Kellett KD-1

Two-Seat Observation Autogiro Aircraft [ 1935 ]

The Kellett KD autogiro design primarily served the United States Army Air Force heading into World War 2.

Authored By: Staff Writer | Last Edited: 11/18/2017 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site.

Image use granted by user David M via email.

VIEW SPECIFICATIONS [+]

The Kellett Autogiro Company was founded during the "Golden Age of Flight" in 1929. Its early work involved licensed production of Cierva autogyro aircraft. Despite their appearance, autogyros were not true helicopters as their main rotor masts were not driven under normal power. Instead an "autorotation" effect was used to develop vertical lift while an engine-driven propeller provided the needed forward pull / push. The concept was developed by Spaniard Juan de la Cierva and an example first-flown in January of 1923.

Kellett produced several of the early-form Cierva products before shifting attention to a more internally-oriented design. This work produced the Kellett "KD-1" which held attributes akin to the Cierva C.30 model autogyro. The aircraft carried a traditionally-arranged airframe which sat the engine at the nose and two open-air cockpits directly aft of this. The engine (Jacobs L-4 radial unit of 225 horsepower) drove a two-bladed propeller. The tail unit incorporated the necessary horizontal and vertical planes while the undercarriage was fixed in flight and wheeled for ground-running actions. The notable physical characteristic of the aircraft was its three-bladed, mast-mounted main rotor which was installed over and ahead of the crew positions and over the engine compartment.

The prototype emerged as the KD-1 and only a single example was built. Upon completing the needed testing and certification, the KD-1 was brought to the commercial sector as the "KD-1A". Three were built to this standard. The "KD-1B" was similar in form and function but offered enclosed cockpits. Two of this mark were built.©MilitaryFactory.com

United States Army interest in the design was enough to warrant formal evaluation of the product. This led to the developmental designation of "YG-1" being issued and covered a single KD-1A example. The follow-up "YG-1A" was given a radio suite and the first U.S. Army production model became "YG-1B" and seven were acquired. One was modified with a constant-speed propeller for testing purposes and became the "YG-1C" (later the XR-2).

An additional seven examples followed in the "XO-60" guise which carried the Jacobs R-755 radial piston engine of 225 horsepower. The "YO-60" differed in its use of a Jacobs R0915-3 radial engine of 300 horsepower. Six were produced to this standard.

The "XR-2" was the YG-1C redesignated but also carried the R-915-3 engine of 300hp. The "XR-3" was a one-off YG-1B model modified to the XR-2 standard but only ever reached the evaluation stage and was never furthered.

In practical service, the KD-1 proved a successful autogyro attempt. It was responsible for the first-ever scheduled delivery of mail by air by a rotary-wing aircraft when it completed such a flight on July 6th, 1939. For the U.S. Army, it also served as the service's first viable rotary-wing platform before more advanced types were eventually acquired. A few variants also emerged from Kabaya in Japan: "Ka-Go" was a prototype based on the KD-1A and Ka-1 was given an Argus As 10 engine of 240 horsepower. Ka-2 carried a Jacobs L-4MA-7 engine of 245 horsepower.©MilitaryFactory.com

Note: The above text is EXCLUSIVE to the site www.MilitaryFactory.com. It is the product of many hours of research and work made possible with the help of contributors, veterans, insiders, and topic specialists. If you happen upon this text anywhere else on the internet or in print, please let us know at MilitaryFactory AT gmail DOT com so that we may take appropriate action against the offender / offending site and continue to protect this original work.

Specifications

Kellett Autogiro Company - USA
Manufacturer(s)

Imperial Japan; United States
Operators

1935
Service Year

United States
National Origin

Retired
Project Status

2
Crew

21
Units

INTELLIGENCE-SURVEILLANCE-RECONNAISSANCE
Surveil ground targets / target areas to assess environmental threat levels, enemy strength, or enemy movement.

28.8 ft
(8.79 meters)
Length

40.0 ft
(12.20 meters)
Width/Span

10.3 ft
(3.14 meters)
Height

1,581 lb
(717 kilograms)
Empty Weight

2,249 lb
(1,020 kilograms)
Maximum Take-Off Weight

+668 lb
(+303 kg)
Weight Difference

1 x Jacobs L-4 radial engine developing 225 horsepower driving a two-bladed nose-mounted propeller unit; Autorotation managed the three-bladed, mast-mounted main rotor.
Propulsion

128 mph
(206 kph | 111 knots)
Max Speed

12,500 ft
(3,810 m | 2 miles)
Ceiling

200 miles
(322 km | 174 nm)
Range

MACH Regime (Sonic)

Sub

Trans

Super

Hyper

HiHyper

ReEntry

♦

None.

KD-1 - Prototype; single example

KD-1A - Fitted with Jacobs L-4 radial engine of 225 horsepower; three examples completed.

KD-1B - KD-1A model with enclosed cockpits; two examples completed.

YG-1 - KD-1A for evaluation by U.S. Army

YG-1A - YG-1 fitted with radio equipment

YG-1B - U.S. Army production model; seven examples completed.

YG-1C - One-off YG-1B fitted with constant-speed propeller for testing; redesignated to XR-2.

XO-60 - Fitted with Jacobs R-755 radial of 225 horsepower; seven examples completed.

YO-60 - XO-60 model with Jacob R-915-3 radial of 300 horsepower; six modified to this standard.

XR-2 - Redesignation of YG-1C; Jacobs R-915-3 radial of 300 horsepower.

XR-3 - One-off YG-1B modified to XR-2 standard

Kayaba Ka-Go - Prototype by Kayaba of Japan; based on KD-1A model.

Kayaba Ka-1 - Fitted with Argus As 10 engine of 240 horsepower.

Kayaba Ka-2 - Fitted with Jacobs L-4MA-7 engine of 245 horsepower.

Military lapel ribbon for Operation Allied Force

Military lapel ribbon for the Arab-Israeli War

Military lapel ribbon for the Battle of Britain

Military lapel ribbon for the Battle of Midway

Military lapel ribbon for the Berlin Airlift

Military lapel ribbon for the Cuban Missile Crisis

Military lapel ribbon for pioneering aircraft

Military lapel ribbon for the Falklands War

Military lapel ribbon for the French-Indochina War

Military lapel ribbon for the Golden Age of Flight

Military lapel ribbon for the 1991 Gulf War

Military lapel ribbon for the Indo-Pak Wars

Military lapel ribbon for the Iran-Iraq War

Military lapel ribbon for the Korean War

Military lapel ribbon for the 1982 Lebanon War

Military lapel ribbon for the Malayan Emergency

Military lapel ribbon representing modern aircraft

Military lapel ribbon for the attack on Pearl Harbor

Military lapel ribbon for the Six Day War

Military lapel ribbon for the Soviet-Afghan War

Military lapel ribbon for the Spanish Civil War

Military lapel ribbon for Special Forces

Military lapel ribbon for the Suez Crisis

Military lapel ribbon for the Ukranian-Russian War

Military lapel ribbon for the Vietnam War

Military lapel ribbon for Warsaw Pact of the Cold War-era

Military lapel ribbon for the WASP (WW2)

Military lapel ribbon for the World War 1

Military lapel ribbon for the World War 2

Military lapel ribbon for the Yom Kippur War

Military lapel ribbon for experimental x-plane aircraft

Images

1 / 1

Image use granted by user David M via email.

Disclaimer | Privacy Policy | Cookies

2024 Military Pay Chart Military Ranks DoD Dictionary Conversion Calculators Military Alphabet Code Military Map Symbols

The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com. No A.I. was used in the generation of this content; site is 100% curated by humans.

Part of a network of sites that includes GlobalFirepower, a data-driven property used in ranking the top military powers of the world, WDMMA.org (World Directory of Modern Military Aircraft), WDMMW.org (World Directory of Modern Military Warships), SR71blackbird.org, detailing the history of the world's most iconic spyplane, and MilitaryRibbons.info, cataloguing military medals and ribbons. Special Interest: RailRoad Junction, the locomotive encyclopedia.

©2023 www.MilitaryFactory.com • All Rights Reserved • Content ©2003-2023 (20yrs)