SWA 737 Departs With Faulty Cargo Sensor or Latch

9lflyguy · Sat Sep 07, 2013 1:46 am

http://abclocal.go.com/ktrk/story?section=news%2Flocal&id=9238123

What do you think happened?

kanban · Sat Sep 07, 2013 2:00 am

open latch indications due to either latch failure or sensor failure happen all the time. The point is the alert system worked. If that is a picture of the plane there don't seem to be any open doors.. so it was probably as proximity sensor.

9lflyguy · Sat Sep 07, 2013 2:09 am

Wouldn't be surprised if that what a stock photo

DocLightning · Sat Sep 07, 2013 2:12 am

The article says that an eyewitness saw that the cargo door appeared open.

WNCrew · Sat Sep 07, 2013 3:03 am

Quoting DocLightning (Reply 3):
ays that an eyewitness saw that the cargo door appeared open.

To be fair, he never says he saw the plane with the door open, he is quoted as saying, "I couldn't believe my eyes," he said. "I couldn't believe a plane as sophisticated as they are would take off with the cargo door open."... it's sort of vague... I'm not saying it wasn't open... but if that's the case then why wouldn't they just say so?

mtnwest1979 · Sat Sep 07, 2013 3:17 am

Quoting wncrew (Reply 4):
To be fair, he never says he saw the plane with the door open, he is quoted as saying, "I couldn't believe my eyes," he said. "I couldn't believe a plane as sophisticated as they are would take off with the cargo door open."... it's sort of vague... I'm not saying it wasn't open... but if that's the case then why wouldn't they just say so?

Well if it wasn't open, there would have been nothing for his eyes to believe. Having heard a couple stories recently, it unfortunately doesn't surprise me anymore.

But wouldn't the open cargo door light be illuminated in cockpit well before the plane takes off?

WNCrew · Sat Sep 07, 2013 3:36 am

Quoting MtnWest1979 (Reply 5):
Well if it wasn't open, there would have been nothing for his eyes to believe.

Is it not possible that the door latch failed? It's plausible that it "appeared" closed and then on takeoff it did, in-fact come open giving "his eyes" something to believe....

Quoting MtnWest1979 (Reply 5):
But wouldn't the open cargo door light be illuminated in cockpit well before the plane takes off?

One would think..

I find it hard to believe that an aircraft would EVER depart with an open cargo door, especially when I can't tell you how many times I've had to open and re-seat the exterior cabin-door handles form the inside simply because someone on the ground spotted that they weren't completely seated in their recess.

kenanc · Sat Sep 07, 2013 3:44 am

It probably just didn't latch correctly, therefore it was open. Just not fully open maybe?

KELPkid · Sat Sep 07, 2013 5:02 am

Suprised it wasn't ripped off in flight by aerodynamic forces

How much luggage/cargo hold contents got sucked out?

This could be a career ender for someone...

BMI727 · Sat Sep 07, 2013 5:08 am

Quoting KELPkid (Reply 8):
Suprised it wasn't ripped off in flight by aerodynamic forces

Don't 737 cargo doors open inward?

maxholstemh1521 · Sat Sep 07, 2013 5:19 am

Quoting BMI727 (Reply 9):

The 737 cargo doors do open inward

BMI727 · Sat Sep 07, 2013 5:25 am

Quoting maxholstemh1521 (Reply 10):
The 737 cargo doors do open inward

That's what I thought but I wasn't sure if there was some extra compartment that opened out. But, to answer KELPkid's question, the aerodynamic forces would try to suck the door shut.

DualQual · Sat Sep 07, 2013 5:45 am

The doors open inward and if one were open a light on the overhead illuminates indicating which door is not closed. If it was open on taxi out the master caution and "doors" should have illuminated when the recall was checked. If it opened on its own then the master caution would illuminate automatically.

user444555 · Sat Sep 07, 2013 5:53 am

The doors on a 737 open inward as was stated. If the door was just cracked open the pressurization probably would have kept it closed. The bins do have some pressure especially the forward where live animals go. If it was all the way open the plane probably would not pressurize. If the pilots took off they were ignoring more than just a door open indicator.

northwestair · Sat Sep 07, 2013 7:57 am

Must be a very and I mean very slow news day in HOU. I looked at swalife and I don't see anything about this flight.

Sinlock · Sat Sep 07, 2013 10:57 am

Quoting user444555 (Reply 13):
The bins do have some pressure especially the forward where live animals go. If it was all the way open the plane probably would not pressurize.

This is a common misconception. Cargo bins are under the same amount of pressure as the cabin, The only difference between bins that carry live animals is that it as a active supply of heated air. Otherwise on flights over about 2 hours the shipment would get the effects of cold soaking.

citationjet · Sat Sep 07, 2013 12:11 pm

http://avherald.com/h?article=4680550e&opt=0

bueb0g · Sat Sep 07, 2013 1:22 pm

The door was not open. Faulty sensor or latch, but the door remained closed.

Oroka · Sat Sep 07, 2013 2:00 pm

Slow news day is slow

BoeingMerica · Sat Sep 07, 2013 2:07 pm

Quoting 9lflyguy (Reply 2):
Wouldn't be surprised if that what a stock photo

Bingo. No chance a newscrew got to the scene fast enough to take a picture of the open door. Furthermore, it does not look like the eyewitness pic.

Assuming it is a stock photo, that is one crappy stock photo. Especially for a news organization in Southwest's backyard.

As for the actually issue, the mechanisms worked. The plane landed safely. The latch probably was not fully secured and the motions of takeoff and the initial climb out triggered the censor.

BoeingMerica

captainstefan · Sat Sep 07, 2013 3:35 pm

Quoting BMI727 (Reply 11):
But, to answer KELPkid's question, the aerodynamic forces would try to suck the door shut.

I think (and hope) he was being just slightly sarcastic

RWA380 · Sat Sep 07, 2013 3:42 pm

A small run of bad luck for WN, I'm sure their PR firm, will have public attentions elsewhere in no time.

longhauler · Sat Sep 07, 2013 4:00 pm

The QRH for FWD/AFT cargo door open annunciaton states:

"If pressurization is normal, then proceed normally"

So I have to assume, since they returned, pressurization was not normal, otherwise they could have continued to destination.

n797mx · Sat Sep 07, 2013 5:21 pm

Off topic/on topic. I've seen a WN plane land after a full flight with it's L1 cabin door handle 90° off flush position. Could anything have happened to that? (no open just turned 90° off stowed)

longhauler · Sat Sep 07, 2013 5:37 pm

Quoting n797mx (Reply 23):
Off topic/on topic. I've seen a WN plane land after a full flight with it's L1 cabin door handle 90° off flush position. Could anything have happened to that? (no open just turned 90° off stowed)

It happens all the time, and not just at WN. The handle is just not "stowed" thats all. It doesn't actually "engage" until you pull it further out, you can turn it all you like, with no effect. The door is locked, the handle ... not so much.

user444555 · Sat Sep 07, 2013 7:09 pm

Quoting longhauler (Reply 24):
It happens all the time, and not just at WN. The handle is just not "stowed" thats all. It doesn't actually "engage" until you pull it further out, you can turn it all you like, with no effect. The door is locked, the handle ... not so much.

And again on cargo doors that open inward the cabin/cargo pressure would keep it closed. Which is another good reason why emergency exits on most planes have to be pulled inward at first also. If the plane is pressurized there is no way a person can do it in flight. Have a good one.

bueb0g · Sat Sep 07, 2013 7:15 pm

Quoting longhauler (Reply 22):
The QRH for FWD/AFT cargo door open annunciaton states:

"If pressurization is normal, then proceed normally"

So I have to assume, since they returned, pressurization was not normal, otherwise they could have continued to destination.

It's still possible they decided it would be best to return, no matter what the QRH says. Perhaps they decided not to chance a pressurisation issue; bear in mind that the indication came up right after takeoff, and the highest they got was 3,500 feet - the valves would still be open, so a problem with the pressurisation would not be immediately apparent, right? In that situation, it might be perfectly good judgement to assume that there would be a pressurisation issue if they continued to climb and instead returned.

Maverick623 · Sat Sep 07, 2013 7:21 pm

Quoting longhauler (Reply 22):
The QRH for FWD/AFT cargo door open annunciaton states:

"If pressurization is normal, then proceed normally"

So I have to assume, since they returned, pressurization was not normal, otherwise they could have continued to destination.

Would you continue a flight that had a cargo door indication at 3500ft on climbout?

FWIW, I've personally seen two air returns because of a faulty cargo door indication. There was no problem except a malfunctioning sensor.

KELPkid · Sat Sep 07, 2013 7:50 pm

Quoting captainstefan (Reply 20):
I think (and hope) he was being just slightly sarcastic

I wasn't, and I didn't know that 737 hold doors open inward. Learn something new every day

BMI727 · Sat Sep 07, 2013 7:51 pm

Quoting user444555 (Reply 25):
And again on cargo doors that open inward the cabin/cargo pressure would keep it closed.

Only if it started to come open in flight. On the ground the pressure is equalized so nothing happens. All that would happen is that if the door were not noticed is that the plane would not be able to pressurize as it climbed. However, the pressure differential due to the Bernoulli's principle would attempt to shut the door. Aircraft pressurization has nothing to do with it because the aircraft isn't pressurized on the ground - especially not in Houston.

Having plug doors will keep the door when the plane is pressurized, but the aircraft isn't really pressurized until it reaches 8,000 feet on a 737.

railker · Sat Sep 07, 2013 8:05 pm

Reminds me of that 'ATC Joke' ...

Tower: "Airline XXX, it looks like one of your baggage doors is open."
Captain (after quickly scanning the FE panel): "Ah, thanks tower, but you must be looking at our APU door."
Tower: "Okay, Airline XXX, cleared for takeoff."
Captain: "Cleared for takeoff, Airline XXX."
Tower, during the takeoff roll: "Airline XXX, ahh ... it appears that your APU is leaking luggage..."

longhauler · Sat Sep 07, 2013 10:00 pm

Quoting Maverick623 (Reply 27):
Would you continue a flight that had a cargo door indication at 3500ft on climbout?

Yes. And have.

If the aircraft if pressurizing normally, then the door is closed. Period. That is what the QRH is indicating.

If you had any other indications that things were not normal, sound, pressure, temperature, etc, then one would assume the door is not closed, and a return where possible would probably be a good idea.

The only reason a return would be a good idea when things appeared normal, would be one's destination. If you are flying to an out station that didn't have maintenance, or maintenace would be difficult to obtain, then you have other considerations. Namely, if a door proximity sensor was malfunctioning (for example, in this case), then you have to either fix it, or address it under the MEL for your next departure. Either of those require maintenance, so a return or diversion to a maintenance base would be a good idea.

HOU to DAL. I am going to guess both of those are maintenance bases for WN, so I am guessing therefore the flight crew had other indications things were not normal.

longhauler · Sat Sep 07, 2013 10:22 pm

Quoting BMI727 (Reply 29):
Having plug doors will keep the door when the plane is pressurized, but the aircraft isn't really pressurized until it reaches 8,000 feet on a 737.

Pressurization starts during the takeoff roll.

Going through 8000 feet, the cabin would already be pressurized to about 2 - 3 psi, toward a target of 7.55 or 7.9, depending on the pressure controller.

EXMEMWIDGET · Sun Sep 08, 2013 12:05 am

Quoting kanban (Reply 1):
open latch indications due to either latch failure or sensor failure happen all the time. The point is the alert system worked. If that is a picture of the plane there don't seem to be any open doors.. so it was probably as proximity sensor.

Uh...it doesn't happen all the time, in fact it is quite rare. An improperly closed/secured door would be noticed by the cockpit crew via a door open warning light while on the ground. A door sensor could give false warnings perhaps, but that would be checked out on the ground by cycling the door again. If it happens in the air, that is another story.