Here is to discuss the aircraft commonality of Airbus & Boing aircrafts.

It is very obvious that Airbus has much better commonality among its aircrafts.

Airbus A330s (twin engine) & A340s (4 engine) use the same airframe except for engines, and with wide capacity range from 253 persons to 380 persons (typical 3-class configuration), so greatly reducing training cost for flight crews, and makes maintenance less costly, even for a large range of route structure.

Not only this, Airbus A330/A340 have very similar cockpit design like A320, and both A320 & A330/A340 have fly-by-wire technology, so greatly reducing the cost & time of training.

For example, it takes only 2 hours of seminar for flight crews to be qualified to fly any member of A320 family (A318, A319, A320 & A321), only 8 days to migrate from A320 to A330 compared to 25 days of full type rate training for aircrafts without commonality (like B737 to B767), only 3 days to migrate from A330 to A340, and 1 day from A340 to A330.

Because of good commonality of Airbus aircrafts, many airlines are switching to full Airbus fleet, like Swissair (now Swiss Air Lines), LTU of Germany, BMI of Britain, South African Airways, Lufthansa, SAS, Air Canada, US Airways, Austrian Airlines, LanChile (Dragonair of HK is full Airbus fleet already.)

Such commonality, however, does not apply for Airbus A300/A310. They are still of old cockpit design, so pilots driving them have to undergo 25 days of full type rate training when they have to fly other Airbus aircrafts. This and the great mechanical difference of A300/A310 with A330/A340 makes it costly to operate both families of aircrafts.

So Airbus should consider cancelling A300/A310 family & replaced with smaller members of A330 families, like -800 model (48m long, capacity similar to A310) & -900 model (54m long, capacity similar to A300-600), to make A330/A340 family more complete, and makes airlines can operate a complete range of widebodies less costly.

There is no commomality among different families of Boeing aircrafts, so a 25 day full type rate training is needed for migration from any family to another. it takes much more time & money for pilots training. The situation is particularly poor for B747, with its unique raised cockpit, so pilots have to be trained with very special raised cart, thus greatly increasing training cost.

The separation of widebodies into 3 families - B767s, B777s & B747s makes maintenance cost very high.

Welcome for discussion.