1.
AIM-174B (U.S.)
- Derived from the SM-6 surface-to-air missile.
- Air-launch advantages:
- Released at altitude (30,000–40,000 ft) → lower drag, higher efficiency.
- Launched at near-supersonic speed → “free” kinetic energy.
- No vertical-launch penalty → missile immediately flies toward target.
- Lofted trajectories in thin air maximize glide before terminal dive.
- Estimated range: 400+ km, nearly double the ship-based SM-6.
- Mission role: long-range fleet defense and very-long-range air-to-air intercepts (e.g., AWACS, tankers).
2.
R-37M (Russia)
- Very-long-range AAM carried by MiG-31 and Su-35.
- Reported range: 300–400 km.
- Launch advantage: MiG-31 can cruise supersonically at high altitude, giving the R-37M a massive kinematic head start.
- Uses a large solid rocket motor and a lofted ballistic arc to reach extreme range.
- Role: designed to kill high-value support aircraft (AWACS, tankers, ISR platforms) well before they can threaten Russian airspace.
3.
PL-XX (China, sometimes called PL-21)
- Still not fully public; believed to be China’s counterpart to R-37M and AIM-174B.
- Likely designed for launch from J-16 or J-20 fighters.
- Projected range: 300–400+ km.
- Expected to employ similar advantages: high-altitude launch, long-burn motor, and lofted trajectory.
- Target set: U.S. and allied support aircraft in a Western Pacific fight.
Comparative Takeaway
While the U.S., Russia, and China have taken different technological paths, the physics is the same:
- Air launch from altitude and speed provides enormous range gains compared to surface launch.
- All three weapons aim to deny adversaries the use of critical enablers—AWACS, tankers, ISR aircraft—by striking them hundreds of kilometers behind the front line.
- The AIM-174B stands out because it leverages an existing naval missile (SM-6), giving the U.S. a cost-effective way to field a dual-role weapon for both ships and fighters, with reach beyond 400 km.
