737 Antiskid Inoperative

[@jimhodgson8225]

Thanks Chris I’m enjoying your channel, spreading the word at Alaska Airlines!

[@ChrisBrady737]

Thanks Jim, much appreciated 👍

[@samuelcv6565]

Chris I m Real cpt., but to be honest the B737 is not so easy we are always learnig somethnig new regarding malfunctions....but your knowleadges are incredible appreciate your work ..

[@ChrisBrady737]

Hi Samuel, thank you for your kind words. Glad to hear that you are finding the videos useful.

[@telescope64]

A good opportunity to remind us about this system.Thank you for taking the time to produce this!Best wishes from Paul.

[@ChrisBrady737]

Thanks Paul. I think we all need reminders with so little work around at the moment

[@jsr8884]

Very very lucid, informative and clear. Thank you very much.

[@ChrisBrady737]

Thank you for watching, glad it was useful.

[@DamianoDeTomassi]

I like the video , but Why do you say not to look at the QRH when there are clear Deferred items to be done differently ? In my view anything issue you have inflight , either carry from before or not, requires a place where you can read the whole procedure on how to land safely . Infact this is a demonstration of it, being the QRH perfect copy of MEL, AFM and Performance requirements on this event all in one. I would like you to speculate on the comment you made about “not applicable “ . We could all benefit , thanks so much .

[@jimhodgson8225]

Thanks!

[@ChrisBrady737]

Thanks Jim, appreciated 👍

[@captainwoodworking1273]

Helo Chris, Marco from Norwegian, another interesting example about anti skid inop is that you are unable to do a CAT3 but if you look the Mel it doesn’t say anything until you look the cat3 checklist or the Mel preamble where it is mention. So you maybe think it is ok to go but you can end up in north of Europe with a CAT3 app and unable to land!

[@ChrisBrady737]

Hello Marco, you raise a great point. Autoland without antiskid is not expressly forbidden by the MMEL as approved by the FAA/EASA. However in appendix E of the operators MEL/DDG you will find reference to this. The usual wording is "The Antiskid System is not required for an Autoland, however, due to a lack of performance data it is not possible to plan for an Autoland with the Antiskid System inoperative." So no antiskid does not affect the Autoland BUT you do not know how much runway you will need, so you cant legally do it!

[@captainwoodworking1273]

@@ChrisBrady737 thanks for your answer very true. Have a good day

[@atiyos]

thank you very much, the info about 5 anti skid functions and the 8 kts and 25 kts ,where can I reference that, thank you so much.

[@ChrisBrady737]

FCOMs and/or AMM.

[@miguelr1784]

Great video as usual! Why the speedbrake wouldn't deploy with the Anti-skid inop? I can imagine the 60 KTS condition could be affected if the speed data to the AACU is incorrect, but at the same time compression of any gear will trigger the deployment. could the latter also be affected by an Anti-skid inop?

[@ChrisBrady737]

Great question, I have not looked into that, I just took it at face value as Boeing state it very clearly.

[@jsr8884]

Boeing says ‘May not’!

[@atiyos]

may i please joint it, first when right stut compress ground spoiler deploy left stut compress flight spoiler deploy, but if I arm the speedbrake for landing, I beleve there is no wheelspeed 60 kts to crosscheck before deployment, in that case fault stut compress sensor could deploy that side's spoiler.

[@yanwan-kf8ph]

I guess maybe the reason of the spark or the flame is the rubber part of tire went off(as you can see there are a lot debris flying around , so the steel part might touching the runway(spark) , and if the pilot using the brake too hard with antiskid iop, the friction between pistons and break disc could be very strong, and there will also accumulate a lot heat which can burning the debris.😃

[@ChrisBrady737]

Very possible

[@UnordinaryPilot]

hi there, whats the most effective way to slow down on a dry runway and a wet runway? Anti skid on a wet runway is more effective?

[@ChrisBrady737]

In the anti-skid inop case, follow the QRH procedure and FCTM advice.

[@danielfreifeldtaisen]

Hi Chris. Referring to a recent accident in my company on a 737-800 with resulting 4 main wheel tires burst and following evacuation. No harm to anyone except the poor tires... Aircraft seems to have been dispatched with the Antiskid INOP according to MEL. Im wondering what went wrong? Wrong braking technic seems as the most probable cause. But is there anything else technical with the aircraft that could have happened. For example. If the crew accidentally set auto brakes. Would they work? Or would you get Autobrakes DISARM light on immediately. E.G. A/B doesn't even arm. I hear from sources that A/B wouldn't work if the Antiskid channels are disabled. My instant thought is crew failure to brake properly according to laid out procedure by Boeing. Your 5cents on this is appreciated. Night landing. Dry runway, Long runway and light winds.

[@ChrisBrady737]

Hi Daniel, I refuse to be drawn into speculation on what could have happened because I do not know all of the facts. We must wait for an official report, if one is to be published. You should not use autobrake with anti-skid inop.

[@danielfreifeldtaisen]

@@ChrisBrady737 Hi Chris, not to get you involved. Just to know if you have an idea if the A/B is able to be armed if the antiskid is INOP. Thanks for a great channel and all your amazing content

[@ChrisBrady737]

I don’t know for sure but I see no technical reason why the autobrake could not be armed. Again I repeat that you should not do this.

[@danielfreifeldtaisen]

@@ChrisBrady737 thanks Chris for always replying in a timely manner. Looking forward to new content! :)

[@obaidurrahman3647]

Can you please elaborate why Locked wheel protection is available only on the #2 and #4, while Hydroplane protection is available on the #1 and #3 only??

[@ChrisBrady737]

It is just the way Boeing designed it, it is all that is necessary to be effective.

[@obaidurrahman3647]

@@ChrisBrady737 Thank you sir, for taking the time to make these videos and answer our question too!!

[@naguganesh5166]

Can u please explain about gear retract inhibit of anti skid prevention..

[@ChrisBrady737]

To permit gear retract braking, the antiskid system stops alternate antiskid operation during landing gear retraction. This occurs during the 12.5 seconds after the landing gear lever moves to the UP position. This permits gear retract braking to stop the wheels during landing gear retraction without antiskid brake release.

[@rikgray9770]

Hi Chris, I couldn't see the incident listed anywhere, was it at Oujda Airport (OUD)? I understand not all incidents are listed. Great channel too, just started watching! Im not a pilot, but still find it interesting as you go into depth.

[@ChrisBrady737]

Yes it was the Oujda incident. Glad you are enjoying the channel.

[@umi3017]

As also a licensed motorsport driver, this topic is really interesting to me, braking on tyre's physical limit without ABS is quite normal practice for racing, but surprisingly how little pilots, as also mostly as daily car drivers, have little knowledge about it. Well, I can't know if you can "feel" the tyres in a 60+ tone vehicle as in a less than 1 tone car. but The basic knowledge about the tyre's behavior under skid and slide is almost absent for most airliner pilots I have met (BTW the Grip - skid/slide angle chart is astonishingly similar to Cl-AOA charts in my view). I also like to share a data source I often quote in my class about 737's braking action(although for -200), it's some analysis and tables from an accident report of JTA611, but the official report only available in Japanese (which I can read), not sure if it could help you then. some tables are in page 37~38 of www.mlit.go.jp/jtsb/aircraft/rep-acci/59-5-JA8444.pdf

[@ChrisBrady737]

Hi Umi, Thanks for your comments. I agree that knowledge of tyre behaviour is lacking in pilots but I have to assume that if it was vital it would be included in the ATPL or type rating. Also as most manoeuvring is in a straight line (on the runway) a lot of the physics knowledge should not be needed. You can feel the tyres to some extent in an airliner but often there is very little you can do about any misbehaviour, simply brake more or less! I checked the tables in the JTA611 reference but alas I could not understand them. Thanks again for your input Chris

[@ATR-42]

lol nice try. Sorry, you cannot associate your little DE track car to a 180,000 pound airplane on 3 points with just 6 tires. I will add the 737 is woefully underbraked, in addition to its artificially high approach speeds.