Statistics Showing United has more mechanicals?
 

Hi All:

I have had an extremely bad run of mechanical delays recently and I am wondering if it is bad luck or if United really has far more mechanical issues than other airlines.

Does the DOT collect data on mechanical delays/cancellations?

Yes, the DOT tracks reason for delay. The reasons included are:

• Carrier Delay
• Weather Delay
• NAS Delay
• Security Delay
• Late Aircraft Delay

All mx should be in Carrier Delay but all carrier delay won't be mx necessarily.

I just pulled the data for January 2017 from DOT. UA had ~42k total flights ad ~8000 flights with a delay. Half of those had "carrier delay" as responsible for part (airlines can assign multiple reasons) of the total delay time. Of ~350 cxl there were ~100 blamed on Carrier reasons.


For AA 73k total flights with 14k delays and 7200 w/ carrier as partly at fault. The AA CXLs were ~300/1185 as Carrier.

United and Delta (others?) report mainline completion rate in their monthly traffic releases. That's not a perfect proxy for delays or cancellations caused by mechanicals - they could roll out another aircraft to complete the flight - but it is something.

High season, high demand, more robust schedule, higher aircraft utilization, fewer spares sitting idle (and less vacation time allocated to employees as a side effect that impacts me)

Not sure how this last measure would hurt reliability. Wouldn't having more hands on deck increase mx resilience?

in terms of reliability, I'm sure it helps. In terms of me (employee) it hurts. It was just a tangent to the topic at hand.

you can look at the international cancelled/delayed thread ... that speak volumes. Lots of maintenance issues still going, although it is better than last year. Recently ... not so good.

Let's keep in mind that UA's safety record is among the best of any airline. WN and others have fudged on safety putting aircraft in the air they shouldn't.

yes and reports it in a variety of formats
Such as
DOT's Air Travel Consumer Report
See page 29 for TABLE 9. CAUSES OF DELAY*, BY CARRIER

The most recent monthly reports covers May 2017 (issued July 2017) and for Carrier Caused Delays UA was below the industry average.

Note -- Express carriers are reported separately from the mainline carriers they service.

That was my reaction to this thread as well. What's the point here?

Also, canceling due to mx can be viewed as safety positive . . . I'd certainly rather they cancel rather than taking undue risk if there's any question about a mechanical issue.

FWIW, I haven't had a UA mx since last December. Of course, the problem with anecdotal reports is they are completely statistically insignificant.

Many people book travel with the expectation of safely getting from A to B at the advertised times.

Yes, but if it also means never getting to my destination on time I'm going to consider the many other airlines flying that also have a spectacular safety record (UA is hardly alone on this front) that will be more reliable in timing.

Yup, which is why the DOT data linked above matters for comparison.

Adding another data point from to the collection I have in my prior reply, DL had 70k flights in January 2017 with 12000 delayed; 6500 were at least partially carrier delay. DL also had 782 cxls for the month, 258 for carrier reasons.

These stats are mainline-only. UA is ahead of DL/AA in cxls and behind in delays. But not by a ton on a percentage of total flights basis.

Nope. No one can answer OP's question on the basis of the published DOT data cited in this thread (and your post) b/c it doesn't break out mx. Carrier caused will include causes other than mx.

Perhaps. From a safety perspective, I personally would rather fly UA than WN , regardless of their mx cancel percentages. As noted above, WN does have a history of getting busted for flying with unsafe aircraft. So comparing mx cancel rates would not tell you which carrier is "safer."

Which, of course, I indicated in the initial reply. :-:

What would? Incident rates? Loss of life per ASM rates?

Safety delays can be seen as positive or negative. If UA's maintenance is consistently excellent, then more delays for safety show that it's more careful than others in this regard. If UA's maintenance is poor, then more delays for safety don't say anything about UA's attitude to safety - merely that its maintenance is poor.

i wouldn't put too much weight on that, UA Also had a $435,000 fined proposed this year for a similar (although limited to a single airframe) thing.