- "Has a form with flowing lines and is a design one can easily distinguish with one look. There is very little swaying of the fuselage, and it offers a comfortable ride."
- ― Ace Combat 3: Electrosphere - Namco Official Guide Book
The R-505U features two off-set closed wings, which decreases induced drag. For added stability, the wing design includes a set of canted tips. This stability is unprecedented for similar aircraft of the era, and passengers hardly feel the aircraft turning.
As with other aircraft of the era, the R-505U apparently utilizes a COFFIN design, eliminating the need for cockpit windows.
The aircraft's specifications are as follows:
- Length: 80 m (262.46 ft)
- Wingspan: 22.6 m (74.15 ft)
- Height: 9.2 m (30.18 ft)
- Weight: 181030 kg (399102.83 lbs)
- Max speed: 3060 km/h (1901.40 mph)
- Crew: 38
Neucom developed the R-505U as part of its R-numeral aircraft series. Despite this, the aircraft was provided to UPEO for their exclusive use.
Within the Nemo simulation, UPEO representative Gabriel William Clarkson, escorted by Fiona Chris Fitzgerald, attempted to travel to a détente conference in Cape Rainy using the R-505U. Nemo and Erich Jager escorted the aircraft. The R-505U came under fire from both General Resource Defense Force and UPEO aircraft over the Lambert Mountains, prompting Clarkson to redirect the aircraft to Neucom-controlled Dennis Airport and defect to Neucom.
Depending on Nemo's decisions, the R-505U will either be shot down and everyone on board killed, or the R-505U will safely land at Dennis, followed by Clarkson, Fiona, and Nemo defecting to Neucom. In the former scenario, Nemo and Erich realized that they were being used by Gilbert Park to shoot down the R-505U, allowing Park to take control of UPEO and fuel the war further.
- The R-505U's airframe and engines appear to be based on the Concorde.