Description
Technical Manual Change 1 (TM 9-1240-309-35) for XM44 Tank Periscope June 1967 FSN 1240-788-5463
U.S. Army Technical Manual Change 1, TM 9-1240-309-35, for XM44 Tank Periscope, June 1967, FSN 1240-788-5463
Item Overview
This U.S. Army publication is Change 1 for Technical Manual TM 9-1240-309-35, covering the XM44 Tank Periscope, FSN 1240-788-5463. Issued in June 1967, it updates the original manual dated May 9, 1966.
This listing is for the Change 1 publication only. It is not the complete original manual unless specifically stated. The XM44 periscope, image-intensifier tube, vehicle, mount, and other fire-control equipment are not included.
Change 1 Update
Change publications allowed the Army to correct or revise technical information without replacing an entire manual. Change 1 was intended for use with the May 1966 base edition of TM 9-1240-309-35.
Depending on its original format, this update may contain replacement pages, added pages, corrected procedures, or instructions for changing the base manual. It documents the maintenance information considered current in June 1967.
About the XM44 Tank Periscope
The XM44 served as the gunner’s primary night fire-control periscope on the M551 Sheridan Armored Reconnaissance/Airborne Assault Vehicle. It combined a unity-power daylight channel with a passive low-light channel offering approximately 9-power magnification.
The night channel used available light and an image-intensifier tube to improve visibility in dark conditions. A reticle-projector system placed a ballistic aiming pattern over the target image.
The periscope consisted mainly of a head assembly and body assembly. The head gathered light and followed the weapon’s elevation. The body contained the viewing optics, image-intensifier system, controls, and projected reticle.
M551 Sheridan Application
The M551 was a lightweight armored vehicle developed for reconnaissance, airborne operations, and mobile fire support. Its main weapon was the 152mm M81 gun/launcher, which could fire conventional ammunition and the MGM-51 Shillelagh guided missile.
The XM44 provided daylight observation and passive night aiming for conventional fire. Separate telescope and tracking equipment supported the guided-missile system.
The XM prefix shows that the periscope retained an experimental designation. Later XM44E-series versions continued the development of the design, but this Change 1 publication specifically updates the manual for the original XM44.
Historical Background
The original manual was issued in May 1966 during the final development and early production period of the M551 Sheridan. The Sheridan entered U.S. Army service in 1967 and later saw combat during the Vietnam War.
Passive night-vision equipment was an important improvement over earlier active infrared sights, which required a separate infrared light source. The XM44 used available light, helping the gunner observe and aim with less dependence on active illumination.
Change 1 appeared in June 1967 as the Sheridan entered service. It records corrections and updated maintenance information developed during this important period in the vehicle’s history.
Publication Details
- Publication: Change 1
- Manual number: TM 9-1240-309-35
- Change date: June 1967
- Original manual date: May 9, 1966
- Subject: XM44 Tank Periscope
- Federal Stock Number: 1240-788-5463
- Manual level: Direct support, general support, and depot maintenance
- Optical functions: Unity-power daylight viewing and 9-power passive low-light viewing
- Equipment role: Gunner’s night fire-control periscope
- Parent vehicle: M551 Sheridan
- Associated weapon: 152mm M81 Gun/Launcher
- Equipment status when documented: Experimental or pre-standardized
- Item included: Change 1 publication only
Collector and Research Value
This publication is a specialized addition to a U.S. Army technical-manual, armored-vehicle, night-vision, or military-optics collection. It is useful for studying the M551 Sheridan and the Army’s early passive vehicle-mounted night sights.
Ideal For
- U.S. Army technical-manual collections
- M551 Sheridan research and displays
- XM44 tank-periscope restoration references
- Vietnam War armored-vehicle exhibits
- Early passive night-vision collections
- Military optics and fire-control research
- Museum and archival reference libraries
Approx length 8", Approx width 10", Approx height .1", Approx weight .1lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item's general condition. The item you receive might be slightly better, or worse, condition than was shown in the pictures.
Please visit our page about order lead times here: Order Lead Times