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DL MD90- Fleet Reliability?  
User currently offlinedebonair From Germany, joined Jan 2004, 2435 posts, RR: 4
Posted (1 year 9 months 3 weeks 1 day 14 hours ago) and read 7267 times:

Hi to you all,

I would like to know, if someone can answer me a question regarding DL MD90's fleet reliability.

DELTA is the world largest MD90 operator and the MD90- flying many "first hand examples" (N901..-N916..).

Beside this fleet, DL is also operating some MD90's with various histories, like N918DH ex AMC Egypt, some ex CHINA EASTERN/NORTHERN, SAS etc.!

I would be most interested, if these birds with previous owner stick out? Are all MD90's despite different maintenance, ownerships in one league?

32 replies: All unread, showing first 25:
 
User currently offlineRoseflyer From United States of America, joined Feb 2004, 9661 posts, RR: 52
Reply 1, posted (1 year 9 months 3 weeks 1 day 7 hours ago) and read 7133 times:

Merging maintenance programs is quite challenging for an airline when acquiring used airplanes. As a first tier operator because they purchased 16 airplanes brand new, Delta does have the full Boeing resources at their disposal (if you are an airline that never purchased any airplanes new, you don’t get the same level of maintenance support which makes it even harder).

Delta is probably the best airline in the world at integrating maintenance programs. They take the established program for the airplane and have to fold in their own requirements to stay compliant with Airworthines Directives, Certification Maintenance Requirements, Airworthiness Limitations, and finally the Maintenance Review Board Report. It is quite challenging to start out since every airline does maintenance on different intervals, and with multiple previous owners, the records get very messy.

Because of the need to get compliant with their FAA approved maintenance program there is a lot of introductory maintenance that goes into the airplanes before they begin service. Delta essentially had to do heavy C or D checks on the airplanes just to ensure they are compliant with everything and can be operated legally.

Delta also went through Service Bulletins to bring the airplanes up to the standards that they want. They incorporate many optional Service Bulletins. They also do some supplementary type certification modifications to bring the airplanes in line with their fleet standards.

When you purchase a used airplane, especially when you under FAA or EASA jurisdiction and the airplane had been operated outside of those regions, there is far more maintenance required to get the airplane meeting the regulations than one would think. It’s a lot more work than replace the seats and add some paint.

After all that work, the differences in the airplane reliability is relatively minimal. You’ll sometimes see pilots or flight attendants or rampers say that one subfleet is horrible compared to the others. That may be true, but only if Delta Tech Ops didn’t do a good job in the first place.



If you have never designed an airplane part before, let the real designers do the work!
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 2, posted (1 year 9 months 3 weeks 1 day 6 hours ago) and read 7103 times:

Quoting Roseflyer (Reply 1):
Delta is probably the best airline in the world at integrating maintenance programs.

What makes them better than LH or other major airlines?


User currently offlinechrisair From United States of America, joined Sep 2000, 2125 posts, RR: 3
Reply 3, posted (1 year 9 months 3 weeks 1 day 5 hours ago) and read 7089 times:

Quoting debonair (Thread starter):
if someone can answer me a question regarding DL MD90's fleet reliability.

MD90 stands for Minimum Delay - 90 minutes.  


User currently offlineBE77 From Canada, joined Nov 2007, 455 posts, RR: 0
Reply 4, posted (1 year 9 months 3 weeks 1 day 5 hours ago) and read 7079 times:

Quoting cmf (Reply 2):
What makes them better than LH or other major airlines?

Probably more experience at actually merging / integrating metal that has been used elsewhere, through the practice of picking up used aircraft and the taking over / merging with other airlines.
(Where was it they got all those DC-9's from a few years back   )



Tower, Affirmitive, gear is down and welded
User currently offlineRoseflyer From United States of America, joined Feb 2004, 9661 posts, RR: 52
Reply 5, posted (1 year 9 months 3 weeks 1 day 5 hours ago) and read 7078 times:

Quoting cmf (Reply 2):
Quoting Roseflyer (Reply 1):
Delta is probably the best airline in the world at integrating maintenance programs.

What makes them better than LH or other major airlines?

Good question and definitely open to interpretation. Delta has more experience than most other first tier airlines. Delta has MD90s, 757s and 767s that were all purchased from other airlines. Delta has airplanes from almost a dozen different customized maintenance programs.

LH doesn't purchase used airplanes for the LH brand. Lufthansa Technic is a leader in maintenance programs, but not necessarily integrating airplanes into the fleets.



If you have never designed an airplane part before, let the real designers do the work!
User currently offlineFlighty From United States of America, joined Apr 2007, 8573 posts, RR: 2
Reply 6, posted (1 year 9 months 3 weeks 22 hours ago) and read 6936 times:

NW also had a long history of buying used DC-9s and DC-10s. The same Tech Ops team who managed those programs is likely part of the M90 story today at DL. It is an unusual business strategy.

User currently offlineBreninTW From Taiwan, joined Jul 2006, 1656 posts, RR: 1
Reply 7, posted (1 year 9 months 3 weeks 20 hours ago) and read 6888 times:

Quoting Roseflyer (Reply 1):
You’ll sometimes see pilots or flight attendants or rampers say that one subfleet is horrible compared to the others. That may be true, but only if Delta Tech Ops didn’t do a good job in the first place.

I think a lot depends on the options the ordering airline selected. On a flight home a few years ago (CX; 744) I got chatting to one of the pilots. He mentioned they sometimes have to be careful to remember which aircraft they're flying because of spec differences -- the one he mentioned was that some aircraft have electrically operated seats, while others have manual seats in the flight deck, but I understand there were other minor spec differences between the various 744 in the fleet.



I'm tired of the A vs. B sniping. Neither make planes that shed wings randomly!
User currently onlineDeltal1011man From United States of America, joined Sep 2005, 9510 posts, RR: 14
Reply 8, posted (1 year 9 months 3 weeks 16 hours ago) and read 6827 times:

Quoting Roseflyer (Reply 1):
That may be true, but only if Delta Tech Ops didn’t do a good job in the first place.

just want to note, the work itself(minus most of the painting) has been by 3rd partys.

Quoting Roseflyer (Reply 5):

Good question and definitely open to interpretation. Delta has more experience than most other first tier airlines. Delta has MD90s, 757s and 767s that were all purchased from other airlines. Delta has airplanes from almost a dozen different customized maintenance programs.

and L1011s (IIRC AC, PA and EA just to name a few)



yep.
User currently offlineatlamt From United States of America, joined Sep 2001, 240 posts, RR: 3
Reply 9, posted (1 year 9 months 2 weeks 6 days 22 hours ago) and read 6636 times:

In general the MD90 fleet is pretty reliable. I can't think of any issues that are only present in a particular subfleet from one previous operator.


Fwd to MCO and Placard
User currently offlineSSTeve From United States of America, joined Dec 2011, 710 posts, RR: 1
Reply 10, posted (1 year 9 months 2 weeks 5 days 6 hours ago) and read 6360 times:

Quoting chrisair (Reply 3):
MD90 stands for Minimum Delay - 90 minutes.

I was going to declare that that's just unfair, but unfortunately my only MD90 flight was SLC-SLC with the fire trucks rolled out for our return.


User currently offlinePGNCS From United States of America, joined Apr 2007, 2830 posts, RR: 45
Reply 11, posted (1 year 9 months 2 weeks 5 days 1 hour ago) and read 6271 times:

Quoting SSTeve (Reply 10):
Quoting chrisair (Reply 3):MD90 stands for Minimum Delay - 90 minutes.
I was going to declare that that's just unfair, but unfortunately my only MD90 flight was SLC-SLC with the fire trucks rolled out for our return.

Wow...a statistical sample of one whole flight. That's valid.  


User currently offlineGoBoeing From United States of America, joined Jun 2000, 2701 posts, RR: 15
Reply 12, posted (1 year 9 months 2 weeks 4 days 20 hours ago) and read 6189 times:

Quoting PGNCS (Reply 11):
Wow...a statistical sample of one whole flight. That's valid.

Well, I've begun to mentally keep track, and my last five in a row on the thing have all been delayed for maintenance, that's five consecutive flights, and the last one was DTW-MSP a few days ago, delayed 3.5 hours.

The thing seems to have some issues. But maybe it's all anecdotal.


User currently offlineLMP737 From , joined Dec 1969, posts, RR:
Reply 13, posted (1 year 9 months 2 weeks 4 days 17 hours ago) and read 6156 times:

Quoting chrisair (Reply 3):
MD90 stands for Minimum Delay - 90 minutes.

As a former MD-90 mechanic I got a good laugh out of that.  


User currently onlineseabosdca From United States of America, joined Sep 2007, 5531 posts, RR: 6
Reply 14, posted (1 year 9 months 2 weeks 4 days 5 hours ago) and read 6036 times:

Quoting GoBoeing (Reply 12):
The thing seems to have some issues. But maybe it's all anecdotal.

Sometimes you can have a run of bad luck. I had four straight UA 757 flights delayed by one hour or more for MX not too long ago. I don't think that shows that UA 757s are inherently unreliable.


User currently offlinePGNCS From United States of America, joined Apr 2007, 2830 posts, RR: 45
Reply 15, posted (1 year 9 months 2 weeks 4 days ago) and read 5962 times:

Quoting GoBoeing (Reply 12):
Quoting PGNCS (Reply 11):Wow...a statistical sample of one whole flight. That's valid.
Well, I've begun to mentally keep track, and my last five in a row on the thing have all been delayed for maintenance, that's five consecutive flights, and the last one was DTW-MSP a few days ago, delayed 3.5 hours.

The thing seems to have some issues. But maybe it's all anecdotal.

By definition 5 flights out of hundreds every day is purely anecdotal.

Quoting seabosdca (Reply 14):
Quoting GoBoeing (Reply 12):The thing seems to have some issues. But maybe it's all anecdotal.
Sometimes you can have a run of bad luck. I had four straight UA 757 flights delayed by one hour or more for MX not too long ago. I don't think that shows that UA 757s are inherently unreliable.

Correct.


User currently offlineSSTeve From United States of America, joined Dec 2011, 710 posts, RR: 1
Reply 16, posted (1 year 9 months 2 weeks 2 days 23 hours ago) and read 5776 times:

Quoting PGNCS (Reply 11):
Quoting SSTeve (Reply 10):
Quoting chrisair (Reply 3):MD90 stands for Minimum Delay - 90 minutes.
I was going to declare that that's just unfair, but unfortunately my only MD90 flight was SLC-SLC with the fire trucks rolled out for our return.

Wow...a statistical sample of one whole flight. That's valid.

Given that you're reading a conclusion into my anecdote that wasn't there, you might want to check your own conclusions, tetchyman.

[Edited 2012-12-18 18:03:22]

User currently offlineRoseflyer From United States of America, joined Feb 2004, 9661 posts, RR: 52
Reply 17, posted (1 year 9 months 2 weeks 2 days 7 hours ago) and read 5666 times:

If you want a realistic sample, go to flightaware. Pull up all MD90 flights. Then look at each flight and get 4 months of history. DL keeps relatively similar schedules. Look to see how often the MD90 is delayed. When you compare it to the 738, the numbers are similar. You'll need a rather large sample size to get a noticable difference in dispatch reliability rates since they are close.

Anecdotal never really works. Unless you see quotes from Delta or Boeing on dispatch reliability, the numbers you get won't be of much value.



If you have never designed an airplane part before, let the real designers do the work!
User currently offlineDalmd88 From United States of America, joined Jul 2000, 2559 posts, RR: 14
Reply 18, posted (1 year 9 months 2 weeks 1 day 3 hours ago) and read 5490 times:

I just checked the numbers today. The MD90 fleet as a whole is pretty much on par with the other short haul fleets. The metrics for each of the former operator subfleets are also pretty much the same as more of each type comes on line. When DL first got the original 16 aircraft they did have a bad reputation for delays. I think it might have contributed to the cancelling of the rest of the order. Most of those problems have been sorted out though.

User currently offlineLMP737 From , joined Dec 1969, posts, RR:
Reply 19, posted (1 year 9 months 2 weeks 6 hours ago) and read 5359 times:

The MD-90 is one of those what might have been aircraft. If MD had made the investment in a new wing instead throwing slat seals and aerodynamic flap fairings on an MD-80 wing they would have had an even more fuel efficient aircraft. Or if they had'nt made such a mess with the electrical system things might have turned out different.

Delta would have exercised those 115 options instead of cancelling them. Maybe AA would have gone with the 90 instead of the 737NG as a 727/MD-80 replacement. Oh well, the MBA's in St Louis decided it was not cost effective and the rest is history.


User currently offlineTrijetsRMissed From United States of America, joined Oct 2006, 2364 posts, RR: 7
Reply 20, posted (1 year 9 months 5 days 18 hours ago) and read 4871 times:
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About 4-5 years ago, as DL considered the MD-90 fleet build-up strategy, management prospected into the dispatch reliability records from SK, MU, and CZ. This occurred during the procurement/negotiation process. All were to have shown far better reliability rates than historic DL levels.

Quoting Dalmd88 (Reply 18):
When DL first got the original 16 aircraft they did have a bad reputation for delays. I think it might have contributed to the cancelling of the rest of the order. Most of those problems have been sorted out though.

I remember seeing an early rundown from MDC on the numbers, and I want to say the dispatch rate was somewhere around 88%. This was as the first 5-10 frames were being delivered - very small sample size. In the spring of 1997, significant progress had been made with MDC personnel stationed at DFW for 6 weeks to work out the kinks. Much of this progress was lost within a year of the merger.

While the early hiccups did not directly influence the cancellation, it was certainly a selling point on the part of Boeing (for the gentleman's agreement) and probably even Henry Stoneceipher - knowing it needed to be cancelled for the merger to go according to plan.

Quoting LMP737 (Reply 19):
The MD-90 is one of those what might have been aircraft. If MD had made the investment in a new wing instead throwing slat seals and aerodynamic flap fairings on an MD-80 wing they would have had an even more fuel efficient aircraft. Or if they had'nt made such a mess with the electrical system things might have turned out different.

In hindsight, MDC would have been better off had the MD-11 resources been put into the respected MD-90 and MD-95 R&D programs. With the MD-11 having never been more than a paper airplane.

The MD-90 never had a chance because the MDC C-level were positioning the company for acquisition, as early as 1993. This lack of leadership and direction is why it took the MD-90 two full years from first flight to EIS. By contrast, it took the MD-81 approx 11 months - in a flight test program that included two crashes!

Quoting LMP737 (Reply 19):
Delta would have exercised those 115 options instead of cancelling them. Maybe AA would have gone with the 90 instead of the 737NG as a 727/MD-80 replacement. Oh well, the MBA's in St Louis decided it was not cost effective and the rest is history.

The reality is DL cancelled the order because Boeing and MDC asked them to. The merger would have been a lot messier with 116 potential options. Before that, DL were planning for deliveries through 2003. Essentially 50 options to be exercised for a fleet of ~75 through that time-frame. Officially, most documents state through 2001, but I know first hand more were planned for.



There's nothing quite like a tri-jet.
User currently offlineTrijetsRMissed From United States of America, joined Oct 2006, 2364 posts, RR: 7
Reply 21, posted (1 year 9 months 4 days 3 hours ago) and read 4609 times:
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Quoting TrijetsRMissed (Reply 20):
Henry Stoneceipher

A typo here. I of course meant Harry Stoneceipher.



There's nothing quite like a tri-jet.
User currently offlineLMP737 From , joined Dec 1969, posts, RR:
Reply 22, posted (1 year 9 months 6 hours ago) and read 4353 times:

Quoting TrijetsRMissed (Reply 20):
Henry Stoneceipher

He who shall not be named.

Quoting TrijetsRMissed (Reply 20):

The reality is DL cancelled the order because Boeing and MDC asked them to. The merger would have been a lot messier with 116 potential options.

Delta probably did not need much convincing. You have to wonder if the MD-90 had started off as a reliable money maker from the start maybe Delta would have chosen differently.

Quoting TrijetsRMissed (Reply 20):
I remember seeing an early rundown from MDC on the numbers, and I want to say the dispatch rate was somewhere around 88%.


I remember seeing a letter at the LB delivery center from he CEO of SAS stating his disappointment in the MD-90.

Quoting TrijetsRMissed (Reply 20):
In hindsight, MDC would have been better off had the MD-11 resources been put into the respected MD-90 and MD-95 R&D programs. With the MD-11 having never been more than a paper airplane.

Or maybe if MD had put in a better effort into the MD-11. IMHO even if the MD-11 and MD-90 had been better aircraft than they were in the beginning and had received more orders it probably would have just delayed the inevitable.


User currently offlineTrijetsRMissed From United States of America, joined Oct 2006, 2364 posts, RR: 7
Reply 23, posted (1 year 9 months 1 hour ago) and read 4306 times:
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Quoting LMP737 (Reply 22):
Delta probably did not need much convincing.

FWIW, they were not going to agree without the special costing terms of the famous gentleman's agreement...

Quoting LMP737 (Reply 22):
Or maybe if MD had put in a better effort into the MD-11.

Not for a lack of effort, but a lack of investment. A very solid aircraft was still engineered.

If you remember correctly, the initial problems with the MD-11 predominately were caused by the higher than expected fuel burn of GE and PW engines. The aircraft was overweight and more drag prone as well, but the engines were most at fault for the range issues. So much so, that MDC even considered extending the wing during the PIP development.

Quote:
Aircraft powered by the PW4460 were found to be 5.7% above the contract guarantee while the CF6-80C2-powered version was 4.5% over. Although Douglas says that the problem is "probably 85-90% engines and 10% airframe drag", the company hopes the extended wing will improve performance by around 2%.
http://www.flightglobal.com/pdfarchi...34.html?search=md-11%20fuel%20burn

In anticipation of cynicism, I will note that GE and P&W never challenged MDC's claims on the performance disparities. And by 1995-96, there was a 9% improvement in fuel burn, which exceeded contract guarantees. Unfortunately, it was not a case of better late than never.

Quoting LMP737 (Reply 22):
IMHO even if the MD-11 and MD-90 had been better aircraft than they were in the beginning and had received more orders it probably would have just delayed the inevitable.

Perhaps. But since the 772ER was such a success, the MD-11 eventually would have been third fiddle anyway.

An MD-90 with 737NG-level R&D could have been the head of its class. Of course, "could have been" is the definition of post 1992 MDC.



There's nothing quite like a tri-jet.
User currently offlineLMP737 From , joined Dec 1969, posts, RR:
Reply 24, posted (1 year 8 months 2 weeks 4 days 15 hours ago) and read 3824 times:

Quoting TrijetsRMissed (Reply 23):
Perhaps. But since the 772ER was such a success, the MD-11 eventually would have been third fiddle anyway.

Just delaying the ineveitable I guess.

Quoting TrijetsRMissed (Reply 23):
An MD-90 with 737NG-level R&D could have been the head of its class. Of course, "could have been" is the definition of post 1992 MDC.

Would have been interesting to see that's for sure.

Quoting TrijetsRMissed (Reply 23):
Not for a lack of effort, but a lack of investment. A very solid aircraft was still engineered.

it did acquire the nickname "The Scud" in it's early years.


25 gigneil : Maybe. But given its EIS date, the A320 had already been flying for 6 years, and was delivering way more on payload and range.... the MD-90 would nev
26 Yukon880 : I see what you're saying Neil, but I think there's more to it than just payload and range. If these were the only criteria that mattered, then the 75
27 gigneil : And you are absolutely right and I didn't mean to imply that, sorry. Of course the MD-90 is a spectacular and efficient workhorse within its range and
28 Post contains images Yukon880 : Excellent points all, and very well said.
29 Polot : Even that is tricky though. One of the problems with tail mounted engines is keeping CG in check- the more weight you put in the back the more you pu
30 Post contains images TrijetsRMissed : A couple of things: First, overbuilt A320s from 1990 didn't equal the performance of a 2010 line number - Airbus had many improvements along the way.
31 Polot : I agree that there was a market for the MD-90, disagree about the MD-95 though. Would it have sold more than just the 717? Yes. But it would have sti
32 TrijetsRMissed : Actually, that was to be the MD-95-50, which I factored into the number. It was the next variant being developed from the family with target EIS in e
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