How Balloon Drawings Work for AS9102 Form 3
A balloon drawing is the bridge between an engineering drawing and AS9102 Form 3 (Characteristic Accountability). Every dimension, tolerance, GD&T callout, note, surface finish, and material requirement on the drawing is assigned a unique balloon number, and Form 3 reports actual measured values keyed to those numbers. Olympus Machining LLC — an ITAR-registered, CAGE 9V9P0 CNC machine shop in Hanover, Pennsylvania — produces balloon drawings as the first step of every FAI workflow.
What Counts as a Balloonable Characteristic
AS9102 Rev C requires that every design characteristic be accounted for. That includes:
- • Every dimension with a tolerance (linear, angular, radius, diameter)
- • Every GD&T feature control frame and datum callout
- • Every surface finish callout (Ra, Rz, lay)
- • Every drawing note that imposes a requirement (material, finish, marking, packaging)
- • Material specification on the title block
- • Threads and threaded features (callout method, class of fit)
- • Special process callouts (heat treat, plating, anodizing, NDT)
Numbering Rules
Balloon numbers are sequential, unique, and never reused within a drawing. For multi-sheet drawings, balloons typically include the sheet reference (e.g., 1.1, 1.2 for sheet 1; 2.1, 2.2 for sheet 2). When a single feature has multiple sub-characteristics — for example, a hole with a diameter, a position tolerance, and a surface finish — each sub-characteristic gets its own balloon, not a shared one.
Reference dimensions are typically excluded from balloon-numbered Form 3 entries (they are not requirements), but Olympus marks them on the balloon drawing as "REF" so the reviewer can confirm they were not overlooked.
Software and Workflow
Olympus Machining produces balloon drawings using High QA inspection planning software. The customer drawing is imported as a PDF; characteristics are identified and ballooned using the software's auto-recognition with manual review. Form 3 is then generated directly from the ballooned drawing — eliminating transcription errors that occur when balloons and Form 3 entries are managed independently.
For model-based definition (MBD) parts where the engineering definition lives in the 3D model rather than a 2D drawing, the same characteristic accountability principle applies — characteristics are extracted from the model annotations and balloon-numbered for Form 3.
Traceability for ITAR Programs
For ITAR-controlled parts, balloon drawings carry the same export-control restrictions as the underlying engineering drawing. Olympus Machining handles balloon drawings under the same controlled-document procedures as customer drawings — they are stored in access-controlled job folders, never transmitted through uncontrolled email channels, and are delivered to the customer as part of the FAI package through the customer's specified secure channel.
Related: AS9102 FAI guide · Full FAI vs Partial FAI · CMM inspection services · Precision CNC machining · CNC milling