Aircraft carriers have limited deck space in which to position and move aircraft on the flight deck. This is where a rather unsung workhorse of US Naval Aviation come into its own. To move these aircraft around, the Navy uses flight deck tractors.
Flight deck tractors first started to make an appearance on flight decks during the intense Pacific campaigns of World War 2. It was discovered that man-handling aircraft to position them for flight operations took too much time. The first integration of the flight deck tractor was actually just a plain old US Army Willy Jeep:
The tow tractors also became necessary because of the increased weight of aircraft like the SBDs, Grumman Avenger and Hellcat. Willy’s Jeeps served as aircraft tractors on fleet carriers (Yorktown and Essex classes) as well as on smaller ships (Independence, Bogue, Sangamon, Casablanca classes) till the end of the war.
At the same time the US Navy adopted the Clarktor 6 Tractor which was already in use with the USAAF. The Clarktor 6 was based on a pre-war commercial tractor design. These tractors were in use on Lexington, Essex and Midway class carriers till the mid-1950s:
The BNO-40 flight deck tractor was also based on a pre-war commercial design that entered US Navy service in 1943. These tractors served on most USN carriers, including veterans like USS Enterprise (CV-6), Essex and Midway class attack carriers, Independence class light carriers and even the smaller Bogue, Sangamon, Casablanca and Commencement Bay class escort ships. By the mid-1950S these tractors also service with the French Navy aboard the R96 La Fayette (ex USS Langley) and R97 Bois Belleau (ex USS Belleau Wood):
The introduction of jet aircraft to US Navy flight decks in the 1950s posed a whole new set of problems with flight deck tractors. The US Navy introduced the MD-1 flight deck tractor which was the first equipped with a gas turbine unit to assist in starting the modern jet powered aircraft. For this reason they become known by the name “huffer.” Huffers served on the served on Essex / Oriskany, Midway and Forrestal / Kitty Hawk class carriers of the U.S. Navy until mid 1960s. They were also used by the Royal Canadian Navy aboard the HMCS Bonaventure:
Introduced in the early 1960s, the MD-3 tow tractor was the first purpose-built flight deck tractor. Introduced in the 1960’s the MD-3 featured a low profile to fit under the nose of modern naval aircraft. To cope with the larger size of aircraft at the time, the MD-3 was also larger and heavier than its predecessors. The MD-3 also featured a gas-turbine starter but also space of a fire extinguisher. The MD-3 served on all US Navy carriers (all classes included the CVN-68 class) and amphibious assault ships of the era:
The current flight deck tractor found on all aircraft carriers and amphibs is the A/S-32A-31A. Introduced in the 1990’s, the -31a looks like the MD-3 but is longer as it has a new starter unit and contains a place to stow equipment. The -31A is powered by a 3 stroke diesel engine, an automatic transmission. Although rear wheel driven the -31A has power assisted steering up front:
The newer SD-2 is a version of the A/S32A-32A designed specifically for use in the aircraft hangar deck. Due to the even more restricted space below the SD-2 has a castoring wheel that enables to fit aircraft into the tighter spaces found on the hangar deck. The SD-2 also does not need to tow bar as the aircraft are handled by an attached brace on the tractor that fits into the nosegear:
Tow tractors enable carriers and other aircraft operating ships to rapidly reposition aircraft to facilitate a rapid tempo of flight operations. Keeping in mind, IYAOYAS, tow tractors and their aviation bosun mates enable that ordinance to be on target in a timely manner. As with other member of the Naval Aviation team, They give creditibilty to US Naval power.