Douglas X-3 Stiletto

Douglas X-3 Stiletto
Země	SPOJENÉ STÁTY
Roli	Pokusný
První let	15. října 1952
Postaven	1

Tá Douglas X-3 Stiletto byl experimentální proudový letoun Spojených států z roku 1950 se štíhlým trupem a dlouhým kuželovitým nosem, vyráběný společností Douglas Aircraft Company. Jeho primárním posláním bylo prozkoumat konstrukční vlastnosti letadla vhodného pro trvalé nadzvukové rychlosti, které zahrnovaly první použití titanu v hlavních součástech draku letadla. Douglas navrhl X-3 s cílem dosáhnout maximální rychlosti přibližně 2 000 m.p.h, ale byl pro tento účel vážně poddimenzován a nemohl ani překročit Mach 1 ve vodorovném letu. Ačkoli výzkumný letoun byl zklamáním, konstruktéři Lockheedu použili data z testů X-3 pro Lockheed F-104 Starfighter, který použil podobnou lichoběžníkovou konstrukci křídla v úspěšné stíhačce Mach 2.

Zdroj: Douglas X-3 Stiletto na Wikipedii

Douglas X-3 Stiletto Walk Around
Photographers	Randy Ray, John Heck
Localisation	National Museum of the USAF
Photos	64

Douglas X-3 Stiletto 01

Douglas X-3 Stiletto 02

Douglas X-3 Stiletto 03

Douglas X-3 Stiletto 04

Douglas X-3 Stiletto 05

Douglas X-3 Stiletto 06

Douglas X-3 Stiletto 07

Douglas X-3 Stiletto 08

Douglas X-3 Stiletto 09

Click on a photo and use the mouse scroll to view all photos

Čekání, Hledání Douglas X-3 Stiletto pro vás ...

Douglas X-3 Walk Around
Fotograf	Garfield Ingram
Lokalizace	Neznámé
Fotografie	35

Viz také:

Douglas X-3 Stiletto Walk Around
Photographer	Meindert de Vreeze
Localisation	National Museum of the USAF
Photos	44

The Shape of Things to Come

Tá Douglas X-3 Stiletto was perhaps the most visually striking experimental aircraft of the 1950s. Designed to test the effects of sustained supersonic flight, it featured a slender fuselage, a long, tapered nose, and tiny, trapezoidal wings. While the X-3 failed to reach its intended design speeds due to being severely underpowered, it became an invaluable research tool for structural engineering, pioneering the use of titanium in aircraft construction and providing the data that made the Lockheed F-104 Starfighter possible.

Attribute	Technical Specification (Douglas X-3)
Roli	Experimental High-Speed Research Aircraft
Posádky	1 (Pilot)
First Flight	October 15, 1952
Pohonná jednotka	2 × Westinghouse J34-WE-17 afterburning turbojets
Thrust	3,370 lbf (15.0 kN) each / 4,850 lbf with afterburner
Maximum Speed	Mach 1.21 (Reached) / Mach 2.0 (Design Goal)
Rozpětí křídel	22 ft 8 in (6.91 m)
Délka	66 ft 9 in (20.35 m)

Design Innovations and Challenges

High Fineness Ratio: The X-3 had an incredibly high “fineness ratio” (length vs. width), designed to pierce the “sound barrier” with minimal drag. Its nose was so long that the pilot sat far back from the tip, necessitating a specialized downward-ejection seat.
The First Titanium Jet: The X-3 was the first aircraft to make extensive use of titanium in its major airframe components. This was necessary to handle the “thermal thicket”—the intense heat generated by air friction at speeds above Mach 2.
Underpowered Reality: The original plan called for Westinghouse J46 engines, which failed to materialize. The substitute J34 engines were so weak that the X-3 could barely exceed Mach 1 in a level flight, usually requiring a dive to reach supersonic speeds.
Trapezoidal Wings: The wings were tiny, thin, and straight (non-swept). This design offered low drag at supersonic speeds but made takeoffs and landings extremely dangerous, with a landing speed of roughly 200 mph (322 km/h).

Inertial Coupling and Legacy

Inertial Coupling Discovery: During a test flight in 1954, pilot Joseph Walker experienced “inertial coupling”—a violent, uncontrollable roll/yaw maneuver caused by the mass distribution of the long fuselage. This data was critical in redesigning the tail surfaces of the F-100 Super Sabre.
The “Starfighter” Connection: The thin, stubby wing data from the X-3 was directly applied by Kelly Johnson at Lockheed to create the F-104 Starfighter, often called the “Missile with a Man in It.”
Tire Technology: Because of its exceptionally high takeoff and landing speeds, the X-3 forced engineers to develop entirely new high-pressure tire compounds and heat-resistant wheel assemblies.
Preservation: The sole surviving X-3 Stiletto is currently on display at the National Museum of the United States Air Force in Dayton, Ohio.