Topic Author
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Mechanical Delays: How Common?

Mon Mar 05, 2001 2:38 pm

I know that major airlines keep track of what causes their flights to be delayed. However, for the most part, the public only has access to stats on the percentage of flight arrivals delayed in excess of 15 minutes, regardless of the reason. I'm curious as to what percentage of these delays, on average, are caused by or contributed to by mechanical problems?

I've always thought that ATC/weather issues that limit an airport's capacity caused the vast majority of delays. However, my family members have experienced many "mechanicals" over the years, and I'm really beginning to wonder how common such occurances are.

For example, my uncle's last four flights on AS have been delayed between 50 mins and 1hr 50 mins, each time due to an issue with the aircraft discovered between flights.

I am MOST GRATEFUL that they discovered the problems, and addressed them. I've heard that Alaska chooses to fix many non-critical items that malfunction during the day, rather than defer them until a regularly scheduled check like some other airlines. But, even still, it does seem like my uncle has had incredibly bad streak of luck.

I realize there are many different causes of "mechanical delays," but just in general, how common an occurance is this? I think my uncle is really having doubts about flying on this airline, and I'm having a hard time convincing them that they truly are very safety-conscious airline.
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RE: Mechanical Delays: How Common?

Tue Mar 06, 2001 12:28 am

Well you have the right attitude. The whole point is that any problems ARE addressed and not swept under the rug in a fit of "get there-itis". Still, your original question is exceedingly difficult to answer; You just never know...it's feast or famine. I've seen days where not so much as a burned out nav light bulb happens...and others where ( usually in the most lousy of weather conditions ) it seems everything that can go wrong...does. There is much head butting between those employed to track statistics and those that are on the front lines: The abstract vs. the real world. Things just don't conform to perfect templates, graphs, pie charts.--Them: "How long will it take to repair?" ... Me: "Depends on what exactly is causing the problem...and if the airplane is smiling or frowning". I can give a decent estimate after a short evaluation but I cannot guarantee it will take X amount of minutes/hours just because another plane last week with similar symptoms took 45 minutes to repair. Yes, mechanical delays DO happen...but not to the degree that it eats the airline out of house and home...You don't earn revenue with a plane on the ground and a stuck passenger.
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RE: Mechanical Delays: How Common?

Tue Mar 06, 2001 2:02 am

In working for Delta AirLines /PHL, I see aircraft and flights delayed or canceled for "mechanicals" every week. Most of our flights that have mechanical isues are the older aircraft in our fleet-727's, 737-200's/300's and your occasional L-1011. All of these aircraft are slowly becoming phased out in exchange for new, state of the Art planes. Also, remember that sometimes, when the gate agents give you a reason for a delay, it may not always be what they say. I've stood at the podium, conferring with agents, whle angry passengers have asked the reason for such a lengthy delay...the gate agent brought up the flight on the computer and many times the reason was a late crew member or something. Now, you may not always want to tell passengers that,because thses crews still have to deal with these people once they fly in. So, just keep that in mind also.
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RE: Mechanical Delays: How Common?

Tue Mar 06, 2001 8:12 am

As usual, NKP S2 has it correct. As a flight line technician for many years, I've experinced the same things. Some days nothing happens at all (usually when the weather is good), and some days the ramp looks like an aircraft junkyard, with more broken down planes than there are technicians on duty. It's no secret that the pilots look harder for problems when the weather is foul.

I've also had my fair share of dealing with impatient gate agents and flight crew members. When the pestering gets to be too much I usually tell them, "You're more than welcome to take the aircraft as is---broken. I hope you've got good life insurance."

They always end up seeing things my way.  Wink/being sarcastic
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RE: Mechanical Delays: How Common?

Tue Mar 06, 2001 9:21 am

This is really not the proper thread for my next statement:
I expect that you can see more mechanical delays in the USA in the near future, given the present management/labor problems in the airline industry.
But if quacks like a duck... ground it!  Big grin
"Eagles soar. But weasels never get sucked into jet intakes.."
Topic Author
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RE: Mechanical Delays: How Common?

Tue Mar 06, 2001 2:21 pm

I appreciate the responses.

I too have noticed that mechanical delays increase during severe weather. Obviously, you don't want to have any complications to deal with when flying in such conditions.
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RE: Mechanical Delays: How Common?

Thu Mar 08, 2001 2:12 am

Hi EIPremeier, Buzz here. I'm also a Line Mechanic for UAL. We generally find problems with an airplane during overnight checks. After working 737's and 757's for several years you have a good idea what fails first. And often we need to send out for parts, so the airplane will be cancelled for half a day. "It costs less to have the parts centralized", OK, so how badly do you want the airplane?

Another factor is that SOME professions are licenced. People expect a certain degree of skill and responsibility in the pilots, same with those of us who bend wrenches and chase sparks. Do they realise that the Acft Maint. Techs. are also licenced? When an airplane crashes, we often survive to face the wrath of the FAA, and Lawyers. So we demand good workmanship out of each other. We're not inclined to sweep problems under the rug. We can address the problem, and have a plan to fix it later, thus the "Deferred Items" that you can fly with.

One more factor in the statistics: Mechanical delays are not counted as a bad thing when airlines get to officially compute their "On-Time Performance". So sometimes we're a convenient catagory to charge a delay to.

In the '20's and 30's, a large percentage of people died in aircraft accidents. We've learned a lot of things since then, dying while flying is fairly rare now. There IS a reason for this.

Buzz Fuselsausage: Line Mechanic by night, DC-3 Crew Chief by choice.
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RE: Mechanical Delays: How Common?

Thu Mar 08, 2001 2:43 am

EIPremier said:
>>>I too have noticed that mechanical delays increase during severe weather. Obviously, you don't want to have any complications to deal with when flying in such conditions.

As Mr. Buzz mentioned, there are some aircraft items that can be deferred. This can sometimes tend to alarm folks (given the media's frenzied misunderstandings of various things to the viewing/reading public), but it does have limitations. For example, if one had a busy day of errands planned and found that your car headlights or windshield wipers didn't work, you could decline to operate the car until you fixed these items. Obviously, none of the errands would get done, but wouldn't be acceptible to restrict your driving to day, dry conditions until the items could be fixed?

That's what deferred items on aircraft are for, and the "Bible" of what's acceptable is called a MEL, or minimum equipment list. The manufacturer and FAA come up a master MEL for each aircraft type, and each airline can then customize from there considering their own equipment choices.

A big reason that you seem to see more mechanical delays in bad weather is because some MEL items have weather-related (icing, thunderstorm, visual weather, etc.) restrictions associated with them, and if the weather no longer permits operation of the aircraft with that item deferred, it has to be fixed, or the aircraft re-routed (swapped) to an operational environment where it *can* operate. This also can mean delays, awaiting a suitable aircraft, while the imperfect one gets fixed, or sent elsewhere...

As Buzz also mentioned, they are FAA-licensed, just as the pilots are, as are we dispatchers who deal with these weather, mechanical, and operational issues. The beauty of serving "two masters" (airline and FAA) is that FAA can (and does) hold us accountable via the license, i.e. no license-no work--no paycheck. I think the system works pretty well...

Was non-rev (incognito, on another airline) years ago when pax next to me was griping about a lengthy creeping MX delay). After about an hour of it, I just asked her: "Would you rather down here wishing you were up there, or up there, wishing you were down here. She was silent the rest of the trip...  Big grin
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
Topic Author
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RE: Mechanical Delays: How Common?

Fri Mar 09, 2001 5:26 am

Thanks for the info Buzz. The only point I might make is that I do believe mechanical delays ARE counted in the airline on-time stats. This was not the case before 1995.

Obviously, the DOT doesn't penalize the airlines for mechanical delays, but the airline on-time stats include all delays, cancellations and diversions (including mechanicals).

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