Ask a touring sound engineer what a flight case is and you get a confident answer: plywood, aluminium extrusions, butterfly latches, ball corners, and a matte-black look that has not changed since the 1970s. Ask a signals officer what a Peli case is and you get an equally confident answer: a moulded polymer shell, an O-ring, a pressure valve, and a lifetime guarantee. Both are "transport cases". Both protect expensive equipment. And people buy the wrong one for their job every single week. 🧳
This guide is for anyone specifying kit that leaves the building: fly-away IT, radios, drones, sensors, calibration gear, training equipment. Nine differences that decide which type belongs in your loadout, a side-by-side table, three real configurations, a short section on when the flight case genuinely wins, and the wording to put in a tender so that you get what you asked for.
Part 1: Nine differences that matter for deployable kit
1. How they are made: built vs moulded
A flight case is assembled. Laminated plywood or honeycomb panels are cut, wrapped in aluminium extrusions, riveted, and fitted with hardware. Every case is a small carpentry project, which is why flight cases can be made to any size, in any quantity, by any competent shop. A Peli case is moulded. The shell is one piece of polypropylene or similar polymer, formed in a tool that costs a fortune and produces identical cases by the thousand. You cannot order a Peli case in a size that does not exist. You can order a flight case in any size you like.
That single fact drives most of the other differences.
2. Seams, rivets and the question of water
A built case has seams. Hundreds of rivets, a tongue-and-groove aluminium closure, panel joins. Good flight cases keep rain off the contents. None of them are submersible, and most are not rated at all. A moulded shell has no seams; the only opening is the lid, and that closes on a gasket. Peli Protector and Storm cases carry an IP67 rating: closed, they survive a metre of water for half an hour. For kit that rides in open vehicles, sits on a quayside, or gets hosed down after a chemical exercise, that rating is not a nice-to-have. We explained what the rating actually promises in waterproof, water-resistant or submersible.
3. Weight: the flight case usually loses
Plywood and aluminium extrusions are heavy. A mid-size flight case can weigh 15 to 20 kg empty. The comparable Peli Protector weighs half of that; the Peli Air version weighs less again. For kit that is carried by two soldiers rather than rolled by a road crew, the empty weight is a line item in the mission plan. It also decides whether the loaded case goes as checked baggage or as freight.
4. Pressure, altitude and cargo holds
A sealed case that goes from sea level to an unpressurised cargo hold and back will vacuum-lock or bulge unless the pressure equalises. Peli cases have an automatic pressure equalisation valve that lets air through and keeps water out. Flight cases do not need one because they are not sealed, which is also why they do not protect against humidity, dust or condensation. For air-transported kit, the valve plus the seal is the combination that keeps electronics dry across a flight.
5. Stacking, palletising and the ISP pattern
Flight cases stack when they are built to the same footprint and fitted with stacking dishes. Two cases from different shops usually do not. Peli's larger Protector cases have moulded stacking ribs, and the Peli-Hardigg ISP2 (Inter-Stacking Pattern) family goes further: every case in the range interlocks with every other, in any combination, on a standard pallet. For units that ship dozens of cases per rotation, the difference between "these stack if you are careful" and "these lock together" is hours on the loading ramp.
6. Repair in the field vs repair in the workshop
A damaged flight case goes back to the shop: panels, extrusions and rivets need tools and a bench. A damaged Peli case is usually repaired on the spot: latches, handles, wheels, O-rings and pressure valves are user-replaceable spare parts, and the shell itself carries a lifetime guarantee against breakage. For a deployed unit without a case workshop within 500 km, that matters. We covered the maintenance side in protecting radios and field electronics.
7. Racks: where the two worlds meet
Rack-mount electronics are the flight case's home turf, and the rack flight case is a mature, sensible product. But a rack in a plywood box is still a plywood box: not sealed, not light, and the shock isolation is whatever foam the shop glued in. Peli-Hardigg rack cases put a 19-inch frame on elastomer shock mounts inside a sealed rotomoulded shell, in 19-inch and metric Euro-V versions. For a server, a radio stack or a cyber fly-away kit that must work after a rough landing, the shock-mounted sealed rack is the one built for it; we walked through real configurations in rack cases for deployable cybersecurity kits and the European-made option in Peli cases for EU-SAFE projects.
8. Lead time and standardisation
A custom flight case takes weeks. A standard Peli case ships from stock, and if the interior is CNC foam, the foam is the only custom part. For procurement, that changes the conversation: a Peli model number is a stable specification that can be written into a contract, repeated next year, and matched by a different supplier. "Flight case, black, approx. 600 x 400" is not a specification; it is a request for a quote.
9. Cost over the life of the kit
On day one, a simple flight case can be cheaper than the equivalent Peli case. Over ten years, the moulded case usually wins: no re-riveting, no delaminated panels, spare parts instead of replacements, and a guarantee that outlives the equipment inside. We ran the sceptic's version of that argument in are Peli cases worth the money?
Part 2: Side by side
| Criterion | Flight case (plywood and aluminium) | Peli case (moulded polymer) |
|---|---|---|
| Construction | Panels in extrusions, riveted | One-piece shell, no seams |
| Water and dust rating | Rain-resistant at best, usually unrated | IP67 (Protector, Storm, Air) |
| Typical empty weight, mid-size | 15 to 20 kg | 5 to 9 kg (Protector), less for Air |
| Pressure equalisation | Not needed (not sealed) | Automatic valve |
| Stacking | Only with matching footprints and dishes | Moulded ribs; ISP2 range interlocks |
| Field repair | Workshop job | User-replaceable latches, handles, wheels, seals |
| Rack electronics | Rack frame in unsealed box | Shock-mounted frame in sealed shell |
| Custom sizes | Any size, any shape | Fixed catalogue of sizes |
| Lead time | Weeks, built to order | From stock; foam is the only custom part |
| Guarantee | Varies by builder, typically 1 to 2 years | Lifetime against breakage (Protector, Storm, Air) |
| Branding and finish | Laminates, colours, printed panels | Labels, engraved plates, limited colours |
| Day-one price | Often lower | Often higher |
| Ten-year cost | Replacement likely once or twice | Spares only |
Shock-mounted rack cases for electronics that must arrive working
Part 3: Three real configurations
A tactical radio kit for a four-person team
Two handheld radios, one manpack, spare batteries, a vehicle adapter, antennas, headsets and a charger. In a flight case, this is a plywood box with glued foam that gets wet on the first exercise and splits at a corner on the third. In a Peli 1600 with CNC foam, every radio has a cavity, batteries sit in a row with separation between cells, antennas lie flat in the lid, and the printed inventory is in a lid organiser. The case is IP67, weighs about 7 kg empty, and goes as checked baggage or on a pallet. When a latch breaks on rotation, the spare in the lid pocket replaces it in five minutes.
A cyber fly-away kit
A 1U firewall, a 1U switch, a 1U server, a patch panel and cable management: 4U of equipment that must be running within an hour of arrival and must survive the flight. A rack flight case holds it, but the rack is bolted to plywood and the shock isolation is foam glued to the walls. A Peli-Hardigg Super-V or Classic-V 4U puts the same rack on elastomer mounts in a sealed rotomoulded shell: the equipment can stay cabled inside, the case rolls on its own wheels, and the pressure valve handles the hold. This is the configuration we described in detail in the deployable cybersecurity article linked above.
A drone survey team's kit
Two drones, four controllers, twenty batteries, a laptop, a base station and a set of ground control points. The temptation is one enormous flight case. The better answer is three Peli cases: a 1560 for the drones and controllers with padded dividers, a 1510 with CNC foam for the batteries (separated, contacts protected, cabin-legal as hand baggage), and a 1650 for the laptop, base station and consumables. Each case is one person's load. Each stacks. Each is sealed. The batteries never travel in the same case as the drone, which matters for airline rules and for fire safety.
Part 4: When the flight case genuinely wins
Odd shapes and very large items
A mixing console, a 2-metre antenna mast section, a bespoke training simulator. If the object does not fit any moulded case and cannot be broken down, a custom flight case is the honest answer. The Peli-Hardigg single-lid range covers a lot of large formats, but not every one.
Kit that never leaves a truck and a venue
Touring production is the flight case's native habitat: roll off the truck, roll onto the stage, roll back. No rain, no altitude, no two-man carry across a field. The weight and the lack of a seal do not cost anything there.
Very low unit cost for one-off internal moves
Moving a lab between two buildings once? A basic flight case, or frankly a good cardboard crate with foam, is fine. Do not over-specify a one-way trip.
Branding and presentation
Flight cases take laminates, printed panels and colours easily. For demo kit and exhibition stands, that is a real advantage. Peli cases take labels and engraved plates, which is enough for most units but not for a marketing team.
Part 5: How to specify the case for a deployable kit
Start with the transport, not the contents
Air freight, checked baggage, helicopter, vehicle, ship, hand carry. Each one changes the answer: checked baggage caps weight and size, air freight wants pallet-friendly footprints, helicopter loads want handles for two people, ships want corrosion resistance. Write the transport chain down before you look at a catalogue.
Decide what "protected" means for this kit
Rain only? Dust? Submersion? Drop from a tailgate? Vibration for eight hours on a track? Electronics need shock and moisture control; optics need dust and shock; batteries need temperature and isolation. The answer determines whether you need a sealed shell, shock mounts, or both.
Interior: foam, dividers or rack
Fixed kit that does not change: CNC foam. Kit that changes between rotations: padded dividers or TrekPak. Rack electronics: a shock-mounted rack frame. We compared the interior options in foam, dividers or TrekPak.
Write the model number into the spec
"Peli 1650 Protector, black, CNC foam to attached drawing" is a specification another supplier can quote and a store keeper can reorder. It also lets you reuse the same foam drawing across a fleet. Model numbers encode the interior size, which we decoded in what Peli model numbers actually mean.
Plan the spares
Latches, handles, wheels, O-rings, valves. A small spares kit per fleet, kept with the cases, turns a broken latch in the field into a five-minute job.
Tender wording that gets you the right case
Tenders that say "flight case" get flight cases, whatever the author meant. If the requirement is a sealed moulded case, say so in terms a supplier cannot misread: "Injection- or rotationally-moulded polymer transport case, one-piece shell, IP67 rated per IEC 60529, automatic pressure equalisation valve, lifetime manufacturer guarantee against breakage, user-replaceable latches and handles, internal dimensions not less than X by Y by Z mm, supplied with CNC-cut closed-cell foam to the attached drawing." Add "stackable with [model family]" if you already own cases, and "19-inch rack frame on elastomer shock mounts, N U" for rack kit. Every phrase in that sentence excludes a plywood box without naming a brand, which is what public procurement needs.
Acceptance testing on delivery
Close the empty case and submerge it in a sink for ten minutes; the inside should be dry. Check that every latch closes with the same force, that the valve is present and unobstructed, and that the foam drawing matches the equipment. Ten minutes on delivery saves a rotation with a case that leaks.
Wheeled Protector cases for kit that travels as baggage or freight
Frequently asked questions
Is a Peli case a flight case?
In the loose sense that both are transport cases, yes, and search engines treat the terms as neighbours. In the trade, "flight case" means the built plywood-and-aluminium type. If a tender says flight case and you want to offer a moulded sealed case, say so explicitly and list the differences above.
Can a flight case be made waterproof?
Splash-resistant, with good gaskets and care, yes. IP67 submersible, no; the construction has too many seams. If immersion or hosing down is a realistic scenario, the moulded case is the only honest answer.
What about Storm vs Protector for military kit?
Both are sealed and shock-resistant. Storm is lighter with press-and-pull latches; Protector is heavier with the widest range of sizes and accessories, and is the one most armed forces standardise on for hard use. We compared them in why armed forces choose Peli Storm cases.
Do moulded cases come in metric rack sizes?
Yes. Alongside the 19-inch Super-V and Classic-V ranges there is a German-made metric Euro-V rack case for European electronics and EU-origin procurement requirements.
Can I get a Peli case in a non-standard size?
Not the shell. What you can do is choose the nearest larger standard size and fill the difference with CNC foam, which is what most "custom" Peli cases actually are. For genuinely oversized items, the Peli-Hardigg single-lid and ISP2 ranges go far larger than most people expect.
How do I move an existing flight-case fleet to moulded cases without replacing everything at once?
Start with the kits that fly or get wet, then the kits with the most expensive contents, then the rest as flight cases fail. Keep footprints consistent within a family so the new cases stack with each other, and reuse foam drawings across identical kits.
Checklist: flight case or Peli case?
- ✅ Rain, dust, immersion or hosing down possible? Moulded sealed case.
- ✅ Air transport, especially unpressurised? Sealed case with pressure valve.
- ✅ Two-person carry or checked baggage? Weight matters: moulded, or Air series.
- ✅ Rack electronics that must survive a rough landing? Shock-mounted sealed rack.
- ✅ Repairs likely far from a workshop? User-replaceable parts and lifetime guarantee.
- ✅ Odd shape, huge item, touring only, or branding first? Custom flight case.
- ✅ Procurement needs a repeatable spec? Model number plus foam drawing.
- ✅ Tender must exclude plywood boxes without naming a brand? Use the wording above.
The short version
A flight case is a box built around your equipment. A Peli case is a sealed shell your equipment is fitted into. For kit that stays on a truck and a stage, the built box is fine and often cheaper. For kit that flies, gets wet, gets dropped, and has to work when it arrives, the sealed moulded case is the one designed for the job, and the one that is still in service when the plywood has delaminated. 🛡️
If you have a kit list and a transport chain, send both. We will tell you which case, which interior, and what spares to keep with it.
