DIA
Topic Author
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4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:33 am

This debate over two or more engines for crossing oceans started years ago. Remember everybody feeling unsure about taking "less-than-three" engines across the Atlantic when were introducing the 767 for trans-Atlantic service?

Seems this debate lives on. My question is to you who travel across the oceans in a twin, a three-holer, and/or a quad: Does it make you any uneasier knowing that you are boarding a twin for an ocean crossing? On the other hand, does it make you feel better boarding a tri-jet or a four-holer for the same type of flights?

I ask this in light of the recent UAL 777 that shutdown an engine over the South Pacific somewhere between the U.S. and Australia area. Anyway, I think it diverted to Hawaii. . .but it took several hours. How do you think those pax felt, or what was going through their minds? I think it stands as the longest ETOPS emergency operation thus far.

DIA

P.S. Virgin thinks it makes a big difference:
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SInGAPORE_AIR
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:37 am

I don't particularly care really.

I can't see it making much of a difference in terms of safety if everything is ticked off the checklist.

Anyone can fly, only the best Soar.
 
cedarjet
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:39 am

It makes a difference to me, in as much as if there is a choice between a twin and something more substantial and the price is the same, I'll take the 3 / 4 engine plane. If the twin is cheaper and it's a decent airline, I'll take it. That's on the Atlantic. On the Pacific, I wouldn't take a twin. Well, kind of (I have flown on a 757 between San Fran and Maui a couple of times). I certainly wouldn't fly a twin to NZ.

Everything in Virgin's fleet has four engines, I don't think that's a bad policy, it gives them an extra margin of safety over airlines that use twins across the pond. I don't think a UA 777 is by definition dangerous, but no one can say it offers the same levels of redundency you get on a 747-400.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
 
Treg
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 12:45 am

Cedarjet, well said.
I couldn't agree more!
 
DIA
Topic Author
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:46 am

Thanks for your answer Cedar707. Big grin On a side note, you caught my eye when you said:I'll take the 3 / 4 engine plane. If the twin is cheaper and it's a decent airline, I'll take it. Now, I'm just being curious here. . .what airlines do you find indecent? Do you mean an airline like a third-world airline, or do you have some well-known airlines in mind?

Cheers,
DIA
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sllevin
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 12:47 am

I wouldn't take a twin. Well, kind of (I have flown on a 757 between San Fran and Maui a couple of times). I certainly wouldn't fly a twin to NZ.

You should actually break out a globe. SFO-Hawaiian Islands is THE longest overwater (without diversion airports) of the pacific crossings. In fact, I believe the only longer stretch is in the deep South Atlantic (for example, the JNB-EZE great circle routing).

Once you've gotten to HNL, the path to NZ has far more alternates.

Steve
 
na
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 12:58 am

I fully agree with cedarjet. If price and flight schedule are comparable, there is only one way to go for me on longhaul:
4 Engines 4 Long-Haul, definitely. That quads look better, is a nice side-aspect too.
 
JayDavis
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 1:12 am

I flew my first trip to Asia on the carrier I work for, Korean Air.
We flew from DFW to ICN on a B-777 aircraft. I did NOT feel unsafe
whatsoever, by only having two engines versus three or four.

Most of you people on this forum are rather intelligent, but some of
you need to pull out a globe! We (KE) did not fly straight across from
DFW to ICN. We flew to the West Coast, flew up the West Coast over
to Alaska, crossed the Bering See and then headed back down to Korea.

I am certain, without a doubt that we would have had PLENTY of time
to make it to a diversion airport if we had needed to.

I think the four engines for long haul is just a great marketing gimmick
that Virgin is using against it's competitors, AA, UA and others which
fly 767's and 777's on the North Atlantic market.

As long as the airline is safe, it doesn't matter whether it has two,
three or four engines for me on a long-haul flight. I've also flown
from SFO to HNL on HA with a 767 and I felt safe on it also.


Jay
 
cedarjet
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 1:33 am

Re airlines I'd avoid if they were flying a twin across water? I dunno, Birgenair, those Turkish charter airlines that have been in business for three years and fly 757s to the Caribbean via Gander. Name some airlines and I'll tell you if I'll fly them. Remember Jezair? A310s from Budapest to Toronto, Melbourne etc? Hmmmmm...

I think it comes down to how collectively experienced the corporation is - every year that passes, an airline's maintenence procedures get better, mistakes are made and learned from, that kind of thing.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
 
EGGD
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:08 am

Flew on an A330 to Canada, beautiful... Systems teacher reminded me today how the wings flap during turbulence, and how they are glued on... lol.

Doesn't bother me, however i'd choose a jumbo over an A340/777 anyday!
 
ConcordeBoy
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:11 am

not only is 4engines4longhaul utter hogwash... but I definitely would go out of my way in both time and money if it meant being able to fly a twin!

~CB
Faire du ciel le plus bel endroit de la terre c'est impossible sans Concorde!
 
DIA
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:20 am

Thanks Cedarjet. I can honestly tell you that I haven't heard of one of the airlines you mentioned!  Laugh out loud That being said, I probably couldn't name an airline that you wouldn't fly. Good analysis on the experience, point well taken. . .never thought of it that way.

JayDavis and Concordeboy: I agree with your statements about hardly ever really making an "ocean crossing" due to the curvature of the Earth and direct-routing. . .but for sake of arguement, ETOPS is very much alive and on the minds of many. It is established for a reason, especially for those stretches that really do cross a bit of big blue.

Cheers,
DIA
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H. Simpson
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:22 am

More Engines = Longer Startup time...
 
mandala499
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:33 am

Call me stupid but...

If there's an engine failure on a tri/quad, wouldn't you divert anyway as you wouldn't be able to attain your normal cruising altitude where fuel burn is ideal?

Any engine failure, whether it be on a 2, 3 or 4 engined plane would be a nuisance and for the pax... 2,3,4 engines don't matter, if one failed, it still failed !

For me, I follow Cedarjet's opinion in general...

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
brons2
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 2:40 am

I would definitely fly a twin before getting on an MD-11, much as you guys love them, I don't view them as safe as Boeing or Airbus aircraft. Delta's air turnbacks due to smoke in the cabin make me uncomfortable, and there have been several. Not good after SR111. Oh well, the MD-11 will be gone soon at DL anyways.
Firings, if well done, are good for employee morale.
 
DIA
Topic Author
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:42 am

Good point Mandala499. Although, in a diversion due to an engine loss, wouldn't you feel more comfortable if you still had two or three engines in reserve rather than one ?
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Arsenal@LHR
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:45 am

No one, Airbus, Boeing or anyone else in the industry have proven that 4 engines is better (safer) than 2 engines. An ETOPS certified 767/777 is just as capable as a A340/747 on transoceanic flights, so really it's not an issue for me. ETOP's sole purpose is to enable long, over-water flights, and it does that exactly.

In Arsene we trust!!
 
brons2
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 2:47 am

Thought I would add a joke to this thread....

ETOPS-Engines Turn Or Passengers Swim.
Firings, if well done, are good for employee morale.
 
JayDavis
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 3:02 am

I find it also very ironic that the four engines for long haul is aimed squarely at Boeing, yet Airbus produces the A-300 and A-330 and those are both two engine aircraft which fly over the water. Sabena used to fly an A-330 from BRU to DFW so is that aircraft not safe, also?


Jay
 
cedarjet
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 3:20 am

JayDavis, "four engines for long haul is aimed squarely at Boeing" - I don't agree at all. Virgin are a major Boeing customer, with a big fleet of 747s and a supporter of the Sonic Cruiser. I think it's aimed at BA, who use a lot of 777s across the puddle; and the US airlines - there isn't a single 'november-reg' quad flown into the UK.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
 
desertjets
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 3:30 am

No difference whatsoever. Rather I believe there have been enough studies about the effectiveness of ETOPS regulations that they should be applied to all aircraft flying overwater. The difference is that a twin is certified to fly sans one engine for 180 mins. No quad or trijet is. The twin is also certified with fire supression equipment that will keep a fire down for the certfied period of time.

If anything the twin operates overwater under a tighter regulatory scheme that is superior to the quad.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia
 
DIA
Topic Author
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 3:31 am

"I think it's aimed at BA, who use a lot of 777s across the puddle; and the US airlines."

My sentiments exactly. I think Cedarjet hit this one on the nose. I would think they would, in a way, be shooting themselves in the foot if it was aimed at Boeing (i.e.A330). That was an interesting angle, though, Jay.

DIA
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caravelle
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 4:08 am

Funny this thread appeared again after so many years. Of course you "feel safer" with three or four engines. But, honest, what time did that really matter? An engine failure in mid flight? Not bloody likely, apart from some odd bird strikes at approx 10 000 feet.
Anybody here who can tell the story to the full? Who really been there and done that?
Though, having said what I said I don't mind an additional two or three engines to take me back to home base...

- caravelle
Trains and boats and planes....
 
brons2
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 4:28 am

there isn't a single 'november-reg' quad flown into the UK.

UA flies some 744 into LHR at high traffic times (ie summertime)
Firings, if well done, are good for employee morale.
 
donder10
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 4:31 am

Well ,with the proposed changes to quads to bring their maintenance to similar levels to twins this might become academic in a few years apart from the very heaviest types.
 
Turbolet
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 4:41 am

Four engines seem 'right' to me when flying long haul. Two engines is adequate for inter-European hopping.
 
Korg747
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 4:46 am

OK I have a question, can any of those big 4 engine planes fly on just one if the other three failed? because if it can't then it doesn't matter if it's twin or not right?
Please excuse my English!
 
mandala499
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 4:50 am

DIA,
Well, not sure if I'll be more scared being in a 4 engined job when there's an engine failure. Been through an engine failure on a dodgy airline on a twin, not that was scary (despite being in a 1hr flight)...

I'd feel safer in a twin on a good airline than being on a quad of a dodgy airline regardless of whether it's a transpac or a 1hr commute... What defines a good or dodgy airline in this case, is based on my own prejudice though  Smile

I agree that ETOPS requirements such as oxygen, fire and other reliability issues (maybe not the engines though) should be applied to Tri and Quads too !

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
Arsenal@LHR
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 4:58 am

OK I have a question, can any of those big 4 engine planes fly on just one if the other three failed? because if it can't then it doesn't matter if it's twin or not right?

Most likely yes, an engine failure on a 747 is a non-event, 2 engine failures and it's still no big deal. As a passenger you will hardly notice it. And engine failure (birdstrike) on a twin jet is no cause for alarm either, if it's ETOP's certified no problem, if it's not, still no big deal. Simply 'glide' the plane to the nearest airport.

In Arsene we trust!!
 
prebennorholm
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 5:06 am

I don't think that there is any safety issue.

But as rules are, then an ETOPS twin with for instance a faulty fault indication on a perfectly well functioning aircon pack might put you (and 300+ fellow pax) down on a winter cold Siberian diversion field with hotel accommodation for 20 souls. While the quad would continue to a decent place or even to its destination.

The risk is small. But when everything else is equal, I would take the quad. But I would never make my travel plan dependent upon number of engines.
Always keep your number of landings equal to your number of take-offs
 
m717
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 5:16 am

There's obviously not a whole lot of people on this thread that have any idea what is involved in ETOPS certification. Particularly requirements for a diversion airport. Putting down on a winter cold Siberian field with hotel accommodation for 20 souls simply doesn't qualify. Besides, the reliability of the engines that power today's 180 min+ ETOPS aircraft are so high, that engine failure is not the number one cause for diversions. Anyone care to guess what is?
 
mandala499
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 5:25 am

M717,
Let me guess...
1. Security alert or unruly pax...
2. Ill Pax
3. Weather
4. actual airplane equipment problem...

in the right order of frequency... my guesses ! LOL
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
m717
Posts: 540
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 5:45 am

Mandala499,

Bingo. In one word, passengers. In other words, those that are making all the noise on this thread about preferring to be on a "quad"  Insane instead of a twin.
 
N754PR
Posts: 2909
Joined: Mon Oct 04, 1999 10:03 pm

RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 9:35 am

I'll take a 747 or A340 ANYDAY over any ocean.
Bush, your a sad, sad man.
 
flight152
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 11:02 am

Most people here fail to understand the fact that 4-engined planes are twice as likley to have an engine failure over a twin-engine plane. Twns can fly on one engine and the chances of the last engine having a problem is just about zero.

The logic that more engines make a plane safer is flawed.
 
BA
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 11:24 am

For me it doesn't matter whether I fly on a twin, or a trijet, or a quad. I trust that planes are maintained well enough for transoceanic travel. If I'm going to die in a plane crash, I'll accept my fate.

not only is 4engines4longhaul utter hogwash... but I definitely would go out of my way in both time and money if it meant being able to fly a twin!

The only thing that's hogwash is that statement and absurd ideology of yours.

Most people here fail to understand the fact that 4-engined planes are twice as likley to have an engine failure over a twin-engine plane.

That's not true at all. The number of engines an aircraft has does not determine the likeliness of an engine failure. The engine model itself is what determines the likeliness of an engine failure.

Ultra high-thrust engines like those found on the 777s have a tendancy to crack (the fan blades and compressors inside) moreso than lower-thrust engines found on quads due to the intense stress they go through.

If anything, quads are less likely to have an engine failure, but like I said earlier, it's all relative to the engine model itself. Some specific engine models have had fatigue problems in the past, but they'd of course resolve the issue.

Twns can fly on one engine and the chances of the last engine having a problem is just about zero.

That's true, nobody's denying it. It wouldn't be a problem to continue the entire trip on one engine really.......passengers wouldn't like it though.  Smile

The logic that more engines make a plane safer is flawed.

No, it's not flawed. It's an old ideology but still applies today and will always apply.

The fact is twins can lose 1 engine and maintain normal flight while quads can lose 3 engines and maintain normal flight. Very little thrust is needed to keep a plane in the air. But if you lose all the thrust, then you're in trouble. Like you said earlier, the likeliness of losing more than 1 engine on ANY aircraft is slim, but it can still happen and in that case, you wanna be on a quad.
"Generosity is giving more than you can, and pride is taking less than you need." - Khalil Gibran
 
schooner
Posts: 138
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:03 pm

I believe (and stand to be corrected) that ETOPS certificated aircraft have to pass more stringent standards for fire suppression in the holds (ie, longer containment etc). I have no preference but just a bit more info for the pot.
Cheers.

As an aside, Have any 2 engined aircraft crashed recently (since ETOPS has been introduced) purely due to the fact they had 2 engines and not four?
Untouched and Alive
 
Shawn Patrick
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:05 pm

Aircraft safety records are enough to comfort me. Actually, aviation safety records are enough to comfort me.

I'm more likely to get killed in a car accident driving to school in the morning than I am to get killed in a plane crash due to an engine failure. (especially the way people drive around here  Nuts)

Come on guys. This is like discussing whether you're more likely to get struck by lighting in your house or in your friend's house.

Pretty slim chances either way.

If you're actually worried about this sort of thing, consult an obsessive compulsive disorder specialist immediately...  Smile

Shawn
 
N79969
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:06 pm

You cannot lose 3 engines on a quad and maintain 'normal' flight. You can stay aloft and land eventually but a quad on a single engine will driftdown like a twin with an engine out and will have a lower airspeed. On the other hand you can lose an engine on a quad and even continue flight to the destination depending on the nature of the problem. A shut-down on a quad does not automatically translate to a diversion. A shut down on a twin necessarily requires diversion.

I don't believe buy the Airbus marketing gimmick here.

Personally, I am partial to all 7-series aircraft twin or quad.
 
BA
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:16 pm

I believe (and stand to be corrected) that ETOPS certificated aircraft have to pass more stringent standards for fire suppression in the holds (ie, longer containment etc).

That's correct. ETOPs aircraft have to pass several stringent standards. Also if an airline gets twin engined aircraft for the first time and decides they want to use them on transoceanic runs, that specific airline has to go through stringest standards as well.

So applying for ETOPs is not just for the specific aircraft type, but also the airline.

You cannot lose 3 engines on a quad and maintain 'normal' flight. You can stay aloft and land eventually but a quad on a single engine will driftdown like a twin with an engine out and will have a lower airspeed.

You just contradicted yourself.

Staying afloat and cruising at a steady speed is normal flight. Yes, if you lose all 3 engines the plane will lose altitude (it won't drop, it will slowly descend) and will lose airspeeds but will stay be able to maintain normal flight and cruise safely. Just at a slower speed and lower altitude. Still "normal".

On the other hand you can lose an engine on a quad and even continue flight to the destination depending on the nature of the problem.

Yes, that's correct. You can lose an engine on a twin and still continue to the destination. With the case of quads, you can lose 3 engines and still continue to your destination.

That's all relative however. All aircraft have an optimal cruising speed and optimal altitude that determine the aircraft's max range endurance. Since you will be changing your speed and altitude when you lose engines, that will change your maximum range endurance. If your max range endurance is reduced by the time the aircraft restabilizes and is not enough to get you to your final destination, you'll have to land elsewhere.

But like I said, it's all relative.

A shut-down on a quad does not automatically translate to a diversion. A shut down on a twin necessarily requires diversion.

True

I don't believe buy the Airbus marketing gimmick here.

Personally, I am partial to all 7-series aircraft twin or quad.


Please don't start an Airbus vs. Boeing argument. It doesn't matter which you like more, we're not talking about that. We're debating about quads versus twins and BOTH manufactuers build BOTH.

Regards
"Generosity is giving more than you can, and pride is taking less than you need." - Khalil Gibran
 
N79969
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:50 pm

BA,

"You can lose an engine on a twin and still continue to the destination. With the case of quads, you can lose 3 engines and still continue to your destination."

Not true.

Flying a 340 or 747 on a single engine is not in any way 'normal' flight. I did not contradict myself. If you lose 3 engines on a quad, you have to divert. Period. You cannot continue to your destination. It's not even a question of endurance anymore.

Actually you have it wrong about twins. If a 767/777/330 lose an engine, the pilot has to divert...they cannot elect to continue to their destination unless that is the closest suitable airport.
 
N79969
Posts: 6605
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 12:56 pm

One minor clarification:

If 340/747 lose 3-engines, they cannot continue to the destination unless that is the closest diversion airport.
 
BA
Posts: 10134
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 1:03 pm

Flying a 340 or 747 on a single engine is not in any way 'normal' flight. I did not contradict myself. If you lose 3 engines on a quad, you have to divert. Period. You cannot continue to your destination. It's not even a question of endurance anymore.

Normal flight is maintaining a steady velocity and altitude. What speed and altitude that is doesn't matter. It's still normal flight. Flight that is not normal would be rapidly losing air speed and altitude due to the loss of ALL engines, or some sort of damage on the aircraft.

Actually you have it wrong about twins. If a 767/777/330 lose an engine, the pilot has to divert...they cannot elect to continue to their destination unless that is the closest suitable airport.

And I said that earlier. By law, twins are required to divert to their destination. However we're not talking about laws. We're talking about capabilities of aircraft and twins are capable of continuing to their destination if they lose an engine.

If 340/747 lose 3-engines, they cannot continue to the destination unless that is the closest diversion airport.

Again, we're not talking about the rules. We're talking about the capabilities of aircraft.

As long as the final destination is within there maximum range endurance, yes they can continue to there destination.

Like I said earlier, a plane requires very little thrust to stay up in the air. It may lose altitude and speed significantly but still maintain normal flight.

Remember, if the pilot wanted to, he could fly an A340 or 747 at the cruise speed of a Cessna 172 (160-180knots).

However, back to that endurance thing. Typically on large airliners, when you travel below 200-250knots, max range endurance is greatly reduced because more thrust is needed to keep the plane flying at that speed. There are many reasons behind this mainly because induced drag is higher at slower speeds, wing design factors, etc.

Regards

[Edited 2003-04-29 06:07:22]
"Generosity is giving more than you can, and pride is taking less than you need." - Khalil Gibran
 
haanz
Posts: 170
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RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 1:18 pm

I never plan my travel based on the number of engines. 4 engines 4 long-haul is a catchy slogan imposed by Virgin Atlantic - and that is what I take it for.

Now, with four smaller engines, rather than two larger ones, wouldn't simple logic dictate that there is a bigger chance of engine failure?

Just like cellphones really, those nifty gadget Nokias have so much that can go wrong with them...

Bottom line is, I leave the questions of two or four questions to the experts - and both seem to be safe for long haul flights.
 
sllevin
Posts: 3312
Joined: Wed Jan 30, 2002 1:57 pm

RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 1:42 pm

Remember, if the pilot wanted to, he could fly an A340 or 747 at the cruise speed of a Cessna 172 (160-180knots).


I want to order three of those 180 knot Skyhawks  Smile  Smile  Smile

Typical 172 max airspeed is like 130 knots  Smile

Steve
 
jwenting
Posts: 9973
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RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:22 pm

Cessna rates the Skyhawk SP at 126 knots max at sealevel, 124 at altitude. that's KIAS of course, so groundspeed could well be around 180 at altitude  Smile.

Turbo Skylane has max speed of 175 KIAS at groundlevel.

To me number of engines is irrelevant, I just choose (given a choice) the aircraft that gives me the best seating arrangements (which will typically be the largest aircraft on the route, which will typically be a 747 which has 4 engines).
I wish I were flying
 
spk
Posts: 431
Joined: Fri Jun 08, 2001 1:56 am

RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:36 pm

Most people here fail to understand the fact that 4-engined planes are twice as likley to have an engine failure over a twin-engine plane.

That was the best marketing twist ever invented by Boeing. Not that I don't fly twin jets; I fly on 777 and A330 regularly without any worry. However, it's interesting that the above marketing twist was so effective that many people mentioned it over and over again.
 
MD-11 forever
Posts: 550
Joined: Wed Mar 14, 2001 12:15 am

RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 2:47 pm

Just a small example out of my professional experience. We happened to receive an engine in our shop which suffered an inflight-shutdown (of course on a quad) and subsequently clocked up 9 (!) hours windmilling time. Now you twin addicted guys, especially you ConcordeBoy tell me that you could do the same on a twin.... I assume hardly any passenger realised this, nor did this cause any inconvenience to the airline or the passengers, as the plane arrived on time, and the engine could be replaced at a maintenance station. Events like this, with all the saved money involved, may be some reason why there are airline preferring 4 engines 4 long haul..........

Cheers, Thomas
 
sllevin
Posts: 3312
Joined: Wed Jan 30, 2002 1:57 pm

RE: 4 Engines 4 Long-Haul, Made A Difference To Yo

Tue Apr 29, 2003 2:57 pm

That was the best marketing twist ever invented by Boeing.

Actually, that adage (which is certainly true) has been around for ages. Long before the 777 was a sparkle in anyone's eye...

I recall learning to fly twins and being reminded "with two engines you're twice as likely to lose an engine so you'd better be prepared for it...

Steve
 
AroundTheWorld
Posts: 268
Joined: Mon Mar 03, 2003 7:42 am

RE: 4 Engines 4 Long-Haul, Made A Difference To You?

Tue Apr 29, 2003 3:02 pm

Okay joke time...

Two friends are on a transpacific flight in a 747 when there is a shudder in the plane...shortly after the pilot announces they have lost 1 engine but not to worry as they have 3 left and they'd only be 20 minutes late. About an hour later there was another bump and the pilot announces they have lost another engine but not to worry there were 2 engines left, however they would be 1 hour 20 mins late. After another hour or so there was yet another shimmy and the pilot announces they lost yet another engine...but they still had one left and they'd end up being 3 hours late. The one passenger looks at the other and says "we loose another engine and we're gonne be stuck up here forever"