
Northrop X-4 Bantam | |
|---|---|
| Paese | Usa |
| Ruolo | Prototipo di aereo senza coda |
| Primo volo | 15 dicembre 1948 |
| Costruito | 2 |
Le Northrop X-4 Bantam era un prototipo di aereo bireattore di piccole dimensioni prodotto dalla Northrop Corporation nel 1948. Non aveva superfici di coda orizzontali, dipendendo invece da superfici di controllo combinate dell'elevatore e degli alettoni (chiamate elevoni) per il controllo degli assetti di beccheggio e rollio, quasi esattamente alla maniera del Messerschmitt Me 163 della Luftwaffe della Germania nazista. Alcuni aerodinamici avevano proposto che l'eliminazione della coda orizzontale avrebbe eliminato anche i problemi di stabilità alle alte velocità (chiamati shock stall) derivanti dall'interazione delle onde d'urto supersoniche delle ali e degli stabilizzatori orizzontali. L'idea era valida, ma i sistemi di controllo di volo dell'epoca impedirono all'X-4 di avere successo.
| Northrop X-4 Bantam Walk Aroundd | |
|---|---|
| Photographers | John Heck, Randy Ray |
| Localisation | National Museum of the USAF |
| Photos | 50 |
Vedi anche:
General Characteristics and Role
The Northrop X-4 Bantam was an experimental jet aircraft developed for the U.S. Air Force and the National Advisory Committee for Aeronautics (NACA, the precursor to NASA) in the late 1940s. Its primary role was to investigate the aerodynamic properties of a tailless aircraft design at transonic speeds (speeds approaching the speed of sound, or Mach 1). It utilized a semi-tailless configuration, meaning it lacked a horizontal tail stabilizer but retained small vertical fins. The tailless design was believed to reduce the shock waves and control issues experienced by conventional aircraft as they approached the sound barrier. The Bantam was built as a small, swept-wing jet to minimize costs and complexity during the high-risk transonic research phase.
| Property | Typical Value (X-4) | ||
|---|---|---|---|
| Ruolo | Experimental Aircraft (Transonic Stability Research) | ||
| National Origin | Stati Uniti | ||
| Produttore | Northrop Corporation | ||
| First Flight | 15 dicembre 1948 | ||
| Equipaggio | 1 Pilot | ||
| Wing Sweep | 35 degrees | ||
| Lunghezza | 7.01 m (23 ft 0 in) | ||
| Apertura alare | 8.23 m (27 ft 0 in) | ||
| Altezza | 4.52 m (14 ft 10 in) | Gross Weight | 3,524 kg (7,770 lb) |
Powerplant and Flight Controls
- Engine: 2 x Westinghouse J30 turbojet engines.
- Thrust (Total): Approximately 1,600 lbf (7.1 kN).
- Maximum Speed: 1,032 km/h (641 mph, or approx. Mach 0.85).
- Control Surfaces: All control was handled by elevons (control surfaces that combine the functions of elevators and ailerons) on the trailing edge of the wing, and twin vertical rudders.
- Stability Issue: Testing confirmed that while the X-4 was stable at low speeds, it experienced severe longitudinal stability issues when flying faster than Mach 0.88, leading to a tendency to pitch up and lose control.
Program Outcome and Legacy
- Test Program: The X-4 completed 81 research flights at the NACA Muroc Flight Test Unit (later Edwards AFB).
- Discovery: The program proved that a simple tailless design was unsuitable for sustained transonic flight due to the poor stability characteristics encountered.
- Influence: This finding was crucial, convincing designers to use a conventional horizontal stabilizer (tailplane) or the all-moving stabilator on high-speed jets, which became the standard design for supersonic aircraft.
- Preservation: Both prototypes built are preserved: one (46-676) is at the U.S. Air Force Museum in Ohio, and the other (46-677) is at the National Museum of Nuclear Science & History in New Mexico.
Numero visioni : 1976


















