News: 1613998985

Can’t wait for flying cars raining down hubcaps, oil, spit and cigarette butts.

Or indeed [1]their entire selves ...

[1] https://www.theregister.com/2021/02/19/airspeeder_alauda_drone_investigation_with_photos/

Must be a new engine failure which is not picked up by regular inspections - OR the inspections themselves was fudged, and never executed properly.

Or it was a Boeing

Early reports indicate internal metal failure of the hollow titanium fan blades, cracking without notice until the crack passes into the external skin surface causing blade separation.

As much as people would like to point fingers at Boeing nowadays :D this is completely not Boeing's fault.

The FAA's emergency inspection will call for additional internal blade inspections, using technologies such as ultrasound.

>this is completely not Boeing's fault.

So P&W also print their own FAA approval certificates ?

Bound to. Have you not heard of "light touch" regulation before? It's great: just ask anyone who's lost money to a bank…

Mine's the one with the signed copy of Heads I Win, Tails You Lose in the pocket!

"light touch" regulation? you mean like the same "regulation" effect recently seen in Texas? the same (purposeful lack of) "regulation" seen over the last four years in the u.s.? the same lack of "self-governance" from certain groups in the u.s. as encouraged by those who for any amount of campaign contribution will champion "light-touch" laws? those?

It's true that, when it comes to the engines, Boeing and Airbus are effectively just renting space to the engine manufacturers and the airlines get to choose these.

And, dramatic as both events were, it says a lot about the industry that they weren't worse and that the precautionary groundings* are standard procedure.

* Though I'm sure Ryanair would like to be able to offer passengers to choice…

Don't know about P&W but RR generally don't even sell their engines.

They rent them on a PAYG basis - you pay for flying hours and RR handle all the maintenance / service / spares etc.

There was a wonderful documentary several years ago about building RR's latest commercial jet engine. The whole rotating core is surrounded by a titanium cylinder. One of the tests is to have an engine at full speed, and then detonate a charge on a fan blade. It fails if any engine part pierces the cylinder.

The RR engine featured also contains its own telemetry module and communicates directly with RR during flights. This means that the pilots only get told when there is something they need to know, rather than having to monitor the engines in detail themselves.

(I have no knowledge of P&W jet engines, or GE ones either, for that matter.)

The "U.S. Robots and Mechanical Men" model.

They (RR) offer "power by the hour" plans, but are happy to sell the engines, too.

Larger operators tend to buy, smaller ones lease. This is purely because of financing cost, not any technical advantages.

There is nothing quite as reassuring, when boarding a plane, as seeing a double R on the side of the engine.

Having worked for them, perhaps not

Ooh! Care to dish?

Aircraft engines (and for that matter Aircraft tyres) are like sausages. It's better not to see them being made

RR have had their own problems, especially with the Trent 1000. And there was the Trent 900 (A380) "she go boom" issue in Singapore a decade ago, which very nearly imperilled the aircraft - major damage. Generally I like RR and the XWB (A350) seems to be doing pretty well. But they need to get back into narrowbodies!

Shouldn't the plane have dumped a few tons of fuel first? Or is this not the case with newer aircraft anymore?

The engine was on fire, and since the only people who could put it out were on the ground, that was the place to go.

Not sure how fire plays out with this (maybe not as much as one would expect, given that I'm sure an engine fire over the pacific ocean half-way to HNL has been considered), but fuel dumping definitely happens for planes whose take off weight is greater than their landing weight or when their nose gear is turned 90 degrees and the plane will come to a stop on its chin.

Given the plane was only going about half its rated distance (pure great circle shit), plus it was less than 2/3 full of pax and this was a domestic flight (less free bag allowances)... it might not have been above its landing weight.

However, I am not sure what the price of fuel is at HNL, and I don't know where that plane was going to next, but it might have been flying with way more fuel than needed if UA wanted to not buy as much fuel at HNL for the next leg.

The final report in 2-3 years will be a fun read, to be sure.

Most likely yes, this is still SOP. However they were over populated areas, and I am pretty sure that fuel dumps are not permitted as living creatures generally react poorly to aviation fuels being sprayed all over them :p

I'm not sure dumping fuel when one of your engines is on fire would be the best option, either.

It depends - some flights carry so much fuel that a landing could break the undercarriage and you'd want to dump that before trying to land. On the other hand you may think it safet to be on the ground near a fire engine than fanning the flames at a few thousand feet.

> On the other hand you may think it safet to be on the ground near a fire engine than fanning the flames at a few thousand feet.

Trade off, you don't know that the wing/control surface isn't damaged or that the engine isn't about to fall off and take your wing with it (El Al Flight 1862)

But landing 32,000lbs overweight with no thrust reversers and the risk of over-heating your brakes, bursting tires and starting a fire - is still risky

Denver has really long runways so even without reverse thrust it should be a reasonably good call to turn round and land ASAP. It is all about risk and it is only after the event that it you can, with confidence assess if it was the correct decision.

In this case it clearly was.

Supposedly these are images of the dump. These are in the responses to the tweet in the article.

https://mobile.twitter.com/LejeuneXa/status/1363246257460887557/photo/1

That is the Dutch incident.

If you are on fire then dumping fuel's a bit like smoking while you fill the petrol tank ... but it would have made a great twitter post!

I suspect that this is taken into account when designing the fuel dumping system for modern airlines. If it is necessary to dump fuel with an engine on fire the Venturi's (basically holes used for dumping fuel) should be far enough away from any engine to avoid the possibility of ignition.

I once spent an entire morning colouring in the fuel flow diagram for the Bae 146 aircraft during the design stage. Crayons are also for grown-ups you see.

Probably had the reduced weight benefit of not having many people on the flight...

You want seville not nacelle oranges for that mate.

With the constant weight reduction, pressure increasing, rpm increasing trend to gain a few percentage points of fuel economy, is this the same problem we are seeing in the auto industry, reducing the longevity of engines?

I know that air travel is still very safe but there seems to have been a few incidents recently that are moving away from pilot and systems error and more into the component fatigue territory.

These engines are 30years old.

The PW4000 is a very old design, going back to the 1980s. The 777 variant of it is early 90s, like the aircraft itself. So this is not a cutting-edge engine. Plenty of newer engines have excellent records, including the Trent XWB and the newer GE90s, etc. So overall I don't believe there's any systemic issue with cutting-edge engine tech, at least not yet...

BOEING; Bits Of Engine In Numerous Gardens

The amazing engineering is that these things don't fall off or set fire to the rest of the plane while explosively destroying themselves in a firery death.

It didn't explode - the front fell off.

That’s not very typical, I’d like to make that point.

Exactly! That the catastrophic failure is so contained is praise to the engineers.

Nice Clarke and Dawe reference.

Ha!

Loved the comment

immediately reminded me of https://www.youtube.com/watch?v=3m5qxZm_JqM

Have a pint

Worryingly, the planes are now made of "cardboard derivatives"

Courtesy of VASAviation. ATC Audio + Radar

[1]https://www.youtube.com/watch?v=G7-zh7Sebr8

There is an interesting comment on pprune regarding the video of the engine...

"What struck my phone savvy spouse immediately when watching this video is that although the engine is in rock steady focus, the edge of the window in the picture is moving around.

It is the smart feature of the phone camera that makes it look like a steady view out the window, when in fact the plane and the passengers were bouncing due to engine vibration.

If you don’t believe me, watch the video again and focus your eyes on the lower right corner of the photo which shows the edge of the window. "

[2]https://www.pprune.org/rumours-news/638797-united-b777-engine-failure-5.html#post10995020

[1] https://www.youtube.com/watch?v=G7-zh7Sebr8

[2] https://www.pprune.org/rumours-news/638797-united-b777-engine-failure-5.html#post10995020

Some ambiguous language involved, but I don't think the 777 incident qualifies as an "uncontained engine failure", the 747 incident is.

The 777 engine fan apparently lost one blade, but its energy was contained in the intact Kevlar ring designed for that and the rest of the fan is in place. I don't know if the detached blade fell to earth or stuck in the containment ring but an uncontained engine failure usually means sending compressor or turbine blades hurtling outwards at rifle velocity through the engine housing and containment structures, often shredding the fuselage and injuring passengers - or even damaging critical aircraft systems making control difficult/impossible.

The main engine case is clearly undamaged although something (lubricating oil?) is burning externally on the reverser parts, but the only pieces obviously missing and decorating gardens below are the engine inlet cowl and most of the nacelle: these are aircraft parts, not engine parts... except for the missing blade, but we don't know where that is yet.

Yes the plane would be shaking, the unbalanced fan even at windmilling speed is going to cause major vibration - and it must have been horrendous just after failure at 100% RPM. Possibly the fan shaft back to the LP turbine has been bent as well.

[1]VASAviation [youtube.com]

[1] https://www.youtube.com/watch?v=G7-zh7Sebr8