video of NW ground collision

[punkalouver]

http://kstp.dayport.com/viewer/viewe...?Art_ID=167944

[Simwings]

Nice to see Avid and Fast Purple put to good use by the investigators there...

Must have been a shock to have been sitting on the airbus, to have been just sat there, then feel the back of the plane push up. It would have only felt normal to somebody who flies harriers the rest of the week.

[con-pilot]

It is one heck of a video. Once after loading the passengers onto the 727 I was flying a bus hit the left wingtip as it pulled away. Although the damage was minor the impact sure got my attention.

I can't imagine what it felt like if you were in the Airbus.

[skibeagle]

So the DC-9 landed and stopped okay, then later couldn't stop.... mmmm leads me to think that maybe he had had accumulator pressure, used it stopping on the runway and then ran out of accumulator pressure perhaps ??? Can any engineer types shed light ????

We all know how great MD's kit is when it comes to multiple-unrelated failures, like an uncontained fan blade failure dumping all three hydraulics.

[Memetic]

A lesson for early unbucklers...

Perhaps those passengers who unbuckle early should be detained (failing to obey a legitmate etc...) and made to watch this video before being sent on their way.

[Dani]

Is there some official investigation (preliminary) report out? Me seems this MD-80 taxies quite fast (even if he hadn't any failures). Why not using full reverse?

[reverserunlocked]

ouch!

[TURIN]

I seem to remember something about DC9/MD80s having minimal brakes if you shut one of the engines down. Can't remember which one or even if my facts are right.

[Eff Oh]

The MD's flight deck was very badly damaged. What happened to the crew? The Captain in particular? (I mean as in injuries if any, not as in blame.)

[matkat]

Originally Posted by skibeagle

So the DC-9 landed and stopped okay, then later couldn't stop.... mmmm leads me to think that maybe he had had accumulator pressure, used it stopping on the runway and then ran out of accumulator pressure perhaps ??? Can any engineer types shed light ????
We all know how great MD's kit is when it comes to multiple-unrelated failures, like an uncontained fan blade failure dumping all three hydraulics.

Cannot understand it Myself because the MD has an emergency braking system which is totally independant of the hydraulics, I was involved in an incident when a DC-8 had total hydraulic failure on the ground and in a turn the aircraft subsequently ran onto the the grass and sank, the first question asked of the Capt was why He did not use the emergency system and the answer was clear and honest, in the panic He had simply forgotten, deja vu perhaps?

[Irish Steve]

From information elsewhere.

They'd lost the right hydraulic system in flight, had landed safely and were holding for a stand, supposedly to be towed on. what happened after that is not clear, the MD was apparently stopped before the incident.

Captain was "seriously injured", FO "injured", and one cabin crew member on each aircraft also "injured".


NTSB short reports

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20051213X01965&key=1
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20051213X01965&key=2

[Capt Sly]

Great video! It appeared to happen a lot faster than I first thought.

Is there some official investigation (preliminary) report out? Me seems this MD-80 taxies quite fast (even if he hadn't any failures). Why not using full reverse?

Preliminary report out on the NTSB site, but is very sparse on the facts. Last year's Pprune thread seems to have been archived, but other details were discussed; Apparently the aircraft landed OK after its hydraulic failure, and on the taxi in they shut down one engine to save fuel. Unfortunately the two weren't compatible, and they lost all hydraulics inc accumulator. P1 thought on his feet and selected full reverse, but due to lack of hydraulics the reverser didn't deploy - however the engines did spool up the MREV, giving plenty of forward thrust. Aircraft ended up completely out of control, and ends up bumping into the Airbus.

Final report should be interesting reading.

[Wiley]

I think the security camera takes fewer images per second than a 'real time' presentation, hence the jerky original footage. (Remember the infamous Pentagon car park video on Sept 11th 2001 that took only one image per second, resulting in no claer image of the 757 crashing into the outer ring?)

The final rerun seems to have been 'optimised for viewing' by the TV station, making the DC9 seem to moving a lot faster than it actually was moving.

I think.

[PAXboy]

What I find 'amusing' is that, the pax who leave the DC-9 from the rear steps ... many of them are carrying their hand luggage and one blurry object, looks like a roll-along cabin bag. So that was an emergency evacuation? I can imagine that, if pax arrive at the exit carrying the bags, you would have to let them take th ebags, otherwise they would pile up just inside. I do appreicate they they exited on the air stairs and not a slide but it does seem inappropriate.

Memetic

passengers who unbuckle early should be detained (failing to obey a legitmate etc...) and made to watch this video before being sent on their way.

Could not agree more.

[av8boy]

passengers who unbuckle early should be detained (failing to obey a legitmate etc...) and made to watch this video before being sent on their way.

Not to mention management from airlines who still have FAs up and about during taxi-out for demo, walk-through, etc. Missus AV8BOY is a grizzled, long-time FA for a major US carrier and is dumbfounded by the fact that her airline requires that she be up and about during taxi-out for various "safety-related duties" such as a walk-through (now that the demos are done via video), but absolutely prohibits her being up during taxi-in. This video proves very well the point that this risks are pretty much the same.

When I originally broached this subject with her many years ago, I asked her whether FAs needed to be up and about during the taxi-out, and she said "yup." When I asked her whether they also got up during the taxi to the gate, she said, "God no! Only if I need to tackle a PAX." I suggested that she might explain how the FA personal safety implications were different in these two situations. That's when she got angry with her company.

But what do I know. I'm just an old, grizzled ATCer who has spent a good part of my career watching aircraft drive around the airport.

-Dave

[Mike Oscar]

Totally different aircraft type, but I was involved in an incident with an ATR42 years ago.

Aircraft had generator failure inbound. No real issue.

Normal procedure was to shut down No.1 on taxiing in. Nothing in the QRH (at the time) to prevent this from still occurring after a gen failure.

Brake check carried out before entering stand (using up residual accumulator pressure) and aircraft failed to stop on stand.....right hand prop sliced through waiting ground power unit, left hand engine hit jetty.

Similar issues to this, and again by the time crew realised what was happening, reaching for the Emergency (parking) brake was too late.

[Simwings]

Originally Posted by Wiley

The final rerun seems to have been 'optimised for viewing' by the TV station, making the DC9 seem to moving a lot faster than it actually was moving.

That would be due to the frame limiter settings being changed...remember that avid computer system I was talking about earlier?

Have 24 frames, with a keyframe every 30 frames...and you have a problem

[Ignition Override]

Capt Sly understands the DC-9/MD-83 systems.
For SkiBeagle, the DC-10 requires hydraulic pressure for all the primary flight controls, as with most heavy airliners etc, but the DC-9 requires none-control tabs can do all the work. Although there is some hydraulic pressure which normally helps to move the actual rudder, loss of normal pressure for the rudder then unlocks the rudder control tab and the min. final approach speed is only 135 KIAS or Vref+5, if greater. Let's see this simplicity on any Boeing jet etc. A Martin B-26 (WW2) had a much higher final approach speed.

I rode on such a plane once where the Captain shutdown the (second) remaining engine about 10-20 feet from the gate and coasted to a stop on level ground. As long as the APU is already running with a normal right aux pump operating, you might get away with it.
But if both brake (maybe 3-5 appl. from each side, left and right) accum. are gone, you are out of luck. Nice time to discover this, as you approach very solid structures. Read up on the A-320, taxied by mechanics, which hit a jetway a few years ago at La Guardia (LGA). This is a sensitive topic (but not my problem): an airline Station Manager can pocket a pay bonus by hurrying staff to reposition aircraft, in order to avoid paying them overtime later. This did include forcing some A-320 passengers to wait 20 minutes before being allowed to park at a gate (also at LGA : a jetway was inop.) years ago, as aircraft were moved around at night. This keeps staff costs down. Isn't that the goal? Nice bonus, boss man. The passengers should somehow be told about this.

Should we forget how much more aircraft maint. is outsourced these days, and how some things are done in a real rush, to keep contract costs down? Want to bet your career on how many brake actuations are available, or for thrust reversers? You won't believe some multiple problems that have happened after one aircraft leaves an "outsourced" maintenance facility. Sure, problems also happened at company hangars in the good old days. But one facility almost lost its license or contract with at least one specific airline, until the airline put their own experienced crew chief 'Down There' full time. In the 80's a Navy Reserve CV-580 crew from NAF Washington (Andrews) died during an emergency return there, due to a problem with the elevator control cable which should have been inspected again by some technicians.... "Sweet Home...^ ...Lord I'm coming home to you...". I hope they went to a much better world when they crashed.

[Huck]

ASA had a Brasilia captain in Anniston many years ago that shut down both and coasted to a stop with the APU.

Problem was, some relays got confused and he lost brakes AND nosewheel steering. Went into a fence. Known for eternity as "The Anniston Chain-Link Massacre".....

[bafanguy]

Originally Posted by matkat

Cannot understand it Myself because the MD has an emergency braking system which is totally independant of the hydraulics...

The DC9 does not have such a system. There are two hyd systems, left & right, both of which can power the MLG brakes in all four wheels. There is a brake selector with left, right, and both selections. It is normally carried in the both position. Where the selector is postioned in a failure of one hyd system may vary with the company.