The FAA MIDO, short for Manufacturing Inspection District Office, is the field-level FAA office that oversees companies producing aircraft, engines, propellers, and replacement parts under federal production approvals. In a 2023 reorganization of the Aircraft Certification Service, every MIDO was redesignated as a Certificate Management Section, but the work is the same and industry still uses the older name.1Federal Aviation Administration. Certificate Management Sections If you manufacture aviation products, this is the office that reviews your application, audits your facility, and monitors your quality system for as long as you hold a certificate.
What the Office Does
The core mission is to make sure every manufactured aviation product matches the design the FAA already approved and is safe to fly. Inspectors assigned to these offices handle production approval and certification, airworthiness certification, manufacturing facility oversight, designee management, and support for Certification Branches during design approvals.2Federal Aviation Administration. Certificate Management Branches Their surveillance and audit work operates under 14 CFR Part 21, the federal regulation governing certification procedures for aviation products and articles.3eCFR. 14 CFR Part 21 – Certification Procedures for Products and Articles
FAA Order 8120.23A lays out the certificate management program these inspectors follow, including a risk-based methodology for deciding how often to audit each manufacturer.4Federal Aviation Administration. FAA Order 8120.23A – Certificate Management of Production Approval Holders During facility visits, inspectors examine whether each unit coming off the line matches the approved prototype. They review materials, production processes, tooling, staff training, and facility maintenance. Findings get categorized, recorded, and analyzed annually for trends so the FAA can focus future audits where risk is highest.5Federal Aviation Administration. Certificate Management / Quality System Audit (QSA) of Production Approval Holders A production certificate remains effective until it is surrendered, suspended, revoked, or the FAA sets a termination date, so audit performance matters continuously.
Older FAA orders, advisory circulars, and industry manuals still refer to the “MIDO.” Those references now point to a Certificate Management Section under the Aircraft Certification Service. Applications for new production certificates go to the Certificate Management Branch that houses the section for your region.
Production Approvals the Office Manages
These offices administer three main categories of production authorization, each aimed at a different kind of manufacturer.
Production Certificate
A Production Certificate lets a manufacturer produce duplicate copies of an aircraft, engine, or propeller under an FAA-approved type design. The holder can obtain airworthiness certificates for completed aircraft without a separate individual showing for each unit.6Federal Aviation Administration. Production Certificates This is the approval large-scale manufacturers pursue once they already hold a Type Certificate for their design. It requires demonstrating a quality system capable of ensuring every unit matches the approved design and is safe to operate.
Parts Manufacturer Approval
A Parts Manufacturer Approval (PMA) authorizes a company to produce replacement or modification parts for existing aircraft. The applicant must show the FAA the specific product the part will be installed on, provide drawings and specifications defining the article’s configuration, and submit test data proving the design meets airworthiness standards. PMA holders must also designate an accountable manager and maintain the same quality system required of Production Certificate holders.7eCFR. 14 CFR Part 21 Subpart K – Parts Manufacturer Approvals
Technical Standard Order Authorization
A TSO authorization covers specific articles, such as navigation equipment, seatbelts, or fire extinguishers, that must meet a minimum performance standard published by the FAA. Unlike a Production Certificate, a TSO authorization focuses on whether the article meets that published standard rather than duplicating a unique type design. The applicant must submit a statement of conformance along with the technical data required by the applicable TSO. If the FAA requests additional information and the applicant does not respond within 30 days, the application is denied.8eCFR. 14 CFR Part 21 Subpart O – Technical Standard Order Approvals
The Quality System the Office Will Audit
Every production approval holder must build and maintain a quality system that ensures each product conforms to its approved design and is in a condition for safe operation. Under 14 CFR 21.137, that system must cover 14 elements, including responsibility and authority, resource management, contract review, design control, document control, purchasing, product identification and traceability, process control, inspection and testing, equipment control, inspection and test status, nonconforming product control, corrective and preventive actions, and handling and storage.9eCFR. 14 CFR 21.137 – Quality System
The manufacturer documents this entire system in a quality manual and submits it to the FAA for approval.10Federal Aviation Administration. Advisory Circular 21-43 – Production Under 14 CFR Part 21, Subparts F, G, K, and O The manual becomes the benchmark inspectors use during every subsequent audit. If your actual production practices do not match what the manual describes, that gap becomes a finding.
Supplier control sits inside that same quality system. If you use outside suppliers for materials, components, or sub-assemblies, you remain fully responsible for the airworthiness of everything that carries your approval. Your quality system must include procedures to qualify suppliers, verify conforming articles at incoming inspection, and report items that are later found nonconforming after release. FAA surveillance specifically targets whether you maintain continuing oversight of your supply chain, not just whether you wrote a supplier control procedure and filed it away.
The Accountable Manager
Every applicant for or holder of a production approval must designate an accountable manager. This person holds authority over all production operations conducted under Part 21, confirms that the quality manual procedures are in place, ensures the organization satisfies applicable regulations, and serves as the primary contact with the FAA.11eCFR. 14 CFR 21.135 – Organization The accountable manager is the person who answers when something goes wrong, so choosing someone without genuine authority over manufacturing operations invites problems during audits.
How the Application and Audit Process Runs
Getting a production approval is not a single-step transaction. It unfolds in phases, and the timeline depends heavily on how prepared you are before you file. FAA Form 8110-12 is the formal application for a Type Certificate, Production Certificate, Supplemental Type Certificate, or amendments to any of those, and a Type Certificate and Production Certificate can be applied for simultaneously on the same form.12Federal Aviation Administration. FAA Form 8110-12 – Application for Type Certificate, Production Certificate, or Supplemental Type Certificate
Document Review
Once you submit the application package, which includes the completed form, quality manual, organizational documents identifying your accountable manager, and supporting technical data, the FAA reviews everything for completeness and regulatory compliance.13Federal Aviation Administration. FAA Order 8120.17 – Implementation of Changes to the Revised 14 CFR Part 21 Inspectors evaluate whether the quality manual adequately addresses all 14 required elements and whether the organizational structure supports the type of production you intend to do. Gaps in documentation at this stage are the most common reason for delays. A thin quality manual that reads like a template rather than a description of your actual operations will get sent back.
Quality System Audit
After the paperwork clears review, the FAA schedules an on-site Quality System Audit. During this visit, inspectors observe manufacturing processes, interview production and quality staff, inspect tooling and equipment calibration records, and verify that the facility matches what the quality manual describes.5Federal Aviation Administration. Certificate Management / Quality System Audit (QSA) of Production Approval Holders Inconsistencies are categorized and recorded, and you must implement corrective actions before the FAA will issue the certificate. The length of this process varies with the size and complexity of your operation and how many findings need to be resolved.
Ongoing Oversight After You Are Approved
Earning a production approval is the start of FAA oversight, not the end. Each manufacturer’s managing office must conduct a risk assessment at least once every 12 months, no later than March 31 of each year, and audit scheduling follows the results of that assessment.4Federal Aviation Administration. FAA Order 8120.23A – Certificate Management of Production Approval Holders Manufacturers with a history of findings or higher-risk products can expect more frequent visits.
Federal regulations also impose a mandatory defect reporting obligation. If you hold a Type Certificate, PMA, or TSO authorization and determine that a product you manufactured has experienced certain failures, you must report it to the FAA within 24 hours. Reportable events include fires caused by equipment failure, engine exhaust damage, structural failures, flight control malfunctions, engine failures, and any malfunction that results in an emergency action, among others.14eCFR. 14 CFR 21.3 – Reporting of Failures, Malfunctions, and Defects You must also report any defect in a product that has left your quality system if you determine it could result in one of those same events. Reports due on a weekend can be delivered the following Monday, and those due on a holiday can be submitted the next business day, but the 24-hour clock otherwise runs from the moment you make the determination.
Finding Your Assigned Office
The FAA assigns manufacturers to offices based on geographic region. You should contact the office nearest to you within the Certificate Management Branch for your area.15Federal Aviation Administration. Certification Branches Submitting your application to the wrong office creates unnecessary delays, so confirming your assigned branch before filing is worth the few minutes it takes. The FAA’s Aircraft Certification Service local offices page provides a starting point for identifying the correct contact.16Federal Aviation Administration. Aircraft Certification Service – Local Offices