I have a couple questions about installing a hobbs meter in my PA-30

I have two tach's that are running away from themselves. Engines have the same time on them but the Tach's are over 200 hours off and getting worse. I want to install a hobbs to monitor aircraft and engine hours. Will I need a 337 for a hobbs meter and does the meter need to be certified with a 8130?

It should be installable with a log entry by an AP. I used an inline pressure activated switch in the pitot line to the airspeed indicator to control the Hobbs meter. The switches are available from
Aircraft Spruce and they come in different speed activation ranges. The big advantage for this type of switch is that it keeps track of air frame flight time more closely to the FAA definition than Tach time, and is also usually lower in recorded time. That is the type of Hobbs switch used by most commercial twin operators.

http://www.aircraftspruce.com/catalog/e ... ckkey=4570

 

That depends on you AP. They are not a required item for flight.

There is no FAA "standard specification" for flight time record keeping. If you want to write down your off and on time with a pencil on a note pad and keep it in the glove box, that is perfectly acceptable, and the pencil and paper needs no TSO...installing Hobbs meter is definitely a minor alteration in my opinion.

Zach