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During a recent Ryanair, Boeing 737 flight, the aircraft went up and down the runway several times before takeoff, whilst modifying the flaps.

Why would this have been? Usually, I thought flaps and adjusted whilst stationary.

I was worried on the flight that they were 'testing' the engines somehow before takeoff.

Further info: I'm not sure what speed this was, but it was slightly faster than usual taxi speed.

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    $\begingroup$ I guess the best thing I can think of is to ask: are you sure you actually were on the runway at the time? (And if so, on what basis did you reach that conclusion?) Some airports can be beasts to navigate along the taxiways. Is it possible that the pilots were in the process of taxiing to the runway, and for some reason the route they took was convoluted? $\endgroup$ – a CVn May 3 '18 at 13:55
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    $\begingroup$ When was this? You might be in luck and Flight Radar 24 may have your position on the ground which will show exactly where you taxied before takeoff. $\endgroup$ – BDLPPL May 3 '18 at 15:11
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    $\begingroup$ @Cloud - 17:40 local time? And what about the date? Please add this info into the question. $\endgroup$ – ymb1 May 3 '18 at 15:20
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    $\begingroup$ Yes Budapest time. On Tues 1st May. I would rather not add to the question for anti-terrorism reasons. (The flight attendant already became suspicious when I asked him if the crew had performed this flight before, he said no...) $\endgroup$ – Cloud May 3 '18 at 15:24
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    $\begingroup$ @MJeffryes right, found a Ryanair one: flightradar24.com/data/flights/fr8207#113a78c4 it seems to have taxied even less $\endgroup$ – Federico♦ May 3 '18 at 16:33
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First, congratulations on facing your fear of flying.

What you saw was nothing out of the ordinary (also, asking the crew things does not make you end up on terrorism watchlists).

From a passenger perspective, it's extremely difficult to judge your whereabouts. Taxiways and runways are difficult to distinguish, especially because your forward view is limited. The layout at Budapest, with runways far apart, does not help. Long taxiways may look like runways (taxiways may be very broad) unless you know exactly what you're looking for. I've invariably completely misjudged my position on the airfield as a passenger despite using the hours before boarding checking out the airfield layout.

Furthermore, the crew may elect to use a higher taxi speed on long taxiways, so when braking for a turn you suddenly realize how fast you were going. However, compared to the size of the plane this is still quite slow. Think of the feeling you experience braking for a bus compared to what you felt in the plane - a plane will taxi at what would be a fairly high speed for a bus. Due to the size of a plane and lack of external reference, cornering may feel exaggerated with respect to reality too - a 90 degree turn may feel like a 180.

Finally, the flaps are configured during taxi, no need to be stationary. This may be done in steps (a little bit before taxi, some more during) Controls can also be tested during taxi (full deflections to all sides). This is completely normal.

So, what you experienced as a sequence of things that are completely normal but feel very different inside the airplane than the way it looks on the outside.

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  • $\begingroup$ Thanks very much.. although I have been worried by some of the answer here :/ :aviation.stackexchange.com/questions/51150/… $\endgroup$ – Cloud May 3 '18 at 15:58
  • $\begingroup$ even though I did the flight, it felt like hell at times so I am trying to do more research so I am more educated and therefore less anxious next time as I desperately do not want to give up on flying and travelling $\endgroup$ – Cloud May 3 '18 at 17:19
  • $\begingroup$ @Cloud Statistics will never put you at ease if you can't put them into perspective. $\endgroup$ – Sanchises May 3 '18 at 18:04
  • $\begingroup$ @Sanchises runway markings are completely different from taxiway markings and they are visible through the side windows. Nevertheless one must know these markings, so I believe a regular passenger might get confused indeed. $\endgroup$ – ElmoVanKielmo May 4 '18 at 22:42
  • $\begingroup$ @ElmoVanKielmo True. I've never confused a taxiway for a runway but I can imagine an average passenger would. $\endgroup$ – Sanchises May 5 '18 at 5:50
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One other possibility not mentioned (and not relevant to Budapest, but this question might get views from people experiencing it at other airports) is backtracking.

On smaller airports it's somewhat common to not have taxiways connecting to the far ends of the runway, but rather a single taxiway connecting to the runway somewhere along its length (either the near the center or at one of the end points).

When aircraft need to take off on such a runway, they may have to turn onto the runway and drive part of the runway at taxi speed before turning around and starting their takeoff. Or after landing they may have to turn around and drive over the runway towards the taxiway.

This of course severely limits the capacity of the airport to handle traffic in volumes so it's mainly used at quiet places that don't get a lot of traffic, and sometimes at larger airports when for example a taxiway is closed for resurfacing.

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  • $\begingroup$ That seems like a horrible design, but I'm sure there is a reason :) $\endgroup$ – Cloud Jul 11 '18 at 10:17
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    $\begingroup$ @Cloud several reasons. Space is one (parallel taxiways effectively make the runway 3 times as wide). Closely associated is cost (less pavement to maintain). And many of these fields have existed since WW2 or before, in places where they were mainly used for the occasional transport or patrol aircraft and construction time was more important than future growth potential. $\endgroup$ – jwenting Jul 11 '18 at 10:23
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    $\begingroup$ @Cloud another reason can be that the prevailing wind is always in the same direction. For the few days a year it comes from the other direction they just have to make do $\endgroup$ – jwenting Jul 11 '18 at 10:24
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Taxiing up and down a runway was once thought to be a great way to lift the visibility limits when early morning fog would make an immediate take-off illegal. Until 1963, that is.

On September 4 of that year, a Swissair Caravelle used this trick with the engines at full power and brakes applied to slow the taxi speed. That worked to disperse the fog, but when the aircraft took off, the brake disks were glowing red hot. Inside the wheel well they cooled down only slowly and the heat crept into the surrounding structure. The magnesium wheel hubs heated up, too, and failed under the tire pressure when the hub material was heated to something close to its melting point. The resulting spray of shrapnel severed the hydraulic lines running through the wheel well and the still glowing brake disks ignited the hydraulic fluid, with catastrophic consequences.

That accident was one of the reasons for the use of fire-resistant hydraulic fluids in commercial aviation.

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    $\begingroup$ This doesn't answer the question at all $\endgroup$ – Cloud May 3 '18 at 15:06
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    $\begingroup$ @Cloud - question lacks crucial details, many regular passengers think any pavement is called a runway. Saying what it isn't is a good answer IMO based on the details given. $\endgroup$ – ymb1 May 3 '18 at 15:21
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    $\begingroup$ The answer does explain why you probably were not going up and down the runway though - beyond the usual "there are probably other planes wanting to use it" $\endgroup$ – Baldrickk May 3 '18 at 16:04
  • $\begingroup$ @Cloud: The question is "Multiple runway laps before takeoff. Why?". The answer gives a reason. What is wrong with that? $\endgroup$ – Peter Kämpf May 3 '18 at 18:15
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    $\begingroup$ @Baldrickk if there are other aircraft waiting to use the runway you'd definitely NOT get clearance to take a leasurely drive over the runway, turn around at the far end, and do it again a few times just for fun. $\endgroup$ – jwenting Jul 11 '18 at 10:07
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Large airliners are not the only planes to taxi down and back. I recently had to taxi down my home runway to scare some geese off the runway, and then keep an eye on them to ensure they stayed clear as we started our takeoff run.

Chasing deer away could be another situation. A low wing plane landing hit a deer over the weekend; killed the deer and dented the lower leading edge of the wing. 65-70 mph can do that. Hitting engine/prop first I imagine would have made a lot more mess. No one in the plane was physically hurt. Mentally shaken up perhaps.

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    $\begingroup$ Please tell me you're not seriously suggesting an A320 was driving up and down the runway to scare off geese :/ $\endgroup$ – Cloud Jul 11 '18 at 14:08
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    $\begingroup$ No, something a little smaller, Cessna 177. Would have called to have someone come out if the operations area had been manned. $\endgroup$ – CrossRoads Jul 11 '18 at 16:06

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