FAA grounds All Cirrus Jets

[FlyingElvii]

“The FAA on Thursday issued an emergency airworthiness directive (2019-08-51) against the Cirrus SF50 Vision Jet that grounds the entire fleet until specified maintenance is performed on the aircraft’s angle of attack indicators.

The AD was prompted by three incidents on Cirrus Model SF50 airplanes of the stall warning and protection system (SWPS) or electronic stability and protection (ESP) system engaging when not appropriate, with the first incident occurring in November and the latest this month.”


https://www.flyingmag.com/faa-grounds-cirrus-vision-jets

 

[BrianNC]

In before all the Cirrus haters come in and comment as if no other plane ever had an AD before.

 

[dtuuri]

The AD was prompted by three incidents on Cirrus Model SF50 airplanes...

...and the crashes of two Boeing B737 Max aircraft, I bet.

 

[Ravioli]

All 85 of them? Says the jealous guy that will never have one.

 

[Clip4]

In before all the Cirrus haters come in and comment as if no other plane ever had an AD before.

The AD resulted from a “quality control escape”. Much worse than improper procedures were used during manufacturing . But if you see the escaped quality control, call Cirrus immediately so they can get these planes flying.

 

[Kenny Phillips]

Yeah, I posted this on Thursday, relating the issue to another recent controversy: https://www.pilotsofamerica.com/com...et-mcas-issues-prompt-ad.118220/#post-2714923

 

[Stan Cooper]

I've always thought the reliability of angle-of-attack sensors could be dramatically improved by replacing the moveable vanes in the slipstream with fixed vanes coupled to strain gauge bridges that would measure the air pressure on the upper and lower surfaces of the vanes. Eliminating moving parts would seem to be a logical way to improve reliability. The bridge output would have to be tied to airspeed to accurately provide the angle of attack.

 

[aggie06]

I've always thought the reliability of angle-of-attack sensors could be dramatically improved by replacing the moveable vanes in the slipstream with fixed vanes coupled to strain gauge bridges that would measure the air pressure on the upper and lower surfaces of the vanes. Eliminating moving parts would seem to be a logical way to improve reliability. The bridge output would have to be tied to airspeed to accurately provide the angle of attack.

Is that not how our small GA AOA sensors work? By measuring air pressure in two spots on the fixed probe? Genuinely curious.

 

[PaulS]

Two set screws improperly tightened and no locktite applied. The simplest things will burn your butt.

 

[Stan Cooper]

Is that not how our small GA AOA sensors work? By measuring air pressure in two spots on the fixed probe? Genuinely curious.

It does appear that some of the GA AoA systems use a fixed vane. The CYA-100 installation and operation manual, for example, says the system uses a vane probe with a rare earth magnet; the magnetic field is sensed by a Hall Effect device to measure the angle at which the vane is "flying."

So, you're right; they do use a fixed vane. Live and learn.

 

[Todd82]

Why put out an AD when they can just pull the chute?

 

[PaulS]

Why put out an AD when they can just pull the chute?

That's always an option, but the nice thing about it is a simple push ( and probably hold) of the red button, plus a little action by the pilots brought the flights to a successful conclusion.