Another Boeing Pratt and Whitney Engine Exploded in the Netherlands | Hacker News Reader

Another Boeing Pratt and Whitney Engine Exploded in the Netherlands

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34 pointszuhayeer23 comments

Substantive article on this incident was discussed when it happened two days ago:

> Boeing 747 loses parts after take-off from Maastricht – 2 injuries (aviation24.be)

> 104 points by UncleOxidant 2 days ago | 40 comments

https://news.ycombinator.com/item?id=26209611

We're still riding the 737 MAX scare wave (from 2019) in the news, so while these incidents are infrequent, they are not as new as this reporting might suggest.

2018, passenger killed when fan blade penetrated cabin. Also mentions a 2016 incident: https://www.seattletimes.com/business/boeing-aerospace/one-s...

2018, A320s grounded due to P&W failures: https://www.businesstoday.in/sectors/aviation/dgca-grounds-1...

2017, similar cowling stripped off in flight on A380: https://www.journalinquirer.com/business/pratt-ge-engine-fai...

Flight frequency is still less than half of normal. With reduced frequency you wouldn't expect a years worth of total engine failures in a week.

Poisson distribution could tell how improbable it is but I'm lazy.

2¹⁰⁴*e-²2/(104!)=2.66523e−136 If annual occurence is 2 and it happens twice every week in a year. But it has not so far :)

Weekly occurence of 0 has 13.5% chance of happening this being the case for 7 weeks before this last 8th 2021, 13.5*7/8= 11.8% so far.

But I'm no statistician.

I've run the numbers here

https://stattrek.com/online-calculator/poisson.aspx

At a weekly probability of 0.04 (2 failures/52 weeks) the probability of 2 failures within a week is 0.077%. The probability of 0 failures in a week is 96%.

Accounting or halving of flight frequency it's 0.02% and 98% respectively.

Oh right k for a week is not 2 but 2/52!

"Another [Boeing's (if you insist)] Pratt and Whitney Engine ..." would be a better title, Boeing has little to nothing to do with the engine, and Pratt and Whitney engines are found on Airbus aircraft too.

But as a European, I enjoy it a little bit after all Boeing has done to us (in our collective imagination anyway).

I can't wait for the Chinese to build aircrafts too so we can get a bit of a kick in the ass and re-focus.

Jet engine metallurgy takes a lot of work to get right. It’s highly technical and the mfgs hold on to their know-how as much as they can.

So aircraft, yes, a number of countries are capable of building their own and do. Jet engines are more specialized and we’ve ended up with three major specialized engine mgfs: Rolls, P&W and GE. Anyone know of other contenders?

Aviadvigatel

I once took an Airbus with a Safran engine (was written on it) and was proud we could do that.

Upon checking it turns out Safran engines are a franco-american partnership anyway with GE, grrr :D

Heh, my father was a designer of the A-12 Archangel, and he always called them "Pratt & Whisky"

I am wondering how much is this a maintenance issue during pandemics - planes are likely flying less often, exposing some issues from standing still; repair crews might not be available all the time or suddenly overloaded and because of these factors the rate of incidents rises?

Planes are grounded if maintenance can't be done. The quality of maintenance can vary from the norm as maintenance companies are starved for work and lay people off.

Normal maintenance doesn't involve disassembling engines and messing with turbine blades.

Normally it's birds causing these blade destructions. All those incidents point to birds. The question should be, why suddenly so many birds near airports?

I would imagine that significantly reduced air traffic over a year would make birds avoid airports less.

Is it all coincidence or is there some environmental factor? These engines aren't exactly new -- they were first introduced in 1984. I'd expect design issues would have manifested already.

The significant environmental factor is that many planes have been sitting idle for months. This is exceptionally unusual in the life of most airframes. Idle time is an opportunity for parts or fluids to settle in a way they might not otherwise.

For example an extremely slow fluid leak could be “reset” every time the engine is operated. Allow time for fluid to accumulate and suddenly there’s enough fluid where it shouldn’t be, perhaps causing just enough mechanical stress to exacerbate an previously unknown wear point or design flaw present in a tiny minority of copies.

(Of course this hypothetical flaw couldn’t cause catastrophe on first flight, as that is generally an empty plane travelling from long term storage back to the airline’s hub airport. The flaw would have to subtly weaken a part which then fails after multiple rounds of uneventful flights.)

Unfortunately that hypothesis might hold true for all engine manufacturers which is a pretty chilling thought.

Or only affect engines from one American manufacturer due to some previously unknown peculiarity in their metallurgic processes.

I recall reading an article in Aviation Week maybe 30 years ago about turbine blades failing for an unknown reason, and it turned out it had to do with contaminates in the water they were using during engine builds or some such.

probably just as easily counterfeit aircraft parts due to economic squeezes

This was an elderly freighter, for which months of idle time in between owners isn't exactly uncommon in normal times. And in the case of this aircraft, it was actually acquired last year because the charter operator saw an increase in demand.

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