Directory of U.S. Military Rockets and Missiles
Appendix 4: Undesignated Vehicles
Copyright © 2006 Andreas Parsch

Naval Research Lab Eager

From 1995 to 1997, the Naval Research Lab (NRL) developed and flight-tested the Eager Electric Preferential Acquisition Decoy vehicle. Eager was a tethered, electric-powered rotary-wing electronic countermeasures UAV. It was developed as a new concept for a ship-based defensive ECM platform, especially in littoral warfare where engagement times are short. In such environments, traditional countermeasures (e.g. chaff launchers) which are deployed after initial threat detection, can't provide adequate protection. The Eager UAV was intended to operate continuously for up to 1000 hours from small naval vessels.

Photo: NRL

Eager was powered by electric motors driving the main and auxiliary rotors. The UAV was permantly connected to the ground by a tether, which contained the power supply for the motors and payload as well as fiber-optic cables for datalinks. Because of the external power supply, endurance was effectively limited only by the overall system reliability. The payload of the Eager demonstration vehicle was an RF repeater for the radar decoy mission. Other mission payloads of up to 6.8 kg (15 lb) weight would have been possible, so that Eager could also have been used as a general-purpose ship-borne elevated sensor or communications platform.

The first flight of the Eager occurred in July 1997. Later that year, the RF payload was integrated with the airframe and its effectiveness measured.


Data for Eager:

Rotor diameter3 m (10 ft)
Weight45 kg (100 lb)
Endurance1000 h (potentially unlimited)
PropulsionExternal electric power

Main Sources

[1] NRL UAV Fact Sheets
[2] NRL's "Eager" Decoy Passes First Flight Test, NRL Press Release, 2 September 1997

Back to Directory of U.S. Military Rockets and Missiles, Appendix 4

Last Updated: 8 February 2006