Mechanical back up

[applecrumble]

Hello,

Does anyone know for sure if during the flight test campaign for the A320 the test pilots landed the aircraft in mechanical back up.
I have heard rumour to this effect but was wondering if anyone knew for sure that this was performed.

Thank you

[fantom]

Why would they? That is not what it is for.

We did it in the 330 sim many times, however.

[Check Airman]

I think it's a reasonable question. Along those lines, has any line crew ever used mechanical backup? I don't recall reading about any such incidents, but want to be sure.

[vilas]

I don't think failure of all computers together has ever happened. Mechanical backup is after that. Safety first surely would have had an article in some issue. Like UAR or Hudson surely would have kicked up a storm.

[vapilot2004]

A couple of gents managed to bring a DHL A300 back to earth after losing all but the THS using differential power as their rudder.

[tubby linton]

An early A320 had a failure of the avionics cooling and I believe they ended up with only one SEC working.

[vilas]

Mechanical backup is not same as loosing all hydraulics. That's what happened to DHL, almost impossible to control. Mechanical backup is not easy but manageable.

[TURIN]

I thought the 320 only had mechanical backup on the THS and rudder?

(Edited to add rudder too)

[vapilot2004]

All modern wide bodied Airbus aircraft have "electric rudders". I understand the A320 has joined them, but it wasn't always so.

Mechanical backup is not easy but manageable.

Sim fidelity suggests, and understandably so, no crosswind landings may apply here.

[Sidestick_n_Rudder]

Electric as in ‘electrically controlled’. You still need hydraulics to power them.

[Hahn]

According to one of the flight test engineers, yes, they did.

[applecrumble]

How did you come by that info Hahn?

[Hahn]

The old fashioned way: by talking to said engineer.

[vapilot2004]

Electric as in ‘electrically controlled’. You still need hydraulics to power them.

Quite true across not just the Airbus fleet, but on all 100+ seat transport category aircraft - unless we include the Mad Dog, whose designers seemingly from another era, eschewed total reliance on hydraulics as well as any electrickery betwixt the cockpit and primary flight control surfaces. :8

[VinRouge]

I fly an M.D. with hydraulic flight controls, electronic primary and mechanical reversion, based on at least one hydraulic system functioning, otherwise back to engine asymmetry only.

I do have 4 separate hyd systems however....

Unfortunately, no pitch power couple in reversionary.....

Basic Electronic rudder, no turn cord or engine out compensation airbourne, but she does the job.

[porch monkey]

737?..........

[vilas]

All commercial aircraft made after B747 require hydraulics for flight controls.

[DaveReidUK]

I think you mean commercial jets ...

[vilas]

Yes. I do.

[172_driver]

Wasn’t early MD80s, spring tab for aileron and elevator?

What about BAe146?

Not flown any, just heard stories