These data, reported by Proschan (1963, Technometrics 5, 375-383), refer to the intervals, in service-hours, between failures of the air-conditioning equipment in a Boeing 720 aircraft. (Proschan reports data on 10 different aircraft. The data from only one of the aircraft is used here. Cox and Snell (1981, Applied Statistics: principles and examples, Chapman and Hall, London) discuss the analysis of the data on all 10 aircraft.) The dataset consists of a single vector of data. They are used in the book `Distributions for location, scale and shape: Using GAMLSS in R' to demonstrate the likelihood function and maximum likelihood estimation.

`data("aircond")`

A data frame with 24 observations on the following variable.

`aircond`

a numeric vector

Cox and Snell (1981, Applied Statistics: principles and examples, Chapman and Hall, London)

rpanel: Simple interactive controls for R functions using the tcltk package. Journal of Statistical Software, 17, issue 9.

Proschan, F. (1963) Theoretical explanation of observed decreasing failure rate.
*Technometrics*, Vol. 5 no. 3, pp 375-383, Taylor & Francis.