Strange noise on take-off

[Moley]

Hi, I am flying from Liverpool to Fuerteventura on Nov 9th, and I am very nervous about it. This will be the third time I have done this trip, and on the first occasion, when taking off at night from Fuerteventura there was a strange low 'woo woo' sound just as the aircraft was getting airborne. It seemed to be coming from the roof and lasted maybe 10 seconds, and I don't think I was the only person scared as the aircraft fell silent. I just thought for those few seconds that I was going to die. Nothing was mentioned on the intercom, and the flight proceeded as normal. The second time I flew to FV I asked a flight attendant about the noise, but he said he had just started the job and didn't know what it was. That noise seemed to increase my intermittent anxiety on planes to a higher level, and now any banking or turbulence makes me terrified. I know that is irrational, but I don't know how to stop it. I'm an ex-driving instructor and think that one of my problems about flying is the lack of control - if I could fly the plane myself I'd be fine! Any advice would be most welcome, Kind regards, Moley

[MathFox]

Well. I don't know the full details about the story, but I know that Airbuses have a noisy hydraulic pump that runs for a few seconds when the wheels of the plane leave the runway.

I'm an ex-driving instructor and think that one of my problems about flying is the lack of control - if I could fly the plane myself I'd be fine!

That's a common issue; the answer is to trust your pilots. I guess you rationally know that the pilots are much more qualified to fly the plane than you are... but there is a less rational part of your brain that has to be convinced. One of the things that helped a lot of our visitors is meeting the pilots before the flight. One of the sticky posts in this thread contains a letter you can hand to the person at the gate desk or the flight attendants.

Furthermore, you'ld be less surprised if you know how a plane does move, watching videos of normal flights or.... taking a few flying lessons yourself may help you a lot!

[Moley]

I'll certainly take your advice. Funny (sort of) the morning after I admit to myself I have a problem and post here, I log on to MSN and am confronted with the horrendous tale of that Japanese plane that turned upside down!!! :eek:

[Falcon]

I have been racking my brains over this, if you could identify the aircraft type. The lack of response from the crew should reasure you. MathFox might have hit the nail on the head with the hydraulic pump called the PTU (power Transfer Unit). This pump kicks in briefly when one engine starts. Is it similar to the noise you heard?

Feeling loss of control is understandable. I can assure you that the training to fly passengers is just as intense as the training you went through to become a driving instructor.

[Moley]

I'm not sure what aircraft type - all I know is that it was EasyJet and held about 100 passengers. Such an unusual noise - been on 4 EasyJet flights (and a few other airlines) and never heard it before. I remember that we were stuck on the runway for ages before take-off, and the pilot cracked a joke (always reassuring!) that we'd been 'put in the naughty chair'. I will listen out when I fly in a few weeks. Thanks again for taking time out from your busy schedule to reply to me - much appreciated! (I think I do trust the pilots really - perhaps it's the mechanics I don't trust - probably due to some 'difficult' experiences with car mechanics!)

Cheers,

:tiphat: Moley

[Falcon]

It was an Airbus. My money is still on the PTU I'll ask around.

[Falcon]

OK, I have cracked it. I have been positioned to France so sat in the middle of the aircraft. The woow woow noise on take off is the PTU. The Power Transfer Unit is a system that powers a hydraulic system using pressure from the other side. If an engine fails it stops providing hydraulic pressure to its side. The PTU senses the difference in pressure and kicks in to keep all hydraulics services running. On take off the crew select gear up, and this causes a drop in pressure to one side. The PTU senses this and powers up briefly ( woo woo ). It stops because once the gear starts to move the hydraulic fluid stabalises. If you listen carefully you will hear in on approach as the crew select gear down.

[Moley]

Thank you Falcon! Sorry for the delay in replying - haven't been here for a while, but I'm off from Liverpool to Fuerteventura in the morning, so I thought a visit would calm my nerves, and I'll listen out for the woo woo!:)
Many thanks again

Moley