Fleet News - Northwest Airlines' aging fleet

Mining through the DOT's 2006 YTD on-time database we came across some neat information. The amount of time Northwest is “losing” because of delays is troubling. A conservative number for delays depends on when it occurs – the first say 10 minutes are easily caught up. But when the delays run over 20 minutes, costs start to rise exponentially. A cost of $100/minute is reasonable.

Looking at Northwest's fleet, the airline's worst five DC9s are:

Tail #	Delayed Min
N922RW	2564
N773NC	2034
N9335	1491
N925US	1455
N9332	1386

If you fly Northwest, watch out for the DC9s, we calculate the airline has seen delays worth 52,000 minutes from this fleet this year. Whereas the fleet average delay is just over four minutes, N922RW averages 22 minutes, N760NW averages 27 minutes. The DC9 is a legendary plane, built like a tank, but even tanks have an end of life. This fleet is simply so old, we think it is costing the airline money.

Looking at the data for their DC10s, the airline's worst five are:

Tail #	Delayed Min
N223NW	300
N239NW	188
N236NW	113
N235NW	91
N226NW	57

N223NW averages 30 minutes delay, N234NW averages 38 minutes, N239NW averages 24 minutes. The airline is retiring the fleet as fast it can. The fleet’s average is 13 minutes delay. The A330s cannot come in fast enough.