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A330 flight control laws saved Voyager, inquiry finds

flightglobal.com

11–20 of 186 posts

Re: A330 flight control laws saved Voyager, inquiry finds

#11
post #5

> with a maximum indicated air speed of 358kt (662km/h), or Mach 0.9, recorded What? 358 knots is much closer to mach 0.5 in air. 358 meters/second is close... 662 mph is close.

358KIAS is in fact (or is close) to the Vne (never exceed) speed of an A330. This is an indicated airspeed limit while mach numbers are based off TAS (True Airspeed).

Here's a link to help explain the differences between IAS/CAS and TAS: https://www.decodedscience.org/airspeed-of-an-aircraft-indic...

Re: A330 flight control laws saved Voyager, inquiry finds

#12
post #9
post #5

> with a maximum indicated air speed of 358kt (662km/h), or Mach 0.9, recorded What? 358 knots is much closer to mach 0.5 in air. 358 meters/second is close... 662 mph is close.

Indicated airspeed is based on the force of the oncoming air, and decreases as air gets less dense. There's some altitude where 358kt indicated is Mach 0.9. Edit: before I get more replies attempting to lecture me on how wrong I am, please look up the difference between true airspeed (how fast the air is moving past the airplane) and indicated airspeed (a measurement derived from the difference between static and dyn…

> There's some altitude where 358kt indicated is Mach 0.9.

Not really: http://www.aerospaceweb.org/question/atmosphere/q0112.shtml

Re: A330 flight control laws saved Voyager, inquiry finds

#13
post #9
post #5

> with a maximum indicated air speed of 358kt (662km/h), or Mach 0.9, recorded What? 358 knots is much closer to mach 0.5 in air. 358 meters/second is close... 662 mph is close.

Indicated airspeed is based on the force of the oncoming air, and decreases as air gets less dense. There's some altitude where 358kt indicated is Mach 0.9. Edit: before I get more replies attempting to lecture me on how wrong I am, please look up the difference between true airspeed (how fast the air is moving past the airplane) and indicated airspeed (a measurement derived from the difference between static and dyn…

Thanks for the clarification. Is it normal to refer to kts with the assumption this is related to pressure on the airframe and not actual airspeed?

The reference to the 365KIAS rating later in the article provides only a clue IMO.

Re: A330 flight control laws saved Voyager, inquiry finds

#14
post #3

I do not understand, it took only one input to put it in a dive with auto pilot engaged but two inputs to cancel auto pilot to get it out of the dive?

Apparently the pilot's control was disabled by the camera, which, until it was removed, prevented either pilot's control inputs from having the intended effect.

Re: A330 flight control laws saved Voyager, inquiry finds

#15
post #3

I do not understand, it took only one input to put it in a dive with auto pilot engaged but two inputs to cancel auto pilot to get it out of the dive?

The camera forced one stick forward, the co-pilot pulled the other one back.

Since the two conflicted the computer decided on its own what to do, and didn't listen to either of them.

Re: A330 flight control laws saved Voyager, inquiry finds

#16
post #12
post #9

Earlier quoted context omitted.

Indicated airspeed is based on the force of the oncoming air, and decreases as air gets less dense. There's some altitude where 358kt indicated is Mach 0.9. Edit: before I get more replies attempting to lecture me on how wrong I am, please look up the difference between true airspeed (how fast the air is moving past the airplane) and indicated airspeed (a measurement derived from the difference between static and dyn…

> There's some altitude where 358kt indicated is Mach 0.9. Not really: http://www.aerospaceweb.org/question/atmosphere/q0112.shtml

Those tables make no reference to indicated airspeed.

Re: A330 flight control laws saved Voyager, inquiry finds

#17
post #3

I do not understand, it took only one input to put it in a dive with auto pilot engaged but two inputs to cancel auto pilot to get it out of the dive?

It looks like the conflicting stick inputs (once the copilot managed to manipulate the controls, from the cockpit ceiling) caused the autopilot to retake control.

Re: A330 flight control laws saved Voyager, inquiry finds

#18
post #13
post #9

Earlier quoted context omitted.

Indicated airspeed is based on the force of the oncoming air, and decreases as air gets less dense. There's some altitude where 358kt indicated is Mach 0.9. Edit: before I get more replies attempting to lecture me on how wrong I am, please look up the difference between true airspeed (how fast the air is moving past the airplane) and indicated airspeed (a measurement derived from the difference between static and dyn…

Thanks for the clarification. Is it normal to refer to kts with the assumption this is related to pressure on the airframe and not actual airspeed? The reference to the 365KIAS rating later in the article provides only a clue IMO.

It literally says "indicated air speed." There's no need for interpretation or assumption.

If I saw a raw airspeed without and qualifier, I'd probably assume it meant indicated speed. But I fly small planes where that's the only airspeed available. If you want true airspeed, you have to take what's indicated and convert manually.

Re: A330 flight control laws saved Voyager, inquiry finds

#19
From the headline, I could not figure out how an A330s flight control system could have any influence on spacecraft launched in 1977. Surely there would be no way to port the code and the storage on the Voyagers is tiny... at least until the V'ger Mk. I upgrade.

Re: A330 flight control laws saved Voyager, inquiry finds

#20
post #7

"seven dented ceiling panels, 50 damaged in-flight entertainment sockets" The article doesn't state it, but that's because the passengers, like the co-pilot, fell towards the ceiling of the airplane during this episode. Apparently, the headphone cables are stronger than those sockets.

It's a safety concern that at least 50 passengers didn't have their seat-belts on!
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