The variables are:
Yr |
year of first manufacture |
Period |
a code to indicate one of three broad time periods |
Power |
total engine power (kW) |
Span |
wing span (m) |
Length |
length (m) |
Weight |
maximum take-off weight (kg) |
Speed |
maximum speed (km/h) |
Source: The data were collected by P. Saviotti and are described in detail in Saviotti (1996), "Technological Evolution, Variety and Economy", Edward Elgar: Cheltenham.