What is FLEX TEMPERATURE? Explained by "Captain" Joe

[@larryluffel777]

I am a FMS developer and have worked on Airbus and Boeing aircraft for 25 years, this was the best explanation I have heard for Flex temperature. Will pass this along to newbies in the office. thanks

[@roberto123nogueira]

You really say calm and good teaching always for us Mr. captain, thank you again

[@flywithcaptainjoe]

Thanks for you kind comment :) Greetings Joe

[@ahmadtheaviationlover1937]

@@flywithcaptainjoe correct me if I’m wrong Flex temperature is the assumed temperature of the engine. The FADEC takes control of the flex temperature and that higher flex temperatures will have a slower performance of the engines due to the higher temperature so has a slow acceleration for takeoff but has a higher speed thus reducing the runway available for a rejected takeoff should an engine failure occurs. Lower flex temperatures will have a higher power setting and a better performance of the engine. This will have a smaller takeoff roll thus having a larger runway available for rejected takeoff. The TOGA throttle setting is reduced to clb thrust and a reduction in engine noise from a passenger perspective

[@jonathanjason1312]

Kkokk

[@jonathanjason1312]

Fdtgde DM enka SMH

[@neurofiedyamato8763]

When I saw flex I imagined the wing flexing based on the temperature:P

[@FlyGuy1]

Same

[@BlueAustinMaxi]

Neurofied Yamato when I saw it I thought of flex-tape ._.

[@theonefrancis696]

It's not that weird tho

[@TwitchKoalabaerchen]

Nooo ): 😞

[@andresferrin4001]

Hahaha you nailed it!!!

[@kd4pba]

Wow very educational. I can recall years ago where I live taking the first plane ride in years with TWA out of KRDU. I believe this was an MD-80 series, it was around 1999. It was overcast morning around 8am and humid but not hot. The plane was full. That takeoff I will not forget. The acceleration felt exponential. We were all pressed back into our seats very hard and as we gained speed it got stronger until we left the ground. I smiled because i love that feeling. It reminds me of being in a high performance card with a lot of torque. I am not sure if we were heavy or in a hurry but it was a great way to go back to flying!

[@LORESEP]

It has been a great help to my students at UTN in mexico city thank so m uch for your time and explanations

[@rosen9425]

It becomes more and more amazing how flying these beastly machines is even possible

[@nicolaslaing4053]

Thank you, Captain Joe! Thanks to you, I have decided I will become a pilot. My ATPL course will start in March 2018 (I couldn't start in September because I had to be 18 at the start of the course). Your videos have, for a part, really helped make my decision. It's not easy, it's not cheap, but damn is it awesome. I wish you all the best! Greetings from Belgium ;)

[@flywithcaptainjoe]

Sounds great my friend, wishing you all the best for your career and it´s my pleasure if my video help you out here and there ;) Greetings Joe

[@nicolaslaing4053]

Cpl and multi-engine training are integrated in the course, I'll be studying in Brussels (CAE Oxford Aviation Academy) and really have no idea yet which airline I'd like to join :)

[@nicolaslaing4053]

Miam ga Thank you!

[@rivsol]

i hope u're doing good as a pilot now

[@enescakr4203]

i cant believe how much knowledge flying an airplane needs

[@pinkdispatcher]

Great and informative video, keep them coming. :) One tiny point: FLEX thrust will generally not save fuel; the lower fuel flow per unit time does not offset for the longer takeoff roll. In general, gas turbine engines are most efficient at higher power. If you don't want to do the complete calculations, the extreme point will give some hint that lower power is not always more fuel-efficient in total: there is a power setting too low to take off and fly at all, yet it will consume a non-zero amount of fuel. So the real main reasons for performing a "reduced-thrust takeoff" (to use a generic term) are reduced engine wear and (depending on the departure profile) reduced noise, although that's also less than you'd think because the climb gradient is lower with less thrust. That reducing mechanical wear is often more important than saving a bit of fuel is shown by the use of reverse thrust. Its main function is to reduce brake wear. Stopping must always be possible without them (except perhaps on ice), but they basically don't cause any wear.

[@dexopdencamp4901]

The more I watch... The more I understand everything... Great video again

[@briansmobile1]

Joe, you're almost to 100k subs congrats!

[@DDelusionMusic]

Now it climbed to 1.37M!!

[@finn7345]

You’re at 391k subs congrats!

[@fmz-4618]

I’m here when he’s at 1.4 mil

[@bharatmaheshwari1060]

Now in March2021 he has 1.46M❤️

[@bharatmaheshwari1060]

@@MySplash911 haha right but Kelsey is going faster than Joe

[@ezequiel1life894]

I'm preparing my performance exam for EASA conversion and your video nailed it and help me where I struggle. Thanks for great explanation, Captain!

[@ikhlaassayeed8139]

joe please make a video on qualifications of a pilot and nessecities

[@flywithcaptainjoe]

Coming up!

[@marcus8036]

Was about to ask the same. will be looking forward to that video. Congrats on 100k

[@tc1817]

Spelling "necessity" is one qualification.

[@marklacy5011]

Joe, Can you explain what and how a side slip is performed? Is this a common practice in commercial aviation?

[@cseblivestreaming]

Bad day?

[@terryofford4977]

Nice to hear such clear and decisive comments, very much appreciated, it also displays the huge differences between the Piston Engined a/c and the modern Pax Jets. Thank you Joe.

[@jaimaansinghmonga3305]

Hi Captain Joe! Please explain SQUAWK...

[@flywithcaptainjoe]

Coming up! Greetings Joe

[@factsverse9957]

Captain Joe Your cheeks are so red....

[@mr_nice.]

It's the transponder code. That's a very good idea. Why do they call it that? I allways wondered how they came up with that name.

[@FanjitaUK2k8]

It was to do with the original British system in the war for friend/foe detection. It was codenamed "PARROT" and had the term squawk connected with it as a result which originally meant to cycle it I believe. In modern times is now associated with the 4 digit code assigned by ATC.

[@rogervandecamp8950]

"It was to do with the original British system in the war for friend/foe detection." IFF Code: Information Friend or Foe

[@troybaxter2916]

Excellent video Joe. I've been an airline pilot for years but I still find myself watching your videos (and usually learning something new) so keep up the good work!

[@lukescott5938]

Joe how did you catch the 'Flying bug' and how did you go about training like picking a school and rasing the funds or did you get a airline to pay for you in return for working for them for X amount of years after passing

[@basilsunny6809]

you always explain well clearly,so that we can catch easily.Hats off captain

[@Nekkitus]

Thank you for a very informative video! I think it would be logical now to explain the thrust reduction and acceleration altitudes and (maybe) noise abatement procedures :)

[@flywithcaptainjoe]

That´s true, but first the speeds video on V1 VR and V2 and then thrust reduction and acceleration altitude :)

[@cppguy16]

I'm very curious about noise abatement takeoffs as well. I commonly experience it in Orange County, California (south of Los Angeles). It's a high acceleration, steep climb takeoff, followed by an abrupt reduction in power, in order to concentrate the noise to the airport. Further climbing is only allowed above the ocean. You can clearly feel and hear the difference even as a passenger. It feels almost as if you were about to land right after takeoff, obviously to reduce the noise over Newport Beach.

[@Alexagrigorieff]

+cppguy16: SNA runway is also pretty short: about 5700 ft (while, for example, LAX runway is 12000 ft).

[@cppguy16]

True, but normally airplanes climb steadily. At SNA, they climb at 25 degrees (10 degrees steeper than usual), then sharply reduce the power. They fly level all the way to the Pacific, then climb normally. It's the most fun airport in the US (or the scariest, depending on who you are). Flight attendants have to warn passengers so everyone is mentally prepared for this.

[@oscarb9139]

@@cppguy16 You are very correct. The normal thrust reduction/acceleration is 800 feet above the ground. In SNA the power is reduced above 1500 feet and acceleration is above 3000. Runway length has nothing to do with this. It is, as you suspected, a noise abatement procedure. SNA has noise sensors off the end of the runway. Too much noise can result in a fine, and enough violations can result in loss of authority to fly here. There is also a curfew. Here is an article. blog.aopa.org/aopa/2018/11/19/nadp-1-versus-nadp-2/

[@johnn2997]

Great channel - I'm glad I stumbled on this. I have always been fascinated with the mechanics of flying as opposed to the actual flying of aircraft. Thanks Captian Joe..you sure do make things a lot clearer.

[@mrtommygunwhite]

Joe been watching a lot of air crash investigation and I was going to ask could you explain "coffin corner" as I think it would make a good video

[@dash8465]

It's definitely a intersting and worthy subject, although the speed ranges have typically widened quite a lot in modern aircraft with greatly improved aerodynamics, sensors, and PFD's with clear and accurate dynamic speed limits displayed... and if violated today's aircraft respond much more tamely, most notably with regard to what part of the wing will stall first.

[@oscarb9139]

The coffin corner is slang for when the low speed and high speed symbols are very close together and is usually at a very high altitude. The airspeed indicator in this aircraft has a red band for the high speed limit and a yellow band for the low speed symbol. Go look it up on the web as my description is poor. At low altitude, the range between going to slow and too fast can be over 150 knots apart. But as the aircraft climbs they get closer together. Example: at sea level, Vls (low speed symbol) might be around 200 knots and Vmo is 350 knots. That same airplane at 39,000 feet might be Vls 230 knots and Vmo/Mmo 270 knots.

[@19TheChaosWarrior79]

Captain Joe another well explained video. I have absolutely no need to know any of this but I love watching videos like this. Well explained by someone who has a passion for what they do.

[@Tom-zs1ev]

Thank you for the explanation..if I may add..Jet engines produce reduced thrust as the ambient air temperature increases. The flex temp is the highest air temperature at which the engines would produce the required thrust. The crew finds that temperature and enters it into the flight management guidance system (FMGS) - effectively telling the computer to assume the specified air temperature instead of the actual temperature. When flex (FLX) thrust is selected during take off, the engine controller produces maximum thrust for the assumed (flex) temperature.

[@ballajurassic9601]

Thank you Captain! This is the best explanation of Flex that I have heard.

[@JJ37_]

Tolles video, die Frage hab ich mir schon sehr oft gestellt 😃 wie ist das eigentlich, wenn ein Passagier mal ins Cockpit möchte? (natürlich auf Boden), ist das grundsätzlich erlaubt? Weiter so mit den (sehr hilfreichen) lernvideos :)

[@donthomas2520]

Hey Captain Joe..Greetings from India..This is Don Thomas and Iam an aerospace engineering graduate..I have had fascinations for aeroplanes since my childhood and I had always wondered how these mighty objects could fly ..and that led me to pursue a degree in aerospace engg..I came across ua channel couple of days back and I was really surprised to see your videos Joe..do you know what I like the most about ua videos Joe? is that you give importance to small details with such a relaxed and positive vibe..you are a cool zen of materialism..I love your videos Joe..they are so helpful to me and it helps me learn even more about airplanes and flying..love you videos and you Joe..jeep doing what you love😃 you are amazing😎

[@SeanHollingsworth]

One of my favorite flights back in 2013 was from LAX to ABQ on a SWA 737-700. There were only 85 people, with crew, on the aircraft. LAX was actually quite cool, ~10C, with some low clouds and some localized fog. Our density altitude was somewhere below sea level. Needless to say, Vr was very low. We got airborne very quickly, and climbed into the night sky like a ballistic missile. ;-)

[@robinfist]

One of the best explanations I have heard. WELL DONE, very very good!

[@mds3697]

Hey Joe, can you explain the difference between ground speed and airspeed? why is the airspeed displayed on the speedometer usually much lower than the actual speed in mach or kilometers/hour? to give an example: I play a flight simulator sometimes and in a 737 the average cruise speed that's displayed on the speedometer is about 320 knots. but when you google 'boeing 737 cruise speed' all answers will be around 500 knots. Why is there such a big difference sometimes?

[@flywithcaptainjoe]

That´s a great question, I will look in to that for you! Greetings Joe

[@SidneyKenson]

The IAS only refers to the static pressure of the air, regardless of temperatures or air pressure through altitude. Then you have the TAS, where all these influences are calculated in, and finally adding the wind gives you the GS. Therefore I had a GS of 575kt at about 300kt IAS. Thank you, backwind of 85kt on FL340...

[@bmanna495]

the ground speed is calculated by the GPS in relation to the position with the ground, the airspeed is calculated by the pitot tube that reads the difference between static air pressure and dynamic pressure(the pressure that the air makes hitting the plane with a certain speed) and calculates the speed using the bernoulli equation. Since the static air pressure is much lower at cruise altitudes the readings are low but that doesn't mean that it's useless because that is the speed that is used for the aerodynamic calculations like stall speed and overspeed corner

[@EinkOLED]

Midas The higher you climb the thinner the air becomes, meaning the pitot tube receives less air, indicating less air speed. If there is a 50 knot heading then this is also added in the indicated air speed, a 50 knot tail would be subtracted (hence why it is important to takeoff into the wind). The aircraft requires indicated air speed in order to fly (stall speed, over speed/flap speed, landing/takeoff speed) etc, etc.

[@blumac9801]

Midas the higher you are the bigger the world is pretty much...

[@FlexCrush1981]

Thanks for taking the time to make this video Joe

[@flywithcaptainjoe]

My pleasure Robbie!

[@nilanjanbanik7509]

Thanks for the great video. What about the Noise Abatement Takeoff Procedures (NATP)? I used to think the reduction in engine power shortly after take off was due to NATP, i.e., flying over residential area.

[@oscarb9139]

It is actually NADP Noise Abatement Departure Procedure. Here is an article that may interest you. blog.aopa.org/aopa/2018/11/19/nadp-1-versus-nadp-2/

[@GastonDwarvenPilot]

I arrived a couple of years later, but still very useful explanation Joe. As always, thank you for sharing!

[@christofferwaltersdorff4303]

Hey Joe could you please do a video on the RAT?

[@flywithcaptainjoe]

Coming out in two weeks, video is already finished!

[@nazimfazilmohamedhanifa9733]

HI Capt Joe , Please explain about different types of altitudes including thrust reduction altitude and acceleration altitude

[@oscarb9139]

@@nazimfazilmohamedhanifa9733 On a takeoff, the power is applied (full power or reduced). This power is maintained until thrust reduction altitude, when the FMA flashes to indicate it is time to pull the thrust levers back into the climb detent (climb thrust is set). Acceleration altitude is when the pitch FMA (pitch controls airspeed) changes from SRS to CLB or OPN CLB and the flight director commands a lower pitch so the aircraft can accelerate and allow to pilots to retract the flaps on schedule at F speed and S speed (that’s Airbus stuff).In this video, at 1:50, you can see that the FMGC (flight management and guidance computer) is programmed to do both at 1500’ above sea level, not ground level. Ok,I just finished packing to fly out tomorrow and I can add to this comment. It appears that Cap’n Joes company uses a 1500 foot thrust reduction and acceleration altitude (I don’t know the field elevation of the airport he entered and I don’t want to leave this comment to go watch the video so I can google it). So, when he takes off, he pushes the thrust levers up to the TOGA or FLX detent and the FADECs will set the proper power for the takeoff. At 1500’ above sea level, the FMA (annunciation in the upper left of his PFD) will change from MAN TOGA or MAN FLX into a flashing LVR CLB in row 2. This is the signal to move the thrust lever back from the takeoff setting to the Climb Detent (two clicks back from TOGA or one from FLX/MCT) and this is the way the pilot communicates to the FADECs that climb power is desired. The pitch bar will move to a lower position on the PFD to command the pilot or autopilot to lower the nose and accelerate. If the flaps were set at “2” or “3”, the pilot will see an “F” on the speed tape (airspeed tape) and once the aircraft is faster than that, the flaps are retracted to the 1 position. Once the flap handle is moved, the F disappears and an S appears on the speed tape. When the aircraft is faster than S speed, the flaps are retracted to the up position and the aircraft will accelerate to 250 knots until 10,000 feet and then will accelerate to “economy climb speed” which is some number that is affected by wind, gross weight, and cost index. Time for dinner. I may add more later.

[@JonOlaivar]

I was on an a320 recently from LAX to Denver and the climb was insane! I didn't hear the engines back down after take off- which caught me by surprise.

[@surf2888]

can you make a video about the priority left, priority right for airbus

[@irockusucks]

I'm sorry but I think it is 40 seconds to latch the system. that is for the airbus 320

[@irockusucks]

I do think it's a bit long but it makes sense to ensure that no accidental takeover happens

[@AgnostosGnostos]

Dear Captain Joe you have just reached 100.000 subscribers in a very short time. Congratulations! I am waiting for the a video with the honorary silver play button that KZbin will send you. Keep on the good work. I have learned a lot from you and I am aware about many things during my flights. Again thank you.

[@ethanwittenberg6172]

another great video Joe!

[@flywithcaptainjoe]

Thanks Ethan :) Greetings Joe

[@muhammedhaneef1798]

U have a grt prsnlty.... We fellow curious students love to learn from you... You are so patient and calm..... Thnx a lottttt......

[@n_g7009]

Kannst du als 100.000 Abo Spezial einen Flug von dir Filmen? p.s interessantes Video wie immer! ;)

[@petemichel8011]

Vielen Dank Joe, das du es unter dem Video auf Deutsch erklärst...Happy flying all the time;-)

[@PPC4]

I'm a little confused. If a higher flex temperature means an assumed higher outside ambient temperature why does that result in a lower power setting when you then say you would use the toga setting in hot or high conditions. Would not a higher assumed ambient temperature mean that more power is given not less (thinking thinner air). Or is it relating to a higher acceleration rate meaning you have more room for a rejected takeoff meaning you can take off at a higher airspeed?

I am sorry I answer to you one year later but as I understood on the video, the higher outside ambiant temperature is harmfull for the engine temperatures, therefore the computer reduces the power of the engines (through a savant calculation) to limit the engine temperatures. Maybe I am wrong of course but I suppose the problem with thin air is less a problem than the problem of engine overheating.

[@Rhythmmical]

Hotter air is less dense I think, so you will need more thrust to get to a good liftoff speed. Now this is probably only in the instances mentioned in the video, such as a higher runway attitude or short runway. When you have more dense air due to lower runway altitude, and/or longer runway, you can use lower thrust in a higher air temperature to save on engine life. I don't think I fully understood your question, but tried answering it the best I could. This is my understanding based on this video.

[@shaunweatherill6651]

The method wasn't completely explained in the video, every airline and aircraft manufacturer has slightly different methods of achieving similar outcomes. There are 2 power settings we calculate for takeoff, the first being rated power (TOGA power) - this factors actual ambient conditions to give us an engine power setting that should not exceed engine temperature limitations should we need to use it, then from rated power we can use the assumed temperature method (or FLEX) to reduce the rated power to what was explained in the video. Like Joe said, there are circumstances that prohibit us from using reduced power and to use rated power instead (bear in mind rated power may not be full power, rated power is max available power that when calculated properly should not exceed engine limitations, even when the ambient temperature is hot).

[@Airblader]

@@shaunweatherill6651 Could you also explain why a "fake" temperature is used as the unit in the first place, and more so with such unrealistic values as ~60°C? It sounds weird to use completely faked numbers rather than inputting factual information.

[@gardemeister]

İt is a reference temperature to TOGA performance . İf outside air temp was 58 C TOGA would does exactly same performance . That means reduction in performance as air gets hot. By that logic flex 48 C will give more performance than 58C .

[@12secyellow98]

Great video Joe, and really helped explain what I feel on takeoff in an Airbus vs. Boeing. I've often wondered why the 737 actually starts accelerating during the climb at times.

[@Rucola2380]

Joe, can you make a video about engine failure? what happens, does it crash immediately or can you glide it safely to the ground?

[@onflightsim32]

ruben korkis you can glide safely back to the airport and with one engine you can still fly good with those commercial airplanes

[@flywithcaptainjoe]

Planes don´t immediatley crash due to an engine failure, I`ll see what I can do! Greetings Joe

[@Rucola2380]

Captain Joe thanks, looking forward to it

[@EdekaKuchen]

Captain Joe kannst du mir Webseiten zeigen wo man zum Beispiel flightstick oder Navigationsgerät für einen Flugsimulator kaufen kann

[@onflightsim32]

Marc Kupper Google?

[@sheelamisrael882]

Hi Joe, I am a big fan of your videos, your absolutely incredible, love the way you explain everything. Looking at you I regret I couldn't tired to become a pilot.

[@flywithcaptainjoe]

Thank you very much my friend, greetings to Israel, going there on holiday soon :)

[@Nilguiri]

Hi Joe Do you have any videos explaining the v1 v2 and rotate speeds? And TOGA? Thanks

[@randolphclarke4674]

Nilguiri I think V1 means the plane has to lift off the ground and it’s too late to abort takeoff

[@PenguinYeet]

V1 Is the point where takeoff should not be aborted.

[@mwr._.306]

V1: take off can't be aborted Vr: the speed where the pilot has to rotate the aircraft V2: The speed where the aircraft can continue it's climb with no problem even in case of an engine failure

[@lucasbrien5008]

TO/GA is the speed for Take Off/ Go Around

[@dpm-jt8rj]

@@lucasbrien5008 There is a PilotsEYE.tv video of a LX A330 flight ZRH - MIA and the FO stated that their flight would be a TOGA take off from ZRH. When would a flight have a TOGA take off and when would a flight not be a TOGA take off? It's has to be an Airbus thing.

[@DougHanchard]

Luxury for Pilots these days. When JT3's and Conways were around, we had to calculate EVERYTHING manually. Converted airliners to freighters, when fully loaded, calculations were pretty simple. Max (stabilized) power. If the air temperature was excessively hot, there was a simple decision. You waited, sometimes hours, if at max weight (*koff*)....

[@micha0001]

58° Celsius??? Has Death Valley an airport??

[@hvnterblack]

isn't it Fahrenheit? it is 14,4 C

[@oscarb9139]

@Alaukikdeep S Boparai you are correct. Entering a higher than actual temperature into the Takeoff Perf Page causes the FADEC to calculate a lower power setting for takeoff.

[@Sebastian-ze2oq]

Dear Captain Joe, thank you very much for another informative video. I have always been confused about flex temperatures & derating, but this has really helped me get my head around it. If you find yourself in the UK and fancy a tour around an engine manufacturer's base then let me know.

[@rubenrocha9]

Hi! I just learn so much from your videos. I want to become a pilot so I'm better paying attention. CAP CAN YOU EXPLAIN WHAT DOES "MORA" mean? Thanks a lot. Ruben

[@flywithcaptainjoe]

Yes, I´m on it !

[@rubenrocha9]

Thanks a lot! I'm Portuguese. have you ever flown to Lisbon? what about the approach? what's the best app for you?

[@Brukn0ws]

Madeira!!!

[@PeterGamerTutoriais]

Açores

[@rubenrocha9]

MalucoHD #ConTV que ilha?

[@hashemhamed4430]

The FCTM says under supplementary green opeartions ,, quoting “ Takeoff with flexible thrust increases fuel consumption compared with takeoff with TOGA thrust, due to the longer takeoff phase “ so flex dose not decrease fuel consumption as you said , but great video capt joe very well explained.

[@jasperstevens8270]

I've a question for a video, what is the little red buttom on the thrustlevers

[@onflightsim32]

Jasper Stevens you can push that in order to switch the autothrust off

[@jasperstevens8270]

OnFlightSim thank you but what is the autothrust is that the autopilot?

[@onflightsim32]

Jasper Stevens it controls the engine thrust so you could say it's an autopilot for the engines

[@jasperstevens8270]

OnFlightSim Ok thank you!!

[@alexxd_1252]

Good Question! As far as i know it is pushed when you discontinue your approach and go around and gives you max power as well as pulling up automatically

[@juliocontagro]

Nice video Joe! Almost 100.000 subscribers! Congratulations

[@siddhantparekh8007]

When the engines are starting up, why can both engines not be started at the same time?

[@flywithcaptainjoe]

Try blowing up two ballons at same time, won´t work due to lack of pressure! Greetings Joe

[@siddhantparekh8007]

Thanks!

[@StephenKarl_Integral]

Some russian (ukrainian in fact) airplanes can. But you don't want to mess up in case you have trouble with one engine on startup. Just do it one after the other...

[@donnyguns1]

if you have four engines, you can put the first one on reverse then cross bleed to start next two together. We do that on C17s

[@martinthor4000]

to talk about the 787 which does start both engines at once :P

[@johannlo1503]

Captain, here's your goal: achieve a status where your KZbin channel is sufficient enough to produce a pilot without going to theory classes. Keep it up with these informative videos! :)

[@flywithcaptainjoe]

Hey Buddy, that for sure sounds like a great goal, I´ll keep it in mind :) Thanks for the head´s up :)

[@Jess-kd8cl]

Neat vid first

[@oscarb9139]

Joe, your verbiage is a little confusing at 2:49. You said something like “the higher the flex temperature, the higher the V-speeds, and the shorter stopping distance”. Actually, with higher speeds, comes longer stopping distances. I think you meant that there would be less stopping distance available with higher flex temperatures.

[@tomstravels520]

But you could also argue if V1 was the same speed but you had a low and high flex temp, with the high temp you’d would have more thrust and reach that V1 quicker than the lower one so there would be more room to stop if you had to abort say just before V1

[@oscarb9139]

@@tomstravels520 You have it backwards. The higher the flex temp, the greater the thrust reduction, and longer it takes to get to V1. High flex Temps are often associated with longer runways where the aircraft has enough runway to accelerate to the increased V1, and yet still be able to stop with a reject at V1 in the remaining runway.

[@HamSweetHam25]

I love how something so important is done by cheating a system! 😂

[@oscarb9139]

It isn’t cheating the system. It is just giving the system a number to make a calculation for a thrust reduction. Boeing does the same thing, but they call it the “assumed” temperature. If it was tricking the system, pilots would give the false temperature on the INIT A page instead of the outside air temperature.

[@mohammadbazzi9759]

Thank you so much captain. I enjoy all your videos. I'm very curious about airplanes and how they works and you give me all the information. I thank you so much for doing this for us. God bless you and bless your family. greatly appreciated your work Capitan. I'm from Windsor Ontario canada.

[@gowthamnaidu3029]

Hi joe....how to become a pilot of Qatar airways or anything...plzz reply

[@cheburatorish]

Not possible, forget it. At least, not in this decade.

[@MrKnutriis]

The longer you can watch this video, the more Flex you have, and Captain Joe likes it even more.

[@martinsivc5769]

Hey Joe! Thanks for helping me out with every video you have. Everything helped me so much, I want to be a pilot when i grow up.

[@sonheromayor]

Thanks Joe for all these good explenations ! It is very useful for my ATPL :)

[@kaktus018]

What I would find very interesting to learn about is laws and regulations onboard. What laws apply to me as soon as I step onto an aircraft? Are there similar regulations like in maritime law? What rights have the crew and in particular the captain? I would love to see a video covering this topic in the future. And as always, keep up to great work Cpt. Joe!

[@flywithcaptainjoe]

Okay, I´ll get in on that! Greetings Joe

[@real_create]

3:50 that is why you have the feeling that you are going down but you are not.

[@sean_bruce]

Fun video. It is interesting to learn that something as mundane as flying has such intricate calculations for the first few moments of the journey

[@hendricstattmann3638]

Dear Joe, thank you for this interesting video. Two questions, though: 1) Why are the V1 and Vr speeds actually HIGHER when using a reduced T/O thrust setting? From my understanding, the V speeds depend on aircraft type, flap setting and take-off weight only, but it looks like I am wrong? 2) How come a derated (flex thrust) take-off saves fuel? For sure, reducing the thrust setting will reduce the fuel flow, but at the same time, the initial climb rate will be reduced as well. From my understanding, a full power take-off should be the most fuel efficient departure, because of: (a) better thermodynamic efficiency from a higher core temperature, (b) lower aerodynamic drag, because of a shorter time and distance from brake release to gear up. Looking forward to hear form you!

[@benstilp7354]

So glad I saw this video. I just departed from Rio de Janeiro Santos Dumont's on a319 which had a very powerful thrust take off. It was quite noticeable. And within a few seconds after take off the jets immediately reduced. I suspected it was because of the short runway.

[@TerenceHorsman]

The more I watch these videos, the more respect I have for pilots. It's a hell of a lot more work than using AP!

[@CloroxBleach-dl2nh]

congratulations captain joe for reaching 100,000 subscribers

[@hainguyen6514]

stumbled on your channel while doing some research about the Concorde. Great channel, never thought aviation could be this interesting. :D

[@pineteam]

Hello, I really appreciate the effort you invest to make those great videos. I just want to correct one important thing: Flex take off actually = More Fuel burned. Flex take off only reduces engine wear.

[@tdc1991x]

This was really interesting - I'd flown out of Lanzarote many times and had always wondered why the engines seemed to throttle back so much just after take off!

[@Funnymemez254]

very educative captain joe...i am a ppl student in kenya and i must say u help out alot

[@Rasmorak]

What a wonderful channel! Thanks for all your hard work, and for sharing your knowledge with us Joe! I'm trying my hardest to end up in one of those two seats in the cockpit!

[@Wackans]

I liked all those videos ! Short videos that helps a lot to understand the Airbus world

[@joelfiction]

I find your videos very interesting and informative and are just the right length to watch while on break. Keep up to good work captain :)

[@halcyondaystunes]

Brilliant and informative video as always Joe.

[@afetsis]

it would be great to make some videos on taxi/takeoff/climb/cruise/approach and landing procedures, explaining checklists in each situation. how is cost index calculated by airliners? how easy is for a pilot to swap e.g. from an a320 to a a340/a380, and how common is for a pilot to swap between airbus and boeing. Awesome channel! Thank you.

[@PEOPLESX]

Hi Joe, but 2 comments: - the FADEC is the name for the whole System, the control unit itself ist called the ECU=Engine Control Unit. Compare to a Fly-By-Wire: It is the name for the whole system (incl. computers, wires, servos, input devices, ect.), the computers itself then are called FAC or ELAC. - the Flex-TO-methode won't give you a better fuel economy, it "just" reduces engine wear. I know, this is often explained in type training and as "proof" they argue, the fuel flow is reduced. In fact, the engines work the most economic way at full thrust (amount of thrust vs. fuel used). Since you need apply a certain energie to reach your ceiling altitude (regardless the power setting) and energy in that case is power over time, it would be better, to use lots of thrust for a short climb-periode instead of lower thrust-setting.

[@xavierlarvor201]

Very clear explanation, Joe, thanks!

[@sebastianbaltazar8213]

Thank you Joe! I have the atpl performance exam very soon, you have helped so much!

[@christianbro2]

Thanks for your video, it is appreciated that you did it on a more complex topic.

[@AramK]

Thanks for the video Captain ! Can you please make a video about, why do planes take off at such a high angle.

[@Kevinmaino]

i dont know if you ever talked about this but something i wanted to know are the takeoff procedures before take off, like how to calculate manually v speeds, or flex temperature, and landing aswell like to know what are minimums, radios, baros, etc. everything very quickly landing and take off procedures

[@mariebcfhs9491]

Last time I travel on an Airbus A320 and I experience this: as we accelerating down the runway the engine sound is pretty quiet but when the aircraft lifted off (no more vibration from the runway) I heard the engines roar as lound as hell and keep climbing as max power for 10 minutes! Please explaine mister Joe, thank you vẻy much :)

[@smarthydroponics]

I’ve always wondered why the power drops off after climbing Thanks for the explanation Cheers

[@fen4554]

We got commercial pilots on youTube now? How awesome is that... Thanks for taking the time to make these!

[@lepilotedu36]

Completely odd the t/o thrust vs climb thrust of boeing, you teach me something soo funny thx, and good luck for this channel

[@INTERSTATEREMOVALISTSAUSTRALIA]

Great information and very clear, thanks very much i'll keep watching

[@aarondowden4244]

Thank you so much for this explanation!! I have to say your videos are really helpful and informative, keep it up Joe!

[@liusteven5332]

Finally understand after watching the video for three times 😃😃 nice explanation.

[@gustavodeibarra3879]

Great video´s Cap Joe. Congratulations. Good Flight´s , Gus.

[@jojieclaudio2124]

please keep on teaching us about flying there are so many questions as pax still unanswered like climb reduction speed

[@n1msu]

Awesome! I filmed my takeoff out of lanzarote last year and it's on YT. I always wondered if it was a relatively short runway because on arrival the braking was extreme!, so much so my ohone was pulled out of my hand and ended up 7 rows ahead! (I was right at the back)

[@ZK-APA]

Its not a short short runway, but yes for a loaded A320 aircraft, one may need medium autobrakes rather than low.

[@VincenzoMaxpower]

Very informative as usual. Thank you Capt. Joe

[@patryk7916]

nearly 100.000 subs! good job captain👨🏼‍✈

[@chrismcclellan8539]

I really enjoy your videos. You do a great job explaining details!

[@JayDS509]

Hi Capt. Joe...Thanks for the consistently clear, engaging and often humorous presentations of aviation topics. I wonder if you would be willing to do a series on emergency procedures for pilots. These could be by cause (e.g. engine out, etc) or by circumstance (e.g. reject takeoff, etc.). Thanks again for the great vids!!!

[@steveemerson4120]

Great video as always and stylish presentation.

[@gjmalek5074]

Hey Cap. Joe its amazing to see you every time on this channel !!! every video is very informative and exciting and its totally changing the way we travel in plane and we can say i know the reason behind .😀😀