Guide · Updated 2026-10-09
Part-66 B1 vs B2 Training Records
Part-66 Category B1 and Category B2 are different privilege sets. Your training matrix should give each its own requirement — with subcategory, limitations, linked type ratings and evidence — so a current B1 never appears as cover for a B2 avionics task, and vice versa.
Quick answer
Record B1 (mechanical / airframe and powerplant privileges within the subcategory held) and B2 (avionics privileges within the limitations held) as separate matrix requirements, even when both sit on the same physical AML. Store the parent AML number and expiry on both rows or on a linked parent record, then attach category-specific type ratings and any company mechanical or avionics authorisation separately. Never use a single “licensed engineer – current” cell for mixed B1/B2 teams.
Why one engineer column is not enough
Planners allocate work packages by privilege, not by headcount of people who own a plastic licence card. A heavy mechanical check needs current B1 scope and the right type; an avionics defect or modification package needs B2. When Excel ages every AML under one date, filters report “enough licensed staff” while the only current B2 for a type is on leave. The failure is a data-model problem before it is a people problem.
| Record field | B1 row | B2 row |
|---|---|---|
| Category focus | Mechanical subcategory and limitations | Avionics category and limitations |
| Parent AML | Shared licence number and AML expiry | Same parent, still shown |
| Type link | Airframe/engine types endorsed | Avionics types or systems endorsed |
| Company auth | Mechanical certifying/support auth | Avionics certifying/support auth |
| Continuation | HF / EWIS / FTS as assigned to role | HF / EWIS / FTS as assigned to role |
What to capture on each row
- Exact category label (B1 with subcategory, or B2) — not “engineer”
- Limitations and exclusions that affect task allocation
- Parent AML expiry so licence currency remains visible
- Named type ratings that apply to that category’s work
- Evidence file that matches the category claim (licence page or verification)
- Company authorisation scope held separately from the category tick
Dual-category holders
Some engineers hold both B1 and B2. That is a reason to keep two requirement rows, not one merged status. A person can be current on B1 type A and expired or missing on B2 type B. Dual rows make the first failure obvious. If your quality system also issues separate mechanical and avionics company authorisations, those are further rows — the AML category still does not equal release authority under the organisation approval.
Operational checks before a shift
- Filter the matrix to the named hangar or line team for the window.
- List work packages that need B1 mechanical versus B2 avionics privileges.
- Confirm type endorsements match the aircraft on the work order.
- Confirm company authorisation is in force for the release scope required.
- Treat blank or ambiguous category cells as unresolved — not as “probably B1”.
CAA context and FieldClear links
Category meanings and licence framework context sit with the CAA’s Part-66 general guidance. Renewal process detail is on the CAA’s renew a UK Part-66 AML page. In FieldClear, keep live views on Part-66 B1 expiry and Part-66 B2 expiry, with the parent UK Part-66 AML expiry tracker and the aircraft maintenance vertical for the full grid.
Honest limits
FieldClear tracks Category B1 and B2 records you assign. It does not grant B1 or B2 privileges, interpret limitations for a specific release, certify airworthiness, or replace Part-145 authorisation systems. This guide is operational record-keeping guidance — not legal or aviation regulatory advice.
Already have a spreadsheet?
Upload your existing matrix and see who’s current, what’s expiring and what’s missing.
14-day free trial. No card required.