Southwest pilot violated braking policy

Chicago Sun Times ^ | 12-15-06 | MARK J. KONKOL

[Aeronaut]

[TalonDJ]

Is it SOP to use them in icy/snowy conditions? I am not aware of if autobrakes have any kind of an anti-lock function. My work is in an unrelated area of avionics so I am not sure on the subject.

[rawhide]

it is "pilot error," against explicit Southwest policy, and therefore Southwest is not liable for the deaths or injuries.

Nope. Under the legal doctrine of respondeat superior, an employer is on the hook for what its employees do, even in violation of the company's policies, unless it is a gross violation from the employee's scope of employment. That's been the law for centuries. In this case (assuming the facts as they are depicted in the article), the pilot's use of the autobrake system is reasonably foreseeable, since it would appear to be an attractive feature that the pilot could use in his typical duties, that is, landing planes. A mere policy against its use, without more, does not protect Southwest from liability for the acts of its employees.

I agree! Southwest can be held liable.

[Pukin Dog]

The airline I fly for teaches that autobrakes in maximum are more efficient than human braking and in these circumstances if it were me in this guys shoes I would be cited for not using autobrakes!

I'm thinking that he missed a setting, though. If he cranked it up under those conditions, he could have a problem on his hands. I've seen guys set brakes to MAX thinking they were in RTO. I bet he though he could get a little help from a 1 or 2 just in case at that runway.

[Blessed]

The key fact is Southwest was using the policy to speed turn around time at the gate.This helped them brag on being on time.Had nothing to do with safety.

[safisoft]

Multiple studies over the past 15 years have had varying conclusions, but most show that with non-carbon brakes, autobrakes usage is best. Boeing has recommened use of autobrakes for as long as I can remember. I have 5,000 hours in the B737, but not the 700. I can't imagine Boeing has changed that principle.

Most aircraft with autobrakes also recommend the highest settings for contaminated runways. The fact that Southwest does use autobrakes is likely in opposition to Boeing policy. That is not ground breaking, airlines do that kind of stuff all the time... but they run certain risks. If this is what this pilot did, he will have a leg to stand on if the B737-700 has a manufacturer's recommendation of autobrakes with contaminated runways. He will have two strikes against him for violating company policy... and one strike for him for doing what the manufacturer suggests.

On the other hand, in my mind this is starting to look like an well-known weakness in the 737 that has caused accidents before. October 1986, Piedmont Boeing 737 in Charlotte, NC - went off the over run on a 8,000' runway. Delay in reverse deployment caused by insufficient wheel spin-up at touch down (wet runway).

[Tallguy]

But I guess the chute didnt pop.

Hehe! These guys are worried about the negative effects on jet turnaround time if the brakes get overheated? Imagine if they did have to re-pack a drag chute after every landing?

[safisoft]

I am not aware of if autobrakes have any kind of an anti-lock function. My work is in an unrelated area of avionics so I am not sure on the subject.

All normal braking on transport aircraft have antiskid. Without antiskid, tires would blow on nearly every application of brakes above 80 knots. Autobrakes give you a set decelleration, with antiskid, in rapid application at touch down. In other words, autobrakes should NEVER hurt you in so far as braking... they will only help.

Passenger comfort, brake wear, and quick turn around times are the reasons for NOT using autobrakes.

[Boundless]

> But I guess the chute didnt pop.

Naw, but we have preliminary reports that the pilot
neglected to deploy the tailhook and failed to bolter
when they missed the 3rd wire.

I hear that the major difference between Midway and a
carrier deck is that the average deck is longer :-)

[MindBender26]

Do you need wheel spin up to get the thrust reversers out? Assumed it would be the squat switch on the gear. What about spoilers?

Covered another SWA accident at Amarillo, TX. 13,500 runway, (former B-52 base.)

Pilot landed in rain/fog at minimums. Tried heavy braking to ensure short trip to terminal, fast turnaround.

737-200 departed runway, sheared off nose gear, sunk into mud. No fire no one hurt. Problem was, where is A/C!?!?!

Fog became so heavy that rescue crews couldn't see A/C from runway or taxiway, and crew didn't know where they were on airport!

Finally had to use radio to route message through control tower, to fire truck with siren on to vector emergency equipment to A/C by sound.

It took more than 25 minutes to find the A/C on the field!

[BatGuano]

My first thought was, given the conditions, why were they landing at Midway? The SW culture of on time, quick turn-arounds, must fly the schedule, seems to forget SAFETY. The cockpit voice recorder and the Flight data recorder will enable the investigators to put the accident together. It will take time. As far as training and checking information, don't count on it. The unions have forced the carriers to have only "vanilla" reports. Satisfactory or Unsatisfactory but no details that can be resurrected at a later date!

[MindBender26]

Years ago, some Canadian outfit flew cargo 727s onto frozen lakes for oil exploration in Arctic.

They never used any braking. Just plowed off about 5 miles of ice, use the thrust reversers, then just let her roll into the wind till she stopped!

[Cobra64]

I fly about 1,500 flights (legs) a year, and I've always wondered why pilots are light on using reverse thrusters. Especially in rain, ice, and snow conditions.

Any pilot on FR who can explain this to those of us who are not commercial pilots?

[saganite]

Autobrakes accomplish the same thing as a pilot manually braking and anti skid is available and used either way. As an analogy think of it the same as using the autopilot. The pilot can disconnect the autopilot and fly the plane manually but the systems that control the aircraft are still utilized by the pilot pretty much the same as the autopilot would utilize them.

In conditions like those at Midway on the day of the accident I believe autobrakes would have been far more efficient. The pilot has other concerns to deal with in those conditions and autobrakes take some of the workload off.

Reverse thrust has some limitations. It can be counter productive to use them in high crosswind conditions, especially in less than optimum runway conditions, as they can cause the aircraft to drift off centerline. Our manual says that if thrust reversers cause the aircraft to drift you should reduce the amount of reverse thrust. If the reversers deploy asymmetrically it can also cause drift. This actually happened to me. However, neither of those things seem to have been a factor here. The Captain said he had trouble deploying the reversers and the First Officer finally got them out.

The runway condition is key here. We (my company) don't land unless the runway conditions are at least fair. That's a description of the braking action on the runway and it's determined by ground personnel taking braking action readings on the runway. There are a lot of factors in play here. It will be interesting to see the final report on this accident.

[JHL]

Eenie meenie miney mo, hit the brakes we need to slow... down.

[aviator]

The 737 autobrakes have settings of 1, 2, 3, Max and RTO (rejected takeoff)

The autobrakes have an anti-skid function very similiar to the ABS systems on cars.

The autobrakes are designed to give a constant rate of deacceleration based on the selection above. The 1 setting is for a normal dry runway, 2 might be used for a shorter runway, 3 would be used for a wet runway and MAX for the worst condition of a slippery runway. If the thrust reversers are used, the airplane gyros will reduce the braking effort because of the thrust reverser contribution toward deceleration.

The more advanced airplanes have carbon-fiber brake pads that are most efficient when hot. The autobrake computer does a better job of braking than human pilots because it senses the deacceleration rates, wheel slip due to icy patches and applies the right braking for the selected setting.

I've landed at MDW and would have been tempted to land somewhere else that night. But that is Monday Morning Quarterbacking.......and we know how that goes.........

[BatGuano]

There are so many points to bring up in this case. Runway conditions, wheel spin-up, spoiler extension, hydroplaning, the list is a longer one that space allows. One problem with reversing late in the landing roll is that eventually the reversers cause the snow to be blown AHEAD of the aircraft, causing visibility to go to zero. The autobrake selector could have been in MAX but perhaps that setting was deactivated...the stopping action with that setting is scary to say the least. My best guess includes the usual problems, too fast on final, long landing (touchdown point) distraction with reversers not operating normally, relying on autobrakes, 250'or so per second, ON A 6500' RUNWAY!! It is a wonder how the plane did not get to the Loop.

[Windsong]

Autobrakes?

tits on a bull.

[safisoft]

Do you need wheel spin up to get the thrust reversers out? Assumed it would be the squat switch on the gear. What about spoilers?

I am not sure about the -700. I think it uses other in-flight inputs (radar altimeter etc.), but to answer your question about the B737-200 in the 1986 accident, yes. Spoilers as well.

[BatGuano]

Probably not radar altimeter input but most likely throttles in idle, weight on wheels. Not sure, I flew the original B-737s. Bad night for all. The cockpit discussion will be a key element to solving the mystery.