121–128 of 128 posts
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That is a nonsensical comparison. Shuttle's glide ratio was 4.5:1 - barely better than a brick
Not quite that bad. I hear a wingsuit can get maybe 2.5:1, and that's clearly better than a brick...
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A 787 that is out one engine will put extra load on the remaining engine, if that one has gone through a similar life as the one that just dropped bits all over the place I'd not wager on the remaining one being as safe as when it was last inspected. That's a lot of eggs in one basket. That's why there are restrictions on which RR engines can be put in a 787 as well as a reduction in the ETOPS certification. There've…
Wow is this really how the industry views it? The notion of having one "less fixed" engine on a twin engine commercial jet aircraft is ok, so long as the other engine is the more fixed version? Sounds incredibly risky. For such a critical component, I figured they would adopt the military position: "2 is one... one is none".
So having one "less safe" engine still means everything is much much safer than the drive to the airport.
Small shards (in great numbers) that according to a witness on the ground were burning or very hot sounds a lot like (pieces of) blades from the turbine or stator/guide vanes. In both cases it's a very significant engine failure.
Given that the aircraft itself seems otherwise undamaged, and people on the ground reported it 'rained' metal shards, I'd say these parts melted off the turbine and fell out. Significant but not catastrophic.
Same term is used for a shattered turbine disc. It destroys the engine and is not contained so there is a risk to other components.
https://www.forbes.com/sites/davidnikel/2019/08/12/norwegian... The plane in question was a 5.5-year-old Boeing 787-8 with the registration LN-LND. The parts are believed to have come from the left engine, a Rolls-Royce Trent 1000, a model that has been plagued with problems. Link about the problems: https://www.theengineer.co.uk/rolls-royce-problems-trent-100... Cracking problems in the intermediate pressure (IPT) s…
I was in Poland and 23 hours before my flight, it was completely cancelled. I spent hours on the phone and finally was able to schedule another flight 3 days later. The problem is the airline knew these airplanes need to be grounded for maintenance much often but continued booking flights as usual. British airlines started losing similar lawsuits recently.
I would not be surprised if someone sued Boeing or RR.
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If a Tesla has a fatal accident because of some 3rd party component, the headlines will blame Tesla, too. Boeing is not free of responsibility here, they chose to sell said engines as an option on their planes. They have worked together with Rolls Royce to integrate their engines with their plane. In theory, engine problems could even be caused by Boeing's software mismanaging the engines.
The comparison with Tesla is not valid: when you buy a Tesla, you buy a Tesla from Tesla. When you buy a Boeing 787, you chose the engines (GE or Rolls Royce) and buy them directly from the engine maker. You would also sign a maintenance/support contract with the engine maker directly. It is not rare for plane contracts and engine contracts to not be signed simultaneously: the engine maker might be decided months aft…
The engines are also mounted to the air-frame at Boeing's facilities (since the plane can't really leave under its own power until that happens), so whether the airline pays Boeing or R-R for the engine is just an administrative detail.
As for the server comparison, if you buy a Dell computer, your warranty is from Dell. If something needs to be fixed, Dell will do it and then argue with Intel about who foots the final bill.
The airplane world is a lot more complex, and that is exactly my point – the blame is not 100% with R-R and 0% with Boeing – or vice versa. There's plenty of blame to go around.
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They are much more reliable, but also much more costly to build and maintain. There was an argument that the A380 wasn't less fuel efficient simply because it had four engines. When you only have two engines they need to be much more reliable, have much higher peak output, and the costs of maintenance are greater. Whereas when you have four engines each engine is cheaper to build, can have more efficient power profil…
I thought A380 was doomed because of lack of configurability for a freight option, and the fact that some narrow bodies were starting to eat it's lunch as direct flights started to become more common instead of hub and spoke. What you've posted though seems way more plausible though I've gotta admit.
I think this is the article I originally read,
https://leehamnews.com/2018/12/13/has-the-a380-worse-economi...
but it's paywalled. Here's an older article with similar points,
https://leehamnews.com/2015/12/11/bjorns-corner-twins-or-qua...
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Wow is this really how the industry views it? The notion of having one "less fixed" engine on a twin engine commercial jet aircraft is ok, so long as the other engine is the more fixed version? Sounds incredibly risky. For such a critical component, I figured they would adopt the military position: "2 is one... one is none".
Not as crazy as you think. We train every 6 months for all types of engine failures. And the plane is required to be able to sustain an engine failure at any point of the flight and still make it safely to an airport with quite a bit of margin, otherwise the flight wouldn't go. So having one "less safe" engine still means everything is much much safer than the drive to the airport.
That's a statement that I'd be happy to see the numerical support for. To hold the number of fatalities of people driving to the airport in total needs to exceed the number of fatalities as a result of airplanes crashing after one engine already failed on a relative scale, related to the number of people on board those aircraft that had one engine fail.
Keep in mind that the chances for messing stuff up increase once one engine is out simply because all your eggs are in a single basket.
https://www.theguardian.com/world/2015/jul/02/transasia-cras...
This puts the counter at 43 against. I'm sure that we can dig up other examples. I think one engine out is a sufficient change of the underlying stats that the per-passenger mile quote might no longer be valid.
Of course the other input required is how many planes have single engine failures.
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The comparison with Tesla is not valid: when you buy a Tesla, you buy a Tesla from Tesla. When you buy a Boeing 787, you chose the engines (GE or Rolls Royce) and buy them directly from the engine maker. You would also sign a maintenance/support contract with the engine maker directly. It is not rare for plane contracts and engine contracts to not be signed simultaneously: the engine maker might be decided months aft…
Are you telling me airlines have to order and directly buy the engines themselves? Surely not?
So airlines sign big contracts with engine manufacturers for new engines, parts, supplies, training, etc.
This also happens even with small single engine airplanes, those engines need overhauls every so many thousand hours, so one option is to trade in your old engine for a refurbished one instead of overhauling and keeping the same engine. For some larger fleets companies have contracts with engineer manufacturers or service centers for this.