txp

Big letdown from Delta today. DL426 from AUS to ATL went MX and is now seven hours late with no end in sight. Not much information from the gate agents. At the DL Skyclub, they told passengers that they need to fly an airplane part from Atlanta. But at the gate they provided no information other than pushing the departure time 15-30 minutes at a time.

It would have been a lot more honest to tell everyone that the plane would not leave for at least seven hours and allow people to make other arrangements. Keeping people by the gate all this time "for the next update" does not seem right.

MX problems are understandable, but the lack of information and lack of alternative arrangements are very disappointing. I expected better from DL, but today they were below Amtrak.

Edited at 5:15 pm CDT to update that the plane finally left the gate.

steveholt

The drip-drip-drip delay has been an unwelcome guest for US airlines - is there something in how the FAA calculates delays that incentivizes airlines to approach it that way? I know AA does this quite a bit. Posting a longer delay would at least allow folks to make more informed decisions about rebooking themselves in the app.

txp

Indeed. I would be curious to hear from others why they prefer this approach instead of just telling people the truth. In contrast with DL, BA is brutally honest with their delays and cancelations. They just tell you as it is.

xliioper

The first 3 adjustments were between 30min and 1 hour. But the 4th was from 12:50 to 3:15. I'm guessing that's when they realized they needed the new part.

mot29

Do airlines no longer swap parts when needed in remote locations? Of course, maybe no one has parts at outstations any more.
Years ago on a flight from MDW flight was delayed while a mechanic drove over from ORD!
And even longer ago, flying from MSY, the APU wasn't functioning. Eventually hooked up 2 or 3 ground units to get enough power to start up the 757 engine (at least that is how I recall the explanation as the pilot complained that they had sent the 757 to MSY with the broken APU).

steveholt

I believe airlines still do swap parts, but since AUS isn't really a hub for anyone, I suppose it's possible nobody had the part laying around.

DTWflyer

Here is how this typically goes.....(for for explanation purposes, not necessarily defending DL here).
Before I get into it, I do believe all parties could do a better job informing passengers, but there are a lot of different functions involved. Plus they also don't do a good job of keeping the gate agents informed of the "why" as well....anyways.

1) A maintenance issue is detected.
This could something that happened on the inbound flight, detected on the ground, or during pre-flight checklists.

2) Dispatch and maintenance are informed from the flight crew.
They need to get in contact with the maintenance center to determine next steps. This can involve the pilots running some additional checklists, "pulling the breaker" on certain items and rebooting, or something they can diagnose onboard. If not, then they must get licensed maintenance onboard. At hubs and maintenance stations they are typically around the airport /terminal/ hangar. At outstations this is typically a contractor who may or may not be at the airport. An airport like AUS most likely has contract maintenance at the airport during normal operating hours, but not always the case at really small outstations.

3) This is where the "rolling delays" come into play. Typically in 15-30-60 minute increments as they are going through the steps above and trying to get maintenance support and diagnose the issue.

4) This is the biggest "unknown" is until the issue is diagnosed, is it something that is a quick "reboot" type of fix, is it something that can be deffered (ok to fly, but needs to be fixed at a certain point when it is flown back to a maintenance base (MEL), or is it something that must be corrected/fixed before the aircraft can fly (AOG / aircraft on ground).

If its a minimum equipment list (MEL) item, that is really only requires some paperwork and sign-off from maintenance and then can be on the way (these are the typical ~30-60 min maintenance delay stuff).
If its an AOG situation, then the repair needs to be done, and at outstations that typically requirement parts and technicans to be flown in (usually on the next scheduled flight) to fix the issue.
Thats when you can see a 30-60 minute delay jump up to 4+ hours, not to mention if the flight crew will also time-out and they need to re-crew / deadhead in reserve crews

Now yes, the airlines can and will "sell parts" to each other. Despite being competitors, they do regularly help each other out. But that is also a judgement call for a variety of reasons. Do they have the right part for the right aircraft? Are they low on that part / won't sell the last part off in case they need it, etc. At a place like DFW or ORD for example, it would be fairly common for AA to sell a part to DL if needed. However AUS may not have much spares for anyone and highly unlikely in the first place.

There are a lot of unknowns in that first 30-60 minutes. However I agree they do a terrible job communicating, explaining the process, and also notorous for the rolling delays when its clear that contract maintenance won't even arrive at the airport for another 90 minutes, yet they still post a delayed departure in 30 minutes,

DLASflyer

Watched a United flight yesterday delayed in small increments from 1:45 pm to 11:30 pm before finally canceling. In a way it has gotten worse because airlines are so focused on completion factor.

paul21

I'm going to be pedantic a bit on the terms:

• Creeping Delay is when the delay slowly gets longer and longer in small chunks
• Rolling Delay is when the delay from one flight rolls into a second flight

The reason is that the "rolling delay" is a specific strategy sometimes used at hubs or busy outstations, where the immediately impacted aircraft is swapped with the next available aircraft typically of the same type. Like this:

1. Flight 1 with AC1 is delayed
2. Flight 2 with AC2 becomes Flight 1
3. Flight 3 with AC3 becomes Flight 2
4. ...
5. AC1 is available
6. Flight 9 is flown with AC1

So the delay from Flight 1 rolls into flights 2-8, but none are significantly delayed alone.


The Creeping Delay is used when there's some uncertainty. The airline is legally required by DOT to give updates about a known delay within 30 minutes of knowing but DOT acknowledges creeping delays are allowed to happen because of unknowns. Strategically this has some advantages for the airline:

• It's difficult to undo a delay if the situation changes
• People will stick around for the shorter delays if it turns out to be a quick fix
• There is a sunk cost feeling that keeps the delayed flight loaded even with a long delay

I wouldn't really call it a conspiracy or anything as the airlines typically goal on a few metrics that impact manager/VP/C-suite compensation:

• D0 flight departed on time
• D15 flight departed within 15 minutes of scheduled
• Completion factor , percentage of flights completed in a schedule day

While passengers tend to care more about on time arrivals, it's easier to game by padding schedules and also it has less direct control due to air traffic uncertainty. However, it does mean that once a flight is delayed beyond 15 minutes there is less pressure to get it out ASAP. The goal becomes just getting it completed at all.

jamiel

Was last fall on a delayed SNA-DTW flight where DL immediately posted a 4 hr delay due to oil deposit within the engine cover; mechanic was driving over from LAX. We ultimately got out about 90 mins late.

The Situation

I have had an abnormally high number of mx issues with my flights in the last 9 months or so. Most of my flights are on A220's now, and I don't keep stats on it, but I would guess between 1/3 and 1/2 of my flights have an mx issue. They have ranged from my most recent flight delaying boarding but still pushing on time to do a computer reboot to diverting mid-flight a few months ago. DL has been much more communicative and specific recently with the cause of the delay and how they were trying to either resolve the issue or find a substitute a/c. This has been much better than a few years ago when I would have to walk up to the counter to ask why the flight was delayed - I am sure a few stations still take this approach.

As far as rolling delays go, I don't have a problem with it IF they are communicating the reasoning behind it. If they aren't communicating, I take that as a bad sign and find a new flight to wherever I am going.

HDQDD

In a former life I was an Irregular Operations Manager for an airline (my friends loved that title). At best, "creeping" vs. "rolling" is a distinction without a difference to passengers. I've always heard the terms used interchangeably.

Your description of a rolling delay strategy is not realistic. Routing decisions are not made by either the stations or the hubs, they're made by system operations. Contrary to pax belief, airplanes don't just fly between the same city pairs all day. They go all over the place. So often downline (or residual) delays are felt in many other cities.

flyerCO

I agree in general. However I've noticed with DL lately, one plane will fly back and for on a route with regular occurrence. Ie ATL-SAT-ATL-SAT-ATL-SAT. Again, it's the exception not the rule, but just a casual observation on number of routes.

txp

For the inconvenience, DL deposited 10,000 skymiles compensation. Does this seem reasonable or should I ask for more?

steveholt

You can certainly ask for more, although 10,000 miles is $100 in DL credit, which seems quite reasonable.