A contour is the shape of the space a compartment allows you to occupy. It is not a height, it is a profile: full width low down, progressively narrower as the fuselage curves in, and a hard stop at the top. Two loads of identical weight and footprint, one in contour and one not.
A PMC is 243.8 × 317.5 cm of flat deck. Everything above the deck surface is cargo, and how much of it you may have is decided by where the pallet sits. In a 747F or 777F main deck the envelope runs to 118 in; in the belly of a 777 or A350 it stops near 64 in. The same physical pallet, the same 6,804 kg max gross, and roughly double the volume on the upper deck.
The IATA ULD Regulations define contours by a single letter, and that letter is stamped on the container and appears in the ULDR tables. The Q-series is a separate convention from carrier and handler loading tables. They overlap but the mapping is not fully documented: A corresponds to Q6 and D to Q7 on the strength of both manufacturer reproductions of the IATA letter table and training material; L (116 in) is plausibly Q4 but the pairing could not be confirmed; for Q5 no matching letter was found at all. Treat Q5 as an industry label with a 118 in height, not as an IATA contour.
| Label | IATA letter | Height | Status |
|---|---|---|---|
| Q4 | L | 294.6 cm / 116 in | Letter established; profile points approximate |
| Q5 | None found | 299.7 cm / 118 in | Unverified against published sources |
| Q6 | A | 243.8 cm / 96 in | Letter established; profile points approximate |
| Q7 | D | 299.7 cm / 118 in | Letter established; profile points approximate |
Height limits are traceable. The width still permitted at each level is not. No public table of fold points could be located, so the profiles shown here are drawn from the documented start-height convention — for Q7, full width up to 244 cm, then narrowing — with the widths above that being conventional approximations. This is stated on each contour page rather than hidden, because a taper you cannot cite is exactly the thing that should not be used to reject a customer’s build.
This is the error with the most consequence. Applying a Q6 or Q7 envelope to a passenger lower-deck position clears loads that will not physically fit: the belly is 162.6 cm. The library therefore records deck per contour, and the compatibility tables deliberately leave a passenger airframe out of a main-deck contour’s aircraft list.
Put cargo into a contourChoose the ULD and deck, place cartons, and see what breaks the envelope in 2D and 3D.