Boeing salesman pointing at the engine display: ‘yes but these go to eleven’

@A330Driver

Жыл бұрын

hahaha

Yesterday I've flown with Ryanair and thought of your insights that you have been giving us about the 737. Truly fascinating 😊

Think the N1 limit is an engine manufacturing thing and not a Boeing thing. It's kinda weird because, for example, on the A340-600 (Trent 500), the 100%, N1 rpm is 3900 rpm, but the redline is 92.5% N1 lol

You never stop learning here :) Nice one!

While on that discussion, though: There is something to be said about the safety culture embedded in the airline industry. When a safety related event happens, like the one that Emanuel mentioned in his company (which I am unfamiliar with), there is an outcome of some sort of mitigation strategy. That event is NOT a result of necessarily a lack of engine power. Yes, more power would have helped them (maybe, and probably not by much, that's more of a case by case thing). Rather, in my opinion, that event would be a result of an inappropriate choice of cruise altitude. In my company, we have separate charts to determine maximum altitude in case of UP TO LIGHT turbulence, and another column of maximum altitude (as well as minimum and maximum speeds) for MODERATE TURBULENCE, which is a lower altitude. That is because the G-Forces that the turbulence induces, also cause momentarily for the overall angle of attack and subsequently the total drag of the airplane to increase, causing the need for more power, which isn't always available. It sounds like the same as 'not enough power', but I would call it 'too high altitude'. Now, to tackle this, the airline could have chosen multiple strategies, each one of them incurring some costs in different way. One of them is to change the power rating, increasing maintenance costs, the other is dedicating more time in simulators and CBTs for the pilots (some additional costs in continuous training of pilots in addition to normally maindated refresher modules). Or both, of course!

@johnhinestrosa2456

Жыл бұрын

Tks, very interesting explanation!👍🏻

@A330Driver

Жыл бұрын

The lack of that additional power was one contributing factor in this incident, but one that could easily be mitigated. One hole less in the swiss cheese model on the way to an accident. Indeed we don't have any of those charts you mention, for us it's still down on the pilot to make the right call there. 2000ft below the OPT FL you are basically safe in the 737-800. Sufficient thrust and manouver margin to overcome pretty much any turbulence I can currently think of.

This one is huge on details. Learned a lot today, definitely implementing CONT thrust setting in my next flight and gonna test it out.

I love modern aviation. It's interesting how close to potential disaster airliners be, as the flight envelope is pretty small. Demonstrates the importance of professional crews in the cockpit and recurrent training. Thank you for these awesome insights into your profession.

Tuned in. Hit "Like" immediately, I was just assuming. Then watched it. I was right.

@A330Driver

Жыл бұрын

haha, nice one! Thanks!

The reason why you see RPMs greater than 100% is, that this generally used to be the limit of the base engine. Not really a Boeing thing.

Hey, i met you on a frequenzy(tower) in Cologne Bonn airport and i was happy to hear your voice because i learned many things from you. epic!

@A330Driver

Жыл бұрын

Nice! On my way back there now!

How I love these golden nuggets of information. Thanks

As always, very informative and explanatory, thank you. I wish you success and safe flights in your new company and/or new aircraft type. I am looking forward to your new video series about Airbus.

@A330Driver

Жыл бұрын

Thank you very much!

Great video!

I knew they were derated in cruise mode and I didn't know you could force max continuous thrust and the whole reasoning behind it. Interesting.

Nice one Emanuel! Curious if Airbus does it in a different way. Cheers

Once again I learned something new. I had never looked at the n1 page during cruise flight. Also this example is very crucial in real life im sure. Probably be hard to duplicate that example in the sim since even still turbulence isn't very realistic yet.

@A330Driver

Жыл бұрын

Indeed in the sim it would be rather hard to replicate, but just think of those silly wind shifts MSFS gives you sometimes. Those might easily bring you into the same situation.

Great video! Can't help but notice that you're now a "former" 737 pilot. Have you shared with us what you're flying/getting rated to fly?

@A330Driver

Жыл бұрын

Thanks x539, see my "Bye bye Boeing 737" video. I'm going to the A330.

Good to see your airline prioritised passenger / crew safety over stretching out engine life and savings on maintenance. I imagine you would have seen some shorter flights by having a noticeably higher cruise power as standard. Happier passengers and crew I'm sure!

@A330Driver

Жыл бұрын

Absolutely, I suppose this falls under the "lessons learned" tag. They used the money saving method since Boeing approved it as save, but when they got doubts they changed back to the safe way. Exactly as it should be.

If you're still taking idea requests, I'd love to see a video explaining when to use MDA vs DH, as I only ever see people using MDA. Thanks for the video, was great as per usual.

@A330Driver

Жыл бұрын

Thanks! This one is quite easy indeed: MDA: Everything that does not include an Autoland DH: Autolands (ILS CAT II and CAT III)

@arlynmcadorey3044

Жыл бұрын

@@A330Driver interesting, maybe that’s different in Europe. I understand that to be the case with Baro vs Radio mins, but here in Canada at least MDA is for any non precision approach, vs DA/DH is used for a precision app. At least as far as I can recall my ground school studies 😶

@Michael-zf1ko

Жыл бұрын

Another difference is that DH "decision height" is simply the height where you make the decision to go around or not. There's a little buffer below it that you are allowed to enter in the course of preforming a go around. MDA "minimum decent altitude" is treated more like a hard floor. You DO NOT cross that altitude at all unless you have already made the decision to continue the approach (with visual contact and everything, of course). So a decision to go around must be made and preformed before you reach that height. I believe most airlines actually have a policy for their pilots to add around 50 feet to the MDA when programming it into the plane, so it can be treated like a DH and have room for a go around when "minimums" is called out without breaking regulations.

At my airline, the thrust limit automatically stays at CLB when reaching cruise altitude in the FMC. If flying an airplane that doesn’t have that option, it’s sop to change it manually to CLB on the N1 limit page. Interesting to see the different procedures airlines use.

@A330Driver

Жыл бұрын

Indeed this automatic change to CRZ mode is something that's quite annoying and it's a pity we don't have that option in the PMDG 737. I didn't even know it was available in the Boeing 737, thanks for confirming it!

Oh, the poor LSK3

since the cruise speed is not changing with selecting mct, the actual n1 (and also poweroutput and heat) should stay the same if selecting mct instead if crz, no? Unclear to me why anyone would want to limit below mct in cruise. in climb, yes, as the additional margin between clb and mct would be used to climb steeper in flch mode, but in cruise it would only make a difference if wind changes occur (or during a further climb). So… a bit unsure what the crz limit actually helps with.

@A330Driver

Жыл бұрын

Helps it maintenance cost. The plane uses the maximum power you allow it to use rather often in flight when winds change or speed needs to be changed. All those cases where it goes above CRZ limit will reduce engine life and increase maintenance cost.

You've programmed the FMS to fly a certain speed (e.g. .78) at CRZ - 73 can do that easily under most conditions. What happens when you go from CRZ to max continous thrust?

@A330Driver

Жыл бұрын

Nothing - it only determines the maximum thrust limit, not the actual commanded thrust.

I just noticed GA thrust is lower than CON and CLB is higher than CON. Isn't that odd? About N1 being over 100% I heard that is because the engines are improved over the years and can operate at higher N1 RPM's.

@A330Driver

Жыл бұрын

I'd need to check the real plane indeed to see if it does the same, it does seem odd now that you say it. Guess it's one of those values I just never actively looked at yet in this phase of flight.

@Housemucic

Жыл бұрын

@@A330Driver Haha same here, I fly B777 but we barely touch these in cruise. Only in the sim during driftdown etc but the B777 has a nice button for CON thrust so I never go to the thrust limit page. But I really cannot imagine that CLB thrust is higher than CON and I expect GA thrust to be the highest thrust setting.

Interesting case study, I did not know turbulence could affect the airspeed of a 737 so significantly. I thought the 737 is so heavy that the speed is not affected by a lot by turbulence. By how much knots did the speed drop then because of that turbulence in the case study you are referring too? Because it sounds like it was affected more then a couple of knots. I mean you would not be flying close to the Amber band in normal flight I assume, as that would be risky.

@A330Driver

Жыл бұрын

There was no number mentioned when the airline presented the case study, however from personal experience you'd be looking at something in the region of 15-20kt speed loss when close to the optimum, 30kt when well below it. The problem with the weight is exactly the reason: The plane moves at a constant trajectory, now the wind around it changes. But the plane keeps moving at the same speed for a while due to its mass. The result is a changing airspeed. Changes of 10 knots can regularly happen in moderate turbulence. I've seen as much as 15, but turbulence set on slowly so we descended to a lower level where we had greater margin, before that 15kt loss struck. Flying "close" to the amber band is quite dependant on ones personal perception. Talk to an Airbus guy and they'd say 30kt away from amber is getting marginal. Talk to a 737 guy and we're at 15kt regularly. The 737NG simply is quite limited when close to the optimum level, let alone above it. The MAX has greater margins luckily!

What was that pilot doing to lose 10 grand in a wings level stall? That’s a lot of altitude to lose for something that should have been an immediate stall recovery.

@A330Driver

Жыл бұрын

The difference between real life and theory (or intentional trainign where you know something's coming). Surprise and Startle Factor play a huge role in these kind of events.

Hm...but when in cruise does this cruise limit even realistically play a part for the airline though, why is it really needed ? In most situations you won't even touch the cruise limit during cruise for any long amount of time so might as well have full con enabled for those emergecies, the engines still run the same thrust to maintain cruise, no matter what the upper limit is. I imagine that if we were getting to those 40000's and telling the plane to speed up to the red, plus higher than normal temps outside, then maybe that safety margin would be touched long enough to increase wear ? Have you ever been thrust limited by this setting during your irl flights for any appreciable length of time that could actually impact the engine life all that much ?

@A330Driver

Жыл бұрын

I'd say you're touching that limit on every single flight. Be it because ATC wants you to speed up or be it because or turbulence or wind changes. Personally I've never been limited by CRZ thrust limit and if we got anywhere even remotely close to a point where we thought we might need extra thrust (such as when encountering any meaningful turbulence) we always manually increase to MCT. However in the case study involved the crew got so busy flying the plane that they missed increasing the thurst limit.

@vedymin1

Жыл бұрын

@@A330Driver Would you say then that this thrust option is seldom practical and this is why you guys always overwrite it x) ? Wouldn't be surprised if it is so, it doesn't serve an actual useful purpose (You may touch the limit but not for long enough to wear engines) and can lead to possible complications if literally anything changes along the route ?

good！