Horror on Bristol easyJet flight as pilot says there's only a 50-50 chance of engines working - Sensationalist Headlines

[QUOTE=DoktorAkcel;52347727]Isn't the chance always 50/50? Either engines work, or they don't[/QUOTE] Oh wow, this brings me back [url]http://www.cc.com/video-clips/hzqmb9/the-daily-show-with-jon-stewart-large-hadron-collider[/url] (skip to 2:35)

[QUOTE=Amplar;52345835]At least the pilot has a sense of humor. I'm pretty certain the crew knew the plane was knackered and was going to be grounded anyways, and decided to have a bit of fun with it. Pissy babies the passengers are.[/QUOTE] eh to be fair, there's been 2 other very notable engine failures in the news on the exact same plane so.... maybe not the right time

[QUOTE=DMGaina;52345940]Even if, the plane wont fall out of the air like a stone when one engine is failing.[/QUOTE] In a twin engine plane, if one fails, the other will always have enough power to get you to the scene of the crash.

[QUOTE=Sableye;52349888]eh to be fair, there's been 2 other very notable engine failures in the news on the exact same plane so.... maybe not the right time[/QUOTE] Well if it's been in the news twice apparently, already, then maybe this is his way to bring attention to them [i]not using this plane anymore[/i].

it's an easyjet flight the fact that one engine was working is a step above what normal easyjet flights have to deal with last time i took an easyjet flight to dublin, the gave us fucking oars and told us to row to the beat of the drummer

I guess its my time to shine the light about this one-engine take off misconception going on around here. ATPL student here, not jet hours yet but we've been pretty much indoctrinated on flying the 737NG since day 1. The rules on light aircraft are a hell lot lighter with shit buckets like Piper Cheyenne which, even though it has 2 engines, it could barely climb 50fpm with a single engine failure on a really good day and on a bad day or any other normal day for the matter of fact, you're better off shutting down the other engine and gliding your ass to safety. BUT! Since we're talking about MRJTs let me go through the basics. In a passenger jet aircraft there are 4 different segments when it comes to the Nett Take Off Flight Path or NTOFP (Remember the Nett part this will be explained later). [B]Segment 1:[/B] Starts from "35ft above ref. zero (for simplicity lets say runway)" a.k.a screen height up to; [B]Segment 2:[/B] Which starts at the moment the landing gears are retracted and locked up to; [B]Segment 3:[/B] Where the pilots will actually lower the nose while retracting the flaps to speed up and finally; [B]Segment 4:[/B] Where the aircraft climbs to 1500ft or whatever the safety altitude is if higher. So lets go over to the rules rules rules and regulation. We all should know that a plane should never ever ever take off unless it has some safety factors built into it. But what are the requirements for those factors you ask? Thankfully our friends at EASA or CAA or JAR or whatever you have in your country have clear cut requirements for these things. In short, a plane should never ever ever ever ever take off unless it can prove that (through thousands of hours in test flights translated into a few pages of performance graphs for convenient use by the airline staff/pilots) under the worst ever possible circumstances, during take off, if an engine failes at or above V1, the plane should at least be able to; [B][I]note these are for 2 engine aircrafts[/I][/B] [B]Segment 1:[/B] Climb at a minimum gradient of [I]0+% (basically not less than zero)[/I], meaning it should at least maintain altitude or climb and not sink until the gears have retracted. [B]Segment 2:[/B] Climb at a minimum gradient of [I]2.4%[/I], in this segment the plane must at least climb up to 400ft if no obstacles are present and if there are then it should clear it by at least 35ft. Eg. if there is an obstacle 1500ft tall then the aircraft must climb to 1535ft. [B]Segment 3:[/B] Climb at a minimum gradient of [I]1.2%[/I] [B]WHILE[/B] accelerating to a speed of [I]V2+60~70kt[/I], if no obstacles are present this can actually be done while flying level to expedite the acceleration. [B]Segment 4:[/B] Climb at minimum gradient of [I]1.2%[/I]. Now some of you may still ask, but what if the engine performance is less than usual / what if the wind changed to a tailwind / what if you're carrying 100 sumo wrestler instead of 100 average passengers? Fear not, because for starters should an airline carry a full flight of sumo wrestler each of them will be individually weighed and their mass will be accounted for when calculating performance. Besides most airlines use a higher than average weight for each passenger when calculating mass. But back to the original point, well this is where the fancy shmancy term [B][I]"Nett"[/I][/B] comes into play. To put it simply, there are two types of performance, Gross and Nett. Gross the actual performance while Nett is the gross performance with more safety factors built it. To put it simply into simplier, Nett performance is an underestimate of Gross performance. Here are some basic safety factors that are put into gross to get the nett; - Always [I]assume that the critical engine fails[/I] (depending on the wind, failure of the left engine can have more or less adverse effect than failure of the right engine (and vice-versa) - Only [I]50% of the headwind is accounted[/I] for (headwind good) and [I]150% of the tailwind is accounted[/I] (tailwind bad) - There's more, but this one is specific to the NTOFP : [I]0.8% of climb gradient is subtracted from the Gross[/I]. Which means even on a really bad day, as long as performance calculations approves should an engine fail the plane would still climb at 0.8% for segment 1, 3.6% for segment 2 and so on. No matter what the weight is because the actual weight for the flight for the day is one of the inputs when calculating performance. Tl;dr : When you're in a flight as long as the pilots decide to go you can be rest assured that even when an engine fails you'll never turn into a flame ball on the ground. [I][B]Bonus content;[/B][/I] the altitude an aircraft can fly is dependent on how much thrust is available compared to how much thrust is needed to fly, (a.k.a more excess thrust = more altitude) of course this works the other way around and a plane with one engine inoperative will never fly as high as a fully functional plane could. But don't worry even in the worst case scenario (full weight, really hot day) a 737-400 can climb up to approx 10,000ft which is more than tall enough for most regular airports out there.

[QUOTE=Chryseus;52347626]All jets can take off and climb with a single engine failure otherwise it would not be safe at all, there have been plenty of cases where an engine has failed before it's off the runway, now if the speed is below V1 the standard procedure is to abort, if it's above there is no choice but to take off which isn't a big deal since it's already going nearly fast enough to take off with little or no additional runway required.[/QUOTE] Well, seeing as they were already at a dead stop, they were going nowhere.

[QUOTE=adam1172;52353508][B][I]"Nett"[/I][/B][/QUOTE] You should ask your instructors why you are being taught "nett" when the word you are looking for is "net"... ... otherwise that's got it.

[QUOTE=Snowmew;52356452]You should ask your instructors why you are being taught "nett" when the word you are looking for is "net"... ... otherwise that's got it.[/QUOTE] God dammit, I was too busy trying to find a way to translate it from the complicated words on my textbook to realize that :v: