How to read an Army technical manual number

An Army technical manual (TM) number is a coded label that tells a reader what kind of equipment a manual covers, which item it is, and which maintenance level it serves. DA Pamphlet (DA Pam) 25-40, Army Publishing Program Procedures, dated February 1, 2024 and revised administratively on October 24, 2024 and February 4, 2025, sets the rules in paragraph 8-26. AR 25-30, the Army Publishing Program regulation dated June 14, 2021, gives the Army Materiel Command Logistics Data Analysis Center (LDAC) the master database of publication sequence numbers. The Army Publishing Directorate's technical manual index shows the rules at work on aircraft manuals.

The four parts of an equipment TM number

Paragraph 8-26 builds the number from four parts joined by dashes.

1. Series number. The general type of equipment, from Table 8-4. Series 1 is Aviation/Aviation Logistics, 5 is Engineers, 9 is Ordnance (missile and munitions), and 55 is Transportation. No zero goes in front of a series number below 10.
2. Federal Supply Classification (FSC) class or group. Four digits. The first two must match the FSC group in Federal Logistics (FED LOG) data for the end items. A manual on one model, or on models in the same class, uses the FSC class. A manual covering models in different classes uses the group plus two zeros. The pamphlet's example is 1500, covering class 1510 (fixed wing aircraft) and class 1520 (rotary wing aircraft).
3. Sequence number. Up to four digits assigned by the LDAC. All TMs on the same item, at every maintenance level, share one sequence number, and different equipment gets a different one.
4. Level of maintenance. Two digits for the level the manual serves.

The pamphlet's worked example is TM 5-5420-210-20: series 5, FSC class 5420 (bridges, fixed and floating), sequence 210, and level 20, maintainer maintenance.

Level numbers and suffix letters

Table 8-5 of the 2024 pamphlet lists three level numbers: -10 for operator/crew maintenance, -12 for operator through maintainer maintenance, and -20 for maintainer maintenance. AR 750-1, the April 29, 2026 maintenance regulation, calls operator and crew preventive maintenance checks and services from the applicable TM -10 series the cornerstone of the Army maintenance system.

Suffixes follow the level number. A P marks a repair parts and special tools list (RPSTL) published separately, as in -20P, for hardcopy and PDF manuals only; the pamphlet prohibits separate RPSTL interactive electronic technical manuals (IETMs). An &P marks a RPSTL included with the instructions, as in -20&P. A further dash and number, such as -2, marks a volume.

Table 8-6 lists special suffixes. Several apply only to aircraft: -CL (pilot and crew checklist), -MTF (maintenance test flight), -PMD (preventive maintenance daily inspection checklist), -PMS (preventive maintenance services), and -S (preparation for shipment). Others, such as -BD (battle damage repair) and -HR (hand receipt), apply to all equipment. These manuals omit the level number, except hand receipts and preventive maintenance checklists, so the pamphlet's example TM 1-1520-228-MTF has none.

Older and combined level numbers

Many active manuals carry level numbers that Table 8-5 does not list. The title table in MIL-STD-40051-2C, the December 15, 2015 Department of Defense standard for page-based TMs, pairs suffixes with titles in two-level terms: -13 is an Operator and Field Maintenance Manual, -23 a Field Maintenance Manual, -24 a Field and Sustainment Maintenance Manual, and -40 a Sustainment Maintenance Manual. For technical bulletins, DA Pam 25-40 states the rule behind such pairs: the first digit is the lowest level and the second the highest, so -24 indicates maintainer and sustainment maintenance combined.

Older titles use older level names. In the index, TM 1-1500-250-23, dated August 24, 1990, is titled for aviation unit and aviation intermediate maintenance. TM 3-4240-276-30&P, dated December 30, 1997, is a direct support maintenance manual, and neither the 2024 table nor the 2015 title table lists -30. TM 3-1040-290-40, dated August 31, 2010, is a sustainment maintenance manual. For any of these, the title in the index names the levels the manual covers.

The CH-47F manuals as a worked example

The index lists the CH-47F manuals under one root, TM 1-1520-271: series 1 for aviation, FSC class 1520 for rotary wing aircraft, and sequence 271. The national stock number in the titles, 1520-01-457-5179, begins with the same four digits.

• TM 1-1520-271-10, Operator's Manual for Army CH-47F Helicopter, December 18, 2013.
• TM 1-1520-271-20&P, an IETM for field maintenance including the RPSTL, December 30, 2025.
• TM 1-1520-271-CL-1, Operator's and Crewmember's Checklist, December 31, 2025.
• TM 1-1520-271-MTF, Maintenance Test Flight Manual, May 31, 2024.

The record for the -20&P says it supersedes TM 1-1520-271-23&P dated March 28, 2025, so the CH-47F field maintenance manual changed from -23&P to -20&P within one year. The record points to a sign-in portal, not a public file. Another sequence, 240, appears on TM 1-1520-240-BD, dated November 25, 2008, which covers battle damage assessment and repair for both the CH-47D and the CH-47F. For manuals prepared to S1000D, AR 25-30 requires a standard Army publication number in addition to the S1000D number, and DA Pam 25-40 says it should be displayed on the cover with the publication module code.

What to check

• Do the series and FSC digits fit the equipment: series 1 for aviation, 1520 for rotary wing, 1510 for fixed wing, 1500 for a mix?
• Does the level number match the work, and for an older -23, -30, or -40, which levels does the title name?
• Is the parts list included (&P) or separate (P), and does it carry the same sequence number as the manual?
• Has the manual been superseded under a new number, as the CH-47F -23&P was by the -20&P, and does a work order cite the current one?
• For an S1000D manual, does the cover show both the Army number and the publication module code?

Azcuna's TRACE is one offline viewer for S1000D, MIL-STD-3001 XML, and PDF technical manuals. It keeps the source location and the markings of everything it shows and never modifies the source. It was proposed to NAVAIR under Navy SBIR Phase I topic DON26BZ05-NV078, and the proposal was submitted on September 23, 2026.

Sources

1. 1DA Pam 25-40, Army Publishing Program Procedures · Headquarters, Department of the Army, February 1, 2024 (administrative revisions October 24, 2024 and February 4, 2025)
2. 2AR 25-30, Army Publishing Program · Headquarters, Department of the Army, June 14, 2021 (administrative revisions 2021 and 2023)
3. 3TM - Technical Manuals (Range 1-8) · Army Publishing Directorate
4. 4Record Details for TM 1-1520-271-20&P · Army Publishing Directorate
5. 5MIL-STD-40051-2C, Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) · Department of Defense, December 15, 2015, via EverySpec
6. 6AR 750-1, Army Materiel Maintenance Policy · Headquarters, Department of the Army, April 29, 2026

Where this shows up in our work

• TRACE, the offline S1000D and IETM viewer opens S1000D, MIL-STD-3001 and PDF technical manuals on a tablet with every marking intact.
• ELLMENT, the offline LLM for E-2D crews answers a crew's question from the aircraft's own manuals and cites the page, with no network.