AN/SPN-35

The AN/SPN-35 is a computerized automatic landing system installed on the Tarawa-class amphibious assault ship and other LHA/LHD-class warships to give control for aircraft during the final approach and landing.

The Joint precision approach and landing system (JPALS) is slated to replace the AN/SPN-35 on U.S. Navy amphibious assault ships.

Description
The AN/SPN-35 is used to offer guidance to the aircraft pilot on final approach. It provides relative azimuth, range, and elevation information to the radar operator, who relays this as verbal guidance to the aircraft pilot on approach.

The AN/SPN-35A variant has two antennas: the azimuth antenna (AS-1292/TPN-8) and the elevation antenna (AS-1669/SPN-35). The azimuth antenna is located above the azimuth drive assembly on the stabilized yoke. The elevation antenna is mounted on the elevation drive assembly adjacent to the azimuth antenna.



History
The AN/SPN-35 was developed from the ground-based AN/TPN-8 landing approach control radar. It was first evaluated on the USS Kearsarge (CV-33) in 1962, as an AN/TPN-8 mounted to an AN/SPN-6 stable pedestal and secured to an AN/SPN-8 platform. A prototype was evaluated aboard the USS Bon Homme Richard (CV-31) about a year later as a replacement for the AN/SPN-8 on ASW carriers and small attack carriers. As of 1965, the AN/SPN-35 was being used "primarily on the ASW type carriers."

The -35A variant was used onboard Nimitz-class aircraft carriers prior to 1996, when it was replaced by the AN/SPN-46A/B. It remains in use on the Wasp-class amphibious assault ship and America-class amphibious assault ship today.

[[australia|🇦🇺]] Royal Australian Navy

 * HMAS Melbourne (R21)

[[spain|🇪🇸]] Spanish Navy

 * Príncipe de Asturias

Royal Navy

 * HMS Ark Royal (R09)

[[united states|🇺🇸]] United States Navy

 * Ship classes known to carry this system:
 * Tarawa-class amphibious assault ship
 * Wasp-class amphibious assault ship
 * America-class amphibious assault ship
 * Nimitz-class aircraft carrier - Replaced by AN/SPN-46 in the late 90s.
 * Individual ships known to carry this system:
 * USS Intrepid (CV-11)
 * USS Hornet (CV-12)
 * USS Ticonderoga (CV-14) - Installed 1965 while undergoing overhaul at San Francisco Bay Naval Shipyard.
 * USS Bon Homme Richard (CV-31) - Initial testing and evaluation
 * USS Kearsarge (CV-33) - Initial testing and evaluation
 * USS Oriskany (CV-34)
 * USS Ranger (CV-61)


 * USS Tripoli (LPH-10)
 * USS Inchon (MCS-12)

Variants

 * AN/SPN-35: Original model that entered service.
 * AN/SPN-35A: Improved stabilization system to compensate for pitch and roll of carrier. Replaces the original mechanical-hydraulic stabilization of the original with an electromechanical stabilization system.
 * AN/SPN-35B:
 * AN/SPN-35C: Upgrade to AN/SPN-35B. Adds Moving Target Detection (MTD), Track While Scan (TWS), and Built-In Test (BIT) capability.