Not all A330 engine options have their Thrust reverser's operated by hyd's.

The CF6 engine uses pnumatic power to deply the T/R's with no backup system. i.e. it if fails, they are stowed and locked out. the B767 T/R's are exactly the same.


I have attached a quick copy from some of our training notes.

The first one is for Falconwings, all other flight controls have redundant hyd power to operate them. for example the flaps are powered by the green and yellow hyd systems. ailerons have 2 servos actuators per surface, one powered by one hyd system, the other is "bypassing" the hyd fluid in normal ops, (depending on which FCPC is in command of the surface at the time) but is powered by a different hyd system. i.e. the L/H outboard aileron has a yellow actuator and a green actuator. the T/R's are one of the very few systems onboard that do not have a redundancy regardless of RR, PW or CF6 powered versions. From what hofer has explained they seem to not bank on them working anyway.

If the hyd pressure drops below 1750psi on any of the Hyd systems, their respective electric backup pump will start up automatically and restore the system to 3000psi. it pretty fast, buildup, I'd say under 1.5 sec, but the deployment of the T/R alone would not drain that much pressure.


Hofer/Mort.

Re: yaw compenastion.

Seems like we are taught differently then, I am a qualified B1 LAME on the A330 and CF6-80E engines. and have been building and maintaining A330's for at least 6 years now.

I can probe deeper for roll and pitch, but when in normal law, the FCPC's and FMGEC's with inputs from the ADIRU's command rudder movements to dampen out unwanted yawing of the aircraft, in this case dutch roll, and turbulence dampening, so there is compensation of some kind, and the notes below show. as to when that begins to work i don't recall/know. I do remember something like 80-100kts the aircraft sytems recognize that as the start of a new flight, and inhibit some maintenance systems .

In the roll axis, there is no trim that the pilot can input. The FCPC's send commands to the aileron servo actuators after reciving data from the ADIRU's to ensure that the aircraft flies level. for that matter, when we change an aileron servo actuator, we rig it to the other servo actuator on the same surface, but we do not "null" or "0" rig the aileron to any position in relation to the wing. the ADIRU data will allow the FCPC's to compensate for the flight control's position so the aircraft flies level. a rig check of the flight controls does happen, but the intervals are quite significant, something in the order of approx every 5-7 years.

It is this automatic compensation that allowed the A380 that lost it's wingtip and just over 2m of its outboard wing at the paris airshow to be flown back home to Toulouse for repairs with nothing more than the damage cleared of the outboard aileron, the structure filled with foam blocks and the whole lot high speed taped over. I saw an Airbus slide pack that was prepared of the incident and the pilots reported that they noted no difference at all to the way the aircraft flew. The FCPC's again with data from the ADIRU's compensated to make sure the aircraft flew straight and level.

Thanks

dave