Good News for SWA Pilots!!!??? Breaking News?

[FN FAL]

It might just be the dumb media, but they just said that the NTSB is focusing on the thrust reversers on the MDW incident...

That's all they said.

 

[indianboy7]

Ya, I think the media has absolutely no idea that airplanes have brakes too.....I heard "they hit the thrust reversers pretty hard" so many times the other night, I ended up puking.........who knows though....that coulda been the problem....imp:

 

[FN FAL]

Ya, I think the media has absolutely no idea that airplanes have brakes too.....I heard "they hit the thrust reversers pretty hard" so many times the other night, I ended up puking.........who knows though....that coulda been the problem....imp:

Yea, I hear ya. It would nice if people could wait until the tenth news article before speculating on events the media presents to the public, It would save a lot of aggravation. I'm just as guilty as the next guy, but sometimes it's hard not to jump in.

 

[TurboS7]

Landing data two engines is based on no reverse, takeoff data the same. The only time reverse comes into play is landing with one engine, and stopping with a failure prior to V1. The bottom line is that MDW is way too short for Part 121 operations in any kind of severe or abnormal weather. The airport managers and airline officals are full of BS. The operate there because it is cheap, cheap, cheap and Chicago Airport Authority like the money. They push the airplanes and the pilots then fault the pilots because we are not perfect. This industry stinks, and the pilots are the ones that take the windfall......and we get paid too much....SURE>>.

 

[FN FAL]

Landing data two engines is based on no reverse, takeoff data the same. The only time reverse comes into play is landing with one engine, and stopping with a failure prior to V1. The bottom line is that MDW is way too short for Part 121 operations in any kind of severe or abnormal weather. The airport managers and airline officals are full of BS. The operate there because it is cheap, cheap, cheap and Chicago Airport Authority like the money. They push the airplanes and the pilots then fault the pilots because we are not perfect. This industry stinks, and the pilots are the ones that take the windfall......and we get paid too much....SURE>>.

I hear you hoss, not getting "pushed" is one of the reasons I like working where I work...It's definitely not for the SEL Turbine PIC time logging.

That Detroit Metro is probably in the same boat with it's runway and "private" extension. I never could figure out what that was about...I kind of surmised that the private extension of the runway was so that the LLC flying in there could work the numbers on their landing data...but I'm probably wrong on that assumption.

 

[EagleRJ]

Landing data two engines is based on no reverse, takeoff data the same. The only time reverse comes into play is landing with one engine, and stopping with a failure prior to V1.

I think you have it backwards. Including reverse thrust is allowable under Part 25 certification, except that single-engine operations must be accounted for. Aircraft manufacturers can and do use reverse along with normal braking to determine landing distance.

14CFR 25.125(b)3
(3) Means other than wheel brakes may be used if that means—
(i) Is safe and reliable;
(ii) Is used so that consistent results can be expected in service; and
(iii) Is such that exceptional skill is not required to control the airplane.

14CFR 25.125(f)
(f) If any device is used that depends on the operation of any engine, and if the landing distance would be noticeably increased when a landing is made with that engine inoperative, the landing distance must be determined with that engine inoperative unless the use of compensating means will result in a landing distance not more than that with each engine operating.

Accelerate/stop distances are determined without reverse thrust on a dry runway, and with reverse thrust on a wet runway.

14CFR 25.109(f)
The effects of available reverse thrust—
(1) Shall not be included as an additional means of deceleration when determining the accelerate-stop distance on a dry runway; and
(2) May be included as an additional means of deceleration using recommended reverse thrust procedures when determining the accelerate-stop distance on a wet runway, provided the requirements of paragraph (e) of this section are met.

(paragraph e is directional stability, exceptional skill, etc.)


I do agree that while the runway at Midway meets the letter of the law, it's dangerous to fly 121 carriers out of there without a sufficient overrun. We have too many airports operating under waivers these days, and the FAA needs to be more stingy in allowing them. MDW should only be allowed to have a waiver for reduced overrun if an EMAS system is installed on each runway approved for 121 operations.

Once again, hindsight is 20/20.

 

[SkyBoy1981]

I don't believe I have ever flown a jet where thrust reversers are included in the landing distances. Since Turbo flies the 738 I'll take it he is familiar with the performance data for it. I don't imagine that the -700 would be very different. I have read some articles mentioning possible faults in the "braking system". I have never flown anything with autobrakes..but how does that system work? Is it possible that autobrakes would not begin application if the reversers have not yet been deployed? Or is this mentioning of the "braking system" merely another case of our clueless media trying to sound as though they know what they are talking about.

 

[Rally]

Reversers or not should'nt the -700 be able to stop in that length of runway with that amount of snow UNLESS they were too fast or too long?

 

[Guitar rocker]

Reversers or not should'nt the -700 be able to stop in that length of runway with that amount of snow UNLESS they were too fast or too long?

Quit speculating Rally! Again, you are making an assumption that perhaps they landed too far down or too fast. All indications point at the fact that they were right where they needed to be. It's unprofessional to make such assumptions and second guess anyone here. One last thing Rally, I hope that you do understand that this could have happened to anyone of us!

 

[EagleRJ]

The Boeing and M/D autobrake systems I've seen have four positions- Min, Med, Max, and RTO. They apply the brakes at the specified level after weight-on-wheels, and a brief delay to allow wheel spin-up (or minimum wheel speed in some aircraft). RTO applies maximum braking if the thrust levers are retarded to idle during the takeoff roll.
The autobrakes are disengaged by tapping the brake pedals, and you can command a higher braking effort by just pressing the brake pedals.

I know there have been some Airbus incidents (and maybe Boeing too) where the squat switches don't function properly, especially after a smooth landing, and the aircraft thinks it's still airborne and won't allow reverse thrust or brake application.
On the ERJ-145, it's possible to apply the brakes in the air, in which case the anti-skid will do you no good when you touch down. On the CRJ-700, the brakes are inhibited until 35 kts wheel speed (or weight-on-wheels + 5 seconds if the wheel speed sensors fail). You can land with the brake pedals on the floor, and you'll hammer the calipers with 3000 psi as soon as the wheels are turning. The SF-340 is similar.
Thrust reverser deployment varies from aircraft to aircraft, too. Some require the nose squat switch to be compressed, while some are just the mains, and some will even allow you to deploy the reversers airborne!

I don't know how the 737-7 handles braking or reverse thrust, but I assume there are conditions that have to be met before they are available. It will be interesting to hear if everything worked as it should have.

 

[satpak77]

the NTSB press conference said they had a slight bounce when they landed, would this delay the TR deployment?

 

[TurboS7]

Boeing certification is not based on use of reverse thrust, Part 25 allows it but Boeing does not use it in it's performance. With that said and done it is obvious that the runway conditons were not such that any aircraft should have been landing. What type of braking action was present, more than likely it was checked by an F-150 slamming on its brakes at 80 MPH. The last time I checked there was a heck of lot of diffrence between a 737-700 and a F-150. Was the runway treated with ice repellent, no, more than likely the runway was plowed just prior to the landing, new plowed runways are very icy and nasty. There will be more, it is just a matter of time. Everytime you land or a newly plowed runway you are a test pilot. MDW doesn't have the length required to be safe under those conditons. Dry snow and wet snow are two diffrent animals, with the proximity of the lake it was more than likely wet snow. They will blame the pilots and say they landed long, the reality is MDW should have been shut down by the airport operations. AA did something right, they cancelled all their operations, maybe they have learned something over the years.

 

[EagleRJ]

Anyone know what the reported Braking Action was at the time of the accident, and how old it was?

One thing we could do to improve the information available to pilots is require BA reports by PIREP or certified friction-testing device only, and update it at least every 10 minutes. Arbitrary BA reports from vehicles are fine for the ramp and taxiways, but pilots need to have a real-world PIREP or MU reading for the runway.
I've seen BA change radically from one arrival to the next, when the preceding aircraft blows away a layer of loose powder, or when the rate or type of precipitation changes. Hourly reports by an airport vehicle are not sufficient.

 

[KeroseneSnorter]

I too have never flown a jet that used thrust reversers as part of the landing data. Everything is based on brakes and lift killing devices (Spoilers etc.)

Dunno about the ERJ but nothing I ever flew in the corporate or airline world is based on thrust reversers for landing.

 

[GVFlyer]

I think you have it backwards. Including reverse thrust is allowable under Part 25 certification, except that single-engine operations must be accounted for. Aircraft manufacturers can and do use reverse along with normal braking to determine landing distance.





Accelerate/stop distances are determined without reverse thrust on a dry runway, and with reverse thrust on a wet runway.

(paragraph e is directional stability, exceptional skill, etc.)


I do agree that while the runway at Midway meets the letter of the law, it's dangerous to fly 121 carriers out of there without a sufficient overrun. We have too many airports operating under waivers these days, and the FAA needs to be more stingy in allowing them. MDW should only be allowed to have a waiver for reduced overrun if an EMAS system is installed on each runway approved for 121 operations.

Once again, hindsight is 20/20.

Nice post concerning required aircraft operating characteristics, but unless you're an experimental test pilot participating in an aircraft certification program, you're reading the wrong regulation. Note the the title: Part 25: AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES. You need to be reading Part 121: Operating Requirements: Domestic, Flag and Supplemental Operations.

I included the hyperlink so you can read Section 25.1 Applicability. Part 25 has nothing to do with operating the aircraft after it has earned it's Airworthiness Certificate unless you are working on an Supplemental Type Certificate.

GV

 

[A Squared]

Nice post concerning required aircraft operating characteristics, but unless you're an experimental test pilot participating in an aircraft certification program, you're reading the wrong regulation. Note the the title: Part 25: AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES. You need to be reading Part 121: Operating Requirements: Domestic, Flag and Supplemental Operations.

I included the hyperlink so you can read Section 25.1 Applicability. Part 25 has nothing to do with operating the aircraft after it has earned it's Airworthiness Certificate unless you are working on an Supplemental Type Certificate.

GV

Hmmm, I don't see a subpart to 121 titled "Operating Requirements: Domestic, Flag and Supplemental Operations."

You got a specific reference for that?

 

[satpak77]

Hmmm, I don't see a subpart to 121 titled "Operating Requirements: Domestic, Flag and Supplemental Operations."

You got a specific reference for that?

That is the name of the Part 121 section

 

[A Squared]

That is the name of the Part 121 section

Ahhh, OK I gocha, it's the title of all of Part 121, I was looking for a subpart with that title. OK, question still stands, where in Part 121 does it address reverse in landing perfomance?

 

[Oakum_Boy]

I too have never flown a jet that used thrust reversers as part of the landing data. Everything is based on brakes and lift killing devices (Spoilers etc.)

Dunno about the ERJ but nothing I ever flew in the corporate or airline world is based on thrust reversers for landing.

Well, maybe. What y'all are talking about is DRY, FACTORED landing performance. The numbers that are in the airport analysis book, or whatever comes over your ACARS is for DRY runways. Those numbers do not "factor" the use of thrust reversers.

Everything changes, however, when you are approaching your destination, and low-and-behold, there is 1/4" of wet snow covering the runway. Now what? Well, you must consult the ACTUAL landing distance numbers for a CONTAMINATED runway. In the CRJ, you will find them in QRH vol. 1. Those numbers have accounted for use of the thrust reversers.

At my airline, we can dispatch to an airport with contaminated runways, based on FACTORED performance numbers for a DRY runway. Sounds dumb, right? Well, the fact is, that runway condition is variable, and may change during your time enroute such as: intensifying or diminishing snowfall, runway clearing, etc.

Personally, I'll take into account all available information, and push for cancellation, or diversion of the flight if it appears landing at the planned destination would not be prudent.

Comments?

 

[Flystr8]

Landing data two engines is based on no reverse, takeoff data the same. The only time reverse comes into play is landing with one engine, and stopping with a failure prior to V1. The bottom line is that MDW is way too short for Part 121 operations in any kind of severe or abnormal weather. The airport managers and airline officals are full of BS. The operate there because it is cheap, cheap, cheap and Chicago Airport Authority like the money. They push the airplanes and the pilots then fault the pilots because we are not perfect. This industry stinks, and the pilots are the ones that take the windfall......and we get paid too much....SURE>>.

This is an awesome statement and I could not agree with you more. Its so true. Pilots are pushed and then blamed when the outcome isn't perfect. Its total BS.......and yes, the pay sucks too. Its no doubt we dont do it for the money. If flying wasn't fun the aviation world would be screwed.