Maybe Think Twice…..

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1. As far as I know, there have been two uncommanded rollbacks in 777’s running the Trent engines. I believe their cause has been blamed on the fuel ice issue you have mentioned. In addition to adding anti-freeze to the fuel, Boeing have recommended applying max thrust frequently during long phases of cruise when in particularly cold weather.

   If none of the civil aviation regulators or pilots are worried about it flying, then neither am I. And to be frank, your post is misleading and sensationalist in my opinion.

2. I don’t think the post is in the least bit sensationalist. It’s this fuel problem that caused a British Airways 777 to land short at Heathrow; you can still see the remains of it there today. Fortunately there were no fatalities, but if it had happened a mile further out, a plane full of passengers would have dropped down on a densely-populated part of London – or am I being ‘sensationalist’?. I, for one, would not get on a 777 flight with any airline that used these RR engines, until the promised modification is installed.

   What we’re also seeing is a difference in emphasis between regulators in the US and UK, with the US taking a stronger line. Perhaps that’s because the problem is with RR engines; we might see the reverse situation if it were GE or PW engines.

3. Actually the post is truthful and to the point.

   How many planes need to crash until problems like this are taken seriously?

   Band-Aid solutions aren’t enough.

   Thankfully the NTSB has issued an ‘urgent’ warning about this problem and it will be rectified.

   Whether pilots are worried about it or not, it totally irrelevant. They only fly the aircraft, they don’t design them and they aren’t aeronautical engineers.

   There’s been one crash already because of this problem and that’s one too many!

   http://www.seattlepi.com/business/403191_boeingengine12.html

   Puppy

4. Hi John,

   I think the US press is more ‘sensationalist’ than I am: http://www.avweb.com/avwebflash/news/boeing_ntsb_trent_rolls_royce_aaib_ice_engine_problem_199963-1.html

   Not that it matters much, press is press….. without it we wouldn’t have half as much ‘fun’ with these global crises, now would we ? 😉

5. And Rolls Royce have already redesigned the heat exchangers to deal with it. The mod is going through testing and certification as it has to before it can be fitted.

   Pups: You cannot deal with a problem until it happens. I was just reading through this week’s Flight International and counted no less than five loss of power incidents reported – across a whole variety of aircraft (including a Cessna, Francois – you’re far more prone to ice-related loss of power than the heavies are.) The engine types involved included both GE and CFM on smaller Boeing types, plus an ERJ and the aforementioned twin Cessna which lost power simultaneously to both engines.

   This is hardly a crisis. It’s happened on a tiny percentage of flights. Shall we ban the USMC from flying Hornets as well? Apparently they just drop out of the sky for no reason at all into houses.

   I agree with John Mc, I’m afraid. I’m sick of the sensationalist reporting on this and other similar stories.

6. This is sensationalism and press hype.
   The fuel, as Ian points out, can freeze on any aircraft no matter what aircraft, and it doesn’t matter what engines it has, they could stop as a result.
   There is an allowable percentage of water contamination in aviation Jet A1 which is like kerosine and when the water in that fuel freezes (it turns waxy) is when you get the problem. Leaving it to heat exchangers in the engines might be a little too late. Should there not be heat exchangers upstream a little.
   I have twice taken my family on a B777 since that event but it had GE engines although the sight of RR on the engines would not have stopped me. Had we been presented with a Dash 8 I may have baulked!

7. I don’t have the report on the redesign of the heat exchanger with me, but from what I understood, the redesign was to move the heat further “upstream”. They can’t put them in the wings or too close to the wings as I understand it because of the risks associated with fuel vapour in the tanks at low fill levels, but at least I believe some of the heat is supposed to be going above the engine into the mount rather than trying to ensure it is all cleared at the injectors.

   One of the big things that is causing these issues is that aircraft are flying with smaller fuel tanks (more prone to temperature changes, for longer ranges (and hence time) at higher altitudes for efficiency (colder temperatures).

   Talking of things that should be fixed, incidentally, I don’t believe the 737 “rudder hard-over” issue was ever resolved, was it?

   Every aircraft flying has some form of limitation or known issue which has to be watched and/or catered for in operating practices, whether it be a PA-38 (don’t spin ’em, they can be irrecoverable) or a B747-400 (still flying with full centreline fuel tanks, in many cases).

   We don’t see B777s, DHC-8s, PA-38s or A320s plummetting out of the sky every day. A heck of a lot more people per passenger mile die because of ground vehicle failure than aircraft failure – but an air crash is far more interesting than yet another fatal accident on the Autobahn or Freeway, isn’t it? Presumably the reason a light aircraft crash still makes the news (local, at least) is because they are, in reality, a rare occurence?

8. It IS sensationalist. The aircraft was flying with idle engines because environmental regulations required a long continuous path idle descent rather than the more regular stepped descent which would have the engines working at normal RPM for a good part of the descent, preventing the fuel from freezing (remember that the fuel is heated by its use as a coolant for the engines).