Do we really need 4 engines ?

chevol · Post by **chevol** » Mon Aug 08, 2005 4:53 am

"Hi all, You?ve all heard of the BA 747 which flew from LA to (nearly) Heathrow on 3 engines. The pilots thought it would be too costly for the company to abort the flight right after take off? Last night, I tried this on my flight PO605 EGPK to KORD. I switched off engine 3 as I was passing 6000 just after take off and I left it off all the way to KORD. The flight was beautiful! Here are some of the parameters: ZFW: 492,650 Cargo: 150,000 Fuel: 204,239 TOW: 691,221 Landing weight: 531,058 Spent fuel: 166,927 Final fuel: 37,312 Flight length: 3250 NM Block to block: 07:44 I reached FL340 without problem. During the flight I maintained Mach 0.80 with a fuel flow of around 30,000 on the 3 remaining engines. It was so comfortable? do we really need 4 engines??? Have a good day "

BarryTheAviator · Post by **BarryTheAviator** » Mon Aug 08, 2005 5:57 am

"<div class='quotetop'>QUOTE(chevol @ Aug 8 2005, 08:53 AM)</div><div class='quotemain'>It was so comfortable? do we really need 4 engines??? [right][snapback]4606[/snapback][/right] </div> Reminds me of the story of a transatlantic flight in 747 - 30 minutes after take-off one engine flamed out & couldn't be restarted. Not a problem - captain announced ""we have had to close down one engine - but don't worry this aircraft can easily run with three, but we may be about 30 minutes later than expected"". 3 hours into the flight another engine flamed out - the captain made another announcement ""we have had a second engine problem but as we are over half way we will carry on - this aircraft can happily continue with 2 engines but we may be another 30 minutes late at arrival"" Sure enough about 1 hour further on the 3rd engine spooled down - the captain announced ""even though I would not choose to fly on one engine the aircraft is perfectly safe and we are not far from our desination however this will add another 30 minutes to our arrival time - please remain calm"" One passenger turned to his partner and said - ""I am really worried now - if they have to shut down the 4th engine we will be two hours late and we will miss the connection"" [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] (Humour never was my strong point)"

James1979 · Post by **James1979** » Mon Aug 08, 2005 7:31 am

"<div class='quotetop'>QUOTE</div><div class='quotemain'>You?ve all heard of the BA 747 which flew from LA to (nearly) Heathrow on 3 engines. The pilots thought it would be too costly for the company to abort the flight right after take off?</div> No I had never heard of that. Maybe this is common, but I find it hard to fathom. I think it is really taking an enormous risk with the lives of the passengers and crew. I can see flying from LAX to maybe JFK on three, hop out and have a look at things. But not keep on trucking all the way across the North Atlantic without knowing the cause of that engine failure. Maybe Bert could let us know if that type of engine out crossing is the norm? But I'll tell ya that if it had been my arse in that cockpit we'd have been dumping some fuel and returning to LAX. I wonder how the passengers felt, ""Ladies and gentlemen, we've just lost an engine. But dont worry, the other three are fine, so we're going to continue on to London..."" Probably 50% of the passengers were completely clueless, and the other half were ""Excuse me miss, I suddenly feel the need to be very drunk. Would you bring me a brandy, and then another, and then another until I pass out? Thank you..."""

BarryTheAviator · Post by **BarryTheAviator** » Mon Aug 08, 2005 8:07 am

"<div class='quotetop'>QUOTE(James1264 @ Aug 8 2005, 11:31 AM)</div><div class='quotemain'>Maybe this is common, but I find it hard to fathom. I think it is really taking an enormous risk with the lives of the passengers and crew. [right][snapback]4608[/snapback][/right] </div> Remember that a LOT of transatlantic flights are now carried out with two engine wide-bodied jets so continuing with three engines is not exactly an enormous risk. "

chevol · Post by **chevol** » Mon Aug 08, 2005 8:54 am

"I should have given the reference of the flight in question ""Flight 268 departed Los Angeles International Airport on a rainy evening Feb. 19 with 351 passengers on board. Shortly after takeoff, the Boeing 747 experienced a power surge in its No. 2..."" Here is one of many articles, about this <a href='http://www.washingtonpost.com/wp-dyn/ar ... Feb28.html' target='_blank'>http://www.washingtonpost.com/wp-dyn/ar ... 28.html</a> cheers,"

James1979 · Post by **James1979** » Mon Aug 08, 2005 9:00 am

"Using that logic I can expect to see 767ERs crossing the Atlantic on No.1 after No.2 blows the fan blades out the tailpipe? Don't think so. The 4 engines on the 747 are there because it needs 4 engines to operate safely in its complete flight envelope. 3 and 4 are not extras, there to keep in your pocket until you need them. There are many things that could make an engine fail, with fuel contamination being at the top of the list of reasons I can think of to not fly across the Atlantic after one fails without knowing exactly WHY it failed. I realize the odds of having another engine fail are exactly the same as the odds of the first one failing, when you only consider mechanical failure of engine parts and components. But there are other factors to consider, like the fueler having his head up his arse over his impending divorce, or potential terrorist activity. If the lawyers and bean counters at British Airways think flying from Los Angeles to London on three engines is an acceptable risk, fair enough. Personally, I would not have made that trip if I had been on the flight deck. $.02 Edit- the link to the story went up as I was posting this..."

James1979 · Post by **James1979** » Mon Aug 08, 2005 9:07 am

"<div class='quotetop'>QUOTE</div><div class='quotemain'>Shortly after takeoff, the Boeing 747 experienced a power surge in its No. 2 engine, causing a loud noise. Los Angeles area residents called the airport to report seeing sparks from the plane and hearing loud pops, according to the airport.</div> HAHAHA Good Lord!! I'm sorry, but thats just rediculous. With a mayday call and precautionary landing to round out the hit parade. Any bets on BA making that same decision again?? I stand vindicated [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]"

BarryTheAviator · Post by **BarryTheAviator** » Mon Aug 08, 2005 9:27 am

"<div class='quotetop'>QUOTE(James1264 @ Aug 8 2005, 01:00 PM)</div><div class='quotemain'>Using that logic I can expect to see 767ERs crossing the Atlantic on No.1 after No.2 blows the fan blades out the tailpipe? Don't think so. The 4 engines on the 747 are there because it needs 4 engines to operate safely in its complete flight envelope. 3 and 4 are not extras, there to keep in your pocket until you need them. There are many things that could make an engine fail, with fuel contamination being at the top of the list of reasons I can think of to not fly across the Atlantic after one fails without knowing exactly WHY it failed. I realize the odds of having another engine fail are exactly the same as the odds of the first one failing, when you only consider mechanical failure of engine parts and components. But there are other factors to consider, like the fueler having his head up his arse over his impending divorce, or potential terrorist activity. If the lawyers and bean counters at British Airways think flying from Los Angeles to London on three engines is an acceptable risk, fair enough. Personally, I would not have made that trip if I had been on the flight deck. $.02 Edit- the link to the story went up as I was posting this... [right][snapback]4612[/snapback][/right] </div> All there was in my reply was the statement that many flights across the atlantic are made with 2 engine aircraft FACT. The decision of what to do in the event of an engine failure on a two engine aircraft was not even mentioned so I do not think that your conclusion on what I said is logical. The decision to continue on three engines was made on the basis that safety was not compromised. The ONLY person who was in a position to know all the facts and make that judgement was the aircraft commander and it appears his decision was right. "

James1979 · Post by **James1979** » Mon Aug 08, 2005 1:13 pm

[img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

Post by **nwadc10** » Mon Aug 08, 2005 1:40 pm

"Three engine ferry flights are permitted on 747's after permission is granted by the FAA for that particular operator. When you read the Pilot Manual, you saw that the FAA has granted us that permission. Solicit the Atlas Administrators to create a three engine ferry flight for you [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img] These three engine ferry flights are, of course, operated on three engines from block out to block in meaning you get to do a three engine takeoff [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img] Our major maintanance facility is located at EGPK. If the flight leaves the US for EGPK you will obviously be crossing the pond on three engines, except that it was planned from the start rather than planning a 4 engine flight and loosing 1 engine. Justin"

James1979 · Post by **James1979** » Mon Aug 08, 2005 4:36 pm

"<a href='http://www.timesonline.co.uk/article/0, ... _1,00.html' target='_blank'>http://www.timesonline.co.uk/article/0, ... 00.html</a> ""BA initially claimed that the engine had failed an hour into the flight. But the airline admitted yesterday that the problem had occurred a few seconds after take-off when the Boeing 747 was only 100ft above the ground. Air traffic controllers at Los Angeles spotted streams of sparks shooting from the engine and immediately radioed the pilot. He attempted to throttle the engine back but was forced to shut it down after it continued to overheat. The plane then began circling over the Pacific while the pilot contacted BA?s control centre in London to discuss what to do. They decided the flight should continue to London even though it would burn more fuel on just three engines. The Boeing 747 was unable to climb to its cruising altitude of 36,000ft and had to cross the Atlantic at 29,000ft, where the engines perform less efficiently and the tailwinds are less favourable. The unbalanced thrust also meant the pilot had to apply more rudder, causing extra drag. The pilot realised as he flew over the Atlantic that he was running out of fuel and would not make it to Heathrow. He requested an emergency landing at Manchester and was met by four fire engines and thirty firefighters on the runway."" I guess safety is a matter of perspective in this case. The Washingon Times was pretty positive about the outcome, the tone of the story in the Times of the UK was a bit less understanding hehe."

Morn · Post by **Morn** » Thu Sep 08, 2005 11:24 am

"There are certain disadvantages to contining with a failed engine, the aircraft is less efficient, you might not be able to reach your destination, as you would have fueled the aircraft up for a 4 engine flight. And if a 2nd engine fails that would make the fuel situation worse."