Some minor observations
-
@Zacke said in Some minor observations:
But the hobbs does not start with the master switch but maybe with takeoff. It's not quite clear to me now. I've done a ground system check collecting 0.4 hours on the engine but the hobbs doesn't count time. Today I did my first flight and realized underway it started to count. There from comes my idea it started with takeoff.
https://community.justflight.com/topic/11138/hobbs-meter/5?_=1789409231747
That's just how the Hobbs meter is implemented in MSFS. It'll only start counting once airspeed exceeds 25 kts.
@Zacke said in Some minor observations:
The fuel estimates (REQ, RES etc.) of the EDM show the values concerning the next flight plan waypoint but not the destination of the flightplan.
That is how the EDM 700/800 is documented to work if there is a valid GPS signal.
@fizzboy said in Some minor observations:
That's just how the Hobbs meter is implemented in MSFS. It'll only start counting once airspeed exceeds 25 kts.
Thanks! That was more or less my assumption. The Commander manual says it start's with the master switch.
@fizzboy said in Some minor observations:
That is how the EDM 700/800 is documented to work if there is a valid GPS signal.
Are you sure? I used that one with the A2A Aerostar and it showed the fuel at the destination. I think that makes much more sense. I think I have to read the EDM manual.
-
Update:
- The hobbs seems to run a little bit faster than the engine tach (or the tach is slower than the hobbs).
- KLN 90B: Today I entered new flight plans for FPL 0 and FPL 1 and the new ones are brought over to the next session. So it seems only blank FPL pages are not saved.
- Do I understand that right the prop does tick over by hand if the engine's hot but not if it's cold?
Thanks!
-
Mechanical tach timers run proportional to engine speed. Slower at low RPM and faster at higher RPM. The RPM at which tach hours equals clock hours varies with different tach models.
The Hobbs meter measures actual clock time that the engine is running.
At low power the tach should run a lot slower increase to near real time at full power.
-
Tach time should be calibrated to approximate accurate time at cruise rpm because that's where you spend most of your time. Here's a good description from https://pilotinstitute.com/hobbs-vs-tach-time/ :
The difference between Hobbs and tach time is the following:
Hobbs Time:
The time from when the engine starts to when the engine stops.
Tach Time:
At cruise RPM, tach time counts like a standard clock.
At an RPM less than cruise, tach time counts slower than a standard clock.
At an RPM more than cruise, tach time counts faster than a standard clock.Tach time can be compared to an odometer in a car. Tach time, which is measured by a tachometer, is primarily used to determine when maintenance should be performed on the aircraft.
Tach time can be thought of as “engine time” because it is a time measure of how much strain the engine has undergone.
Tach time is generally 20% less than Hobbs time, depending on the types of flights undertaken.
Both tach and Hobbs time are logged in the aircraft’s logbook (often referred to as a flight folio). This ensures that, if either the tachometer or Hobbs meter were to malfunction, the discrepancy between the two times would be noticed. It is imperative that you, as the pilot, confirm that both the tach and Hobbs time written in the flight folio corresponds to the indications in the aircraft before and after your flight.
-
Tach time should be calibrated to approximate accurate time at cruise rpm because that's where you spend most of your time. Here's a good description from https://pilotinstitute.com/hobbs-vs-tach-time/ :
The difference between Hobbs and tach time is the following:
Hobbs Time:
The time from when the engine starts to when the engine stops.
Tach Time:
At cruise RPM, tach time counts like a standard clock.
At an RPM less than cruise, tach time counts slower than a standard clock.
At an RPM more than cruise, tach time counts faster than a standard clock.Tach time can be compared to an odometer in a car. Tach time, which is measured by a tachometer, is primarily used to determine when maintenance should be performed on the aircraft.
Tach time can be thought of as “engine time” because it is a time measure of how much strain the engine has undergone.
Tach time is generally 20% less than Hobbs time, depending on the types of flights undertaken.
Both tach and Hobbs time are logged in the aircraft’s logbook (often referred to as a flight folio). This ensures that, if either the tachometer or Hobbs meter were to malfunction, the discrepancy between the two times would be noticed. It is imperative that you, as the pilot, confirm that both the tach and Hobbs time written in the flight folio corresponds to the indications in the aircraft before and after your flight.
@MiRexer Yep. I believe that's how it generally is in real life.
Asobo decided to implement Hobbs Time and Tach Time not like that at all.
Hobbs Time: https://docs.flightsimulator.com/msfs2024/retail/programming-apis/simvars/aircraft-simvars/aircraft-engine-variables/#GENERAL-ENG-HOBBS-ELAPSED-TIME
Tach Time: https://docs.flightsimulator.com/msfs2024/retail/programming-apis/simvars/aircraft-simvars/aircraft-engine-variables/#GENERAL-ENG-ELAPSED-TIME
I haven't actually tested if the GENERAL ENG ELAPSED TIME has an RPM% component to it (if it counts slower at low RPMs and faster at high RPMs). All I know is that it really doesn't matter.
-
@MiRexer Yep. I believe that's how it generally is in real life.
Asobo decided to implement Hobbs Time and Tach Time not like that at all.
Hobbs Time: https://docs.flightsimulator.com/msfs2024/retail/programming-apis/simvars/aircraft-simvars/aircraft-engine-variables/#GENERAL-ENG-HOBBS-ELAPSED-TIME
Tach Time: https://docs.flightsimulator.com/msfs2024/retail/programming-apis/simvars/aircraft-simvars/aircraft-engine-variables/#GENERAL-ENG-ELAPSED-TIME
I haven't actually tested if the GENERAL ENG ELAPSED TIME has an RPM% component to it (if it counts slower at low RPMs and faster at high RPMs). All I know is that it really doesn't matter.
@fizzboy said in Some minor observations:
Asobo decided to implement Hobbs Time and Tach Time not like that at all.
I make no claims to be a flight simulator historian, but I believe it's been like that since the 80's.
-
@fizzboy said in Some minor observations:
Asobo decided to implement Hobbs Time and Tach Time not like that at all.
I make no claims to be a flight simulator historian, but I believe it's been like that since the 80's.
@Black-Square I always keep in mind that "legacy" is just another word that means "actually makes money".
