8 ms·

Technically they’re grounding the Pratt & Whitney engine model that happens to be attached to their aircraft. When one buys a big jet you pick out what engine

by JCM9 6y ago

Technically they’re grounding the Pratt & Whitney engine model that happens to be attached to their aircraft. When one buys a big jet you pick out what engine you want to buy and slap onto it. It’s a particular engine they’re concerned about, not the 777 airframe itself.

balaa 6y ago
Cool, you work at Boeing media relations?
arnon 6y ago
The P&W-powered 777 is just one variant. British Airways for example went with GE90s, and some airlines like El Al went with Rolls Royce Trent 800s.
- ninkendo 6y ago
  Are there any Airbus (or other comapanies’) planes that have the affected engine? Or just Boeing?
  - arnon 6y ago
    Airbus A300-600/A310 Airbus A330 Boeing 747-400 Boeing 767/KC-46 Boeing 777 McDonnell Douglas MD-11
    - rob74 6y ago
      ...however the exact type of engine Boeing is using for the 777 (PW4000-112 - https://en.wikipedia.org/wiki/Pratt_%26_Whitney_PW4000#PW4000-112 https://en.wikipedia.org/wiki/Pratt_%26_Whitney_PW4000#PW400...) is not used by any other airliner. I'm no expert, but as the most powerful -112 version has almost twice the thrust of the -94 version, I wouldn't automatically conclude that problems with one type mean that there are also problems with the other types. OTOH, if they take a closer look at the 777 engines and find a lot with problems that went undetected until now, I assume the other PW4000 engines will get a closer inspection as well...
      - arnon 6y ago
        The core is the same. The different model numbers typically represent other configurations of the stages or pump throughput, type of FADEC, and all of these things.
      - kayfox 6y ago
        Its noted that a 747 had a very similar issue the same day as this 777 with the same series of engine. Since the issue is most likely with fracture detection during maintenance inspection and P&W introduced new procedures for that a few years back, its likely the issue is with the tech being used or the procedures. Which would mean any P&W engines using the same technologies and procedures to detect fan and turbine blade cracks would be affected.
imglorp 6y ago
Also, this is not the first incident and it it's not the first Airworthiness Directive against the PW-4077. https://duckduckgo.com/?q=PW-4077+%22airworthiness+directive%22&t=ffcm&ia=web https://duckduckgo.com/?q=PW-4077+%22airworthiness+directive...
- Pasorrijer 6y ago
  While I understand the point you're trying to make, I'd just like to note that if you type any mature engine for any aircraft into a search engine, you're going to find more than one Airworthiness Directive for that engine
  - imglorp 6y ago
    No point really, just interesting that they've had an eye on various metallurgy inspections for a while. This is at least the third engine--with Trent and GE--so maybe those guys had their share of AD's. Also props to the 777 platform for being modular here and bulletproof in general. edit. It's obviously a tradeoff of accepting a certain number of (usually) contained survivable fan events vs being able to afford flying them.
tibbydudeza 6y ago
That seems like a complicated way to sell airplanes - why is that ???. It is like me buying a car from Ford and saying I don't want the Ecoboost turbo 4 but rather that V8 from the Raptor.
- 0xcafecafe 6y ago
  This might be due to a car being a more common retail purchase compared to a plane. Airlines might want to customize their plane for the usage and different engines might provide different benefits.
  - croutonwagon 6y ago
    I’m guessing it has most to do maintenance training and supply chains. If x carrier standardized on PW or Rolls engines, it makes sense to try and keep their fleet on that engine. It simplifies maintenance, what parts need to be kept in stock etc. If you have a fleet of rolls engines and one batch of planes running PW then you have to set aside entire storage, training and supply chains for a single batch. From Boeing’s perspective, they can sell more airframes with a modular setup that allows the carriers to choose their powerplants. Especially in a worldwide setup where a rolls Royce may be cheaper in one market and a PW cheaper in another across a pond
- re-actor 6y ago
  Most car models come with various engine options, sure you can't get a V8 in your focus but you can choose between various displacement Gas/Diesel/Hybrid options. In fact the current model year ford focus ships with 14 engine variations.
- dd82 6y ago
  https://aviation.stackexchange.com/questions/38156/why-bother-having-different-engine-options-on-one-aircraft https://aviation.stackexchange.com/questions/38156/why-bothe... might be helpful
  - dmurray 6y ago
sandworm101 6y ago
>>It’s a particular engine they’re concerned about, not the 777 airframe itself. While literally true, in all practical terms those airframes are grounded. Engines can be swapped but it isn't as simple as swapping a V8 for a V6. These are expensive and physically large objects. There aren't enough spares available to re-engine so many airframes, and it would take years to build a new supply. So any airframe with the listed engines is essentially grounded until the problem can be addressed.
- huntertwo 6y ago
  That’s only about 60 in service planes.
  - sandworm101 6y ago
    Try ordering 120 new airliner engines. It will take a while. There is no real surge capacity for these things. You would probably have better luck buying used.
    - croutonwagon 6y ago
      Maybe. But most airline companies can ground a small portion of their fleet and it not really affect their outcome. They should have some redundancy built into their maintenance schedules so that 60 planes, even in a single company shouldnt have too much of a flight schedule burden.
- nemetroid 6y ago
  Only the 777s that have PW4000 engines. The 777s with GE or Trent engines are fine.
4cao 6y ago
That's a good point. As far as I know, newer B77* generally use GE or RR engines. The PW ones are old at this point, and also represent the smallest and decreasing share, so most planes of this type aren't affected. United (or one of its predecessors) was an early customer, and I think PW was the only engine option at launch. (Not my area of expertise, so I'd appreciate a correction if I got something wrong.)
- sjm-lbm 6y ago
  Pretty much correct. The Pratt engine was in service six or so months before the GE engine (and a year or so before the RR), and United was the 777 launch customer. The only thing is that the newest 777 variants (777-200LR and -300ER) only offer GE as an engine option, there isn't even a RR choice.

by JCM9 6y ago

balaa 6y ago

Cool, you work at Boeing media relations?

arnon 6y ago

The P&W-powered 777 is just one variant. British Airways for example went with GE90s, and some airlines like El Al went with Rolls Royce Trent 800s.

ninkendo 6y ago
Are there any Airbus (or other comapanies’) planes that have the affected engine? Or just Boeing?
- arnon 6y ago
  Airbus A300-600/A310 Airbus A330 Boeing 747-400 Boeing 767/KC-46 Boeing 777 McDonnell Douglas MD-11
  - rob74 6y ago
    ...however the exact type of engine Boeing is using for the 777 (PW4000-112 - https://en.wikipedia.org/wiki/Pratt_%26_Whitney_PW4000#PW4000-112 https://en.wikipedia.org/wiki/Pratt_%26_Whitney_PW4000#PW400...) is not used by any other airliner. I'm no expert, but as the most powerful -112 version has almost twice the thrust of the -94 version, I wouldn't automatically conclude that problems with one type mean that there are also problems with the other types. OTOH, if they take a closer look at the 777 engines and find a lot with problems that went undetected until now, I assume the other PW4000 engines will get a closer inspection as well...
    - arnon 6y ago
      The core is the same. The different model numbers typically represent other configurations of the stages or pump throughput, type of FADEC, and all of these things.
    - kayfox 6y ago
      Its noted that a 747 had a very similar issue the same day as this 777 with the same series of engine. Since the issue is most likely with fracture detection during maintenance inspection and P&W introduced new procedures for that a few years back, its likely the issue is with the tech being used or the procedures. Which would mean any P&W engines using the same technologies and procedures to detect fan and turbine blade cracks would be affected.

imglorp 6y ago

Also, this is not the first incident and it it's not the first Airworthiness Directive against the PW-4077. https://duckduckgo.com/?q=PW-4077+%22airworthiness+directive%22&t=ffcm&ia=web https://duckduckgo.com/?q=PW-4077+%22airworthiness+directive...

Pasorrijer 6y ago
While I understand the point you're trying to make, I'd just like to note that if you type any mature engine for any aircraft into a search engine, you're going to find more than one Airworthiness Directive for that engine
- imglorp 6y ago
  No point really, just interesting that they've had an eye on various metallurgy inspections for a while. This is at least the third engine--with Trent and GE--so maybe those guys had their share of AD's. Also props to the 777 platform for being modular here and bulletproof in general. edit. It's obviously a tradeoff of accepting a certain number of (usually) contained survivable fan events vs being able to afford flying them.

tibbydudeza 6y ago

That seems like a complicated way to sell airplanes - why is that ???. It is like me buying a car from Ford and saying I don't want the Ecoboost turbo 4 but rather that V8 from the Raptor.

0xcafecafe 6y ago
This might be due to a car being a more common retail purchase compared to a plane. Airlines might want to customize their plane for the usage and different engines might provide different benefits.
- croutonwagon 6y ago
  I’m guessing it has most to do maintenance training and supply chains. If x carrier standardized on PW or Rolls engines, it makes sense to try and keep their fleet on that engine. It simplifies maintenance, what parts need to be kept in stock etc. If you have a fleet of rolls engines and one batch of planes running PW then you have to set aside entire storage, training and supply chains for a single batch. From Boeing’s perspective, they can sell more airframes with a modular setup that allows the carriers to choose their powerplants. Especially in a worldwide setup where a rolls Royce may be cheaper in one market and a PW cheaper in another across a pond
re-actor 6y ago
Most car models come with various engine options, sure you can't get a V8 in your focus but you can choose between various displacement Gas/Diesel/Hybrid options. In fact the current model year ford focus ships with 14 engine variations.
dd82 6y ago
https://aviation.stackexchange.com/questions/38156/why-bother-having-different-engine-options-on-one-aircraft https://aviation.stackexchange.com/questions/38156/why-bothe... might be helpful
- dmurray 6y ago

sandworm101 6y ago

>>It’s a particular engine they’re concerned about, not the 777 airframe itself. While literally true, in all practical terms those airframes are grounded. Engines can be swapped but it isn't as simple as swapping a V8 for a V6. These are expensive and physically large objects. There aren't enough spares available to re-engine so many airframes, and it would take years to build a new supply. So any airframe with the listed engines is essentially grounded until the problem can be addressed.

huntertwo 6y ago
That’s only about 60 in service planes.
- sandworm101 6y ago
  Try ordering 120 new airliner engines. It will take a while. There is no real surge capacity for these things. You would probably have better luck buying used.
  - croutonwagon 6y ago
    Maybe. But most airline companies can ground a small portion of their fleet and it not really affect their outcome. They should have some redundancy built into their maintenance schedules so that 60 planes, even in a single company shouldnt have too much of a flight schedule burden.
nemetroid 6y ago
Only the 777s that have PW4000 engines. The 777s with GE or Trent engines are fine.

4cao 6y ago

That's a good point. As far as I know, newer B77* generally use GE or RR engines. The PW ones are old at this point, and also represent the smallest and decreasing share, so most planes of this type aren't affected. United (or one of its predecessors) was an early customer, and I think PW was the only engine option at launch. (Not my area of expertise, so I'd appreciate a correction if I got something wrong.)

sjm-lbm 6y ago
Pretty much correct. The Pratt engine was in service six or so months before the GE engine (and a year or so before the RR), and United was the 777 launch customer. The only thing is that the newest 777 variants (777-200LR and -300ER) only offer GE as an engine option, there isn't even a RR choice.