Fooling hobbs, logging full time

Discussion in 'Lessons Learned' started by Messup, Jun 9, 2022.

  1. Whitney

    Whitney Ejection Handle Pulled

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    How some pilots/students would treat an airplane.
     
  2. DFH65

    DFH65 En-Route

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    karma can be...well you know.. Assuming you are not a troll, this disgusts me, well trolls kind of disgust me too :) . You are not even upset about what you did but are upset you got caught. Go away and don't come back.
     
  3. bradg33

    bradg33 Pattern Altitude

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    While I have thoughts on this whole thing, it's so hard for me to take my "lawyer" hat off. And because of that, I just can't get over the OP actually admitting to the flight school that he did this...
     
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  4. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    Well, at least he IS smart enough to fool an inanimate object like a Hobbs meter.
     
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  5. Lindberg

    Lindberg Final Approach

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    The instructor may have just be trying to instruct in proper engine operation.
     
  6. frfly172

    frfly172 Touchdown! Greaser!

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    Wow I hope the poster didn’t really think they would get compassionate responses.
     
  7. Matthew

    Matthew Touchdown! Greaser!

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    Might have been stealing those hours at a discounted block rate, too.
     
  8. Dan Thomas

    Dan Thomas Final Approach

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    The POH should be the authority on that, and the typical training-airplane POH will have cruise settings right up to redline RPM or full throttle, whichever comes first.
     
  9. Whitney

    Whitney Ejection Handle Pulled

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    And in cruise, the altitude reduces power for you, so just firewall it, and forget it.
    Next week I am doing a long trip, my 180 will spend 98% of time with the throttle full forward.
    I'm making it into a 2 day trip, same goes for both days.
    When I pull out the prelanding check list, the power comes back some.
     
  10. Lindberg

    Lindberg Final Approach

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    The POH covers takeoffs and landings as well. Instructors still teach them.
     
  11. Dan Thomas

    Dan Thomas Final Approach

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    I inferred from your other post that the instructor was trying to teach the student to use less power to make the engine last longer or something. The POH gives power settings for various RPMs and altitudes along with fuel burns and airspeeds. All of those settings are approved for continuous operation unless otherwise noted.

    The cruise chart from a 172M:

    upload_2022-6-10_21-5-45.png

    The redline for that engine is 2700. How many pilots cruise at 2600 or 2650, or even at 2700 if they're at 8K? That's 75% at that altitude. I've seen pilots using 2400 at altitudes like that and wondering why the airplane is mushing along so slowly. They don't use the POH. Some don't even have one in the airplane.
     

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  12. RyanB

    RyanB Super Administrator Management Council Member PoA Supporter

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    I’ve got the power table on the sun visor in the Archer. I like to run it around 65-68% power in cruise. That’s generally in the 2450-2475 range, maybe 2500 if I’m a little higher. Running at 2600-2700 just seems too hard on the engine - I’d really dislike running it that fast. Personally, 75% continuous all the time seems like it would accelerate engine wear, no?
     
  13. geneseib

    geneseib Line Up and Wait

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    It wasn't Hobbs that was made the fool.
     
  14. Joe_B1

    Joe_B1 Line Up and Wait

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    It sounds like the guy who got caught cheating on his PPL test and wanted to know how to scam his instructor. Seems like the same style of BS writing anyway.
     
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  15. TrueCourse

    TrueCourse Line Up and Wait

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    You mean the thread that no longer exists? (Unless my search skills have failed me). I think you are right.
     
    Last edited: Jun 11, 2022
  16. Kenny Phillips

    Kenny Phillips En-Route

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    Except you get ripped off, time-wise, with the tach when practicing slow flight.
     
  17. Salty

    Salty Touchdown! Greaser!

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    I've heard of students in puppy mills that didn't have hobbs idling on the taxiway for an hour before a flight.
     
  18. Dan Thomas

    Dan Thomas Final Approach

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    We ran the flight school Lycomings at 2500 in cruise all the time. They all reached TBO, and all had compressions in the upper 70s when we changed them. Those engines, unless they have a time limit on full power (such as five minutes for takeoff and climb) are certified to produce full power their whole lives. Some of them do it, too, hauling parajumpers or towing gliders. The geared engines run at RPMs much higher than that, too. Some ops, like pipeline or powerline patrolling or fish spotting, run at high power levels for over 3000 hours on an engine.

    Lycoming even tells you to run the thing at full throttle, redline RPM, in the break-in process SB.

    Cessna wouldn't put cruise charts showing high power settings in their POH/AFM if it was going to wear the engine out sooner.
     
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  19. TommyG

    TommyG Pattern Altitude

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    Many students and renters beat up airplanes pretty bad. I see the flight schools I have worked with have real nice planes when they get them online. And a couple years later, beat into the ground.
     
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  20. Whitney

    Whitney Ejection Handle Pulled

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    How do you get ripped off in slow flight?
     
  21. Whitney

    Whitney Ejection Handle Pulled

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    Exactly.

    Most training planes, and a lot of rentals, are naturally aspirated, and most airplane engines such as Cont & Lyc run low compression ratios, and low rpm. These are not highly stressed engines at all, even at their full rated power, only made at sea level, on a cool day. But who just flies around at sea level? Most of the time we take off already above sea level, so even at take off the engine doesn't make 100% of its rated power, and then we climb up to 6500, 7500, 8500, 9500, 10500, 11500, or whatever cruise altitude we choose, and that fire walled throttle means nothing to the engine, because the altitude cut the power way back, without the pilot ever pulling the throttle back.
    Next week I am doing a long trip up to Yellowknife, a trip I've done numerous times. Weather permitting, I usually cruise around 9500 or 10500, so despite my never once inching the throttle back from take off, till ready to land, my engine is never stressed. Heck I don't even take off at sea level, so it is not making full power even on the roll.
     
  22. Daleandee

    Daleandee En-Route

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    Thread drift Alert!!!

    Great discussion here about NA and turbo power at altitude (old thread but very good):

    https://www.pilotsofamerica.com/community/threads/calc-max-available-hp-by-altitude.121246/
     
  23. Bell206

    Bell206 Final Approach

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    Tachs are calibrated to one RPM value which is usually a specific cruise value. Turn less RPMs and less time is recorded for the same actual time period.
     
  24. RussR

    RussR En-Route

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    I'm with @Whitney on not understanding how that's getting ripped off. If you're billed by tach time, then you're getting an hour of practice for 0.9 or 0.8 or whatever hours of billing. That's not getting ripped off, it's exactly the opposite, getting free training. If you actually log the tach time, then you're breaking even, but if you log the real clock time, once again you're ahead. So in no case do I see the student getting ripped off while practicing slow flight.

    What am I not seeing?
     
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  25. luvflyin

    luvflyin Touchdown! Greaser!

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    That gots me wondering. Probably ain’t no thang with your plane, but. What about some planes where over stressing the engine might be a problem. Up there in it’s colder than a well diggers azz in Fairbanks in February country, do some folk not use full throttle for take off when it’s seriously cold.
     
  26. Palmpilot

    Palmpilot Touchdown! Greaser! PoA Supporter

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    If the plane doesn't have a Hobbs meter and he's logging based on the tach, maybe he's talking about the fact that he would be logging less time than he was in the air.
     
  27. Bell206

    Bell206 Final Approach

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    I took it as logging your personal time per the tach which you lose the .1 or .2.
     
  28. Whitney

    Whitney Ejection Handle Pulled

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    That's a good thing. Gaining extra experience is always desired.
     
  29. Whitney

    Whitney Ejection Handle Pulled

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    Brought this topic up with some pilot friends, only 3 out of 7 even have a hobbs meter in their plane.
     
  30. Palmpilot

    Palmpilot Touchdown! Greaser! PoA Supporter

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    Sounds like they're all owners. Among rental planes, I've never even seen one without a Hobbs. Of course, I've never rented one in Canada or Mexico.
     
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  31. IK04

    IK04 En-Route PoA Supporter

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    Hey, if you're going to be stupid, how about shutting off the engine to stop the tach time also?

    What could go wrong?
     
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  32. Daleandee

    Daleandee En-Route

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    Great Idea ... save fuel too!
     
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  33. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    If you fly into a thunderstorm that way, you could probably climb pretty fast, too.
     
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  34. Mxfarm

    Mxfarm Line Up and Wait

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    until you don’t?
     
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  35. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    Pretty much right up to then.
     
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  36. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Touchdown! Greaser! PoA Supporter

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    Not much.

     
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  37. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

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    Except one who wouldn't recant and was "pressed" to death.
     
  38. Justin Brady

    Justin Brady Pre-Flight

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    I don't see anything wrong with running a rental closer to the edge than you would your own plane. (in this situation it's really a moot point as explained above, pretty tough to hurt the ole 172 with the throttle).
    If I'm paying for a plane wet I have no responsibility to run it at peak efficiency, I see zero moral issues with running it at any fuel burn I'd like.
    There's not much I could do that would be more abusive than 95% of the student pilots in the plane on any given day.
     
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  39. Whitney

    Whitney Ejection Handle Pulled

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    I agree.

    Just wonder if it doesn't cause some people to rush, knowing that hobbs is clicking away, all the time, during warm up, taxi, run up, and especially since they are rookies, contribute to some accidents, and also poor learning.
    But I know if it was me in a rental 172, that thing isn't coming off full throttle till i am going to enter the pattern to land.
     
  40. Palmpilot

    Palmpilot Touchdown! Greaser! PoA Supporter

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    Couldn't you get an overspeed if you descend without pulling the throttle back? Not all descents occur at the end of a flight, and we should avoid abuse, e.g., exceeding POH limitations.