OT - Southwest crash

[Guest WesFlight]

Yes, My conclusion of the accident as of now stands right along with yours. The way I see it is this. That particular aircraft and the conditions the plane was landing in should have been ok landing with just reverse thrust, spoilers, and manuall braking (As per SW regulations). As far as autobrakes go, they can only help you. The 737 is designed to stop without using them. However, if you choose to use them, it applies greater efficiancy of stoping and gives your precise cargo (people) a smoother ride. Therefore, I firmily believe that the thrust reversers will also be a determining factor. The weather is of course a majior factor along with the amount of runway. The runway was to short for this particular weather pattern. I am 99.9% sure that the 737 would have had no problem landing on this runway in clear conditions.

[Guest WesFlight]

Regardless of what you think, southwest has yet to kill any of its passengers. Must I remind you that the fatality was on the ground. The 6-year-old boy riding in a car that was struck by the plane. This will not go down as Southwest killing someone because of its operations.Second, we all must remember that the United States is not Canada or France. Our laws do not govern what other airlines do in other countries. The crash in Canada this year is in no way related to what happen with the Southwest flight here this past month. Comparing those two crashes is like comparing the ocean to the land, not very much in common. As far as contaminated runways go. On any given day I would say there are more than half of all runways and approaches less than fair in the United States. Blue Skies is not a common thing with regards to flight. Just look at our own Flight Simulator. Most of us do not want blue skies. We go out and buy programs that make weather realistic. I have flown a lot this year on business and I can

[AlaskanFlyboy 7]

Considering the auto-brakes simply maintain a rate of deceleration with the brakes, adding spoilers and reverse thrust may very well slow you faster then that rate and the autobrake system may simply not use braking pressure at all, which may be the reason for some airlines not using it.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

[Guest tmetzinger]

>Regardless of what you think, southwest has yet to kill any>of its passengers. Must I remind you that the fatality was on>the ground. The 6-year-old boy riding in a car that was struck>by the plane. This will not go down as Southwest killing>someone because of its operations.Actually, yes, it will. When the NTSB lists the accident it will have a fatality associated with it. Not a passenger, but a victim nonetheless. Also note I never said Southwest has ever killed a passenger. This is the first SWA accident where ANYONE has died - an enviable record.You also say " have flown a lot this year on business and I can

[Guest tmetzinger]

>Considering the auto-brakes simply maintain a rate of>deceleration with the brakes, adding spoilers and reverse>thrust may very well slow you faster then that rate and the>autobrake system may simply not use braking pressure at all,>which may be the reason for some airlines not using it.Are you SURE that's all that autobrakes do?

[Guest D17S]

A projected 3500 foot stopping distance seems short, but this is just a subjective reaction (doesn't it seem short to you too?) . . . But it must be even more seriously considered that everyone who had a technical basis to know agreed the runway was an appropriate length for this landing. This will be interesting to watch unfold. Also, it will be interesting to see how much reversers contribute to an airplane's stopping power. Would ~15 seconds of reverse thrust shortened the rollout by 2000 feet? There

[Guest D17S]

The MMs for the 767,757 and the 747-1/200s go on and on about AB's target of deceleration only. . . . then it sends me out to the airplane with a pressure gauge to make sure I get 3000 psi at each and every brake bleeder fitting with the AB's armed and engaged at Max. I hate skydrol! (Do you see the contradiction?)Although operationally, are manual and autobrakes are considered equivalent? Again who has an MEL. Is there any penalty for ABs being inop?

[N562Z 4]

Saved flight files for the SWA Chicago Midway accident flight. Unzip to a temporary directory then copy and paste both files into the folder where you save your FS9 flights. In Windows XP, mine is My Documents / Flight Simulator Files. Select the flight when you first start FS9, looking for "PMDG_737-700 SWA Chicago Midway Accident Approach" Make sure to read the preflight carefully. An approach chart for ILS Runway 31C would be helpful. With MAX autobraking and IMMEDIATE reverse thrust, stopping in time was successful. http://www.graphics-free.com/animations/tr...ges/plane_6.gifAlex ChristoffN562ZBaltimore, MD

[AlaskanFlyboy 7]

That's what I've gotten from the information I've read on them, they make it sound like it's like Anti-Lock Brakes plus a deceleration limiter.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

[Guest D17S]

Just to follow up a bit. I had a chance to look up some MEL stuff. I don't have access to 737 docs, but I have full sets for some other stuff. The 747/1-200, 757, 767 and MD11 MELs all speak to the same philosophy. Autobrakes, autospoilers and reversers are all systems necessary to allow an airplane to remain normally operational. For instance, if the airplane is certified for Cat 3b, then 3b would be considered its optimum capability. There's nothing magic about Cat 3b . . . actually it's totally magic, but it is not a bonus. From a performance / technical standpoint, it

[Guest adl320]

O.k. We've been getting good technical information and perspectives here from RW pilots, NTSB preliminary reports, and others on this post. Lots of speculation regarding causes, factors, etc. Let's forget all this for a minute and put yourself in the seat of that 737 on approach to MDW that evening.Without getting specific, we all know there were certain things regarding actual ground conditions that could not have been known by the flight crew. True. But, I think we can all agree on what was known. Keeping it brief, and in no particular order:1. Snowing conditions2. Contaminated runway (snow)3. Poor visibility4. Tail wind5. Short runwayEven though as a RW pilot I don't fly heavy iron, faced with these "known" conditions I mentioned above, I would NOT have attempted this approach. Period. If I flew into MDW often, and knew (as many RW MDW visiting pilots do) that the apch/ldg requires more "vigilance" than an apch at say, LAX, then numbers 2, 4, and 5 above would have sealed it for me.Every pilot learns that flying is always about managing risks. Even if I could have "legally" made this approach, or even if my company policy states that these conditions allow for an approach, I firmly believe sometimes "legal" can still get you into trouble if risks are not, or cannot be managed to help produce the desired outcome.Certainly LOTS of other factors were probably considered by the pilots of this flight. Ultimately they decided the probability of stopping the plane on the runway outweighed the probability of not stopping. As other pilots can probably testify, there are many situations where you've made a go/no-go decision based on "all available information".Perhaps it WAS legal for SWA to make the approach/landing, but should they have? It's hard to be totally subjective since we know the outcome in this incident, but, My question in this case, What would you have done?

[Guest Darren Howie]

From what i understand there is no benefit for autobrakes given in performance charts.On the 320 the autobrakes give you a decel rate not a braking pressure.IE.At AB low the brakes are applied 4 seconds after a registered touchdown and will give you 1.7m/sec decel rate.This is measured by the IRU's.3.0m/sec at AB medium after a 2 sec delay.THis is simply a rate of decel so if the reversers are working the brakes work less hard.If the reversers are inop then more brake pressure is applied to meet the decel rate.I'd imaging the 73 system is similar in many repects.Wondering if the crew asked for a windcheck on final.Given an 11kt wind was blowing almost down the runway i'd be most surprised if they didnt.Darren

[Guest D17S]

That was a well considered post. You put me right in the seat. I'm the pilot . . ."I know, full well, that my company has made thousands of landings on this runway in all sorts of weather in the identical airplane I'm sitting in. 31C at MDW. It's as plain as vanilla and as well known as the worn-out chairs in the crew lounge there. A 10 knot tail wind and prevailing runway conditions are all factorable variables that I have the tools to analyze. Every number I'm seeing tells me (that even with poor braking) it is legal to land by a clear and unarguable margin. I cannot even call it close. (Now here's where the real problem starts. . . ) In my professional peer group -- management and fellow pilots -- legal means doable. Doable means do it. If I wave off, I will have no argument. Being part of the inner circle of the pilot

[Guest tmetzinger]

If the runway was unknown . . . or at least less>known, maybe I could sell that. But its 31C at MDW. No chance.>And the numbers say this is a safe maneuver . . . with a>margin. I gotta land. It's what I do for a living."That's it exactly. Now multiply it by two, because there are TWO highly trained and experienced pilots in the cockpit, and both of them looked at their data and said "let's do this". When I had two hundred hours of flight time, I'd have diverted. Now that I've got over a thousand hours, and some experience operating for hire, I'd absolutely have made the call to proceed. Flying to the prescribed safety margins are what professionals get paid for.So, in EVERYONE's judgement (the guys in the plane, the dispatcher on the ground, the controller in the tower), this was an approach that could be completed safely. The fact that it didn't happen means that either:The data they used (runway braking action, wind, etc) was wrong.The airplane malfunctioned (reversers didn't unlock?)The flight crew malfunctioned (didn't deploy the reversers?).Since the data we have so far indicates a well-flown approach, it's reasonable to assume (and boy, isn't that the analytical equivalent of standing on a roof and saying "hey y'all, watch this?" - you just KNOW something bad is gonna happen) that the pilots were fully involved, and didn't commit any major errors until after touchdown (if they committed any at all).I look forward to the final report on this - there's just not much more else to say until we get more flight data recorder info (did the spoilers deploy? were reversers commanded right after touchdown?).Best Wishes,

[Guest Darren Howie]

G'day TimBe nice if you could let us know what they find out on this one being closer to where its happening.I think the report will still leave some holes on this one with things like exactly what the tailwind was on the approach.How much contmination was on the rwy will never be known.I guess it will be simple facts in the end like decel rates and times for reverser and spoiler deployment etc.I'll say one thing they must have been light to be able to take 10kts tail on that rwy as looking at our 320 figures leaves us a long long way from being able to use that Rwy in those or similar conditions.Cheers and have a great New Year.Darren