Boeing XP-4
Boeing · United States · first flew 1927 · fighter
The Boeing XP-4 was a single-seat biplane fighter prototype developed for the United States Army Air Corps in the mid-1920s. It was an evolution of the PW-9 series and served primarily to test supercharging technology.
Recognition (WEFT)
| W — Wings | Mid-mounted, straight |
|---|---|
| E — Engines | 1 × piston, nose-mounted |
| F — Fuselage | 7.29 m fuselage |
| T — Tail | Conventional |
WEFT is AircraftIQ's four-point recognition method — how it works.
Spot it by:
- Single-engine biplane pursuit prototype
- Sesquiplane layout with smaller lower wing
- Turbo-supercharged Packard engine trial
Recognisable as a 1920s Boeing biplane with the characteristic sesquiplane lower wing, open cockpit, and large water-cooled inline engine in the nose.
Specifications
- The Boeing XP-4 has a length of 7.29 m (24 ft).
- It has a wingspan of 9.78 m (32 ft).
- Its maximum speed is 270 km/h (168 mph).
- Typical crew: 1.
Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.
History
First flown in 1927, the XP-4 was a modified Boeing PW-9 fitted with a turbosupercharged Packard engine to investigate high-altitude performance. Only one prototype was built and it did not enter production, as the technology was not yet reliable enough for service use.
Variants
Only a single XP-4 prototype was constructed; the type did not spawn production variants.
Where you'll see it
The XP-4 served as an experimental testbed with the USAAC and did not enter operational service.
Related aircraft
AircraftIQ — the aircraft field guide: 4,893 recognition guides, live overhead identification, works offline.