Are P&W motors so bad?
Posted by olddoglearnsnewtrick@reddit | aviation | View on Reddit | 106 comments
This italian newspaper article states that 50% of the Airbus 320neo with Pratt & Whitney motors are grounded for inspections and that there's a rush to find alternatives and a boom of acquisition of older planes.
Is this true or is it a journalist having to earn its supper without much understanding?
Far_Breakfast_5808@reddit
It's a major problem. A large part of the international PW-powered A320neo family fleet is grounded due to engine issues. It's actually brought down a few airlines like India's Go First, and contributed to Spirit's bankruptcies. It's such a problem that it's even causing some planes to be cannibalized for spares.
It's not just the A320neos that have this issue. The A220 is also having similar problems, to the point that several planes are grounded. There were even recent reports that Swiss grounded its fleet of A220-100s for spares to keep their -300s flying.
Python_07@reddit
Is it still the overheating issues?
j-rocMC@reddit
No the issue is contaminated powdered metal that can only be assessed through off-wing inspection
Python_07@reddit
Interesting. What is the contamination?
OracleofFl@reddit
Key engine parts are made through something called "powder metallurgy" where a pure alloy powder is pressed under very high temperature and pressure into the formed part in a mold like thing. My understanding is that a P&W subcontractor making these parts for them had a flaw in their process leading to contaminants getting into the powder and thus a weakness in the part.
Stepho_62@reddit
Powder Met process is a 2 step process where the powdered metal is put into a die and pressed at very high pressure to form part. This post press stage is called the green stage. They are then put into a sintering oven at a very high temperature which allows the metal alloy to fuse together. The part then goes into post sintering processes where it is ground/machined to it final form
Jiggly_Meatloaf@reddit
This is not at all how jet engine disks are made when using powder metal.
Stepho_62@reddit
So how are they made? What I've got explained above is the conventional method. Enlighten me WRT how powder met technology is used in the aviation industry
Jiggly_Meatloaf@reddit
Apologies for my delayed response and if my tone came across as condescending. u/EclecticEuTECHtic has a good synopsis below in this thread on how jet engine disks are made using powder.
Source: I've been in the jet engine powder metal supply chain for over 10 years.
Python_07@reddit
Thanks
EclecticEuTECHtic@reddit
There are also turbine disks being made from powdered metal in a slightly different process where the metal is poured into a simple cylindrical case, hot isosotatic pressed to consolidate and then forged like any other nickel billet. The billets are then isothermally forged into disk blanks and machines to final shape.
OracleofFl@reddit
...and that is part of the reason these engines cost millions of dollars a pop!
EclecticEuTECHtic@reddit
The powder route even seems less complicated in some ways than the traditional triple melt (VIM-ESR-VAR) approach :)
Sinhag@reddit
Can we use Ceramic Matrix Composits in turbine disks instead of triple melt alloys or powdered metal?
EclecticEuTECHtic@reddit
No, not nearly as durable yet. They can probably work as blades though and the effect will be to reduce the needed mass of the disk as the blades are lighter and will have less rotational inertia that the disk needs to contain.
ScipioAfricanusMAJ@reddit
We got carbon fiber blades now right. Seems like moving forward that will be commonplace
MehImages@reddit
you're probably thinking of fan blades, not turbine blades
ScipioAfricanusMAJ@reddit
Ah yes, although I thought all compressor blades were ceramic as well? Are we still using aluminum?
EclecticEuTECHtic@reddit
Titanium and nickel in the later stage compressors. It get hot even before the fuel is injected!
zipper77@reddit
Best explanation yet. And great username. I’m a metallurgist and used to work at a plant that made this type of disk forging (not the ones in question though)!
Python_07@reddit
Thanks
ProgressExcellent609@reddit
Tragedy upon tragedy
Momsfartbox@reddit
It wasn't so much contamination, but more mixture ratio form damage screens that control the powder mix. The wrong ratio leads to internal failures due to metallurgical markup.
Only_Razzmatazz_4498@reddit
Powder metal and 3D printing they both have the issue that to get certified parts you have to control things much more than for regular metal cutting. It’s not enough to know the chemistry, things like exposure to air or humidity etc all affect the results. I don’t know what the contamination was but it doesn’t necessarily have to be particular material it could be as simple as the powder being too fine or too coarse or a container material change.
discombobulated38x@reddit
To be fair for critical parts (rotating discs and shafts) you don't have to be any more tightly controlling of material quality than you do for conventional material sources.
Only_Razzmatazz_4498@reddit
True. It’s just an extra level of process control to n top of an already tight process and material control for powder and additive manufacturing.
Go_Loud762@reddit
I don't know what the contaminate is, but it causes the part to fail.
G25777K@reddit
Combination of many issues since 2016
Today your lucky for the engine to stay on wing for 35% of what was promised, its not just the powdered metal issue, any GTF engine coming out of the shop today does not have this issue, but there plenty of other issues. Hopefully one day it will get better.
Far_Breakfast_5808@reddit
I'm not sure if it it's that or if it's that paint thing that was affecting the blades. What I do know is that the PW issues are such an issue that it's actually affecting the A220, while some A320neo operators have considered switching to the LEAP. What I am not sure of is why it doesn't seem like the E2 is affected as much despite also being PW-powered.
j-rocMC@reddit
1900 is definitely also affected. Just smaller fleet, more recent date of manufacture. Even V2500 is affected.
aitorbk@reddit
As far as I understand it, the stress the engines way less.
Far_Breakfast_5808@reddit
Does that mean that the issue with the metallic powder has actually been around for ages, but because old engines were not as stressed, it only became an issue now?
aitorbk@reddit
It must be a very complicated to test issue, because very smart engineers have been caught by the problem. My educated guess is that yes, it has been an issue for a long time, but it is related to high power cycles, like toga, etc micro cracking. These are the type of issues that have made the Chinese be so behind in modern aviation engines, they are difficult to solve, predict, and detect.
ManifestDestinysChld@reddit
How does this issue manifest in engines that are in service? Is it a risk of catastrophic destruction, or more like an inability to produce thrust (or something else)?
aitorbk@reddit
Vibration and egt anomalies. Difficult to detect without a boroscope and checking for cracks. It can lead to catastrophic failure. There are a series of failures,most of them already addressed, but there is a backlog.
ManifestDestinysChld@reddit
Gotcha. Thanks for the context!
alteregooo@reddit
the powder metal issue is exclusive to the PW1100G; the others are have short time on wing (tow) than airlines would like, which causes maintenance facilities and supply chain to be overwhelmed. factor in the PW1100G inspections/replacements and you have a shitshow on your hands
hadshah@reddit
The PW1900 is on the E2, which is a lighter aircraft than the A220. Thus, it gets less wear and tear as it usually requires less thrust than the A220 in the most deteriorative condition (take-off). It’s enough to make a difference.
scotsman3288@reddit
This is how I understand the difference also, but that's not to say that some airlines haven't had issues them. KLM grounded their E2 jets for a short time for engine issues. Porter here in Canada has not had any issues to my knowledge.
Far_Breakfast_5808@reddit
Porter can't afford to have issues. From what I understand, their E2 operation hasn't exactly been profitable, and Porter's finances are not necessarily in a good state at the moment. If things go south, it could potentially bring down the entire company if they're not careful.
scotsman3288@reddit
I don't think Porter is in a negative operating position, as they have a pretty sweet leasing agreement with a few firms. Their Q400 operation has been profitable since 2011. If they decide to expand into western market, then that might get risky if they can't order more Q400s.
hadshah@reddit
It’s because there are 2 different issues - powdered metal issue and a hot section time-on-wing (ToW) issue.
All GTF and V2500 regardless of thrust class are equally susceptible to the powdered metal issue from what I understand.
The ToW issue is where the PW1900 fares better because the E2 is lighter, thus doesn’t impart as much of a thermal impact on the hot section as compared to the A220, or the higher thrust engine PW1100.
Python_07@reddit
Right. PW 1900 on the E2? That’s an interesting fact.
V8-Turbo-Hybrid@reddit
I do know nothing in current aircrafts, but I can’t believe P&W so bad.
F-22 and upcoming F-47 use their jets.
discombobulated38x@reddit
They got really unlucky with a bad batch of disc alloy, beyond the usual new engine project management hubris of believing the engineers are capable of defying physics this time unlike every previous time where that wasn't successful (specifically with respect to HP turbine blade/guide vane degradation) .
V8-Turbo-Hybrid@reddit
That sounds same issue like Boeing, oof.
discombobulated38x@reddit
Not so much that, as project management drawing a trend through half a century of gas turbine development and naively assuming that temperatures/efficiency would continue to increase and everything else would continue to get better, only for every engine in the last ~20 years to run into issues that have caused that trend to flatten off.
Fatal_Explorer@reddit
Completly not comparable. PWC fired huge amount of staff during covid, which turned out to be a disaster decision later. They lost vast amount of experience, good staff and networks. PWC also quit many subcontractor contracts during the covid time, which lead and still leads to immens spare part problems. Imagine, many parts that go into the engines where made by companies, that then shut down or went into different parts and businesses, after they lost the PWC contracts. PWC chased long time for new producers, and they had immense quality issues once they finally were able to actually produce parts (powered parts, turbine blades etc).
And these engines here in question are geared turbofan engines, which have their own part of issues for years now which PWC is only slowly to fix, and it's very costly.
TLDR: Pratt and Whitney does not have bad engines, they have very bad management
V8-Turbo-Hybrid@reddit
Now, I get it. So, that's also a reason why F-22 unable to produce it again, right ? It's too costly to rebuilt it, as they need new suppliers to built new parts.
mkosmo@reddit
PWC isn’t responsible for the GTF.
Fatal_Explorer@reddit
How so? On the A220 they are indeed. CFM is a different topic of course.
mkosmo@reddit
The A220 uses the PW1500G family, which is a Pratt engine, but not a Pratt Canada engine.
PWC is specifically Pratt & Whitney Canada. Think the PT6 and smaller PW800 turbofans.
Fatal_Explorer@reddit
Fair. But outside of the GTF engines, especially the PT6 and the PW306 engines where also a fiasco with turbine blades, coatings coming off, overhaul taking 14+ months because of new subcontractors and missing parts.
I wasn't aware that P&W and PWC are distinctly different companies. Got to talk to my field rep about that next time I speak to her.
JT-Av8or@reddit
It’s not P&W, it’s that specific geared turbofan design that everyone is still working the kinks out of. Notice how 757s with the PW 2000 series engines never make the news? Because those airframes and engines are from the 1990s when the built strong first, efficient later
Sinhag@reddit
New gear works suprisingly well, it's the other parts that are troublesome
JT-Av8or@reddit
I heard my A-220 buddy say that. Like somehow they messed up basic stuff but got the complex part right.
anactualspacecadet@reddit
No, i would argue they are the best in the world
olddoglearnsnewtrick@reddit (OP)
From the comments I think the issue is related to the whole supply chain being inefficient forcing too much time on the ground. Did I understand correctly?
SuperFaulty@reddit
First Boeing, now P&W... Looks like American quality in the aerospace industry has lowered its standards to match the Russian or Chinese quality. Sad.
ScienceMechEng_Lover@reddit
They were bad enough to bankrupt entire airlines (GoAir and Spirit). I'd be surprised if they recover from the reputational damage anytime soon tbh.
Expo737@reddit
I've been calling them "Pratt & Shitney" for years, never liked them.
Though to be fair to P&W, my only engine failure was a CFM and that was a very long time ago when reliability was not the same as it is now. Never had a problem with RR ;)
mdp300@reddit
It's crazy that these companies, which have been doing the same thing and leading the industry for a century, are running into so many problems now. Are we reaching the limits of what is possible with metallurgy, or is it cost cutting?
And it happens in so many industries. Boeing had the MAX and can't finish the 777X, Bombardier forgot how to make trains that work, etc.
Messyfingers@reddit
The powdered metal problem wasn't a cost cutting issue as much as it was a glaring lack of oversight of the supplier involved with the contaminated powdered nickel. Getting it resolved has apparently been difficult because the supply chain is already stretched thin from the ramp up in production for the 320NEO and 737MAX. COVID messed up a lot of industries, supply chain issues, early retirements for a lot of industries meant brain drain and the hiring activity at a lot of places before covid was lagging.
Next_Requirement8774@reddit
Stop blaming Covid, the issue here with P&W and Boeing is the freaking outsourcing and on top of that, lack of supplier oversight.
discombobulated38x@reddit
The MAX and the 737 are both just symptoms of ruthless cost cutting and corporate idiocy at Boeing.
Company ending engine and aircraft issues aren't new though - RR and Lockheed both needed bailing out over the tristar/RB211 debacle as the most notable one.
GE (including CFM), RR and PW are all very much scraping the boundaries of the possible as far as material capability goes with their civil engines though, which is causing them all issues.
The disc alloy defect that is driving the biggest issues with the PW GTF offerings is just pure bad luck though, there have been similar issues at GE and RR, just not quite so public or costly.
Small-Policy-3859@reddit
It's more than likely mainly cost cutting. But probably also in part because of margins getting smaller and smaller. So both basically.
derp2086@reddit
RTX’s stock price and recovery would disagree with the reputational damage standpoint
ScienceMechEng_Lover@reddit
I meant reputation in the civil aviation space. Not many airlines are going to order new planes with Pratt & Whitney engines for a long time after what's happened so far with both the GTF engines as well as the PW6000 on the A318. Pratt & Whitney are still doing well with defense though, which is probably also where a large chunk of their money comes from.
UserRemoved@reddit
I was shocked PW got a new contract this millennium.
jbethel811@reddit
Related question: Why did so many carriers choose the Pratt & Whitney GTF engines? And why are aircraft still being ordered/manufactured with the GTF engines despite these problems? The CFM Leap 1B has been successful with not just the A320neo but also the 737 MAX (albeit Leap 1A). I remember hearing something along the lines of better performance for long-haul flying whereas the CFM Leap 1B had better takeoff and climb performance. Surely there has to be something else?
Senior-Cantaloupe-69@reddit
I know they can’t get parts for business aviation engines either. The rumor is they outsourced much of the blade and disc manufacturing and then let those shops fail during Covid when no one was flying much. Now, no one can do the metallurgy required.
Zinger21@reddit
I'm already working on getting hot sections scheduled on our PW306Cs and they are not due till mid 2027. Heard it's a nightmare, so might as well get on it. At least P&W has been good about offering extensions if needed and the engines meet certain parameters.
UserRemoved@reddit
Wow, 50% is way up from its historically grounded status. PW is a joke.
xwell320@reddit
P&W pushed technology to the limits for fuel efficiency gains, CFM LEAPs are slightly less fuel efficient, but FAR more reliable, I know which one I'd rather have.
fresh_like_Oprah@reddit
Kinda like automobiles these days. Give me a 90s E 30
sonnyempireant@reddit
It's one specific PW1000 series model that's so troublesome, the PW1500G. The reason it's grabbing so many headlines is because it's been adopted by Airbus across its Neo range of A320s and also the Bombardier-designed A220.
Interestingly, Embraer's latest E2 line of regional jets is using the PW1900G and that one appears to be much more stable and reliable. So I wouldn't go as far as to say that Pratt & Whitney are making bad engines as a whole now.
Hylax1@reddit
It makes sense as it was the first geared-turbofan on the market for commercial aircraft. It's a shame too because it is such a promising technology.
curiousnc73@reddit
The 1700 was for all intents and purposes killed as no one wants e175 e2
DoorBuster2@reddit
No, PW had the powder coating escape issue and that grounded roughly 1/3rd of engine produced. RTX/PW voluntarily decided to ground all suspected engines, and do a full inspection and replacement.
To me, this screams reliability and commitment to safety. They could have just as easily waited for a Boeing incident.
Additionally, the engine is more powerful and requires less fuel, so it's overall a lower cost to the airlines. Coupled with the fact that PW has another 1000 engine backlog and cannot produce them fast enough, they are fine.
Did the stock take a hit? Yes. Did PW suffer reputational damage? Yes. But, I think it showed a a commitment to safety and the numbers speak for themselves, airlines are still buying these engines and they'll be in the skies for generations to come.
Not to mention all the military engines that PW produces
kc_dal@reddit
Raytheon stock hasn’t really taken a hit. I’ve been pretty happy with it, because I agree with all your other points and their commitment to reliability and safety helped avoid any major nose dives over the last five years.
RTX has been one of my most resilient holdings, despite the PW GTF-related headwinds.
PozhanPop@reddit
It caused an airline to India to go bust. Look up Go First ( Go Air). The GTFs were not suited for Indian conditions apparently.
discombobulated38x@reddit
Yeah that's pretty much on the money.
If your purepower GTF needs to be removed from wing because it's lifed out you won't get the engine back for somewhere between a year and 18 months at the moment, because they're that swamped with replacing defective discs/just can't get the material to make more.
It's an absolutely awful situation for them/Airbus, wouldn't wish it on anyone.
They've put such a dent in the disc material supply chain that it's put up costs and lead times for GE and RR too.
curiousnc73@reddit
Everyone makes their own disks the problem is ge and prat switched to blisks/ones which require way more machining than a traditional disk. Also there are minimal repairs for blades on these so one blade with an unserviceable nick can require a whole disk replacement
discombobulated38x@reddit
Yes everyone makes their own but their alloys are more or less all supplied by Special Metals, Haynes International, ATI and a couple of others, all of whom use the same sources for the various rare earth metals that go into superalloys used in discs.
So when PW suddenly needs a decades worth of alloy for the entire industry in two years, the price goes up by a fair whack.
Boundish91@reddit
Airbus should have bought European engines.
bankkopf@reddit
The European option is the CFM Leap engine. It’s not that the NEO only has one engine option like the A350 or newer 777(x) variants. Airlines decided they wanted to go with the PW engine instead of the CFM option for various reasons. The issues weren’t known at the time, but now the airlines have to live with the consequences of their choice.
BigDiesel07@reddit
Outside of using the same engine manufacturer across the entire fleet, what other benefits does the PW have over the CFM that made it a choice.
Pontius_the_Pilate@reddit
Geared fan?
revilohamster@reddit
The PW GTF are said to have slightly better fuel burn than the CFM LEAP. Less fuel = higher profit. This makes it an easy choice for bean counting MBAs with simplified cost-benefit spreadsheets, that do not properly take into account maintenance costs and downtime.
mkosmo@reddit
If it weren’t for the manufacturing defect, maintenance would have been similar enough that it wasn’t a significant consideration.
EclecticEuTECHtic@reddit
The GTF was a technological "leap" (heh) rather than CFM just using improved materials and incremental designs to achieve the same fuel economy improvements.
hadshah@reddit
The PW engines are lighter due reduced stage count, which reduces # of airfoils, which then theoretically should heavily reduce $ of maintenance. Also, different business models and maintenance package offered by both companies.
astral__monk@reddit
A220 has been having massive issues with their PW1500G. It was also the only option on the aircraft, so if operators bought them they've been stuck in this mess.
astral__monk@reddit
A220 has been having massive issues with their PW1500G.
But it was also the only option on the aircraft, so if operators bought 220s (both -100s and -300s) they've been stuck in this mess.
No_Information2012@reddit
CFM engines, which airlines can choose over the P&W ones, are a joint venture between Safran (French) and GE.
BackgroundGrade@reddit
The engines run fine. The problem is durability. They need to be inspected/rebuilt on very short intervals. This leads to availability.
Lazlorian@reddit
How does manufacturer warranty work in this case? Or is there even such a thing for these engines? Do they have guaranteed uptime?
Grounding planes for months means tens of millions lost, and I wonder if the manufacturer is in a way responsible for the costs.
swirler@reddit
The last good engine P&W built was the JT8D.
Winbot4t2@reddit
PT6??
BackgroundGrade@reddit
Pratt & Whitney Canada is a completely different company than P&W commercial. Almost zero shared engineering.
langley10@reddit
PW100 for that matter?
EclecticEuTECHtic@reddit
There's something going on with P&Ws commercial engine organization. You don't hear about F-35 engine problems like this. Even when I was in the industry at a supplier we didn't hear about that.
nasadowsk@reddit
Gah, they've been getting a good rep for fucking up everything they touch...
just_kos_me@reddit
The airline I work at is getting rid of all A32N with PW GTF's to then switch over the whole fleet to CFM LEAP. PW is just not able to deliver parts and engines at a sufficient pace. Such a shame, especially since the technical issues are not related to the innovative GTF design itself. Especially since the PW GTF is a bit more fuel efficient than LEAP.
The cost benefit of less fuel expenses dwarf in comparison to having AOG.
FilipM_eu@reddit
I’ve been to NATO days last month in Ostrava and was surprised to see a lot of brand new airplanes in long term storage there, mostly A321s belonging to Wizz and some belonging to American Airlines.
LifeguardGlobal952@reddit
Really good article here about Swiss
https://simpleflying.com/swiss-airbus-a220-100-withdrawals/