Hobbs Meter in a BL65

[charliestith]

I would like to install a battery driven Tach/Timer, mostly just for the engine run time timer. Installation is pretty simple, just some double sided tape or Velcro and a wire wrapped around one of the spark plug wires. This is ok in an experimental but with a certificated aircraft with no electric and a non TSO'd instrument and amateur installation, not so much. So, just wondering if I am going to get hit if I ever get a ramp check or if there is some exception for this kind of thing. I know I can use the Tach time, just like to have a Hobbs type meter for total time for maint and flight time logging.

Thanks in advance.

[waltermrich]

Personally if it is that simple I would not worry about it, Im not an A&P but have plenty of time owning aircraft, and I would do it, if you got checked or your annual inspection finds a discrepancy just take it off . Personally I like Mike Bush's interpretation of regs he keeps emphasizing that the owner is ultimately responsible for the airworthiness of the aircraft. Of course there are others who think you have to replace every piece of the aircraft down to the last AN bolt to its original part and cannot deviate from the least regulation, but Im not that extreme.

[PA1195]

Excellent idea! I have one on my snowblower and backup home generator to track the engine governor and routine maintenance. Might not work with a shielded ignition system but unshielded wires should be ok. Just velcro it onto something and don't fix it with hardware. Few inspectors would know or care in my experience about the supplemental data provided. They are inexpensive and appear to work. I've checked mine against digital tachs and they are accurate when set to the engine type.
Gary

[astjp2]

Tach time works just as good! And no question of approval

[PA1195]

I never met a cable driven aircraft tach that was accurate for rpm or eventually TT. Any external digital tester will confirm that. These gizmos work.

Gary

[astjp2]

Never questioned that Gary, other than approval...

[PA1195]

No argument intended or approval required as long as the primary source(s) of tach and time remain airworthy. Now the question becomes what's the concern about sticking a tach/timer to the plane with temporary fastening material and wrapping the insulated probe wire around an insulated but RF transparent source of ignition pulse? It's auxiliary and supplementary information not required for flight nor is it the primary instrument that is required per CFR 91.205. There's all matter of non-required but potentially supplementary information sources affixed to aircraft...like here's the door handle or here's the survival gear and here's the N-number and so on.

I use my Tru-Tach sitting on velcro over the instrument panel of the plane to detect any rpm-dependent error in my mechanical tach. What I then do about it is my business as a pilot.

Edit: I might add holders for writing instruments, handheld aircraft radios, and various electronic devices such as portable intercoms and electronic flight bags plus their supplemental source of battery power (temporary battery - or, if hardwired then should be approved). It may be the method of attachment - temporary and portable vs permanent - is what Tim refers to as requiring approval.

There's more to learn and clarify I assume. Also see CFR 91.21 for testing and determining compatibility with navigation or communication equipment: https://www.ecfr.gov/cgi-bin/text-id....1.3.10.1.4.11

Gary

[3Dreaming]

Tach time works just as good! And no question of approval

In his case, if it has original instrumentation the tach does not record time. It would be one of the Stewart Warner 6" instrument clusters.

[Robert Lees]

I never met a cable driven aircraft tach that was accurate for rpm or eventually TT. Any external digital tester will confirm that. These gizmos work.

Gary

For years and years, all my flying around Europe in my Taylorcraft (in fact two of them) between 1984 and 2012, I kept an accurate record of the recording tach time against a stopwatch, from engine start to engine shut-down.
So including warm-up, taxi, flight, land, taxi, cool down, shut down.

The recording tach over-reads by about 4%, which is neither here nor there.

Rob

[PA1195]

Yes Rob it's lots to do about nothing unless we are commercial where every minute and penny count. I've not owned but have observed the current trend towards glass cockpits versus steam and cable driven gauges installed in a few local planes. It's all there in a package including accurate recording of flight performance and engine parameters to be reviewed later.

Oh for the simpler days when flight was about flying and less about device monitoring.

Gary

[astjp2]

Yes Rob it's lots to do about nothing unless we are commercial where every minute and penny count. I've not owned but have observed the current trend towards glass cockpits versus steam and cable driven gauges installed in a few local planes. It's all there in a package including accurate recording of flight performance and engine parameters to be reviewed later.

Oh for the simpler days when flight was about flying and less about device monitoring.

Gary

There seems to be a real lack of “airmanship” in our current crop of new airline pilots, it’s almost scary compared to pilots of yesteryear. Too many buttons to push, and not looking out the cockpit, situational awareness is relative I guess.

[PA1195]

The flight reviews I've recently encountered have been about airmanship and CFIT (controlled flight into terrain). That may have been function of focusing on my age (73) and my typical flight profile (recreational bush flying in Alaska) which is admittedly slowing down. Now for the other younger pilots I know it appears that airmanship is taught (not sure to what extent) but so is glass cockpit management. If they wish to pursue a career in aviation they'll need both but the latter is emphasized for Part 135 and 121 ops...not sure about one over the other but comments regarding how we survived without GPA and EFB's (but with lots of experienced maintenance support) is an alarm.

Gary