NW747-400
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NW DC-9 "Late Acceleration"

Tue Nov 06, 2007 3:44 am

I often hear DC-9 crews call tower prior to takeoff clearance to inform the local controller that they will be maintaining 200kts to 3000AGL. What is the purpose of this? Is this just a NW specific procedure or all DC9's?
 
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jetjack74
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RE: NW DC-9 "Late Acceleration"

Tue Nov 06, 2007 5:44 am

Quoting NW747-400 (Thread starter):
I often hear DC-9 crews call tower prior to takeoff clearance to inform the local controller that they will be maintaining 200kts to 3000AGL. What is the purpose of this? Is this just a NW specific procedure or all DC9's?

I believe it's just a procedure to avoid traffic interference with smaller, slower aircraft that might be taking off ahead of them on the climbout.
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oly720man
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RE: NW DC-9 "Late Acceleration"

Tue Nov 06, 2007 12:43 pm

Quoting Jetjack74 (Reply 1):
I believe it's just a procedure to avoid traffic interference with smaller, slower aircraft that might be taking off ahead of them on the climbou

Wouldn't ATC tell them to go slow in that case??

Could it be so that ATC know that they'll be slow and can inform anyone taking off behind them?
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NW747-400
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RE: NW DC-9 "Late Acceleration"

Tue Nov 06, 2007 7:09 pm

Quoting Jetjack74 (Reply 1):
I believe it's just a procedure to avoid traffic interference with smaller, slower aircraft that might be taking off ahead of them on the climbout.

I don't believe this is the case, because I usually hear these radio transmissions in ATL, and the local controllers have to allow additional spacing between a NW DC9 departure and another aircraft in order to accomodate their "late acceleration."
 
lowrider
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RE: NW DC-9 "Late Acceleration"

Tue Nov 06, 2007 8:06 pm

At least one of the departures (I believe it is the Atlanta 5) calls for acceleration to 250 knots as soon as possible. The call is a courtesy to help controllers time departures.
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NW747-400
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RE: NW DC-9 "Late Acceleration"

Sun Nov 18, 2007 4:23 pm



Quoting Lowrider (Reply 4):
At least one of the departures (I believe it is the Atlanta 5) calls for acceleration to 250 knots as soon as possible. The call is a courtesy to help controllers time departures.

I understand that, but my question is why do NW DC9's require an acceleration altitude much higher than any other aircraft?
 
ex52tech
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RE: NW DC-9 "Late Acceleration"

Sun Nov 18, 2007 5:03 pm



Quoting NW747-400 (Reply 5):
I understand that, but my question is why do NW DC9's require an acceleration altitude much higher than any other aircraft?

They do that so that they have time to cool off those high quality, outsourced, engines that they get from a repair facility in Mexico, before they have to pull power on them again.

They told us that the Atlanta engine shop was just too expensive, and we were lazy.
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avioniker
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RE: NW DC-9 "Late Acceleration"

Sun Nov 18, 2007 6:07 pm

It also has to do with the fact that they aren't -200 series engines like on the MD fleet and make a lot more noise and smoke on climb and higher power settings and would have to pay some pretty hefty noise curfew penalties for busting the limits.
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tb727
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RE: NW DC-9 "Late Acceleration"

Sun Nov 18, 2007 7:21 pm



Quoting Ex52tech (Reply 6):

They do that so that they have time to cool off those high quality, outsourced, engines that they get from a repair facility in Mexico, before they have to pull power on them again.

They told us that the Atlanta engine shop was just too expensive, and we were lazy.

Sad but true. Promised so much to the ATL guys then stabbed them in the back after they did an awesome job with the hushkit program and everything else. I think that was the beginning of the end to NW maintenance. I remember when EVERYTHING was done in house at NW. It's too bad people will sacrifice safety to save $75 on a ticket, the sad thing is, no one even thinks about it. I will always back and trust an original NW mech, none of these new guys. Off my soapbox now...


Anyways, they might be flying a profile as mentioned. Mostly for noise I would bet, in the jets I fly, which are loud, we pitch up for V2 and pull the power back some at the airport boundary when we are near sensitive areas. If you fly the profile Dassault made for the Falcon 20 for instance, you are supposed to climb at 200 KIAS until 10,000', we just never do it because you would get run over.
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113312
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RE: NW DC-9 "Late Acceleration"

Sun Nov 18, 2007 9:48 pm

ICAO standard noise abatement climb requires V2 plus 10 knots to 3000 AGL/AFL. Some local USA airports have negotiated with dominant carriers a non-standard procedure to reduce climb gradient and accelerate to 250 KIAS at some lower altitude. Since the DC9 is a noisy aircraft, some carriers would prefer to stick with the standard climb and so notify ATC. Other operators with other Stage 3 compliant wide body aircraft also climb at the ICAO standard profile.

It should also be noted that some departures, from secondary airports below Class B airspace, have departures operating below the Class B airspace. Although ATC does not assign a speed restriction, it is assumed that the flight crew will comply with FAR airspeed restrictions.
 
tdscanuck
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RE: NW DC-9 "Late Acceleration"

Sun Nov 18, 2007 11:37 pm



Quoting Tb727 (Reply 8):
It's too bad people will sacrifice safety to save $75 on a ticket, the sad thing is, no one even thinks about it.

When was the last NW crash? Their safety doesn't appear to have taken a hit (yet).

Tom.
 
IAHFLYR
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RE: NW DC-9 "Late Acceleration"

Mon Nov 19, 2007 1:32 am



Quoting Jetjack74 (Reply 1):
I believe it's just a procedure to avoid traffic interference with smaller, slower aircraft that might be taking off ahead of them on the climbout.

Nope, that is the responsibility of the local controller to provide initial separation between successive IFR departures.

Quoting NW747-400 (Thread starter):
I often hear DC-9 crews call tower prior to takeoff clearance to inform the local controller that they will be maintaining 200kts to 3000AGL. What is the purpose of this? Is this just a NW specific procedure or all DC9's?

Where do you hear this type of operation?
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tb727
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RE: NW DC-9 "Late Acceleration"

Mon Nov 19, 2007 1:58 am



Quoting Tdscanuck (Reply 10):
When was the last NW crash? Their safety doesn't appear to have taken a hit (yet).

That's the problem. Who heard of any Valujet problems until after their accident in MIA? Unfortunately I think it's going to take another similar incident to bring outsourced maintenance problems into the light again so the public can see what is actually going on. I certainly hope it doesn't happen but a lot of the majors are playing with fire when it comes to foreign and even domestic outsourced maintenance. It's a topic for another thread but it is something that is near and dear to my heart for many reasons. Anyways, the DC-9's are old and therefore probably have different profiles to fly sometimes, that's my guess.
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IAHFLYR
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RE: NW DC-9 "Late Acceleration"

Mon Nov 19, 2007 2:15 am



Quoting Tb727 (Reply 12):
Anyways, the DC-9's are old and therefore probably have different profiles to fly sometimes, that's my guess.

Most of them on a hot day near MTOW are just glad to climb!  Smile
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Cubsrule
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RE: NW DC-9 "Late Acceleration"

Mon Nov 19, 2007 5:36 pm



Quoting Tb727 (Reply 12):
Unfortunately I think it's going to take another similar incident to bring outsourced maintenance problems into the light again so the public can see what is actually going on.

Is there any empirical evidence that outsourced m/x is worse? We have the 1900 crash in CLT in 2003, but the vast majority of accidents caused by faulty m/x occured with carriers that were doing the m/x in house.
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tb727
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RE: NW DC-9 "Late Acceleration"

Mon Nov 19, 2007 7:20 pm



Quoting Cubsrule (Reply 14):

Is there any empirical evidence that outsourced m/x is worse? We have the 1900 crash in CLT in 2003, but the vast majority of accidents caused by faulty m/x occured with carriers that were doing the m/x in house.

Is there any evidence supporting in house mtx is worse? All I can go by is from what I have seen from getting up into places normal people can't go and see examples of shotty work. I am not just an armchair airliners.net guy, I have gotten out there and gotten my hands dirty and have taken a look around from both sides. I've seen tools left behind on runways in Lake City, FL, a big Timco airport, because they were forgotten in the wheel wells or whatever. I've had an airplane at a major airline I was supposed to be on as a passenger come back because it couldn't pressurize because the 3rd party didn't even clamp the bleed lines that they had undone for an "inspection" and the lines had finally come off. When it comes down to it, a 3rd party mtx company plain old isn't going to put as much care into work as someone in-house would. Their company name isn't on the side of that airplane. They get paid to get something done in X amount of days based on what it is. It is going to be done in that amount of days whether it is good to go or not, otherwise they get their pay docked. Don't even get me started on mtx at foreign bases in Asia and Central America, there isn't even regulation over the people working on these planes!
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Cubsrule
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RE: NW DC-9 "Late Acceleration"

Mon Nov 19, 2007 8:32 pm



Quoting Tb727 (Reply 15):
Is there any evidence supporting in house mtx is worse?

I'd be very curious to see evidence either way, but it seems to be in short supply. Instead, we hear pro-management types whining that carriers don't get any added value for the increased cost of in-house m/x and pro-labor types whining that moving jobs offshore (or out of the company) compromises safety. I feel like it can't be both ways.
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TrijetsRMissed
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RE: NW DC-9 "Late Acceleration"

Tue Nov 20, 2007 5:39 am

Interesting thread. I remember the 727 being a slow climber, same reasons apply?

Quoting Tb727 (Reply 12):
Who heard of any Valujet problems until after their accident in MIA?

Actually there were several Valujet incidents in the 18 months or so prior to the crash.

Quoting Tb727 (Reply 15):
Is there any evidence supporting in house mtx is worse?

That would be interesting to see. Some bad accidents such as AA 191 or UA 232 were a direct or partial result of in house maintenance. AS 262 is a perfect example, luckily it was the last such accident of that kind in the US. I'd still prefer airlines do it themselves, or outsource to a reliable source, like G4 does with AA.
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BR715-A1-30
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RE: NW DC-9 "Late Acceleration"

Sun Nov 25, 2007 10:35 pm



Quoting TrijetsRMissed (Reply 17):
Actually there were several Valujet incidents in the 18 months or so prior to the crash.

All of these are Ship 904 - N904VJ before it crashed... Several air turnbacks

1/3/1995 -- ATL/TPA - FLT 531 - RETURNED TO ATL DUE TO A NR 1 CSD OVERHEAT AND THE CSD WOULD NOT DISCONNECT. REMOVED AND REPLACE NR 1 CSD.

1/20/1995 - IAD-ATL - FLT 175 - FLIGHT EXPERIENCED A LT SYSTEM HYDRAULIC LOW PRESSURE LIGHT, 300 PSI AFTER PERFORMING THE GEAR UPLATCH CHECK. FLIGHT RETURNED TO IAD FOR REPAIRS. REMOVED AND REPLACED HYDRAULIC PUMP NR 1 ENGINE.

4/10/1995 - DFW/ATL - FLT 234 - HAD TO DIVERT TO MEM DUE TO CABIN DE-RESSURIZATION. AUTOPRESSURIZATION FAILED AND OXYGEN MASKS DEPLOYED, EXCEPT 4 AT ROWS 5C, D, AND E. REMOVED AND REPLACED OYGEN BOTTLE AND DROP-CHECKED OXYGEN MASKS. OPS CHECK OKAY, PLACED AUTOPRESS ON MEL.

10/18/1995 - FLT NR 547 - PHL - AIR RETURN, AFT AIRSTAIR DOOR LIGHT ILLUMINATED. RECYCLED AFT STAIRS, SYSTEM CHECK NORMAL. (M)

Christmas Day, 1995 - IAD/MCO - FLT 467 - AFT AIRSTAIR LIGHT CAME ON AND CREW COULD NOT HOLD CABIN ALTITUDE. CABIN ROSE TO 8,000 FEET, DESCENDED AND RETURNED TO IAD. LANDED 3,000 POUNDS OVERWEIGHT. INSPECTED ALL AIRCRAFT DOORS AND SEALS. FOUND FOD ON RT FORWARD EMERGECY EXIT DOOR SEAL. REMOVED FOD. NO OTHER DEFECTS. PERFORMED PRESSURIZATION FUNCTIONAL CHECK IAW MM 21-30. PERFORMED OVERWEIGHT LANDING CHECK.

1/4/1996 - PHL/PHL - FLT 545, CREW ADVANCED THROTTLES ON TAKEOFF AND GOT A TAKEOFF WARNING HORN AT APPROXIMATELY 15 KNOTS. CYCLED FLAPS AFTER CLEANING THE TAKEOFF WARNING SWITCH. NO DEFECTS NOTED.

1/19/1996 - ON FLT NR 116 - ATL-ATL - AIR RETURN, RIGHT PACK INOP AFTER TAKEOFF, NO PRESSURE INDICATION OR AIR FLOW. FOUND CLAMP LOOSE ON RIGHT ACM AND BROKEN CLAMP ON RIGHT WATER SEPARATOR. SECURED LOOSE CLAMP ON ACM AND INSTALLED CLAMP ON WATER SEPARATOR. PRESSURIZATION AND AIR CONDITIONING OPS CHECK NORMAL. (M)

3/15/1996 - ON FLT 236, DFW-ATL, DIVERTED TO MSY WITH THE LEFT AC BUS INOP. FOUND THE LEFT GENERATOR CONTROL PANEL LOOSE IN THE RACK, SECURED PANEL, RAN ENGINES WITH AC LOAD, OPS CHECKED NORMAL.

4/1/1996 - ON FLT 235, ATL-ATL, GATE RETURN, THE AFT CARGO DOOR LIGHT CAME ON TAKEOFF ROLL. ADJUSTED SWITCH PER 52-30, OPS CHECK NORMAL. (M)

And then on 5/10/1996, they were having SEVERAL electrical failures, including problems with the PA, Circuit Breakers popping, Engine Generators malfunctioning.

This is just for one airplane.

Source: http://av-info.faa.gov/isdr
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PC12Driver
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RE: NW DC-9 "Late Acceleration"

Mon Nov 26, 2007 12:57 am

Quoting TrijetsRMissed (Reply 17):
Actually there were several Valujet incidents in the 18 months or so prior to the crash.

Indeed...
But I think the point Tb727 was trying to make is that these incidents were largely unknown to the public until *after* the Valujet crash in Florida occurred.

The mysteries initially surrounding the crash prompted the media to start investigating Valujet's maintenance history, and their findings eventually made the general public aware of the problems Valujet had been having up to that time. But up until the crash, the many people flying with them weren't worried about Valujet's safety.

In other words, we should start "digging up the dirt" on poor maintenance procedures *before* a tragic accident occurs. We shouldn't have to wait until people die before doing something about substandard maintenance. (That is, if the maintenance in question here is, in fact, substandard. That's something I can't judge from here).

[Edited 2007-11-25 16:59:43]
 
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tb727
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RE: NW DC-9 "Late Acceleration"

Mon Nov 26, 2007 2:40 am



Quoting PC12Driver (Reply 19):
Indeed...

Yeah, what he said, nailed it on the head pretty much, thanks!
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