Vueling A320 - Takeoff issue

Member for

4 years 6 months

Posts: 1

Fellow aviation enthousiasts, I would like to pose a question after an unpleasant experience earlier this week (17-05) in a Vueling A320 flying RTM - BCN.

As we stepped into the brand new 2014 A320 (EC-MES) I was pleasantly surprised, usually the Vueling flights on this route are older models.
All was going well, we left on time and had a smooth takeoff. Untill we reached an altitude of 2200 feet, the very present sound of the enigines reving at full speed stopped suddenly and the plane lost a lot of speed. The cabin went silent and luckily the sound and feeling of thrusting engines came back after about 10 seconds, this happened another two times after that during the climb but lasted only a few seconds.

I checked the flight replay on Flightradar and can only see the first drop in speed (222 - 137 knots), which seems like a significant loss. (http://www.flightradar24.com/data/flights/vy8337/#64800ff)

My question is, what was this? It felt like the engines were experiencing issues as I can find no other reasonable explanation.

I would love to hear your opinion on this as I am very curious what happened.

Regards.

Original post

Member for

8 years

Posts: 5,852

Thx for your testimony.

It would be hard to comment on it, given that there are none known other similar occurrences on the Airbus jets.

Of course we can trace it back to the other Airbus PropJet crash (ATR72 and A400M) and conjuncture that something lies underground with the Modular avionics (all those aircraft shares a commune architectures - see a former post on the ATR crash that I made). But it would be a bit too far to make such conjuncture with the amount of data that have been shared so far by Airbus.

It's sad since Crowd Cognitive Sourcing works in a certain way and facing the immense complexity of today systems, with the raw numbers of them flying, it's a step forward in the contest of time and life lost (the law of statistics).

Member for

8 years 8 months

Posts: 388

Does 'TomcatVIP' indeed expect us mere mortals to actually understand his last paragraph?

Repeating engine issue = get it back on the ground as fast as you can, not continue calmly to original destination as planned. To me your experience is not an engine related problem. After all it most be aviation rule number one, engine power loss/fluctuation, land it as soon as you safely possibly can, you cannot just ignore it.

I reckon two possibilities, or maybe a combination of the two. Firstly, noise abatement applied heavyhandedly. The feeling of sudden quiet, combined with de-acceleration and apparent sink can be rather unsettling in the cabin, but whenever I've experienced this the flight crew have either provided prior warning or quickly come on the intercom to explain the situation. Should only happen once in the flight though while still low enough for noise to be an issue.

Alternatively, being a factory fresh aircraft, the proximity alarm (TCAS) set over sensitively, commanding a stop to the climb due sensing potential collision risk with an aircraft above. A simple nose down would 'balloon' the trajectory through the path of the other aircraft, a reduction in power countering this with sink. Even so the crew should have informed the passengers that the smoothness of the climb-out had been interrupted by TCAS overide. On a similar theme ATC may have asked for flight level to be held several times during the climb due to conflicting traffic above. The autopilot/electronic flight systems have commanded a decrease in power to halt the climb-out and hold altitude and also to prevent the aircraft accelerating in level flight on climb-out power . Cannot say I've experienced this myself though, just an idea.

I am not in the aviation industry, just thoughts as a passenger and I'm not an Airbus (or Boeing) knocker.

Member for

14 years 7 months

Posts: 962

I fly a lot and see this sort of experience quite often (although maybe not so harsh as you suggest), my feeling is that it is a combination of altitude clearance (You need far less thrust to maintain altitude vs. climb hence the feeling of the engines throttling back) and noise abatement. Nothing to be too concerned about, and if it was then a return to base would be initiated.

Member for

8 years

Posts: 5,852

we reached an altitude of 2200 feet, the very present sound of the enigines reving at full speed stopped suddenly and the plane lost a lot of speed.

I checked the flight replay on Flightradar and can only see the first drop in speed (222 - 137 knots),


The cabin went silent and luckily the sound and feeling of thrusting engines came back after about 10 seconds, this happened another two times after that during the climb but lasted only a few seconds.

Obviously nothing abnormal for MMr GetOutOfThere & NothingToSee. If it have been flight deconfliction, the plane will have banked left or right instead of loosing that much speed in the climb

137Knot nose up... And the Stalling speed right after take off is ?

Oh and.. just to point at it:

This happened another two times after that during the climb but lasted only a few seconds.

Flight Routine and SOP obviously... Ben voyons

Member for

13 years 2 months

Posts: 8,840

Could be noise abatement as mentioned, there are monitors near airports so they often throttle back as they climb over them, it used to have the opposite effect at my local airport as the older noisy stuff used full power for take off the throttled back as they went over them before opening up again, so those in the local vicinity actually got more noise as they climbed on take off the gain height speed at higher power settings than actually needed. I would also ask on pprune.