The Queen is a sentimental favorite, but understand the economics of phasing it out.  I actually thought lower fuel costs would keep it around longer.

Certainly fuel costs are less of a factor now. I heard that Virgin Atlantic now have put back the retiring of their A340 fleet because fuel costs have dropped so much and its now more financially viable to keep them going.

 

 

The whole reason for a 4 engine jet was because the engines had a tendency to coming apart in the earlier days.

Not to mention the max thrust they could muster on a continuous basis was paltry compared to a GE90, hence needing 4 of them to push the plane along.  If there was a GE90 back then...we'd most likely be flying  2-engined 747s. (if you could convince the decision-makers of the period that these suckers (pun intended) were way more reliable than the 1st generation PWs they stuck on her) :smile:   

 

 

Well stated, Steve.

 

 

Did not quite make it on a Pan Am one, but made it on a BOAC one, not across the Atlantic though.

Funny you should mention that as my Pam AM 707 flight was an Atlantic crossing....KPHL to Rota, Spain.  Even at 13 years old....I still vividly remember the sun rising fast as we sped towards it, the rays glinting off the shiny nacelles. 

The whole reason for a 4 engine jet was because the engines had a tendency to coming apart in the earlier days.

Jets were always much more reliable than piston engines, and have got ever more reliable as time went on. So having four jet engines was really about performance. Twin jets simply didn't have the thrust to compete with quads on long haul routes in the 1960s. When the 747 entered service the JT9D-3A engines only just had enough thrust for the job, so less than four engines simply wasn't practical. What made the twin viable is the incredible thrust growth of the high bypass ratio turbofan. That and ETOPS rule making which step by step has allowed the twin to go way beyond the original 60 minute engine out limit (dating from the unreliable piston engine era). Basically if you have enough installed thrust for the engine out case a twin will always be preferable to a quad in economic terms. The quad is now a niche aircraft for long range high capacity routes, as sales of the A380 and 747-8 show.

 

The 777 is a very reliable and safe aircraft, but there have been incidents which could have turned into fatal accidents but for good fortune. The BA 777 that lost power on approach to Heathrow is one. Modern large twins are all on a similar level of safety as the 777.

There's still enough BA and Qantas 747's to keep everyone happy.

BA to a EGLL-KSFO flight using their 747-400's

Qantas are keeping their planes going until 2020.

long time ago but when i dispatched 747 classic and -400 we had a 180 limits due to in board fire ...

 

there is at least one operator that is using -400 with EROPs rules and that is also 180 min ...

 

all the best.

 

Phil 

Firstly, I didn't quote the wiki article that was somebody else. Wikipedia isn't always true and they definitely don't know SOPs of BA. These days, if anything happens to an aircraft during takeoff or initial climb, it turns around. Whether it's four or two engined.

A 777/330 being able to cross the Atlantic on two engines doesn't mean a 747 can on three because it has more engines. A 747 is not a 777 with two extra engines, that's not how physics works. If it did work like that we'd have 6-8 engine passenger aircraft because it's safer right? It's a lot heavier, each engine produces much less thrust, and it's a lot more inefficient than a 777. Again, I go back to my point about ETOPS. ETOPS is all about reliability. How can a two engine aircraft have a higher ETOPS rating than a four engine if four is better than two with engines out? That alone shows that something like the A350/777 can handle flying single engine much better than 747s.

In all honesty, no single commercial aircraft would be certified to fly if it could not easily operate with one engine. 777/A350 etc can clearly handle flying single engine, otherwise they wouldn't let them fly over 6 hours away from a suitable airport!!

You can use a Piper Apache for commerical operations but good luck making it anywhere on one engine my point is just because the book says it will work doesnt mean it will in reality. You can quote all the figures you want sometimes it goes beyond figures. You can't deny the fact that if two engines fail on a twin jet your going swimming but if two engines fail on a quad jet your going to land safely.

 

 

You can't deny the fact that if two engines fail on a twin jet your going swimming but if two engines fail on a quad jet your going to land safely.

 

Since your dad was a "real world 744 pilot" and you're also a "pilot", you'll know all about how powerful the 744s engines were. Good luck getting a 744 anywhere on two engines. You may as well have none.

 

Known RW 744 pilots have said the complete opposite to what you're arguing but you know...you're a pilot so you must be right?

If I recall correctly United has already ordered around ten 777-300ER's - an aircraft that can carry as many passengers as a 747-400, with two less engines and the same range/cruising speed. Airplanes with 4 engines haven'd died off yet, but they are only profitable on certain, high-frequency routes and cover a rather small niche in commercial air travel. Just look at British Airways with the A380 and rather old 747-400 fleet or Lufthansa that operates a quite large A380 and mixed 747-400/747-8  fleet (with the 747-400's and A340-600's to be replaced by the 777-9 from around 2020). And who knows if Airbus decides to stretch and re-engine their A380 - the damand is still there and turbofan engines are getting more efficient every year. 

I hid a few posts, unfortunately, due to the lack of signatures.

 

 

 

You can use a Piper Apache for commerical operations but good luck making it anywhere on one engine my point is just because the book says it will work doesnt mean it will in reality. You can quote all the figures you want sometimes it goes beyond figures. You can't deny the fact that if two engines fail on a twin jet your going swimming but if two engines fail on a quad jet your going to land safely.

 

 

Since your dad was a "real world 744 pilot" and you're also a "pilot", you'll know all about how powerful the 744s engines were. Good luck getting a 744 anywhere on two engines. You may as well have none.

 

Known RW 744 pilots have said the complete opposite to what you're arguing but you know...you're a pilot so you must be right?

 

Chris,

 

I'm going to be very blunt about this: you're incorrect on this point. I can see how you might be inclined to believe someone who claims to be a 744 pilot, but either they're not speaking as precisely as they should have been (sorry for the unintentional Giver reference), or they didn't actually fly the plane (in a situation similar to your own post with accusations of people's experience in the hobby here).

 

Aircraft certification requirements specify that a four engine aircraft function reliably with two engines inoperative, in a worst possible case scenario (FAR 25.123): unfavorable CG, the critical engines out, on a hot day. That alone points to the fact that the aircraft had to be proven reliable enough to get somewhere safe after the loss of two engines, just as the 777 is required.

 

This is backed up by UAL811, which was a 747 that successfully returned to the field with only two engines operative. An explosive decompression put debris in engines 3 and 4 - the remaining engines also had to overcome increased drag on the dead side due to the debris deforming the wing on that side as well - yet the aircraft made it back just fine. JAL46E had one engine (number 2) come clear off, damaging the wing significantly, along with the number 1 engine (http://www.tailstrike.com/310393.htm), but it still managed to make it back. JAL46E isn't directly a loss of two, but the loss of thrust in number 1 combined with the damage to the wing (loss of much of the leading edge devices, along with damage to the trailing) made it relevant enough to me. According to a few news articles, a UAL97 was able to land on a single engine at the new (at the time) Narita after shutting down 3 of the 4 (though I haven't found any official aviation-specific references - then again, that time frame isn't very well documented online unless the event was higher in profile). Pilots also train for these kinds of approaches in sim training.

 

While I wouldn't press on to the destination with a loss of two, it's not inherently more unsafe than in the 777 in the same situation (half of available engines lost). You'd be hard pressed to find any crew who - in a situation outside of combat, at least - would lose half of their engines and continue to a destination. You will find many cases, however, where the aircraft lost half of its engines and made it successfully to an airfield.

 

 

 

Determining the risk of these types of occurrences, as I mentioned earlier, is debatable. The survivability of a loss of half (and occasionally more) of the engines, however, has been proven, particularly when the engine power loss is the only factor in the incident (that is to say, airframe damage was not also a significant factor).

 

 

 

And who knows if Airbus decides to stretch and re-engine their A380 - the damand is still there and turbofan engines are getting more efficient every year. 

 

ETOPS 370 essentially covers the globe. ETOPS 330 covers just about any normal route. There really isn't much more to stretch other than simple reliability, not from an ETOPS perspective.

ETOPS 370 essentially covers the globe. ETOPS 330 covers just about any normal route. There really isn't much more to stretch other than simple reliability, not from an ETOPS perspective.

 

True, but as of now there just is no twin on the market that has the same seating capacity as the double-decker A380. Just look at Emirates replacing all their 777 services to major Hubs with A380's.  Range and ETOPS - spicific restrictions aren't really a factor these days...even 4-engine aircraft have to be ETOPS certified for all sorts of reasons.  

ETOPs isn't just about losing an engine guys, it's about how long an aircrafts fire suppression system can suppress a fire for. Aircraft with longer ETOPs will be fitted with multiple Squibs for suppressing fires.

ETOPS is no more ETOPS it is called EROPS.

ETOPS is no more ETOPS it is called EROPS.

 

Still ETOPS in FAA land, regardless of the number of engines. EROPS was the old term, pre-twin acceptance.

Agreeing with Kyle with one note too add. No matter what aircraft you fly, if you lose one engine (or more), you always try to land. That's safety. A pilot don't know the whole scenario why an engine fails. If it's an oil leak, pilot doesn't know if it's bad maintenance or another reason. So you always try to land before all engines is out. But a four engine is always safer than two engine. You can lose three engines and still have one engine with thrust enough for cruise. On a twin, if you lose one, you only got one left, after you got a $100 million+ glider.