Directory of U.S. Military Rockets and Missiles
Appendix 1: Early Missiles and Drones
SAM-N-2/SAM-N-4
 
Copyright © 2003 Andreas Parsch

Fairchild KAQ/SAM-N-2/CTV-N-9 Lark
Convair KAY/SAM-N-4/CTV-N-10 Lark

The Lark anti-aircraft missile program began in late 1944, when the U.S. Navy needed a new weapon against the ever more serious Japanese suicide-bomber (Kamikaze) threat. In January 1945, a Lark configuration had been established, and requirements included ship defense against Kamikaze attack, reconnaissance aircraft, and enemy aircraft launching standoff weapons. In March that year, a contract was awarded to Fairchild for the production of 100 Lark test missiles. Because of slow progress by Fairchild, in a backup contract for another 100 Larks was awarded to Consolidated-Vultee in June 1945. In October 1945, the Fairchild and Convair Lark were designated as KAQ and KAY, respectively, and flight testing of KAQ-1 and KAY-1 vehicles began in June 1946.

The KAQ-1/KAY-1 was propelled by a Reaction Motors LR2-RM-2 two-chamber liquid-propellant rocket engine, and used two solid-fueled rocket boosters for take-off. Later Larks used a slightly improved LR2-RM-6 engine, and the designations KAQ-2 and KAY-2 most probably apply to missiles with the upgraded engine. The Lark had cruciform wings and tailfins for stability and control, and the booster assembly used a peculiar "square" fin arrangement. The KAQ's wings had flaps, while the KAY used variable-incidence wings. The Lark was armed with a 45 kg (100 lb) high-explosive warhead, which was detonated by a radar proximity fuze. The early test flights used a simple manual radio-command guidance system, but by 1947 the development of guidance systems requiring no human operator had begun.

Photo: Smithsonian Institution
KAQ-1/2 (XSAM-N-2/2a) (exact model unknown)


In September 1947 and early 1948, the Lark models were redesignated as follows:

Old Designation September 1947 ca. February 1948
KAQ-1 XSAM-2 XSAM-N-2
KAQ-2 XSAM-2a XSAM-N-2a
KAY-1 XSAM-4 XSAM-N-4
KAY-2 XSAM-4a XSAM-N-4a

The Fairchild SAM-N-2 eventually used a guidance system known as "Skylark", consisting of radio-command mid-course guidance and semi-active radar guided terminal homing. A ship-borne radar and fire-control system tracked both the Lark and the target aircraft, computed the interception course of the missile, and sent steering commands when necessary. Within a range of 16 km (10 miles) from the target, the SAM-N-2 could use its AN/DPN-7 radar to home on the radar reflections from the target. The Convair SAM-N-4 used a radar beam-riding mid-course guidance system known as "Wasp", and had an AN/APN-23 radar for active terminal homing.

Testing of the Lark from ship-borne launchers began in 1950 on the missile test ship USS Norton Sound, and several interceptions of target drones succeeded. However, the Lark anti-aircraft missile program was terminated in late 1950, because the contemporary Bumbleebee program of the Bureau of Ordnance (Lark was a Bureau of Aeronautics program) showed much more promise (and would eventually lead to such missiles as the SAM-N-6/RIM-8 Talos, SAM-N-7/RIM-2 Terrier and RIM-24 Tartar).

Photo: USAF
CTV-N-9b


After the tactical Lark had been cancelled, the remaining missiles continued to be used as control test vehicles. As such, the SAM-N-2 and SAM-N-4 were redesignated as CTV-N-9 and CTV-N-10, respectively. There were several variants of the CTV-N-9, designated CTV-N-9a, CTV-N-9b and CTV-N-9c, but I don't know specifics about these versions. The CTV-N-9 and -10 were used throughout the early 1950s by the U.S. Air Force, Navy and Army to evaluate radar guidace systems, and equipment and procedures related to missile launching, stability and control. The U.S. Army also used Lark test vehicles (designating them as RV-A-22) to develop the guidance system for the SSM-A-12/MGM-18 Lacrosse surface-to-surface missile.

Photo: U.S. Army
RV-A-22


Specifications

Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!

Data for XSAM-N-2:

Length (w/o booster)4.24 m (13 ft 11 in); booster: 1.40 m (4 ft 7 in)
Wingspan1.88 m (6 ft 2 in)
Finspan1.22 m (4 ft)
Diameter46 cm (18 in)
Weight (w/o booster)550 kg (1210 lb); booster: 370 kg (810 lb)
SpeedMach 0.85
Ceiling?
Range55 km (30 nm)
PropulsionSustainer: Reaction Motors LR2-RM-2 liquid-fueled rocket (XSAM-N-2a: LR2-RM-6)
Booster: Solid-propellant rocket
Warhead45 kg (100 lb) high-explosive

Main Sources

[1] Norman Friedman: "US Naval Weapons", Conway Maritime Press, 1983
[2] Frederick I. Ordway III, Ronald C. Wakeford: "International Missile and Spacecraft Guide", McGraw-Hill, 1960
[3] Bill Gunston: "The Illustrated Encyclopedia of Rockets and Missiles", Salamander Books Ltd, 1979
[4] US Navy: "Model Designations of Naval Aircraft", 1947 and 1950
[5] National Air and Space Museum Website


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Last Updated: 4 February 2003