― Expansion of Scope through MOSAIC ―

Light-Sport Aircraft (LSA) is an aircraft category established by the US FAA (Federal Aviation Administration) in 2004 with the objective of introducing a framework different from the traditional type certification system for relatively small, low-speed aircraft. For landplanes, the conventional LSA was subject to operational and design limitations such as a maximum takeoff weight of 1,320 lb (approx. 600 kg), a maximum of 2 seats, a maximum level flight speed of 120 kt CAS, a stall speed of 45 kt CAS or less, a single reciprocating engine, and fixed landing gear. Particularly for S-LSA (Special Light-Sport Aircraft), unlike the traditional certification method based on Type Certificates by the FAA, a certification system utilizing compliance with consensus standards developed by ASTM International was adopted. This is a distinctive system in that it rationalizes the burden required for aircraft development and certification while maintaining safety at a certain level.

Comparison between Conventional LSA and MOSAIC

The range of aircraft covered by the conventional LSA is easiest to understand when compared with the Cessna 152, a representative light trainer aircraft. The Cessna 152 has a maximum takeoff weight of approximately 757 kg, and although it is a small 2-seat trainer, it did not satisfy the 600 kg weight requirement of the conventional LSA. A major revision of these specification-based limitations is the FAA's MOSAIC (Modernization of Special Airworthiness Certification). One of the key changes in MOSAIC is the elimination of the uniform maximum takeoff weight limit for aircraft. The system has shifted from the conventional classification based on "being under a certain weight" to one that emphasizes the performance characteristics of the aircraft, starting with stall speed. Along with this, the scope of application for airplanes has been expanded to a maximum of 4 seats, a maximum speed of 250 kt CAS, and a VSO of 61 kt CAS or less. In addition, the previously existing configuration limitations, such as a single reciprocating engine, fixed landing gear, and a fixed or ground-adjustable propeller, have also undergone major revisions.

Application to 1,200 kg Class Aircraft

An example demonstrating the expansion of scope under MOSAIC is the aircraft developed by Tecnam. The 4-seat single-engine P2010 has a maximum takeoff weight of approximately 1,200 kg, which corresponds to about twice the weight limit of the conventional LSA. With MOSAIC in mind, Tecnam is proceeding with compliance for a clean stall speed of 59 kt CAS, which is one of the aircraft performance requirements for a Sport Pilot. Furthermore, the P2006T NG is a 4-seat twin-engine aircraft with a maximum takeoff weight of approximately 1,290 kg, equipped with two Rotax 912 iS series engines. Tecnam has presented specifications for this aircraft corresponding to MOSAIC Part 22. These examples indicate that the policy changes brought about by MOSAIC are not merely an increase in the weight of LSAs, but rather expand the applicability of the category to aircraft configurations that were previously excluded from the conventional LSA framework.

The Future of the LSA System

Initially in 2004, the LSA targeted relatively simple aircraft of approximately 600 kg, with 2 seats, a single engine, and fixed landing gear. On the other hand, under MOSAIC, the possibility has emerged for 4-seat aircraft and twin-engine aircraft exceeding 1,200 kg to qualify under the Light-Sport Category. However, under MOSAIC, it is necessary to distinguish between the "requirements for certifying an aircraft under the Light-Sport Category" and the "requirements for an aircraft that can be operated by a Sport Pilot." Being certifiable under the Light-Sport Category does not immediately mean that all operations by a Sport Pilot are permitted. The technical significance of MOSAIC lies in the shift from a method that uniformly classifies aircraft by weight, number of engines, landing gear type, etc., to a performance-based system that emphasizes actual performance characteristics, such as stall speed, and compliance with consensus standards. Therefore, LSA is evolving from a "system targeting lightweight aircraft of 600 kg or less" into a certification framework for relatively flexibly introducing new aircraft designs, propulsion methods, and equipment technologies while maintaining safety. MOSAIC is considered to be one of the critical regulatory changes when considering the direction of aircraft development and certification in future General Aviation.