The first wide body airliner built in Europe has many characteristics that are still present on today's A330. The general appearance of the A300, A310 and A330 is the same. This includes the cockpit windows with the typical cut-off top corner of the last window and straight underside of side windows. Furthermore the row of cabin windows on the rear fuselage, towards the tail cone, appears to be curved up compared to the rest of windows. Also the tail section looks identical. The main landing gear has four wheel bogeys and are not tilted when the aircraft is in the air.

The different versions of the Airbus A300 and A310 can be recognised by looking at

• the length of the fuselage
• the presence of Kruger flaps at the wing root leading edges
• the number of cabin doors
• the shape of the engine nacelles
• the presence of cabin windows
• the presence of small winglets
• the presence of a large cargo door

Details will follow later.

Two prototypes of the A300 were built, both designated A300B1. There were powered by General Electric CF6 engines, with their long core exhaust with a conical core in it (see detail photo of the main gear above). The A300B1 is the shortest of the A300 versions, 2.6 metres shorter than for example the B2, but yet much longer than the A310. It still has four large doors on each side, but the third door is close to the wing trailing edge.

The first production version of the A300 was 2.6 metres longer than the B1 versions. This is best visible in location of the third cabin door from the front. On the B2 and later models it is abeam the wing tips, on the A300B1 close to the trailing edge, although that is not clearly visible. Both the A300B2-1A and -1C have CF6 engines, each a slightly different version, not distinguishable from the outside.

Externally, all these variants differ from the A300B2 versions above by the addition of Kruger flaps in the wing's leading edges, close to the wing roots. This is of course only visible when they are extended. The mutual differences are in the additional fuel tanks, in the wing centre section and/or rear cargo hold. Also, they have a slightly different version of the General Electric CF6 engine. But that cannot be seen from the outside.

The '2' as the second character after the dash points to Pratt & Whitney engines being used, in this case the JT9D engines. The nacelles of these engines have a short core exhaust and no conical plug inside. Mutually, they differ in the same way as the General Electric powered models above, which have a '0' as second character after the dash.

The convertible and pure cargo version of the A300B4-203 retain its cabin windows, but have a large cargo door in the left forward fuselage, in between the first two cabin doors. If not immediately visible, you can also recognise the A300C4-203 & A300F4-203 by the fewer cabin windows between these doors. Note that some may have their cabin windows painted over or replaced by metal plugs when being used for cargo only. Then they cannot be distin­guished from the cargo conversions of true passenger aircraft.

You would not expect that a dedicated cargo aircraft still has many cabin windows, but the A300F4-203 has. Additionally, it has a large cargo door of course. (photo: Ken Fielding/WikiMedia)

These are passenger to cargo conversions of the A300B4-103 and -203 respectively. They have a large cargo door like the A300C4-203 and F4-203, but no cabin windows. These have been replaced by metal plugs. If this has been done on A300C4-203 and A300F4-203, then you cannot distinguish the A300B4-103F/203F from them.

The second generation A300 has some elements of the A310, in particular the more modern engines. All the mentioned models have General Electric CF6-80 subtype engines, still with a core plug, but a larger one than on the CF-6-50s of the older A300s. The most typical characteristic of the A300-600s are the small triangular winglets though. The subtypes only differ in range and weights, where the A300B4-605R has a fuel tank in the horizontal stabilisers.

These are all cargo conversions of the pure passenger aircraft above. So they have a large cargo door and cabin windows re­placed by metal plugs. They can be recognised from the A300B4-620F & A300B4-622RF below by the General Electric engines.

It is still visible that this aircraft once had cabin windows, so given the GE engines you could judge that this is a A300B4-605RF. (photo: Anna Zvereva/WikiMedia)

This is a special version of the A300B4-600 series that is used to transport large aircraft components between Airbus factories. Compared to the standard aircraft the cockpit is lowered, allowing (un)loading through the large doors above it, in the fuselage with a significantly enlarged diameter. The resulting shape clarifies the name Beluga. On top of that, a dorsal has been added, as well as end plates on the horizontal stabilisers.

Like the first generation A300s the 600 series has variants with Pratt & Whitney engines. The nacelles of these engines have no core plug like on the General Electric. The widest part of the nacelle has more or less a continuous diameter. Mutually, the versions are only different in performance and operating weights. Like the -605R the -622R has elevator fuel tanks.

These converted aircraft are similar to the A300B4-601F, 603F and 605RF, but have Pratt & Whitney engines, so different nacelles.

The basic convertible passenger/cargo version of the 600 series is only built as A300C4-620, so with Pratt & Whitney engines. In has many cabin windows and a large cargo door in the left forward fuselage. Where the cargo door crosses the cabin windows, it misses a few windows.

The A300C4-620 is the only 600 series aircraft with cabin windows and a large cargo door. Note the absence of cabin windows at the seems of this cargo door, a typical aspect. (photo: Kambui/WikiMedia)

The pure cargo version of the GE powered A300-600s is designated A300F4-605R. It is recognised from the cargo conversions windows by the lack of any traces of cabin windows, because it never had them.

Similarly, the A300F4-622R is the pure cargo variant with Pratt & Whitney engines, so without the core exhaust plugs.

The short body version of the Airbus A300 was first to be called A300B10, but in the end received its own main type designation, A310. The A310 is so much shorter than the A300, that is has only three doors of both sides, of which the middle one is smaller than the front and rear ones. The A310-203 and -204 are both General Electric powered versions, but slightly different versions. They have no winglets.

The convertible version of the A310-203 has a large cargo door in the left forward fuselage, but still cabin windows. Where the cargo door intersects the line of cabin windows, there are no windows.

The single A310-203C was operated by Martinair, and later as pure cargo aircraft by FedEx. Note the interruption of cabin windows near the cargo door. (photo: Pedro Aragao/WikiMedia)

When A310-203s and -204s are converted with large cargo door and metal plugs instead of cabin windows, they are known as A310-203F and A310-204F.

Pratt & Whitney engines are the only differences of the A310-221 and -222 compared to the A310-203 and -204. The shape of the nacelles is similar as those of the A300-600s with P&W engines, so without a core exhaust plug.

This is the cargo conversion of the A310-221 and -222. So it is the same as the passenger A310-221 and -222 above, but with a large cargo door and metal plugs in place of the cabin windows.

The extended range version of the A310 is the series 300. Externally, they are different from the series 200 by having small winglets up and down, similar to the ones on the A320s. The A310-304 and -308 are the General Electric models.

The cargo conversions of the A310-304 and -308 get an F as suffix to the designation. The winglets are of course the way to recognise them for the 200 series freighters.

Both the Canadian and German air forces acquired secondhand A310-304s and converted then to multi-role transport (MRT) aircraft by adding a cargo door, but retaining the cabin windows. Some are capable of refuelling other aircraft through hoses extending from pods under the wing tips. These are known as MRTT, multi-role tanker transport. In Canadian service these aircraft are designated CC-150 Polaris.

There are three subtypes of the A310-300 with Pratt & Whitney engines. These are externally the same.

Finally, these are the cargo conversions of the P&W powered A310-300s. So they have a large cargo door and no cabin windows anymore, but do have winglets.

Pratt & Whitney engines, winglets and a lack of cabin windows are the way to recognise this A310-324F, although it could also have been a -322F or -325F. (photo: shimin/WikiMedia)