OK-2998

OK-2998 is a Nimbus Aircraft Nimbus-4 — likely a private operator. SkyMeter has tracked 52 flights totalling 202 hours of airtime via ADS-B. The most frequent segment is LOXN to LOAN. Service window in our records spans 363 days. Of those flights, 2 (3.8%) carry at least one detected incident — go-around, unstable approach, stall warning, or runway excursion. The Nimbus Aircraft Nimbus-4 has a maximum takeoff weight of 1,874 lb, light wake category.

About the Nimbus Aircraft Nimbus-4

The Nimbus-4 is a high-performance racing sailplane designed and built by Nimbus Aircraft GmbH in Germany, first flown in the late 1990s. Representing the pinnacle of Open Class glider design, the Nimbus-4 features a 26.5-meter wingspan optimized for cross-country racing and record attempts, with exceptional L/D ratios exceeding 60:1 in ideal conditions. Its sleek composite construction and sophisticated wing design allow pilots to exploit even weak thermals and ridge lift across hundreds of kilometers.

Unlike powered aircraft, the Nimbus-4 relies entirely on atmospheric energy—thermals, wave lift, and ridge soaring—to remain aloft. Pilots launch via aerotow behind a powered tug or winch, then disconnect to begin their soaring flight. The type has been flown to numerous national and world records in the Open Class, with flights regularly exceeding 1,000 kilometers and altitudes above 30,000 feet in mountain wave conditions. Its 850-kilogram maximum weight includes water ballast that pilots dump strategically to optimize performance as conditions change throughout a flight.

The Nimbus-4 remains a sought-after mount for serious competition pilots and record chasers, though its size and cost limit the fleet to dedicated soaring enthusiasts. Registration tails like D-KIDX and HB-2448 reflect its European heritage, while North American examples demonstrate the type's global appeal among the soaring community. SkyMeter has tracked flights across airframes and operators, with the largest observed operator.