Hobbs

"Ron Natalie" wrote in message
m...
Peter R. wrote:
On 7/3/2007 6:50:49 AM, Ron Natalie wrote:
Bonanza's don't even have recording tachs anymore. All they have is the
hobbs. My plane is similar, but it's on the gear so I don't pay for
taxi.

Interesting. So Hobbs time is what gets logged in the aircraft/engine
logbooks?

Exactly. Time in service.

Context please? Every engine/airframe log book I've ever seen (small, single
engine) is based on tach time.

--
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Travis
Lake N3094P
PWK

"Orval Fairbairn" wrote in message
news

Sometimes, unscrupulous owners will wire the Hobbs to the master switch,
so you get charges whenever the MS is ON.


It's not unscrupulous if you know about it up front.

Unscrupulous is when you go to rent a U-haul truck for $19.99 a day, but
they consider a day to be the calender day(s) you use it. Pick it up at 8:30
Friday night, drop it off at 8:00 Saturday night, and that's 2 days. The
best one was when they said the would charge me a $50 cancellation fee. I
drove down, picked up the keys, and returned the truck thirty seconds later.
cost me $19.99 for the 'day'.

Orval Fairbairn wrote:

Sometimes, unscrupulous owners will wire the Hobbs to the master switch,
so you get charges whenever the MS is ON.

My Hobbs is on the master, but the airplane has never been rented.

B A R R Y wrote:
Orval Fairbairn wrote:

Sometimes, unscrupulous owners will wire the Hobbs to the master
switch, so you get charges whenever the MS is ON.

My Hobbs is on the master, but the airplane has never been rented.

Which brings up a very interesting question. I'm building a plane that will
be licensed as an Experimental. Once inspected I'll have to test fly for 40
hours for phase one. If I use a Hobbs as the official time and hook it to
the MS I would probably end up reducing the phase one time considerably.

Gig 601XL Builder wrote:

Which brings up a very interesting question. I'm building a plane that will
be licensed as an Experimental. Once inspected I'll have to test fly for 40
hours for phase one. If I use a Hobbs as the official time and hook it to
the MS I would probably end up reducing the phase one time considerably.


That is interesting. Does the FAA specify tach vs. oil pressure Hobbs,
vs. electric Hobbs?

Think of how many pilot logbooks are based on electric Hobbs time.

B A R R Y wrote:
Gig 601XL Builder wrote:

Which brings up a very interesting question. I'm building a plane
that will be licensed as an Experimental. Once inspected I'll have
to test fly for 40 hours for phase one. If I use a Hobbs as the
official time and hook it to the MS I would probably end up reducing
the phase one time considerably.

That is interesting. Does the FAA specify tach vs. oil pressure
Hobbs, vs. electric Hobbs?

Think of how many pilot logbooks are based on electric Hobbs time.

I can't think of a single second in my log book that isn't based on Hobbs
time. Some were oil pressure activated but the vast majority were MS
activated.

Gig 601XL Builder wrote:

I can't think of a single second in my log book that isn't based on Hobbs
time. Some were oil pressure activated but the vast majority were MS
activated.

Me too.

B A R R Y wrote:
Gig 601XL Builder wrote:


Which brings up a very interesting question. I'm building a plane that
will be licensed as an Experimental. Once inspected I'll have to test
fly for 40 hours for phase one. If I use a Hobbs as the official time
and hook it to the MS I would probably end up reducing the phase one
time considerably.


That is interesting. Does the FAA specify tach vs. oil pressure Hobbs,
vs. electric Hobbs?

Think of how many pilot logbooks are based on electric Hobbs time.


If I understand, the stipulated value is "flight time". Not ground time.
Not hobbs time, not engine time.. nor master switch time.

But the feds are also taking it on the honor system that you will not
tie it down and let it run up 40 (or 25) hours on the ground, then sign
off phase 1.

My particular install has an engine monitor that records hobbs time,
when the engine is operating, and flight time, when the ASI is above 30 mph.

Dave

"Dave S" wrote in message
nk.net...
B A R R Y wrote:
Gig 601XL Builder wrote:


Which brings up a very interesting question. I'm building a plane that
will be licensed as an Experimental. Once inspected I'll have to test
fly for 40 hours for phase one. If I use a Hobbs as the official time
and hook it to the MS I would probably end up reducing the phase one
time considerably.


That is interesting. Does the FAA specify tach vs. oil pressure Hobbs,
vs. electric Hobbs?

Think of how many pilot logbooks are based on electric Hobbs time.


If I understand, the stipulated value is "flight time". Not ground time.
Not hobbs time, not engine time.. nor master switch time.

But the feds are also taking it on the honor system that you will not tie
it down and let it run up 40 (or 25) hours on the ground, then sign off
phase 1.

My particular install has an engine monitor that records hobbs time, when
the engine is operating, and flight time, when the ASI is above 30 mph.

Dave

There's flight time and then there's PIC time. I log PIC time from engine
start to engine shutdown. I know some that log PIC time only when they're
moving. I know a guy who logs PIC time from ropes off to ropes on.

I log flight time from wheels off to wheels on (or the amphib equivilant).
None of that is based on tach time. I have no use for Hobbs time.

My personal checklist has Tach at S/U, Start time, T/O time, T/D time,
Shutdown time, Tach at S/D.

--
-------------------------------
Travis
Lake N3094P
PWK

That is interesting. Does the FAA specify tach vs. oil pressure Hobbs,
vs. electric Hobbs?

Think of how many pilot logbooks are based on electric Hobbs time.


Neither is correct to the letter of the regulation, both are acceptable
to the FAA.

Pilot time is the real time from the time that the aircraft first moves
under its own power for the purpose of flight until it comes to rest at
the destination. The oil pressure time is pretty darned close (I
assert the aircraft moves forward a tiny bit as soon as the engine
starts and isn't really at "rest" until it stops). Unless you leave
the master on for a long time in a prolonged preflight, the difference
is probably within the tenth of an our accuracy of the unit.

For maintenance, it's time in service. Frankly, even putting the hobbs
on a gear switch is acceptable to the FAA (saves you some time if you
operate out of places like Dulles where you can wait / taxi for a long
time before taking off).