737 Flaps and Slats 

As somebody who is going through the 737 type rating, your videos (and the book) are invaluable. After them, FCOM feels like an a dummy's guide of sorts :) Many thanks for sharing your knowledge and putting so much effort into this!

Such an incredible attention to detail. If I ever find "canoe" on ebay, I'll have to notify you first. Kind of curious myself to float on that thing. Thank you for your presentations, as always.

It’s like reading history along with with current affairs! Insightful. Must have been lot of hard work too. Much appreciate Capt.

As always, thank you very much Cpt. Brady. These videos are of invaluable importance for both 737 pilots and 737 enthusiasts as such. I cannot believe I sat through an almost 2 hours long video just about flaps and slats but the delivery of the presentation is so detailed and interesting you just cannot turn away, and you always manage to do that. I am very lucky to be undergoing the type rating on the NG and MAX with an archive of information like your channel available whenever I feel like going way deeper than the FCOM does and looking “behind the scenes” a bit, with your photos and explanations of areas on the aircraft we may never have access to in a whole career. I wish Boeing or carriers would provide the AMM paired with the FCOM to pilots so that we could have possibly a boost in system knowledge which one day could (but hopefully won’t) turn out of vital importance during a non normal situation or just to satiate the curiosity of knowing how these machines operate every time we flick switches, move levers and whatnot. I respect you and I’m inspired to be as knowledgeable like you one day. Thank you.

Thank you for all those videos. They have been an absolute joy to watch and your amount of knowledge is amazing. I used to fly the classic about 20 years ago and now I’m back on 73, this time on the Max. They help me a lot during my transition, thank you. Please keep up the excellent work.

Thanks for all the detailed information and pictures you share! As our company regularly operation on high land, here is some thing I know about the flap altitude limit: It's a real risk for us, because some airports are 14000'+ and terrain is well over 20000', while the flight procedure doesn't require flaps over 20000', sometime if you want get rid of the speed to better settle in the valley, you'd better check that, for take off, our SOP required to set FL197(6000m) on MCP if initial altitude given by ATC is higher than that. And the very recent SOP reversion added the call for "speed and altitude check" before set the first flap on approach. As Boeing's replay to us, the limitation is 20000' on STD, so if the QNH is different than 1013, since some airport have TL higher than FL200 here, there must be some caution on that too. If the Flaps system to be failed extended, on most of these airports, you have to go above FL200 to clear the terrain and get space and time to sort that out, on these condition, Boeing have suggested reduce 10kt of limitation speed for every 1000' above FL200 with an email exchange, no bulletin have been filed though (A319 have this same number written on a bullentin as I know). Also our company had one instance that on a guesty days, flap relief retracted flaps to 25 from 30, then speed drop back, so it starting to extended back to 30, at the same time the crew noticed the overspeed condition and starting to move flaps lever back to 25, this jammed the flaps, we guess it's because FSEU think that is an uncommand movement, and it's perfectly replicable on our simulator.

Excellent job as always! There were also flt ctrls design and operational changes in 2002, to prevent LE and TE flaps lockouts, or fail to move to commanded position. Boeing found a lot of causes, including debris in LE slat pressure relief valve leading to stay in open position and many more. O-rings were and few more components were redesigned and checklist were revised (crews oftenly became confused and failed to choose proper checklist during flight controls failure event). That's also good topic for video in the future!

This video is very helpful for maintenance also!

Super like for one of the greatest video I´ve seen on RU-vid. Thanks for the photos. Just one note, in my Fcom says that UCM works with 2 o more LES. Cheers

Hi Chris. Thank you for a fantastic presentation. Much appreciate the helpful study tool and I very much enjoy the worked in technical side of the presentation with regards to systems,rods and pump locations. Thank you once again

Thanks for sharing Chris! I appreciate your vast amount of knowledge, and for you to kindly share your knowledge with all of us. Merry Christmas!

Thank you for the great videos. This series is the best systems ground school I've had!

Appreciate the efforts and hard work gone in to put the pics, videos and content together.. Very informative. Loved it Capt. Brady!

Absolutely amazing! Thank you so much for your work!

Once again- amazing presentation. Thank you Captain!

Thanks for sharing all this great info! That’s the way learning should be!

Thanks for sharing your knowledge Chris.

Great video Chris! Your knowledge is amazing..

Super cool, Chris! Thanks a lot!

Great video, much appreciated.

Thanks for the sharing Chris, looking forward for more useful content! Subscribed!

Very interesting Chris. I’m glad to can understand always more about the plane with you. An suggestion for a possible future video is to show better the LE control valve and the depressurization valves too. Have a good day 😀

WOW! Just found this channel and these Videos are AMAZING THANK YOU SO MUCH BRADY!! :)

Just for the slat proximity switch slide, the circled items are slat upstops, and are shimmed as required to achieve correct clearance between slat trailing edge to wing leading edge. The actual slat position sensors are beside the respective slat aux tracks. The aux tracks have sensor targets for this exact purpose. Otherwise, good presentation.

27:41 Hello, correction: the circuled parts are the slat upstops at the LE. The proximity sensors are located at the vicinity of the aux tracks.

Brilliant!

Damn, that's some great explanation. Thank you very much! Subscribed, liked, whatever is there.

Thanks Chris as always very interesting and educational! Merry chistmas and happy new year 🎊

Thanks for the thorough presentation. Could you do one on the 737 start considerations, including the system components and explanation on the procedures, etc. I appreciate your knowledge

Thank you!

Helpfull for Typewriting

Amazing

Hi Capt!! The FCOM for the MAX does state that Flaps are secondary flight controls.. As per you it's now upgraded to Primary! But the Max fcom is the latest. Greetings from India. Flying the Max!

Question: on the NG and MAX, why is the manuevering speed for flaps 5 and 10 the same? Great lectures on the systems! I’m thoroughly enjoying your presentations! I’m a captain for AA.

@ 33:43 That's not right. The reason why they moved from the triple-slotted flaps to double-slotted flaps was not because of fewer moving parts. It was because the triple-slotted flaps where a hold over of the design from 737 Originals (100/200) series which used Pratt & Whitney JT8D engines. The engines are smaller in diameter then the CFM's used in the later series. The JT8D's where tucked under the wings much further aft. The engines and the thrust reversers also extended aft past the flaps as well. This created a need for the triple-slotted flaps to be split with the engine pylon and allowed for a smoother operation of the clam shell style thrust reversers that the JT8D employed. When the 737 Classic (300/400/500) series came out it had limited design changes from the Originals (100/200) series. The triple-slotted flaps was one of the many hold overs in design. Mechanicaly the Originals and the Classic share a majority of the same parts with a number of exemptions. Using the same components with the same part numbers and parts being interchangeable between them. The Classic series used engines CFM56-3 which didn't go as far aft as the JT8D did . The Classic did have some pylon changes but for the most part structural stayed the same. The CFM56-3 engine used a different style of thrust reverser as well. They used a Cascade vanes thrust reverser style which operated very well, much farther forward of the flaps. When it to the NG's move to the double-slotted flaps design. Was because the NG's was a completely new design. A redesign from the bottom up and really whole different aircraft. Not using same part numbers with parts not being interchangeable between them. The only thing they really have in common is the name 737 It's from the bottom up a whole different aircraft. Some of the components may function the same. But they are not the identical part that the Originals and the Classic shared. Note: Please don't take this as criticism. I don't mean that way. I just knew something I wanted to share. I think your videos are very informative and you do a great job explaining the subject. And, It's easy to follow along.

Under the Autoslat section you mentioned a clean wing. Looking at the image, the wing is filthy and could do with a wash. Okay that's a joke 😅

Very surprised the FCU and flap levers still are entirely mechanical on the Max, that must carry quite some weight penalty compared to if they updated it to something electronic. I expect the conical vs tapered trailing edges are primarily to avoid those structures generating as much flow separation in different angles of attack.

Hey Chris can you please make a video of the flight controls? As a 737 Captain I have everything memorized and over several books it’s still a bit blurry. Thank you so much for sharing your knowledge with us less smart pilots.

Great work on LEDs and Flaps,I learned so much from this presentation, it's obvious you put hours and hours of time into it's production,many thanks. One query that crossed my mind ref uncommanded flap/slat movement was,there must be a time delay between lever demand and flight control movement to the demand position.Obviously initially there is disagreement, but this is normal,is it a fixed time,or something more nuanced? Keep the videos coming!Best wishes from Paul.C.

Chris, thanks for your explanation about these they are one of the most important devices for proper maneuvering in the aircraft. I'm a Boeing 737 technician in Brazil, and couple of days ago I had an insight that caused me to lose or am: why Boeing flaps position are 0, 1, 2, 5, 10, 15, 25, 30 and 40? What these numbers mean? I'll be very thankful if you could clear my mind. Thanks.

Hello Chris!! Thanks for this great video! I have a question: we fly a SFP, we configure F40 and LE flap transit happens. What do you think is the best course of action. QRH says to land F15.

At UA we are further limited by company policy to 240kts for flaps 1 and 230kts for flaps 5. I am guessing this is for even further service longevity.

Hey Chris! Got a question - Will the takeoff config warning horn sound if I enter flaps 5 as my take-off flaps in the CDU but set flap 10 for takeoff and advance thrust during takeoff? Thank you

27:38 red circles in photo are the Slat up stops, not prox sensors.

"After prolonged operation in icing conditions with the flaps extended... :​"Do not retract the flaps to less than flaps 15 until the flap areas ​have​ been checked to be​ free of contaminants" Why specifically F15? Thank you very much for your great work

Good Day Capt Brady, the sequence to extend flash 15 is geardown first then extend flash 15.Any technical or stability reason behind these sequence?

Why does 737 have those bars next to lever position at flaps 1 and 15? Thank you

1:30:50 In almost every instance, the flap limits are either equal to or lower than the next largest 737 variant… except for flaps 25. Does anyone know why the -600 has a higher limit than the -700, and ONLY for this particular flap setting? Note: I don’t fly the 737. I just have too much time on my hands. Please forgive me if I’m asking a question with an obvious answer.

Sorry to correct you,but the part about the planes projected about the leading edge has the wrong info... !,,🎉

Is there somewhere I can download your PowerPoint(s) so I can use them for note-taking?