Old news but good article by Wm Langewiesche on Air France 447

[nauga]

For AF296 they blamed the accident on pilot error before the fires were out - and there are longstanding claims that the FDR data used in the investigation was tampered with (of course objected to by Airbus).

IIRC it was also rebutted by Airbus using a system-level analysis of the parameters on the FDR rather than intuition.

Sometimes a control law designer has no attractive options. Would you rather hit the ground with a high sink rate but wings level with some roll control remaining (strict AOA limiting) or with a high sink rate, angle of bank, and no roll control ('soft' or overridable AOA limiting and a subsequent stall)? Hopefully line crew will never have to see either one function, but when one slips through you will have made the wrong decision, regardless of the one you chose.

Nauga,
and the horns of a dilemma

 

[Matthew]

Can the crew switch the control laws manually?

 

[Greg Bockelman]

Can the crew switch the control laws manually?

Yes, there are ways that the crew can downgrade to a lower control law. No real reason for them to ever do that on purpose.

 

[RotorAndWing]

Can the crew switch the control laws manually?

Sure. Reach up and turn off a FAC and it will go from Normal to Alternate.

But why would you want to?

 

[Matthew]

Sure. Reach up and turn off a FAC and it will go from Normal to Alternate.

But why would you want to?

Just wondering how much control the flight crew has over the automation.

 

[RotorAndWing]

Just wondering how much control the flight crew has over the automation.

The level of automation is at the discretion of the crew under most operating conditions.

 

[Hawker800]

Finally read the article. Should be titled "The Three Stooges."