AN/SPN-35 explained

AN/SPN-35
Country:	United States
Manufacturer:	ITT-Gilfillan^[1]
Frequency:	9.0 to 9.2 GHz band
Prf:	1200
Pulsewidth:	.2 microseconds^[2]
Power:	200
Related:	AN/TPN-8

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.^{[3] [4]}

The Joint precision approach and landing system (JPALS) is slated to replace the AN/SPN-35 on U.S. Navy amphibious assault ships.^{[5] [6]}

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.^[7]

History

The AN/SPN-35 was developed from the ground-based AN/TPN-8 landing approach control radar.^{[8] [9]} It was first evaluated on the 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 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."^[10]

The -35A variant was used onboard s prior to 1996, when it was replaced by the AN/SPN-46A/B.^[11] It remains in use on the and today.

Platforms

Royal Australian Navy

• ^{[12] [13]}

Spanish Navy

• Príncipe de Asturias^{[1] [14]}

Royal Navy

• ^[15]

United States Navy

• Ship classes known to carry this system:
  • Tarawa-class amphibious assault ship^[3]
  • Wasp-class amphibious assault ship
  • America-class amphibious assault ship^{[16] [17]}
  • - Replaced by AN/SPN-46 in the late 90s.^[11]
• Individual ships known to carry this system:
  • ^[18]
    • • - Installed 1965 while undergoing overhaul at San Francisco Bay Naval Shipyard.
  • - Initial testing and evaluation
  • - Initial testing and evaluation

• • ^[19]
  • 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.^[20]
• 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.^[21]

See also

• AN/SPN-46(V)1
• List of military electronics of the United States

External links

• Refer to page 7 of Sept. 1963 issue for discussion of impact for SPN-35 relative to what came before.

Notes and References

1. Book: Moore, John Evelyn . Jane's Fighting Ships 1984-85 . Jane's Information Group . 1984 . 9780710607959.
2. Maiuzzo . M . Compatibility Factors Affecting Concept Development of Approach and Landing Guidance System . IIT Research Institute .
3. Web site: AN/SPN-35 Aircraft Control Approach Central . Pike . John . 1999 . Federation of American Scientists.
4. News: Capt. Brett Easler . Cmdr. Bruce Herman, USN (Ret.) . On Glide Path, On Course: Past, Present and Future . Naval Aviation News . 18–19 . 96 . 3 . 2014 . 2023-01-02 .
5. Navy Program guide 2011 . U.S. Navy . 43 . 2011 .
6. Defense Acquisitions: Assessments of Selected Weapon Programs . Government Accountability Office . 81 . March 2010.
7. Book: Simmons, Larry D. . Electronics Technician . Ace III . Floyd L. . NAVAL EDUCATION AND TRAINING PROFESSIONAL DEVELOPMENT AND TECHNOLOGY CENTER . 1995 . 7 . 229-230 . 12 Jan 2023 . October 1995.
8. Book: Friedman, Norman . Naval Radar . Conway Maritime Press . 1981 . 0851772382 . London.
9. Web site: AN/TPN-18 - Radartutorial . 2022-11-19 . www.radartutorial.eu . en.
10. Naval Aviation News . December 1965 . 14 . For Unerring Performance of Their Duties . Fuchs . William C.
11. Book: Elward, Brad . Nimitz-class aircraft carriers . Osprey publishing . 29 . 2010 . 978-1-84603-759-7.
12. News: A4G Pilot Survives Ramp Strike . Thompson . Phil . Slipstream . Fleet Air Arm Association of Australia . 25 . 2023-01-02 . March 2020 . 31 . 1.
13. News: Two Australians at Glynco Taking NATTC Electronics Course . Naval Aviation News . June 1968 . 49 .
14. Web site: Principe de Asturias . 2023-01-03 . Naval Technology . en-US.
15. Book: Hobbs, David . British Aircraft Carriers: Design, Development and Service Histories . 2013 . Barnsley, UK . Seaforth Publishing . 978-1-84832-138-0 . 295.
16. Book: Saunders . Stephen . Philpott . Tom . Jane's fighting ships 2015-2016 . 978-0-7106-3143-5 . 919022075 . 2015 . 960.
17. Web site: Amphibious Assault Ship (General Purpose) Photo Index LHA-6 America . 2023-01-05 . www.navsource.org.
18. Book: Stille, Mark . Essex-Class Aircraft Carriers 1945–91 . Bloomsbury Publishing . 2022 . 9781472845795 . 1617, 32.
19. Commanding Officer, USS Tripoli . Command History for Calendar year 1972 . 9.
20. Book: Shipboard Electronic Equipments . U.S. Navy . 1969 . NAVSHIPS 10794-C . Chapter 12-Miscellaneous Facilities . 213–214.
21. Book: Navy Training System Plan for the AN/SPN-35C Aircraft Control Approach Central . 2001 . U.S. Navy . 1.