Field and sustainment maintenance in Army aviation

Two-level maintenance is the Army's division of all materiel maintenance into field maintenance, which repairs equipment and returns it to the operator or user, and sustainment maintenance, which overhauls end items and components and returns them to the supply system. AR 750-1, the Army maintenance policy dated April 29, 2026, sets the two levels and requires every task to follow the technical manual (TM) and its maintenance allocation chart (MAC). For aircraft, ATP 3-04.7, the Army techniques publication on aviation maintenance dated October 20, 2020, names the units that do the work at each level, from the aviation maintenance company to Corpus Christi Army Depot.

Where the two levels are written down

AR 750-1 is the policy. The 2026 edition is a major revision and supersedes the edition dated February 2, 2023. Paragraph 3-8 holds the definitions. The aviation section of the regulation adds that sustainment maintenance for Army aviation consists of aircraft rebuild, overhaul, crash and battle damage repair, and major airframe modifications.

ATP 3-04.7 is the doctrine for doing the work. The October 2020 edition is approved for public release and supersedes the edition dated September 11, 2017. The publication describes a tiered two-level strategy meant to give the tactical formation the maintenance capabilities it needs most to respond rapidly. ATP 3-04.7 refers readers to AR 750-1 for field maintenance policy, but the two documents do not always use the same lists.

Field maintenance in the aviation brigade

ATP 3-04.7 places field maintenance in three kinds of company.

• Aviation maneuver company. The flying company performs field-level maintenance within its capability, including preflight, postflight, and daily inspections. Crew chiefs document maintenance in aircraft logbooks and historical records.
• Aviation maintenance company (AMC). The AMC is organic to aviation battalions and squadrons, and in attack and cavalry units it may be a troop. The AMC manages the battalion maintenance program, conducts phase maintenance, troubleshoots, removes and replaces components, and performs maintenance test flights.
• Aviation support company (ASC). The ASC belongs to the aviation support battalion (ASB). The company performs scheduled and unscheduled field-level pass-back maintenance for work above the capacity or capability of the maintenance companies it supports.

AR 750-1 adds Army National Guard Aviation Classification and Repair Activity Depots (AVCRADs) and Army aviation support facilities to the field providers. At this level, component disassembly and repair is normally limited to cleaning and replacing seals, fittings, and common hardware.

Sustainment maintenance: depots, theater groups, and contractors

ATP 3-04.7 defines sustainment maintenance as off-system repair that returns the item to the supply system. National-level providers perform it unless the owning unit is granted an exception. The ATP names three main providers: original equipment manufacturers and their contractor field service representatives, Army sustainment facilities at fixed bases in the continental United States, and the national maintenance program (NMP) source of repair. AR 750-1 gives a different list in 2026: the AVCRADs, the theater aviation sustainment maintenance groups (TASMGs), manufacturers, organic industrial base facilities, and designated contractors.

The ATP lists four TASMGs, in Fresno, California; Springfield, Missouri; Gulfport, Mississippi; and Groton, Connecticut, with a theater sustainment headquarters in Edgewood, Maryland. At home they provide sustainment maintenance, limited depot capabilities, and backup field maintenance; deployed, the ATP calls them a "depot minus" capability. AR 750-1 places the four groups in the Aviation Depot Maintenance Round-Out Unit program, under the operational control of their State Adjutants General in garrison.

A brigade can also reach up. Through the Aviation and Missile Command (AMCOM) logistics assistance representative, a combat aviation brigade may obtain a specialized repair authorization, one-time repair, or aircraft repair authorization, if engineers at the Combat Capabilities Development Command Aviation and Missile Center approve.

Corpus Christi Army Depot

ATP 3-04.7 calls Corpus Christi Army Depot (CCAD) the Army's organic facility for the repair and overhaul of rotary-wing aircraft. The depot partners with industry to overhaul, repair, and modernize aircraft, engines, and components. AMCOM, a major subordinate command of the Army Materiel Command, has direct operational control of CCAD and Letterkenny Army Depot. AR 750-1 transfers accountability to the Army Materiel Command when an aircraft is accepted for programmed depot maintenance. An aircraft accepted for unprogrammed depot maintenance is normally repaired and returned to the user.

Depot work also travels. An October 2023 army.mil story describes a CCAD field team sent to the 3rd Combat Aviation Brigade at Hunter Army Airfield, Georgia, where several CH-47F helicopters with airframe issues needed repairs. The schedule called for 16 working days, and the team returned the aircraft within ten days. A July 2026 story reports that in fiscal year 2025 the depot field team restored 61 rotary-wing aircraft to fully mission-capable status. By working in theater, the story says, CCAD cut traditional induction timelines from 180-270 days to about 15-30 days.

The MAC sets the level for each task

Whether a task is field or sustainment work is written into each equipment TM. ATP 3-04.7 ties a maintenance company's field-level authority to the source, maintenance, and recoverability (SMR) code, the MAC, and the tools and qualified people on hand. The aviation MAC format in MIL-STD-40051-2C, the December 15, 2015 Department of Defense standard for page-based TMs, gives two columns under each level:

MAC column	Level	Organization
O	Field	Aviation maintenance company
F	Field	Aviation support battalion
L	Sustainment	TASMG and other organizations with NMP certification
D	Sustainment	Depot

The standard states that the MAC assigns tasks to the lowest level of maintenance. AR 750-1 lets the commanding general of the Army Materiel Command grant field units authority to perform sustainment-level tasks in the MAC when skilled maintainers, tools, and test equipment are available.

What to check

• Does a plan cite the April 29, 2026 edition of AR 750-1 or the superseded edition of February 2, 2023?
• Is the task coded O or F in the aircraft TM's MAC, or L or D? If L or D, what authorization lets a field unit do it?
• Is a repair above field level covered by a specialized repair, one-time repair, or aircraft repair authorization?
• Does a statement about who performs sustainment maintenance follow ATP 3-04.7 (2020) or AR 750-1 (2026)? The two lists differ.
• Is an aircraft at CCAD in programmed depot maintenance, where accountability passes to the Army Materiel Command, or in repair and return?

Azcuna's ELLMENT for the CH-47 puts the Chinook's public technical manuals, the Army sling-load manuals and a unit's own SOPs on a laptop or tablet that answers a repairer's or flight engineer's question with no network and cites the manual and page. Azcuna submitted it as a concept white paper to the Army's xTech|Search 10 competition in October 2026.

Sources

1. 1ATP 3-04.7, Army Aviation Maintenance · Headquarters, Department of the Army, October 20, 2020
2. 2AR 750-1, Army Materiel Maintenance Policy · Headquarters, Department of the Army, April 29, 2026
3. 3MIL-STD-40051-2C, Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) · Department of Defense, December 15, 2015, via EverySpec
4. 4CCAD field teams travel worldwide performing repairs · U.S. Army (army.mil), October 11, 2023
5. 5Rapid Repairs, Global Impact: CCAD Recognized for Excellence in FY26 AAME · U.S. Army (army.mil), July 2, 2026

Where this shows up in our work

• ELLMENT for the CH-47 Chinook answers a repairer's or flight engineer's question from the Chinook's manuals and the Army sling-load manuals and cites the page, with no network.
• TRACE, the offline S1000D and IETM viewer opens S1000D, MIL-STD-3001 and PDF technical manuals on a tablet with every marking intact.