Boeing 737 Max at it again

[vh20]

Hell you dont even have to turn the autopilot off and the airplane will autoland on 3 engines.

Reminds me of the Squawk List joke,
Problem: Autoland very rough on this aircraft
Solution: Autoland not installed on this aircraft

 

[E. Bryant]

Let me paint a very real picture of reality in a manufacturing environment. Stolen from a good friend who knows and nailed it.

“It looks like the entire structure around the door is gone.
Structures guy inserts frame, adds three or four klekos to hold it in place. Goes to lunch.

Skin guy comes over and attached attaches skin panel.
Airframe fails pressurization test, so they glob on sealant until it passes.

Paint guy paints it.”

So yes, this was also a QA failure. Inspections, when related to safety items, are critical. You can bet your sweet ass that this particular failure mode will be over-inspected for a long time.

My point - specifically being made to the non-manufacturing types who widely spread the myth of "QA checks" - is that quality is generated by processes that don't allow for mistakes rather than having yet another check in an attempt to catch mistakes by upstream processes.The real world doesn't operate like the average handloader thinks that it operates.

 

[beetroot]

My point - specifically being made to the non-manufacturing types who widely spread the myth of "QA checks" - is that quality is generated by processes that don't allow for mistakes rather than having yet another check in an attempt to catch mistakes by upstream processes.The real world doesn't operate like the average handloader thinks that it operates.

Aviation doesn't have QA checks though, for safety critical systems you inspect and test everything, not just QC 1:10 etc.

I don't actually working in aircraft manufacturing but I know people personally who have been and done customer acceptance checks on different aircraft components, and once you see the calibre of person assembling/manufacturing the items you don't take anything for granted.

If Boeing aren't doing duplicate inspections on something like door plugs, then it's further proof this way a system failure not a diversity hire failure.

 

[E. Bryant]

Aviation doesn't have QA checks though, for safety critical systems you inspect and test everything, not just QC 1:10 etc.

I don't actually working in aircraft manufacturing but I know people personally who have been and done customer acceptance checks on different aircraft components, and once you see the calibre of person assembling/manufacturing the items you don't take anything for granted.

If Boeing aren't doing duplicate inspections on something like door plugs, then it's further proof this way a system failure not a diversity hire failure.

Correct, you still do manual inspection - but you do so knowing that it's at best 80% effective at catching errors, so you certainly as heck don't rely on it long-term to save your bacon.

 

[Mr.BR]

Let me paint a very real picture of reality in a manufacturing environment. Stolen from a good friend who knows and nailed it.

“It looks like the entire structure around the door is gone.
Structures guy inserts frame, adds three or four klekos to hold it in place. Goes to lunch.

Skin guy comes over and attached attaches skin panel.
Airframe fails pressurization test, so they glob on sealant until it passes.

Paint guy paints it.”

So yes, this was also a QA failure. Inspections, when related to safety items, are critical. You can bet your sweet ass that this particular failure mode will be over-inspected for a long time.

Sounds like it

 

[Mr.BR]

Passengers doing preflight checks


Almost Boeing levels of QC


And full diversity hire crew

 

[E. Bryant]

https://leehamnews.com/2024/01/15/unplanned-removal-installation-inspection-procedure-at-boeing/#comment-509962

Current Boeing employee here – I will save you waiting two years for the NTSB report to come out and give it to you for free: the reason the door blew off is stated in black and white in Boeings own records. It is also very, very stupid and speaks volumes about the quality culture at certain portions of the business.

A couple of things to cover before we begin:

Q1) Why should we believe you?
A) You shouldn’t, I’m some random throwaway account, do your own due diligence. Others who work at Boeing can verify what I say is true, but all I ask is you consider the following based on its own merits.

Q2) Why are you doing this?
A) Because there are many cultures at Boeing, and while the executive culture may be throughly compromised since we were bought by McD, there are many other people who still push for a quality product with cutting edge design. My hope is that this is the wake up call that finally forces the Board to take decisive action, and remove the executives that are resisting the necessary cultural changes to return to a company that values safety and quality above schedule.

With that out of the way… why did the left hand (LH) mid-exit door plug blow off of the 737-9 registered as N704AL? Simple- as has been covered in a number of articles and videos across aviation channels, there are 4 bolts that prevent the mid-exit door plug from sliding up off of the door stop fittings that take the actual pressurization loads in flight, and these 4 bolts were not installed when Boeing delivered the airplane, our own records reflect this.

The mid-exit doors on a 737-9 of both the regular and plug variety come from Spirit already installed in what is supposed to be the final configuration and in the Renton factory, there is a job for the doors team to verify this “final” install and rigging meets drawing requirements. In a healthy production system, this would be a “belt and suspenders” sort of check, but the 737 production system is quite far from healthy, its a rambling, shambling, disaster waiting to happen. As a result, this check job that should find minimal defects has in the past 365 calendar days recorded 392 nonconforming findings on 737 mid fuselage door installations (so both actual doors for the high density configs, and plugs like the one that blew out). That is a hideously high and very alarming number, and if our quality system on 737 was healthy, it would have stopped the line and driven the issue back to supplier after the first few instances. Obviously, this did not happen. Now, on the incident aircraft this check job was completed on 31 August 2023, and did turn up discrepancies, but on the RH side door, not the LH that actually failed. I could blame the team for missing certain details, but given the enormous volume of defects they were already finding and fixing, it was inevitable something would slip through- and on the incident aircraft something did. I know what you are thinking at this point, but grab some popcorn because there is a plot twist coming up.

The next day on 1 September 2023 a different team (remember 737s flow through the factory quite quickly, 24 hours completely changes who is working on the plane) wrote up a finding for damaged and improperly installed rivets on the LH mid-exit door of the incident aircraft.

A brief aside to explain two of the record systems Boeing uses in production. The first is a program called CMES which stands for something boring and unimportant but what is important is that CMES is the sole authoritative repository for airplane build records (except on 787 which uses a different program). If a build record in CMES says something was built, inspected, and stamped in accordance with the drawing, then the airplane damn well better be per drawing. The second is a program called SAT, which also stands for something boring and unimportant but what is important is that SAT is *not* an authoritative records system, its a bullentin board where various things affecting the airplane build get posted about and updated with resolutions. You can think of it sort of like a idiots version of Slack or something. Wise readers will already be shuddering and wondering how many consultants were involved, because, yes SAT is a *management visibilty tool*. Like any good management visibilty tool, SAT can generate metrics, lots of metrics, and oh God do Boeing managers love their metrics. As a result, SAT postings are the primary topic of discussion at most daily status meetings, and the whole system is perceived as being extremely important despite, I reiterate, it holding no actual authority at all.

We now return to our incident aircraft, which was written up for having defective rivets on the LH mid-exit door. Now as is standard practice kn Renton (but not to my knowledge in Everett on wide bodies) this write-up happened in two forms, one in CMES, which is the correct venue, and once in SAT to “coordinate the response” but really as a behind-covering measure so the manager of the team that wrote it can show his boss he’s shoved the problem onto someone else. Because there are so many problems with the Spirit build in the 737, Spirit has teams on site in Renton performing warranty work for all of their shoddy quality, and this SAT promptly gets shunted into their queue as a warranty item. Lots of bickering ensues in the SAT messages, and it takes a bit for Spirit to get to the work package. Once they have finished, they send it back to a Boeing QA for final acceptance, but then Malicious Stupid Happens! The Boeing QA writes another record in CMES (again, the correct venue) stating (with pictures) that Spirit has not actually reworked the discrepant rivets, they *just painted over the defects*. In Boeing production speak, this is a “process failure”. For an A&P mechanic at an airline, this would be called “federal crime”.

Presented with evidence of their malfeasance, Spirit reopens the package and admits that not only did they not rework the rivets properly, there is a damaged pressure seal they need to replace (who damaged it, and when it was damaged is not clear to me). The big deal with this seal, at least according to frantic SAT postings, is the part is not on hand, and will need to be ordered, which is going to impact schedule, and (reading between the lines here) Management is Not Happy.

However, more critical for purposes of the accident investigation, the pressure seal is unsurprisingly sandwiched between the plug and the fuselage, and you cannot replace it without opening the door plug to gain access. All of this conversation is documented in increasingly aggressive posts in the SAT, but finally we get to the damning entry which reads something along the lines of “coordinating with the doors team to determine if the door will have to be removed entirely, or just opened. If it is removed then a Removal will have to be written.” Note: a Removal is a type of record in CMES that requires formal sign off from QA that the airplane been restored to drawing requirements.

If you have been paying attention to this situation closely, you may be able to spot the critical error: regardless of whether the door is simply opened or removed entirely, the 4 retaining bolts that keep it from sliding off of the door stops have to be pulled out. A removal should be written in either case for QA to verify install, but as it turns out, someone (exactly who will be a fun question for investigators) decides that the door only needs to be opened, and no formal Removal is generated in CMES (the reason for which is unclear, and a major process failure). Therefore, in the official build records of the airplane, a pressure seal that cannot be accessed without opening the door (and thereby removing retaining bolts) is documented as being replaced, but the door is never officially opened and thus no QA inspection is required.
This entire sequence is documented in the SAT, and the nonconformance records in CMES address the damaged rivets and pressure seal, but at no point is the verification job reopened, or is any record of removed retention bolts created, despite it this being a physical impossibility. Finally with Spirit completing their work to Boeing QAs satisfaction, the two rivet-related records in CMES are stamped complete, and the SAT closed on 19 September 2023. No record or comment regarding the retention bolts is made.

I told you it was stupid.

So, where are the bolts? Probably sitting forgotten and unlabeled (because there is no formal record number to label them with) on a work-in-progress bench, unless someone already tossed them in the scrap bin to tidy up.

There’s lots more to be said about the culture that enabled this to happened, but thats the basic details of what happened, the NTSB report will say it in more elegant terms in a few years.

 

[rjacobs]

https://leehamnews.com/2024/01/15/unplanned-removal-installation-inspection-procedure-at-boeing/#comment-509962

HOLY FUCK THAT IS EPIC ON LIKE 7 DIFFERENT LEVELS....

 

[Mr.BR]

 

[E. Bryant]

HOLY FUCK THAT IS EPIC ON LIKE 7 DIFFERENT LEVELS....

It's standard human behavior, which is why this was easy to predict, and why great men went to such trouble to implement methods like Toyota Production System. Management and leadership are welcome to replace those methods if they can develop something better, but doing nothing and letting matters devolve to this sort of "inspect quality into defective product" approach eventually fails - always.

...this check job that should find minimal defects has in the past 365 calendar days recorded 392 nonconforming findings on 737 mid fuselage door installations (so both actual doors for the high density configs, and plugs like the one that blew out). That is a hideously high and very alarming number, and if our quality system on 737 was healthy, it would have stopped the line and driven the issue back to supplier after the first few instances.

Even if those more-that-once-daily findings had nothing to do with the fasteners that secure the plugs, it's indicative of processes that are generally out of control and worse, it's indicative that management and leadership accepts this. This probably occurred because someone's performance metrics are based upon maximizing airframes shipped and not minimizing rework percentage or increasing first-time yield or completing a certain number of continuous-improvement activities... or better yet, just eliminate all those bullshit numerical metrics like Deming proposed a half-century ago.

If a leadership team is smarter than Toyota execs circa 1990, feel free to reject this reality and substitute it with your own. Everyone else should follow the principles that have been established for 50+ years and proven to when time and time again.

 

[_Windrider_]

This was a 757 which at best is probably 20 years old. The 757 is without question the best narrow body aircraft ever built. It was designed and built before Boeing became compromised. This issue isn’t because of the type of stuff we are seeing on the Max.

 

[Threadcutter308]

This was a 757 which at best is probably 20 years old. The 757 is without question the best narrow body aircraft ever built. It was designed and built before Boeing became compromised. This issue isn’t because of the type of stuff we are seeing on the Max.

This would seem to be a Delta maintenance issue and cannot be reasonably be blamed on Boeing.

What concerns me though is that Delta maintenance appears to possibly be suffering from the same/similar incompetence and or process breakdowns as what Boeing appears to be.

 

[_Windrider_]

This would seem to be a Delta maintenance issue and cannot be reasonably be blamed on Boeing.

What concerns me though is that Delta maintenance appears to possibly be suffering from the same/similar incompetence and or process breakdowns as what Boeing appears to be.

I would reserve holding any kind of opinions on that because this kind of stuff just happens sometimes we don’t know if this is where in tear if there was negligence if this was something else, it could be any number of 1 million things

 

[DIBBS]

The morning news said loose bolts are being found on other 737 planes' plugs" this am. Not sure of the number or how widespread the issue is, but I am glad that I don't fly.

 

[rjacobs]

What concerns me though is that Delta maintenance appears to possibly be suffering from the same/similar incompetence and or process breakdowns as what Boeing appears to be.

Meh... I wouldnt go that far. Delta MX is excellent as far as I know.

We do a walk around before every flight... tires are looked at visually... Here's the problem. The tires hold 200 psi... You can have a tire thats "flat" in essence 0 PSI and it looks fully inflated or damn near so. There's no real good way, outside of a tire pressure check, to catch this before something happens like a tire rolling off a rim, a tire burst on takeoff, landing, etc... I think we do a TPC(tire pressure check) either daily or every 3rd day, cant remember. Ever seen a trucker hit the tires with a wood stick? Same problem on semi trucks with "flat" i.e. zero psi tires. You cant see it visually due to every other tire picking up the load and a trucker isnt going to check pressure on every tire of his truck every time he pre-trips...

The 737 has a little thing that sticks out and if you have a tire burst on takeoff and its slinging rubber around, will knock this little piece off and wont allow the hydraulic system to raise the gear, it will drop back down. Thats the only way most guys I have flown with knew they had a tire burst on takeoff. And they said landing they had no clue they landed on a single tire. I've never had a burst tire.

 

[Mr.BR]

The morning news said loose bolts are being found on other 737 planes' plugs" this am. Not sure of the number or how widespread the issue is, but I am glad that I don't fly.

So which is better Loose bolts or no bolts at all ,as was reported on the blow-out plane build logs

 

[BJames]

Years ago, on an old 737-200, we were getting ready to go until the ground crew told us something looked off with one of the nose tires. One was completely flat and had the bead broken, but you could only tell from a certain angle. If you just glanced at it, like I admittedly did, you would never catch it, even from multiple angles except that one. A lesson was reenforced that day, just because 2 other maintenance techs looked at it previously, doesn’t mean it’s right. The lowest paid guy on the ramp caught it.

The point is, we’re all human and make mistakes, but how they’re responded to is what’s important. In my case, all 3 of us who performed external preflight inspections had to explain how we missed a blown tire. And it made an impression. As far as Boeing is concerned, they’ve fucked up so many times with just the max’s and the 787, it’s going to be hard to trust them for a long time. From this, I personally hope it kills the max10. The max 9 is such a gutless pig, I can’t imagine the 10 being any better.

 

[rjacobs]

The max 9 is such a gutless pig, I can’t imagine the 10 being any better.

The Max 8 is gutless above FL330-FL350 with any kind of weight on it... it says itll go to 370 or whatever, but if it goes higher than FL355 its staggering and you end up having to come back down. We tried to go to 370 the other day in one and it got to like 363 and just simply wouldnt go any higher. I think the FMC said we could make 380 or whatever... aint no way in hell. We went back down to 350.

Now down low its a BEAST. Those huge fans make a ton of power down low, but up high its anemic at best.

 

[beetroot]

This was a 757 which at best is probably 20 years old. The 757 is without question the best narrow body aircraft ever built. It was designed and built before Boeing became compromised. This issue isn’t because of the type of stuff we are seeing on the Max.

Consdering how many A320s are still on order I'm pretty sure many airlines would question that claim.

Considering the A320 family was introduced in the 80s it's pretty astounding how modern of an aircraft it feels.
IMO it feels more up to date than a 777 does, and is less of a POS than the 787 by a long way.

 

[beetroot]

This would seem to be a Delta maintenance issue and cannot be reasonably be blamed on Boeing.

What concerns me though is that Delta maintenance appears to possibly be suffering from the same/similar incompetence and or process breakdowns as what Boeing appears to be.

I guess if you completely ignore the obvious casue which was running over FOD during taxi.
For the tyre to come off completely it wasn't just 20psi low.

We had a 787 puncture both nose wheels just a few months ago, crew only noticed due to an Status message.
If the 757 doesn't have TPIS then there is no way for anyone to know when the fault occured.

 

[_Windrider_]

Consdering how many A320s are still on order I'm pretty sure many airlines would question that claim.

Considering the A320 family was introduced in the 80s it's pretty astounding how modern of an aircraft it feels.
IMO it feels more up to date than a 777 does, and is less of a POS than the 787 by a long way.

Well Boeing sunk their teeth in to the 737. They shut the 75 production line down and destroyed the tooling. The 75 is far more capable than any a320 variant out there. It’s faster by a lot. But it uses a lot of fuel too. It is a go anywhere do anything plane which is why they are still in service. Airbus has had a big advantage these past two decades as they really stepped up their game and Boeing has really been stuck in the past. But the 777 is a mighty bird. The 787 is a great airplane. But I’ll give credit where credit is due. The a350-1000 is the best airplane being built today in the wide body category.

 

[Threadcutter308]

The Max 8 is gutless above FL330-FL350 with any kind of weight on it... it says itll go to 370 or whatever, but if it goes higher than FL355 its staggering and you end up having to come back down. We tried to go to 370 the other day in one and it got to like 363 and just simply wouldnt go any higher. I think the FMC said we could make 380 or whatever... aint no way in hell. We went back down to 350.

Now down low its a BEAST. Those huge fans make a ton of power down low, but up high its anemic at best.

Is this generally due to "higher efficiency" engine design/"fuel savings" ?

 

[_Windrider_]

Is this generally due to "higher efficiency" engine design/"fuel savings" ?

All engines on commercial airliners are neutered the A3 21 Neo is the same way it’s gutless above 32 to 34 if it’s super heavy 36 as a pipe dream

Not to mention the fact that the wing on the A3 21 is grossly undersized

 

[Threadcutter308]

All engines on commercial airliners are neutered the A3 21 Neo is the same way it’s gutless above 32 to 34 if it’s super heavy 36 as a pipe dream

Not to mention the fact that the wing on the A3 21 is grossly undersized

Understood. But, what is the motivation for "neutering" ? Increased fuel efficiency ? If not, what then ?

 

[alpine44]

Is this generally due to "higher efficiency" engine design/"fuel savings" ?

The LEAP engines are a higher bypass ratio design. The first set of blades you see from the front is basically a ducted turboprop. Most of the ingested air gets pushed out between the outer shell and the inner jet engine core. A smaller percentage goes through the inner compressor section, the combustor and then through the high pressure turbine wheels that are on the same hollow shaft than the high pressure compressor disk set. This combo generates the power and rotates at the N1 speed. The visible big fan blades are connected via a separate, concentric shaft to a turbine whel set in the exhaust stream of the hot section and rotate at the N2 speed.
Since the majority of the thrust is generated in these engines by something that resembles a propeller you'll get a similar thrust loss with decreasing air density at higher altitudes. But the whole process is thermodynamically more efficient and saves fuel.

https://leehamnews-5389.kxcdn.com/wp-content/uploads/2012/02/leap_1.jpg

 

[Threadcutter308]

The LEAP engines are a higher bypass ratio design. The first set of blades you see from the front is basically a ducted turbofan. Most of the ingested air gets pushed out between the outer shell and the inner jet engine core. A smaller percentage goes through the inner compressor section, the burner cans and then through a set of turbine wheels that is connected to the compressor disk set. This combo generates the power and rotates at the N1 speed. The first disk of the visible big fan blades is connected via a separate, concentric shaft to a turbine set in the exhaust stream of the hot section and rotates at the slower N2 speed.
Since the majority of the thrust is generated by something that resembles more a propeller than a multi stage jet engine

Thank you. I can't say that I knew any of that to that degree of detail. But, I was aware of some of that in a very general sense.

 

[_Windrider_]

Understood. But, what is the motivation for "neutering" ? Increased fuel efficiency ? If not, what then ?

Yes, it’s a trade-off between speed and fuel economy

 

[_Windrider_]

Understood. But, what is the motivation for "neutering" ? Increased fuel efficiency ? If not, what then ?

And I can’t speak to what the efficiency is on a 737 max with the leaps, but I know on the airbus between the Neo and the classic on a given flight say between JFK to LA on a Neo Al burn anywhere from 1000 to 1500 gallons less fuel on the same route However in order to do that I have to go a little bit slower like say Mach 76 versus Mach 78

 

[beetroot]

Understood. But, what is the motivation for "neutering" ? Increased fuel efficiency ? If not, what then ?

Most airlines tend to fly a bit slower even on older generation aircraft, so the slower speed isn't really an issue.
Fuel efficency is pretty much the only thing airlines care about these days.

Oh and paying employees as little as possible.

 

[Threadcutter308]

And I can’t speak to what the efficiency is on a 737 max with the leaps, but I know on the airbus between the Neo and the classic on a given flight say between JFK to LA on a Neo Al burn anywhere from 1000 to 1500 gallons less fuel on the same route However in order to do that I have to go a little bit slower like say Mach 76 versus Mach 78

Wow ! 0.02Mach difference to save 1,000 gallons ? Geez, who's going to notice the speed difference ?

I wonder if john kerry gets those (proportional) fuel savings on his G5 ?

 

[_Windrider_]

Most airlines tend to fly a bit slower even on older generation aircraft, so the slower speed isn't really an issue.
Fuel efficency is pretty much the only thing airlines care about these days.

Oh and paying employees as little as possible.

Yes and no. Mach 78 is probably the standard. But the 757 is typically doing like 82-85. We can fly slower if we have a good tailwind and take advantage of a lower fuel burn with high GS. But we use cost indexing. Sometimes it wants us to be slower. Sometimes it wants us to be faster. Sometimes ATC wants us faster or slower. It’s all a trade off. On a short route the time savings between cruising at .76 and Mach 78 is negligible and difficult to measure. But in a trans con or longer it can be the difference by 15 minutes.

 

[_Windrider_]

Wow ! 0.02Mach difference to save 1,000 gallons ? Geez, who's going to notice the speed difference ?

I wonder if john kerry gets those (proportional) fuel savings on his G5 ?

His G5 is at FL450 and is burns way less gas. The A321 NEO sips gas. Usually by the time we land in LGW or somewhere we are only burning maybe 2200 aside. That is significant fuel
Savings. But of course it doesn’t start out that way. Obviously as you burn fuel you weigh less and you can climb higher and burn less. That’s why we step climb as we fly long distances. At max TOW no way you are getting that efficiency.

 

[Threadcutter308]

His G5 is at FL450 and is burns way less gas. The A321 NEO sips gas. Usually by the time we land in LGW or somewhere we are only burning maybe 2200 aside. That is significant fuel
Savings. But of course it doesn’t start out that way. Obviously as you burn fuel you weigh less and you can climb higher and burn less. That’s why we step climb as we fly long distances. At max TOW no way you are getting that efficiency.

Yeah, no, that's why I said "proportionally"........

And, correct me if I'm wrong, but if you are trying to design more efficient engines/powerplants, you are by necessity having to look at total fuel consumption averaged over all "typical" flight profiles. Which, being able to say that any two flight profiles are the same or "identical" is probably foolish.

But, I would guess that there is more than enough data available to be able to say with a moderately high degree of confidence that you are improving things, relative to efficiency. But pushed too far and I would guess that you end up with some "pigs".

 

[_Windrider_]

Yeah, no, that's why I said "proportionally"........

Man those gulfstreams are so efficient. They have huge wings and way overpowered engines. I bet they get way better efficiency and their engines aren’t neutered.

 

[BJames]

The Max 8 is gutless above FL330-FL350 with any kind of weight on it... it says itll go to 370 or whatever, but if it goes higher than FL355 its staggering and you end up having to come back down. We tried to go to 370 the other day in one and it got to like 363 and just simply wouldnt go any higher. I think the FMC said we could make 380 or whatever... aint no way in hell. We went back down to 350.

Now down low its a BEAST. Those huge fans make a ton of power down low, but up high its anemic at best.

Haven’t flown the max 8 yet as work has just acquired its very first one. The 9 on the other hand gives you 1500 fpm at FL200, that’s what you get. The best we could do In a heavy max 9 FL320-340, and VNAV is going to give you the porpoising climb to get there. I honestly think the 900ER’s are a little better, but they sure burn a bunch more fuel.

I am a little curious to see the max 8, and really want to see the max 7, if it ever gets in the air. I absolutely love the 700’s.

 

[Mr.BR]

 

[_Windrider_]

Haven’t flown the max 8 yet as work has just acquired its very first one. The 9 on the other hand gives you 1500 fpm at FL200, that’s what you get. The best we could do In a heavy max 9 FL320-340, and VNAV is going to give you the porpoising climb to get there. I honestly think the 900ER’s are a little better, but they sure burn a bunch more fuel.

I am a little curious to see the max 8, and really want to see the max 7, if it ever gets in the air. I absolutely love the 700’s.

I hate the porpoiseing. The 700 is a climber.

 

[rjacobs]

Is this generally due to "higher efficiency" engine design/"fuel savings" ?

more the high efficiency design and less "fuel savings"...

When you put MASSIVE fans on an engine its going to make a lot of power down low where it can bite into thick air. Up high where air is thin(molecules are less for those science nerds) it makes less power... Its a trade off...

turbo jet aircraft of old took 10k foot of runway, but would run away from us at altitude doing .90 mach... yea they burned an ass load of fuel, but they made power differently than a turbo fan. Its a trade off... is what it is... not good or bad.

Lets say a 737 NG burns 5000lbs an hour... a max will burn 4000(or maybe slightly less) in the same conditions. So 1000lbs an hour total... On a 4 hour flight thats 4k lbs fuel burn difference... 6.767 lbs per gallon thats 591 gallons less fuel at say $2.50 per gallon... So $1500 less on that flight. My airline fly's around 4000 flights per day... I bet we average 2 hours per flight so call it $750 in fuel savings. If we had a complete fleet of Max's that $750x4000x365... thats a billion dollars a year in fuel savings. Obviously simple math that leaves out a ton of variables, but its a lot of money. The Airbus NEO is in the same boat.

 

[BJames]

Word on the street is the feds have approved the mx(maintenance) procedures a couple days ago. Minimum 12 hour inspection process. Work was supposed to have the first one flying today, albeit they’re doing the first flights of each tail with min crew only.

 

[rjacobs]

Minimum 12 hour inspection process.

horse hockey...

12 minutes is more like it...

5 hours to remove the interior... 12 minutes to click a torque wrench on every bolt on each plug... 1 hour to document everything in the electronic logbook system thats so convoluted nobody can make sense of it. 5 hours to reinstall the interior... :48 to drink beer and slap each other on the backs for a job well done at the titty bar up the street after 3rd shift... Did my math add up to 12 hours???

 

[BJames]

And, correct me if I'm wrong, but if you are trying to design more efficient engines/powerplants, you are by necessity having to look at total fuel consumption averaged over all "typical" flight profiles. Which, being able to say that any two flight profiles are the same or "identical" is probably foolish.

Just to add to the conversation, you‘re not wrong. The high vs low altitude fuel burn that @rjacobs just talked about is a huge factor. Another piece to the puzzle is, most every operator adjusts the take off, climb, cruise and descent profiles based off a bunch of stuff like atmospherics, aircraft weight, fuel cost, etc, in an effort to reduce the fuel costs. It’s called cost index and is uploaded directly into the bird‘s computers. Reduced power take offs are standard, though that’s more of an engine maintenance/longevity thing, but is a part of that equation. My company also pushes single engine taxi out/in, and minimal APU usage, as another means of fuel cost savings, it all adds up.

 

[BJames]

horse hockey...

12 minutes is more like it...

5 hours to remove the interior... 12 minutes to click a torque wrench on every bolt on each plug... 1 hour to document everything in the electronic logbook system thats so convoluted nobody can make sense of it. 5 hours to reinstall the interior... :48 to drink beer and slap each other on the backs for a job well done at the titty bar up the street after 3rd shift... Did my math add up to 12 hours???

Maybe the extra time is the 3-5 other techs standing there supervising the work and guy #1. Guys #2-5 supervise each other. Standard phraseology is: Great job everyone, we’re hero’s today.

 

[rjacobs]

Maybe the extra time is the 3-5 other techs standing there supervising the work and guy #1. Guys #2-5 supervise each other. Standard phraseology is: Great job everyone, we’re hero’s today.

Yea they dont say 12 "man" hours... If you got 12 dudes(which would look like a gang bang in the back of a 737 to have 12 dudes working on 2 doors) its only 1 hour per man...

all at the sweet cha-ching of 1.5-2x+ overtime pay....

When we had to inspect every NG fan blade after the 2nd Southwest engine failure supposedly guys were sleeping on cots in the hangars. I asked "was that mandatory"... "oh hell no, but we were making triple pay so fuck it"...

 

[Mr.BR]

Sounds like Boeing stock buy season

Too big to fail ,so are the stocks low enough ?

Boeing Discovers "Mis-drilled" Holes On 50 Undelivered 737 Max Jets​

https://www.reuters.com/business/ae...liveries-after-new-quality-defect-2024-02-05/

 

[Longshot231]

 

[E. Bryant]

Boeing Discovers "Mis-drilled" Holes On 50 Undelivered 737 Max Jets

https://www.reuters.com/business/ae...liveries-after-new-quality-defect-2024-02-05/

Nope, no evidence of systemic problems here...

 

[DIBBS]

Quality Control... or lack thereof.

Mis drilled holes, how the hell does that happen. Wouldn't there be a template? On the other hand, pot IS legal in WA , one of the libtard states.

News just said over 50 % of jets in service were from Boeing.

This shit keeps up and they may lose some of their market.

 

[rjacobs]

Mis drilled holes, how the hell does that happen. Wouldn't there be a template? On the other hand, pot IS legal in WA , one of the libtard states.

Probably a template or a jig thats worn the fuck out, but it wont get replaced until shit like this happens because it could be like a 10k+ dollar drill jig fixture... Buddy of mine worked in QC at a Lockheed Martin contractor and he said he saw shit like this all the time due to worn out jigs and the company would be hesitant to replace them...but when he would refuse to sign off on composite parts worth hundreds of thousands of dollars, they would replace the drill jig that cost like 20-30k to replace...

And this stuff was made at Spirit in Wichita... I dont know if pot is legal in KS, but I doubt it.

 

[E. Bryant]

Probably a template or a jig thats worn the fuck out,

One of our own members already covered this back in post 100 of this thread:

Boeing 737 Max at it again

Glad that phone landed safely . Now we wait for plug to pop up on ebay 🤡 Imagine walking down the road minding your own mutha fawking business and getting your noggin caved in by some pos iphone....lol

www.snipershide.com

Then our resident edgelord (who has mysteriously disappeared from this thread) told him to shut up and go away:

Boeing 737 Max at it again

http://aeropeep.com/the-door-responsible-for-temporary-grounding-of-boeing-b737max9-fleet-has-been-recovered-by-ntsb/

www.snipershide.com

I think one of these guys knows more about the specific problems than the other.

 

[rjacobs]

One of our own members already covered this back in post 100 of this thread:

Boeing 737 Max at it again

Glad that phone landed safely . Now we wait for plug to pop up on ebay 🤡 Imagine walking down the road minding your own mutha fawking business and getting your noggin caved in by some pos iphone....lol

www.snipershide.com

I think one of these guys knows more about the specific problems than the other.

To be fair to the guy who works in CHS... on the 787... on CNC drill's... on carbon fiber...

He has only 1 thing in common with the 737 fuselage, built in kansas, out of aluminum, by Spirit.... he could probably go to Spirit and show them a thing or two about cnc drilling... if they use CNC drills at all and not hand drills and a large drill jig of some kind.