Due to the inherent high level of elegant control of electronic equipment, it is possible to reduce the stresses imparted to the aircraft. The present steam catapult has relatively high peak-tomean acceleration profiles (nominally 1.25, with excursions up to 2.0). This results in high stresses in the airframe and generally poor performance. With an electromagnetic system it would be possible to correct for deviations in the acceleration profile in typically hundreds of milliseconds, which would result in low peak-tomeans. A simulation was conducted that analyzed the level of controllability of the proposed design. The acceleration profile is smooth and flat, compared with a typical steam catapult profile. The simulation shows that for various load conditions, the EMALS is capable of operating within the 1.05 max peak-to-mean acceleration requirement. The result of this reduced peak-to-mean is reduced stress on the airframe. To quantify the effects of a reduced peak-to-mean, a Fracture Mechanics analysis was conducted on the airframe [4] with both the steam catapult and EMALS peak-to-means. The results from this analysis show a peak airframe life extension of 31% due to the reduced stresses on the airframe. This is becoming more important as tight budgets are forcing the Navy to procure fewer aircraft. This also has the benefit of a safer operational environment, since when the EMALS experiences any unforeseen problems during a launch, it has the capability to quickly adjust and correct for them, even if a component fails during the launch.
