AFTO Form 99, the Limited/Special TMDE Certification Label, is a calibration label affixed to Air Force test, measurement, and diagnostic equipment (TMDE) to document that the item passed calibration only under limited or special conditions.1Air Force E-Publishing. AFI 21-101 Incirlik AB Supplement – Aircraft and Equipment Maintenance Management It is not a form maintenance personnel complete themselves. Precision Measurement Equipment Laboratory (PMEL) technicians fill it out during calibration, and the label then travels with the equipment so anyone using the tool can see what it can and cannot be trusted to measure.
What the Label Tells You
Every piece of TMDE in the Air Force inventory has to meet calibration standards before it can be used. Equipment that passes a standard, unrestricted calibration receives a different label. AFTO Form 99 applies specifically when calibration is limited or carries special conditions. A common example: an instrument certified accurate only within a narrower range than its full capability, or a multi-function tool where certain functions did not pass calibration.
The label identifies the equipment, the calibration date, the next scheduled calibration date, and the specific limitations or special conditions that apply. That last part is the reason the label exists. A torque wrench certified only within part of its range could give misleading readings outside it, and using an improperly calibrated tool during aircraft maintenance can produce dangerous results. Making the limitation visible at the point of use is what prevents the mistake.
Who Completes It
PMEL technicians complete AFTO Form 99 in the calibration laboratory. They determine, during calibration, whether the item meets standards fully, partially, or only under specific conditions. When the result is limited or special, they document the applicable conditions on the label and affix it directly to the equipment. Maintenance personnel do not initiate or fill out this form.
How to Use Equipment That Carries the Label
If you pick up TMDE bearing an AFTO Form 99 label, read it before you use the tool. Confirm that the certified range and any noted conditions cover the specific measurement you need to perform. If the task falls outside the labeled limitations, set the tool aside and use a different calibrated instrument. The label is the record of what the equipment is currently trustworthy for, and it governs any use until the next calibration.
Where the Governing Procedures Live
The Air Force Metrology and Calibration (AFMETCAL) program is governed by TO 00-20-14, which sets the methods and procedures for managing calibration across the Air Force. That technical order details when AFTO Form 99 applies versus other calibration labels, PMEL responsibilities in completing the label, and the scheduling requirements for recalibration. For specific procedural guidance, go to TO 00-20-14 through the Enhanced Technical Information Management System (ETIMS).
ETIMS is the Air Force’s enterprise system for managing technical orders and related records, including TO cataloging, subscriptions, distribution, and electronic TO access.2Department of the Air Force. TO 00-5-1 Air Force Technical Order System Active-duty, Guard, Reserve, and civilian Air Force personnel can reach it at https://etims.cce.af.mil with a Common Access Card. Personnel without access through a local Technical Order Distribution Office can contact the Global TODO point of contact.3Tinker Air Force Base. Technical Orders – Tinker Air Force Base
If You Meant AFTO Form 22 Instead
AFTO Form 99 is often confused with AFTO Form 22, the Technical Order Improvement Report and Reply. They are unrelated. Form 22 is the mechanism for reporting errors, safety hazards, or missing information in technical manuals, and ETIMS has largely replaced the paper version with a digital Recommended Change process. AFTO Form 22 remains available as a backup when ETIMS is unavailable.4Department of the Air Force. TO 00-5-1 Air Force Technical Order System If you are trying to flag a problem with a technical manual, that is the process you want. If you are trying to read a calibration label on a piece of test equipment, AFTO Form 99 is the right form.