How to Balloon Notes and General Tolerances for FAI

I reviewed a ballooned drawing where the quality engineer had placed 72 perfect balloons on dimensions and GD&T callouts, but zero balloons on the general notes block. The Form 3 had 72 characteristics. It was missing the 6 most important ones: the tolerance standard (ISO 2768mk), the edge treatment requirement, the surface finish default, the GD&T standard reference, the material callout, and the parent assembly reference. The reviewer rejected the FAI because those 6 notes create inspectable requirements that govern the interpretation of all 72 other characteristics. Learning how to balloon notes and general tolerances for FAI is the difference between a complete submission and a predictable rejection.

We covered the overall ballooning process in how to balloon a drawing for FAI. This guide focuses specifically on the hardest part of ballooning: turning text notes into Form 3 rows.

NOTES AND GENERAL TOLERANCES COUNT TOO

The characteristics people miss most are in the notes and title block. Mavlon balloons those too, not just the obvious dimensions.

Bring your hardest drawing. Watch it become a Form 3 live.

How to Balloon Notes General Tolerances for FAI: The Classification

Notes That NEED Balloons (They Create Inspectable Requirements)

General tolerance standard. "General tolerances per ISO 2768mk" or "Unless otherwise specified, tolerances are +/-.005 / +/-.010 / +/-.030." This note governs every untoleranced dimension on the drawing. It becomes characteristic 1 (or one of the first characteristics) in the Form 3. We covered the ISO 2768mk table in ISO 2768mk tolerance table for CNC machining.

The Form 3 row: Requirement: "General tolerances per ISO 2768mk." Actual: "Applied to all untoleranced dimensions per size range." Status: Verified.

Edge treatment. "Break all sharp edges 0.3 to 0.5mm" or "Deburr all edges." This creates an inspectable requirement with specific acceptance criteria. We covered edge treatment in edge break and chamfer requirements on aerospace drawings.

The Form 3 row: Requirement: "Break all sharp edges 0.3 to 0.5mm." Nominal: 0.4mm. Upper: 0.5mm. Lower: 0.3mm. Inspection method: Edge gauge/tactile. Actual: 0.4mm conforming.

Surface finish default. "Surface finish Ra 3.2 unless otherwise specified" or "Surface roughness per spec reference]." This governs every surface without an individual callout. We covered surface roughness in [surface roughness symbols on aerospace drawings explained.

The Form 3 row: Requirement: "Surface finish Ra 3.2 max per general note." Actual: Ra 1.8 (worst case across general surfaces). Status: Pass.

GD&T standard reference. "GD&T per ISO 1101" or "Dimensioning and tolerancing per ASME Y14.5M-1994." This tells the reviewer (and the CMM programmer) which interpretation rules apply to every GD&T callout. We covered the differences in ISO 1101 vs ASME Y14.5 GDT differences for aerospace.

The Form 3 row: Requirement: "GD&T per ISO 1101." Actual: "Verified, all GD&T interpreted per ISO 1101." Status: Pass.

Blanket profile tolerance (Boeing style). "All features subject to surface profile .020" per Datum A/B/C." This single note creates an implicit GD&T requirement on every feature. We covered this in AS9102 Form 3 for Boeing drawings.

Blanket hole classification (Boeing style). "C/H: .100 +/-.004, position .010 dia MMC. P/H: .100 +/-.008, position .055 dia MMC." This defines tolerance rules for entire categories of holes. Each classification gets its own Form 3 row.

Process requirements in notes. "Heat treat per AMS 2770 after machining" or "Penetrant inspect per ASTM E1417, accept/reject per ASTM E433." These create inspectable process requirements. We covered process documentation in AS9102 Form 2 material and process documentation guide.

Material specification (when in notes). Sometimes the material is called out in the general notes rather than (or in addition to) the title block: "Material: Al 7075-T6 per AMS 4050." We covered material specs in AMS material specifications for aerospace CNC machining.

Tool radius modification. "Tool radius modification +/-0.6mm permitted on undimensioned shapes." This note modifies how the part geometry is interpreted and affects profile inspection.

Notes That DO NOT Need Balloons

Drawing format notes. "Third angle projection." "Dimensions in millimeters." "Scale 1:1." These are drawing conventions, not inspectable requirements. They inform how to read the drawing but do not create characteristics.

Document control notes. "This drawing supersedes DWG-0145 Rev B." "Do not scale drawing." "Interpret per company drafting standard]." These are administrative notes.

Approval and revision blocks. Names, dates, and signatures of approvers. These are Form 1 data (traceability), not Form 3 characteristics.

Copyright and IP notices. "Proprietary. Not to be reproduced without authorization." Not inspectable.

Reference notes. "For assembly, see DWG-ASSY-0200." "See customer spec for packaging." These point to other documents and do not create inspectable requirements on this specific part.

See how the current ballooning software tools handle this step automatically, compared side by side.

The Gray Zone: Notes That Require Judgment

"Interpret per [customer quality clause]." This references an external document that may add inspectable requirements. The note itself gets a balloon, and the Form 3 notes column should reference the external document. Whether additional characteristics are created depends on the content of the referenced document.

"Marking per [spec]." Part marking (ink stamp, electro-etch, engraving) is sometimes inspectable (correct location, content, durability) and sometimes just informational. Check with your customer.

"Packaging per [spec]." Packaging is typically outside the scope of dimensional FAI. But some customers require packaging verification as part of the first article process. Check.

How to Place Balloons on Notes

Notes are text, not dimensions with leader lines. Placing a balloon on a note requires a different approach:

Option 1: Balloon in the margin with a leader line to the note text. Place the balloon in clear space adjacent to the general notes block, and draw a leader line pointing to the specific note. This is the most common approach.

Option 2: Balloon directly on the note text. Circle the note number (if notes are numbered: "Note 1: General tolerances per ISO 2768mk") and write the characteristic number next to it.

Option 3: Highlight and number. Highlight the note text in color and write the characteristic number next to the highlight. Less formal but acceptable for hand-marked ballooned drawings.

Key rule: The balloon must be unambiguously associated with one specific note. If the general notes block contains 8 notes and your balloon points to the entire block, the reviewer does not know which note corresponds to which Form 3 row. Point each balloon to a specific note.

How Many Form 3 Rows Do Notes Create?

On a typical aerospace drawing, general notes create 3 to 8 Form 3 characteristics. On a Boeing PVS drawing with dense notes (blanket profile, classified holes, wall thickness ranges), the notes can create 8 to 15 Form 3 characteristics.

Here is a typical breakdown from the 7-sheet bracket:

On the Boeing 777 fitting (single sheet, dense notes):

Mavlon Extracts Notes as Form 3 Characteristics

Mavlon reads every note in the general notes block, classifies each one as inspectable or non-inspectable, and creates Form 3 rows for every note that creates an inspectable requirement. The output includes the note text, the tolerance value (if applicable), the source reference (sheet and note number), and the inspection method. No notes are missed. No non-inspectable notes are incorrectly included.

Bring Your Drawing to a Demo to see notes extracted as Form 3 characteristics.