How much internal clearance should a Military Air Transport Case leave?

Answer: 10 mm to 12 mm per side, foam cut at 15 mm and set to 12 mm, plus a 35 mm notch for gloves.

Can a case over 25 kg still be handled by hand?

Answer: Two people manage 50 kg with handles near the centre of gravity; beyond that, add forklift pockets.

Four tie-down points or six?

Answer: Two under 40 kg, four to 120 kg, six above, each rated 1500 N.

Is a fully sealed case safer than one with a breather valve?

Answer: Long legs want a valve opening at 12 kPa; short legs under 30 L can run sealed with 30 g of sieve per 10 L.

Can marking go on one side only?

Answer: No. Four sides carry the mark and the QR code, sized 80 mm and 30 mm.

Military Air Transport Case: 5 Selection Criteria

Quick answer: Choose a Military Air Transport Case in five passes: clearance, route and aircraft, tie-downs and stacking, sealing versus relief, documents and marking. In that order, quotations become comparable.

Start From the Internal Clearance
Work Back From Route and Aircraft
Check Tie-Down Points and Stacking
Weigh Sealing Against Pressure Relief
Documents and Marking to Hand Over
FAQ

1. Start From the Internal Clearance

The first decision is the cavity, not the shell. Measure the load envelope to the millimetre, then add foam, finger clearance and lid ribs. A 10 mm to 12 mm margin suits most loads: foam cut at 15 mm compresses to 12 mm, a 12% to 18% ratio.

Gloved clearance is separate: 20 mm per side and a 35 mm notch, or a 12 kg module needs two people to pry out. Tolerances run 2 mm on length, 1.5 mm on depth, 3 mm between diagonals.

Item	Value	Failure
Side foam	Cut 15 mm, set 12 mm	Load shifts, corners rub
Finger clearance	20 mm per side, 35 mm notch	Bare hands cannot lift
Cavity tolerance	2 mm, 1.5 mm depth	Lid offsets, seal pinched
Top and lid	25 mm foam, 14 mm rib	Lid sits high, latches slack

Keep the heaviest module near the handles: 40 mm of offset doubles the load on one latch.

2. Work Back From Route and Aircraft

The route sets the shape. A narrow-body belly door clears about 1.2 m by 0.9 m, so a 1.0 m case goes in at an angle; an LD3 container of 1534 mm by 1562 mm by 1626 mm caps a body at 1400 mm; a 463L pallet takes 2200 mm.

Military Air Transport Case: four olive green cases lie on a hangar conveyor, one open on a pallet showing grey foam and metal parts

One person carries 25 kg, two carry 50 kg. Past that a Military Air Transport Case needs forklift pockets and 100 mm of ground clearance, and corners at R25 keep a loaded case from catching on a door frame.

Carrier	Case limit	Unit weight
Narrow-body belly	900 by 700 by 600 mm	32 kg
Wide-body LD3	1400 by 1500 by 1500 mm	750 kg
Freighter 463L	2200 by 2700 by 1600 mm	1100 kg

3. Check Tie-Down Points and Stacking

Tie-downs on a Military Air Transport Case scale with weight: two points under 40 kg, four to 120 kg, six above, each on a corner casting. Rate every point at 1500 N for 30 seconds and keep corner movement under 0.8 mm; past 0.15 mm of residual movement the insert has yielded.

Strap angle matters more than count. At 30 to 45 degrees the pull turns into restraint; below 15 degrees it dents the lid and lifts the latches. Points sit a fifth of the body length from each end.

Stacking is checked at four high: 120 kg on the lid, sink inside 1.5 mm, held 24 hours and re-checked after 48 hours at 40 °C. An 8 mm plywood pad spreads the load.

4. Weigh Sealing Against Pressure Relief

Three routes exist and the wrong one costs more than the dear one. A full seal suits optics; a breather valve suits high-altitude sectors; a seal plus molecular sieve suits cavities under 30 L held below 40% RH.

Silicone cord at Shore A40 runs at 20% to 25% compression in a 7 mm groove 5 mm deep. A valve opens at 12 kPa and passes 200 mL per minute; the case takes a 30 minute IP67 immersion. At minus 30 °C for four hours, compression set must stay under 20%.

Sieve dose runs 30 g per 10 L. Skipping the valve is the quiet error: on a sealed Military Air Transport Case the vacuum at opening pulls the cord from its groove, so cycle the latches three times at acceptance.

5. Documents and Marking to Hand Over

Four documents travel with a reusable air package: packing list, tie-down drawing, material statement, reusable class declaration. The list carries net weight, gross weight and three dimensions.

Marking goes on four sides, and a Military Air Transport Case is no exception: an 80 mm by 80 mm low-temperature label flat at minus 40 °C, and a 30 mm QR code resolving to the packing list number. Past 50 trips use in-mould labels, which cannot wear off; under 20, adhesive is enough, but never over a latch or seal groove.

Conclusion

Clearance decides whether the load fits, route and aircraft whether it passes a door, tie-downs whether it flies steady, sealing whether it opens on arrival, documents whether it clears. Written as one checklist, those five points make quotations comparable, which is the whole point of choosing a Military Air Transport Case.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.