Lockheed YO-3 "Quiet Star"

Le monomoteur spécial d'observation Lockheed YO-3 "Quiet Star" par Wikipedia.en

[Vous devez être inscrit et connecté pour voir ce lien]

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

The [Vous devez être inscrit et connecté pour voir ce lien] YO-3 "Quiet Star" was an [Vous devez être inscrit et connecté pour voir ce lien] single-engined, propeller-driven monoplane that was developed for
battlefield observation during the Vietnam War.

It was designed to be as quiet as possible, and was intended to observe troop movements in
near-silence during hours of darkness.

Design and development


The YO-3A was designed to a U.S. Army specification of 1968, which called for an observation aircraft that would be acoustically undetectable from the ground when flying at an altitude of 1,200 feet at night.

[Vous devez être inscrit et connecté pour voir ce lien] was approached to produce such a design. In 1966 the company built a prototype QT1 "Quiet Thrust", also known as [Vous devez être inscrit et connecté pour voir ce lien], using a modified [Vous devez être inscrit et connecté pour voir ce lien].

This was abandoned for two prototypes of a two-seat version called the QT-2 "Prize Crew".

The QT had a silenced engine and a propeller operating at [Vous devez être inscrit et connecté pour voir ce lien] tip speed for quiet operation.

Following operation trials with the QT-2 in Vietnam, 1968, a production version, designated the YO-3A was ordered by the Army.

Based on the QT2's SGS 2-32 platform, the YO-3A was highly modified. It had a low-mounted wing, retractable main-wheel landing gear and a modified fuselage with tandem seating for a pilot in back and an observer in the front seat using a NVAP (Night Vision Aerial Periscope) and infrared illuminator.

The YO-3A was powered by a 210 hp [Vous devez être inscrit et connecté pour voir ce lien] engine driving a six-bladed, fixed-pitch propeller; the propeller was
later changed to a wooden three-bladed constant-speed version.

Nine of the eleven YO-3As in production by LMSC operated in South Vietnam, at night, from 1970 to 1971 (14 months) and never took a round or were shot down.

The YO-3A was very successful in spotting movement by the North Vietnamese, but its deployment late in the American
involvement in Vietnam reduced its value in that war.

By 1975 all American troops were out of Vietnam.

Operational history

Vietnam War

Following combat evaluation of the QT-2s in Vietnam by the Army, nine production YO-3As were sent to Long Thanh North, Vietnam, in 1970.

Three were sent to Phu Bai and two to Binh Thuy.

The aircraft were used at night, at low altitudes. Observations were initially made visually (80%), later followed on with a [Vous devez être inscrit et connecté pour voir ce lien] Aerial [Vous devez être inscrit et connecté pour voir ce lien] developed by Xerox Electro-Optical of Pasadena, California.

The YO-3A had a specially designed propeller operated by 12 belts, an exhaust system that ran the length of the aircraft and other sound quieting technologies.

The mission equipment on the YO-3A was a Night Vision Aerial Periscope with [Vous devez être inscrit et connecté pour voir ce lien] illuminator.

One YO-3A was equipped with a [Vous devez être inscrit et connecté pour voir ce lien].

The laser system was never used.

The YO-3A operated silently at 1,000 feet, or lower, depending on terrestrial background noise.

Some pilots were known to have gone unobserved over the enemy at 200 feet.

Occasionally, daylight flights were made over the rivers.

Crew chiefs would monitor the YO-3A flying over the maintenance section prior to deployment, listening for rattles, whistles or other noises.

The propeller, even at 500 feet over the maintenance area, made only a light flutter, heard just as it approached.

This was followed by a light rushing of wind over the wings.

There was no audible sound once the plane had passed over.

If any abnormal noises were heard, the plane returned to the runway, where [Vous devez être inscrit et connecté pour voir ce lien] and other measures were employed to quiet noticeable sounds.

Post-war usage

After Vietnam, two YO-3As, 69-18006 and 69-18007, were used by the [Vous devez être inscrit et connecté pour voir ce lien].

The plane was effective at catching [Vous devez être inscrit et connecté pour voir ce lien].

The FBI eventually acquired the aircraft, and operated the planes for several years, assisting the apprehension of kidnappers and extortionists.

[Vous devez être inscrit et connecté pour voir ce lien] took possession of one YO-3A, 69-18010, in the late 1970s.

The plane was used in rotorcraft research. Most recently, it was in operation at [Vous devez être inscrit et connecté pour voir ce lien], California.

This aircraft was to be returned to NASA's [Vous devez être inscrit et connecté pour voir ce lien] research facility at [Vous devez être inscrit et connecté pour voir ce lien], California in early 2009.

Variants


QT-1 Quiet Thrust

Prototype single-seat glider conversion

QT-2

Two-seat version, two built for combat evaluation

Q-Star

One-aircraft for propeller development

YO-3A

Production aircraft for the [Vous devez être inscrit et connecté pour voir ce lien], 11 built

QT-2

[Vous devez être inscrit et connecté pour voir cette image]

Q-Star

[Vous devez être inscrit et connecté pour voir cette image]

YO-3

[Vous devez être inscrit et connecté pour voir cette image]

Operators


Military operators


[Vous devez être inscrit et connecté pour voir cette image] [Vous devez être inscrit et connecté pour voir ce lien]

• [Vous devez être inscrit et connecté pour voir ce lien]
  

Civil operators


[Vous devez être inscrit et connecté pour voir cette image] [Vous devez être inscrit et connecté pour voir ce lien]

• [Vous devez être inscrit et connecté pour voir ce lien]
  
• [Vous devez être inscrit et connecté pour voir ce lien]
  
• [Vous devez être inscrit et connecté pour voir ce lien]
  

References

[Vous devez être inscrit et connecté pour voir ce lien]

• John Andrade, U.S.Military Aircraft Designations and Serials since 1909, Midland Counties Publications, 1979, [Vous devez être inscrit et connecté pour voir ce lien] (Page 140)
  
• The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing
  

Un site totalement dédié au YO-3

[Vous devez être inscrit et connecté pour voir ce lien]