What is this?

[Gavin Woodman]

Installed under the left wing. The POH mentions a landing gear safety switch built into the airspeed indicator which prevents the gear from retracting below something like 90KTS but it doesn't describe how it works. Is this related to that? Clearly a switch that activates at speed but I can't figure out what it's for. I don't recall the Ovation or Acclaim having this.

[N201MKTurbo]

There has been a thread about this before, but I don’t remember what it was. It was like a Hobbs meter or an autopilot or something like that. I don’t think it is your airspeed Safety switch, I think it is with some auxiliary equipment.

[Gavin Woodman]

interesting.... the plot thickens... anyone else?

[jackn]

There was another thread on this maybe a year ago. Was an airspeed safety switch. 

[Ragsf15e]

Definitely not the normal gear airspeed safety switch.  That’s a big brass diaphragm connected to the pitot line right behind the airspeed indicator. 

[LANCECASPER]

1 hour ago, Gavin Woodman said:

Installed under the left wing. The POH mentions a landing gear safety switch built into the airspeed indicator which prevents the gear from retracting below something like 90KTS but it doesn't describe how it works. Is this related to that? Clearly a switch that activates at speed but I can't figure out what it's for. I don't recall the Ovation or Acclaim having this.

@201er couldn't sleep last night so he flew his 201 non-stop out to San Diego and put on an AOA for you . . lol. Just kidding 

[ZuluZulu]

I haven’t been here long, but I think I already know what to do: @M20Doc 

[Andy95W]

4 minutes ago, ZuluZulu said:

I haven’t been here long, but I think I already know what to do: @M20Doc 

Careful with that.  It's like Beetlejuice, if you say his name three times he'll show up and start talking about his Comanche 400.

[carusoam]

Do a search for that airspeed switch...

Start in your own log book.

Somebody put it there.

Os and Acclaims are way to new for that device...

Somebody else did start a thread with a pic and asked... what is this for?

Best regards,

-a-

[PT20J]

On my ‘78 J it was a switch for the Davtron clock flight time function. 

[Guest]

An airspeed switch to trigger a Hobbs meter, and according to Jose’ connected to aKR-87 ADF timer.  

Not something ever used on a Comanche 400, it was too much drag.

Clarence

Edited December 26, 2018 by M20Doc

[Gavin Woodman]

Thanks for the help is solving the mystery! This marvelous piece of technology might be why our Hobbs doesn’t work. 

[carusoam]

On a modern Mooney, including rockets, there are so many methods of starting flight time, and engine time....

Adding an airspeed switch is simple logic... but extra work...

The landing gear may already have an airspeed switch...

The engine may already have an OilP switch...

PP thoughts only, not a mechanic or a data maven...  

Best regards,

-a-

[thinwing]

That is a -2kt speed reduction device..very rare

[rbridges]

On 12/25/2018 at 5:04 PM, Andy95W said:

Careful with that.  It's like Beetlejuice, if you say his name three times he'll show up and start talking about his Comanche 400.

Or else he flies his Comanche 400 and the price of 100LL starts going up. 

[bradp]

It’s the machmeter 

[Hank]

2 hours ago, bradp said:

It’s the machmeter 

Mine has read up to 0.28 in level cruise!  Ground speed, of course . . . .

[bradp]

Retractable gelato spoon. European Mooney group modification.  Needs to be replaced or overhauled every 10 hrs or 3 calendar months, whichever is sooner, according to EASA regulations.