Grob G 520

The Grob/E-Systems/AlliedSignal Egrett was a surveillance aircraft developed in Germany in the 1980s by an international partnership. It was intended to fill a joint Luftwaffe-USAF requirement for a high-altitude, long-duration surveillance platform for treaty verification and environmental monitoring. Known as "LAPAS" - Luftgestütztes, abstandsfähiges Primär-Aufklärungssystem in Germany and "Senior Guardian" in the US, the programme initially attempted to acquire the Lockheed TR-1 (U-2) for this role, but when this did not succeed, a new aircraft was sought.

The Egrett (its name derived from the three companies involved in its design: E-Systems, Grob Aircraft, and Garrett, the latter firm later changing its name to AlliedSignal) was a conventional mid-wing monoplane with extremely high aspect ratio wings. Power was provided by a single turboprop, and it was equipped with tricycle undercarriage, the main units of which retracted into fairings on the wings.

The initial D-450 Egrett I development aircraft flew in 1987, and in September the following year set a class altitude record of 16,394 m (53,787 ft). Two pre-production machines followed in 1989 and 1990 as the D-500 Egrett II and then fitted out to the finalised G-520 design in 1991. These latter two aircraft were owned by E-Systems and Grob respectively, and used for promotional purposes, E-Systems' for various sensor packages, and Grob's (renamed the Strato 1) to market the design to civil authorities as a resource management platform.

In 1992, the Luftwaffe placed an order for production of nine Egrett IIs, to be supplemented by G 520T two-seat trainer and one of the demonstrators. However, in February 1993, before much production had taken place, the whole programme was cancelled when Eastern Europe ceased to be perceived as a threat. The two seater was eventually completed, however, and sold to Airborne Research Australia in Adelaide.

Operators

 * Airborne Research Australia
 * Luftwaffe
 * Luftwaffe
 * Luftwaffe