data("AirPassengers")

acf(diff(AirPassengers))
pacf(diff(AirPassengers))

airmod <- arima(log(AirPassengers), order=c(1,1,1), seasonal=c(1,1,1))

?arima

airmod$loglik
-2/length(AirPassengers)*(airmod$loglik-length(coefficients(airmod)))

Box.test(residuals(airmod), lag=12, type="L",
         fitdf=length(coef(airmod)))

library(tseries)
jarque.bera.test(residuals(airmod))