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It looks like Forbes agrees with the general consensus on this forum about the positive effect the DC9 has had on NWA's financial health. Forbes is certainly one of the more reputable financial publications, so it seems like a strong validation of NWA's fleet management policy.

http://www.forbes.com/associatedpres...feeds/ap/2005/02/20/ap1838610.html

One question on that article I'd like to ask though, is in regards to this:

"The Federal Aviation Administration doesn't care how old an aircraft is, just how many times it has been flown. It measures that by the number of times it has been pressurized and de-pressurized - generally, once per flight. The DC-9, based on testing, is approved for 105,000 of these cycles.

Bach said some of Northwest's DC-9s are hitting that limit and being retired. In January, the company said it would retire 10 DC-9s this year."

My question is, iss there any retrofit an airline can perform to get around having to retire aircraft when they reach that limit in the number of cycles, or is that the legal maximum usage for a given airframe?

-WGW2707

Great article. I fly on the DC-9's all the time, they do have character for sure.

The article did not metion with the -30, -40 and -50 varients NW can do equipment changes as needed sometimes when loads are up for certain city pairs, that is some nice flexibility to have.

unfortuneatly once the airframe life is met (105,000 cycles) there is no way to legally extend the plane for part 121 flying.

Quoting WGW2707 (reply 0): It looks like Forbes agrees with the general consensus

Not to pick nits, but that's actually an Associated Press article that Forbes -- as well as other publications -- reprinted. Interesting read, though. Thanks for posting it.  

>>>It measures that by the number of times it has been pressurized and de-pressurized - generally, once per flight.

"Generally?"

Does NWA have any city-pairs where they operate unpressurized?

As to your question I would like to know if the cycle lifetime is for the pressure bulkhead or the entire airframe. Wings, control surfaces, wheel assemblies and systems apart from the pressurized area would seem exempt from this. If it is the entire pressure vessel (cabin tube) then I think you can understand a problem with expenses. What does the DC9 pressure bulkhead consist of? Do the aft stairs present an added unique problem with that aft bulkhead assembly?

Need some tech help here.

Check me out on this - 105,000 cycles at (low) average of 4 flights a day equal 26250 days. Divide that by 365 for 71.92 years of service - Wow. One tough airplane. I started my career when the plane first flew - 1965 and I'm retiring now. I bet she is in better shape than me.

[Edited 2005-02-21 00:57:00]

Quoting OPNLguy (reply 3): Does NWA have any city-pairs where they operate unpressurized?

I noticed that, too, OPNL. DTW - FNT, perhaps?


2H4

No city pairs are operated unpressurized.

The 105,000 cycle limit is based upon the pressure bulkhead. There is no economical solution to extend the life of the aircraft beyond this point. It can be done, it just isn't economical. Other movable/rotable parts, pumps, surfaces, landing gear, etc. is inspected, repaired, and replaced on a set schedule.

I believe the average cost per aircraft for the DC-9-"2000" project to upgrade each aircraft was around $5 million a piece.

Subtracting the DC-9 fleet, NW is very much on par in terms of average fleet age with the rest of the US network carriers.

In terms of fuel burn, the DC-9's are still economical since, for the most part, they are flown on shorter stage lengths. Most DC-9 flights are under 90 minutes flying time. Only a handful of routes are greater than 800-900 miles. Fuel savings of operating an A319 versus a DC-9 on a 300 mile flight are minimal. Add it the lease payment of a new aircraft and it negates any sort of fuel savings.

unpressured....add LAN-DTW. That leg is 4m to 8m ft. MBS-DTW is 7m to 11m ft.
I have done FNT, LAN or MBS to DTW a few gadzillion times. I'm the guy with over 500 legs on DC9 alone and 1millionmiler may be right in there too.
safe

This is a GREAT thread!!! I always figured a plane's life was based on rotations and hours. Never did I consider the pressurization factor. It's like how many times can you blow up a balloon?

It's like how many times can you blow up a balloon?

I would guess that is apparently a relevant analogy.

It's interesting to wonder, will NWA's strategy of not always having to have the newest, shiniest aircraft be adopted by other airlines? I think for short haul applications especially, using older aircraft might become an increasingly attractive option... Interesting to speculate...

-WGW2707

This is great. A thread about the NWA DC-9 and not one cry baby has come to "trash" one of the greatest airliners in history. Unfortunately, the thread is "young" and I'm sure one will come in from 'left field'

I was very impressed when I flew on a NW DC-9-30 three years ago for the first time. I flew it PVD-DTW, the return trip was on a A319. From the interior the DC-9 looked just as new. An amazing job that NW did with it's retrofit.

This is great. A thread about the NWA DC-9 and not one cry baby has come to "trash" one of the greatest airliners in history. Unfortunately, the thread is "young" and I'm sure one will come in from 'left field'

I think no one wants this NWA DC-9 thread to turn into, well, for lack of better words, an NWA DC-9 thread  

-WGW2707

"The Federal Aviation Administration doesn't care how old an aircraft is, just how many times it has been flown. It measures that by the number of times it has been pressurized and de-pressurized - generally, once per flight. The DC-9, based on testing, is approved for 105,000 of these cycles."

does anyone know how many cycles other aircraft have been approved for...for instance the 737??

From the interior the DC-9 looked just as new. An amazing job that NW did with it's retrofit.

Agreed. Northwest understands that most of the flying public doesn't know the difference between an "old" DC-9 and a "new" A319....and doesn't care. Why saddle yourself with debt when you own something that works?

Agreed on the DTW-LAN flights. Just about every time I've flown that one, we've been at 6000 feet. I'm sure that the view would have been great, but it is after all Michigan, so cloudy cloudy cloudy everytime.

One has to wonder what this article will do to NWA's strategy. To me, an integral part of the 'Flying-DC9s-til-they-fall-apart-or-reach-their-cycle-limit' strategy is the illusion created by the upgrades done a few years ago. As we have discussed (at great length), the average flyer wouldn't know the difference in age between a DC-9 and one of their factory-fresh 330s. Now that this article is out in the open and has been published in Forbes and the Detroit Free Press and the information that NWA has the oldest fleet is widely available, I wonder if any people are going to think twice about flying on a 40 year old aircraft.

(not that they should think twice, of course. NWA has some of the best maintenance crews in the business and I would jump at the chance to fly on a -9, especially if someone else was paying for it)

The Detroit media, especially FOX 2, a few years back used to heavily criticize NW.

They ran numerous reports about the age of NW's aircraft, and it has had no effect. The general public has such a short term memory, they don't even remember.

Quoting Mawelsh (reply 14): Agreed. Northwest understands that most of the flying public doesn't know the difference between an "old" DC-9 and a "new" A319....and doesn't care. Why saddle yourself with debt when you own something that works?

Especially in this low yield environment. New shiny airplanes are nice but very expensive. It's just my lawyer once told me....."It's cheaper to keep her"!!

I have flown on 1 of their DC9-10s and one of their DC9-30s. Basically they were identical, and looked BRAND NEW to me.

Questions about the DC9. I was flying through DTW on my way back from FLL and noticed that the starboard engine nozzle on the DC9 is always covered with more black soot than the port engine. Any particular reason for this?

Thanks, Jason

Quoting Jblake1 (reply 20): Questions about the DC9. I was flying through DTW on my way back from FLL and noticed that the starboard engine nozzle on the DC9 is always covered with more black soot than the port engine. Any particular reason for this?

The APU exhaust vent is located over the starboard engine nozzle.

Ever notice that pesky black streak on the aft starboard side on almost any CRJ over a few months old? Same thing!

>Fuel savings of operating an A319 versus a DC-9 on a 300 mile flight are minimal. Add it the lease payment of a new aircraft and it negates any sort of fuel savings.<

Are there actual fuel savings with the A319? Sure, its seat mile is much better, but the DC-9 is a smaller, lighter aircraft. I would guess that the trip costs are lower, hence the financial risk lower on an operational standard as well as a purchase standard. Also, as compares to 50 seat RJs, the seat-mile is better. That brings to question, are the seat-mile costs for the DC-9 lower than 70 seat RJs as well?

Does NWA have any city-pairs where they operate unpressurized?

I once flew on a 747-100 (or -200?) DTW/MSP that remained unpressurized for the entire flight.

If memory serves, upon takeoff a warning light came on in the cockpit that one of the forward doors was not properly closed.

Instead of returning to DTW, everyone had to move to rear of the aircraft and we flew low and slow all the way to MSP.

So was the story communicated to the passengers. I wouldn't believe it if I hadn't been there.

Great article!

I think that is the same reason why the are keeping the DC-10's for a while.
 

Northwest's DC-9's are great...good plane and a good airline...

I don't mind their interior, but NW DC-9's with me onboard seem to have terrible track record. Out of six flights on NW 9's I have never arrived on time (avg. 6 hour delay), 2 never took off, 1 burned AC on TO roll at MEM. That is main reason why I don't fly NW no more.

N1120A

As for the lighter, acft I wonder what the difference in landing fees are. Now if you compare a -50 or -40 with the 319 pax loads get more comparable.

Quoting Lockheed1011 (reply 24): I think that is the same reason why the are keeping the DC-10's for a while.

Actually, if I'm not mistaken; doesn't NW want to phase out their DC-10s soon?

Quoting WGW2707 (reply 0): "...In January, the company said it would retire 10 DC-9s this year."

Does that include the DC-9-10s that NW recently retired?

As aNW elite I really appreciate the DC-9.

For example I get to fly DTW-MYR on the DC-9 and my upgrade always goes through. On a RJ well I'm just stuck on a RJ

congrats to the DC-9
Chris

"I don't fly NW no more" "avg. 6hr delay"

Please give us the details of your last 6 DC-9 flights that averaged a 6 hour delay. Doesn't seem likely to me, but I'll wait for your reply.