throttling up on the taxi way.
Hi,
Just a quick question, a while back flew back from freidrickshaven and as the plane taxied out to the runway the pilot throttled up before we entered the runway, turned while the plane was accelerating and took off, all in one movement. The cornering was quick! I ask because it's never happened quite like that before or since. I am used to a turn on to the runway, run up the engines then throttle up as a minimum.( to make sure the engines are stable?) Any help would be appreciated as it was quite un nerving and felt rushed. Cheers, |
Nicky
It's a technnique called a rolling take off. Nothing to worry about, although I agree with you it is not so common to experience one on a scheduled flight at large airports, alhtough it's not rare either. If you fly small aeroplanes off soft grass runways (e.g. in winter) it is pretty much standard practice to keep the little darling moving, so that the wheels don't sink into the turf. Although it felt rushed to you, as you were not expecting it, it would not be rushed for the pilots. You now have another little nugget of info to add to your flying knowledge. |
Rolling takeoff. Reduces the strain on engines and props, and saves time if another aircraft is close behind on final.
|
Guy's,
I fly very regularly, klm gold card, flybe, ryan air, easyjet and more, this was not your normal roling take off, even with a roller the engines are run up, stabilised and then pushed to around 85% for take off. This was spool up on the taxiway before turning. I have carried out plenty of rolling take offs at EGBJ, i'm trying to beat the weather and the flu to get my ppl finished (currency+test required) Rolling a 737 onto the runway and then throttling up without stopping is no problem, this was bloody quick. From a couple of trips in a sim at Gatwick, the pilots i have operated with alway's look for engines stable at 20% then push upto 85% for take off, this was way past 20% before turning onto the runway. One thing, it was a Ryanair flight that was tight on time but what's their SOP for take off ? |
Guy's, I fly very regularly, klm gold card, flybe, ryan air, easyjet and more, this was not your normal roling take off, even with a roller the engines are run up, stabilised and then pushed to around 85% for take off. This was spool up on the taxiway before turning. I have carried out plenty of rolling take offs at EGBJ, i'm trying to beat the weather and the flu to get my ppl finished (currency+test required) Rolling a 737 onto the runway and then throttling up without stopping is no problem, this was bloody quick. From a couple of trips in a sim at Gatwick, the pilots i have operated with alway's look for engines stable at 20% then push upto 85% for take off, this was way past 20% before turning onto the runway. One thing, it was a Ryanair flight that was tight on time but what's their SOP for take off ? Dear oh dear! Nicky, give up the 'expert' opinion on the professionals' flying techniques, hold fire on the sim sessions and enrol in apostrophe school instead! |
A little knowledge . . .
No criticism? How about:
this was bloody quick this was way past 20% before turning onto the runway it was a Ryanair flight that was tight on time To be absolutely clear, you cannot judge from the back what they were doing up front. Nobody - Ryanair or anyone else - is going to apply 'way past 20%' before turning onto the runway. It don't happen. What you experienced was routine - sorry if you don't like the answer, but that's what you're going to get from professional pilots on a professional pilots' website. |
In my experience this happens often, what I find slightly uncomfortable is when you line up for takeoff at the start of the runway and just sit there waiting for ages when previously entering the runway you have seen three planes lined up approaching your runway for landing. I realise it is all normal procedure and not a problem.
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Nobody - Ryanair or anyone else - is going to apply 'way past 20%' before turning onto the runway. |
Requirement on the 800 is to set min 40% N1 and have both engines stabilised before TOGA, not the 20% you quoted; that is idle N1 and a heavy 800 won't move from stationary without about 34% N1.
Also if they had been taxi ing for a long time in icing conditions they would have done a quick fan de ice before TOGA which is 70% N1. All quite normal Boeing procedures. |
TRSS
That's interesting to hear. I've also done some sim time for fun, on an old type (non Boeing) and don't remember any particular value being set, just being instructed to push the thrust levers to an approximate position on the quadrant and then to wait for the rpm gauges (!) to stabilise. Although this new insight has absolutely no practical use for me, I do appreciate you making my day a little more interesting by sharing this data, even though this was not the purpose of your post. Also, interesting to see the breakout power needed to move a heavy -800, which reminds me how large the 737 has become. I travelled in the 70s and 80s on the -100/200s and remember the -300 feeling significantly longer when it arrived, now it looks rather compact next to an -800 or -900. And yet the -100/200 felt like a step up from a 1-11 or a DC9-10 ;) Given your comments, would it be reasonable to think that the OPs experience was a normal rolling take off, possibly with a light aircraft enhancing the feeling of swift acceleration? |
F3G
The 800 is more like a 757-100 than a 737-300. If you see the 800 parked next to one of the classic 737s you realise just how big it is. FR have 26K CFMs which can be derated via the FMC to 24K and 22K: essentially it is like unbolting the 26K engine and fitting a less powerful one, as the selection lasts for the whole flight. The engine can then be operated at reduced N1 by using an assumed temperature - fooling the engine management computer by telling it the air less dense. At very light weights, less than 55 tonnes it is very quick, even with a derate and assumed temp: if the runway is short, a la Belfast City, then 24K will probably be used and it goes off like a rocket. |
Just remember ladies and gentlemen, most ot the 'pilots' here have gained their experience playing Flight Sim.
Sitting in front of a computer with your joy stick in your hand doesn't make you qualified to comment on the real world of aviation. Rainboe is on it |
Good to see some decent people about.
Real slim,
Thanks for that, i'm an engineer and your info makes logical sense and could well explain what was a very different experience to the 300+ take-off's i've sat through in 73's over the last couple of years. I'm not a nervous passenger, just one with a question that had been nagging me. As for rainbow, what can i say ? does he fly ? for a living ? if he does it's about time he looked for something else, he's lost the plot. Seriously, he can't be a pilot, that attitude will get someone killed one day, if not in a plane then a car. |
Fogive me Wiley, but I don't see too many people claiming to be pilots on this thread.
I made my original reply on the basis that I have a few hundred hours in lighties and a rolling take is err, a rolling take off, even though I know how little a few hundred hours in a lightie teaches about flying. Who else do you mean? nickyjsmith Although I do not like the way that Rainboe sometimes contributes, he is in fact very experienced in line flying and knows the industry inside out. You don't get to be a 747 captain with Big Airways unless you are very good at your job and he was in this role for many years. Unfortunately, you did rather play into his hands with your second post :\ Good luck with your PPL. I've held one since 1994 and as your experience builds, you will begin to realise that line flying is really a different kettle of fish to private flying. I'm not being patronising and we all go through the learning curve, in fact it doesn't really end. There are things I would do at 100 hours that I woudn't at 200 etc....... |
Cheers Final 3, thanks for that.
As for rainboe, sounds like he's got a bit bitter and twisted since he had to retire maybe, not a good advert for the profession or any airline if he still flies. Poor old git.;) |
Oh Dear...
It's amazing! - yesterday before work I checked this forum and everything was sweetness and light: I then worked to LAX, had a G&T and slept 8 hours and wake up to discover that World War III has apparently broken out - it's the speed of escalation that is slightly unnerving.
I've culled the posts on this thread, attempting to restrict the surviving posts to those that are central to the topic. If your post has been deleted, please do not assume that this is a criticism of your point of view, just that your words may not have been central to the topic. I have retained a couple of Rainboe's posts, which may not please all of you: As usual with Rainboe, although he has the tact and people skills of a Great White Shark, he also has a point. For those who wonder, I've thought long and hard about simply banning him from this forum, but my view remains that, on balance, the place benefits more from having him, than not. This is a subjective call, and one that is reassessed every time he starts a fight. On this particular thread, I don't see any one person having 100% of the correct ansers: The truth, as usual, may be found in a cocktail of the combined opinions expressed. There is a very real problem on PPRuNe with pseudo-technical postings about aviation from those that have (literally) no flying experience at all beyond Microsoft. This frequently results in the pollution of threads in various forums, a practice that can be maddening to the professionals (and the mods) and sometimes creates an unnecessarily volatile atmosphere. That said, those who have posted the forum description on this thread are absolutely correct to do so: This forum is a place for passengers to ask questions, and I believe it is at its' best when technical questions are asked and answered. Professionals must appreciate that many of those posting in here have massive experience of air travel, in all classes and on all routes, and this must be acknowledged and respected. I'll leave this thread open, but please may we all try and raise our game - Rainboe is on the Naughty Step just now, but will return I feel sure. I'm off to Denny's now |
Thanks tight slot, it was a genuine question, basically things seemed very rushed compared to my experience of 737 rolling take offs, thats why i asked.
i mentioned my passenger time to get the point accross that i'm not the frightened passenger that only flies twice a year. i asked the question here because i know i'm not a pro and thought it the most appropriate place after reading the description. Rainboe must have a stressful time if he needs to come here and rant, i wish him well, again.:ok: |
Nicky
Not everyone will jump down your throat if you ask a question - even Rainboe. He has a huge amount of expertise to pass on, it just depends on how you ask. Same as me: some things get right up my nose, some things don't. We are all different. |
TightSlot
Location: UK I'm off to Denny's now Theres a dennys in the UK?! :confused: |
Sky Toddler [good name!!] you might want to read TS's post a little more closely. :p
Personally, I think that our forum would be the poorer without Rainboe. His main job is to counterbalance all of us that are soft-soapers, and he takes his job very seriously! These are public forums, supplied at no cost to us, so no one should expect an easy ride. Having participated in this kind of forum for 12 years, I don't expect anything of anyone. If someone persists in being deliberately unpleasant, then they can go in the 'kill' file and I never see their posts. |
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