The first "commercial" flights were used primarily for the mail rather than passengers – they came along later as planes got bigger. Today, air freight is a huge business though the industry has gone through several interesting stages.

Most commercial flights (with the notable exception of the budget airlines) carry freight, an essential part of their revenue mix, though not all "air freight" goes by air ! Read on.

In its early days the industry carried all types of freight but then road haulage and, more importantly, sea-borne shipping, grew in stature and size and the air freight industry moved into handling higher value goods, or those that were needed in a hurry. All the major carriers carried freight in the aircraft belly – and still do. With the development of world industry and in particular the "just-in-time" method of ordering supplies, thus cutting down on expensive inventories, airlines began to offer a premium service for specific delivery dates and times and the industry grew even more.

There was also a need for express courier services and people like Fred Smith developed FedEx. Initially this service was for documents and small packages, mainly weighing less than one kilo. Hub-and-spoke operations were put into effect using all available means of transport, road and air in particular, though the aircraft used could be a one-man single engine operation linking the hub with some small, but financially important location.

Larger companies linked their own transportation system into one of these larger companies, like FedEx, DHL, TNT and UPS. In Europe several "express" companies also established networks, though many used road transport, especially between fairly close cities – Paris-Brussels; Brussels-Amsterdam; Brussels-Frankfurt – though light aircraft and even scheduled flights were used for longer routes (Stockholm-Milan for example). At the same time there was a huge increase in heavier shipments, those that would fit in a normal commercial aircraft but were too big for the smaller operators and although "air freight" was the option bought by many shippers within Europe, 80% of their shipments never went by air, it being found cheaper and, interestingly, faster, to take it by road from Manchester to Munich, for example.

At the same time several freight only airlines developed, prime among them Cargolux, based in Luxemburg. Cargolux has been the launch customer for several important freight aircraft including the 747F and, with orders in the process, the upcoming 747-8F from Boeing.

Uniquely the Boeing 747F has freight loading doors at the front of the aircraft below the cockpit (though to be honest the British built Carvair back in the 1950s had the same nose configuration, being front loading for cars on the cross-Channel routes from Southend to Le Touquet and Ostend).

But nothing has stopped the onward progress of the so-called express operators, FedEx, UPS and DHL in particular (TNT, originally from Australia) went through several metamorphoses and is now part of the Dutch post office) and today the largest air-freight carrier in the world is FedEx, with 15 million tonne-kilometres flying through the night skies. Korean Air, Lufthansa. UPS, Singapore, Cathay Pacific and China Airlines are also all massive cargo-movers.