R44: Any comments on the correct method for conducting a power check?
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R44: Any comments on the correct method for conducting a power check?
Gotta do a BFR tomorrow and am reading over some old theory notes..got to the section on power checks prior to operating in confined areas at high density altitudes. There's a section in the theory I'm not sure I understand with regards to flight ops.
On a R44 the margin required between maximum manifold pressure and conducting a hover OGE is 6". Best rate of climb is 53kts. So say the charts say at 3000ft density altitude , 25 deg OAT the max MAP is 26" Assume the pad is at 3000ft AGL I can safely land if the chopper will maintain straight and level at 53kts and 20" of manifold pressure i.e the max MAP of 26" less the 6" of margin for an out of ground effect hover and 53kts is best rate of climb..right?
Ok here's the bit I don't get ..the theory manual says having confirmed the maximum manifold pressure off the charts confirm this by increasing the collective to the maximum without observing a drop in RRPM. What it doesn't say is what flight condition I should be in when when checking this ..I presume straight and level as a climb will reduce RRPM and I presume I start at VNO?
The thing that seems erroneous about the instructions in the theory manual is if I pull max MAP in straight and level then I imagine I would soon be outsde the limitations within the 44's flight manual ..which says never exceed 100kts IAS when operating at max MAP.. ..which makes sense to me as I'd imagine with low fuel, low weight if you pull max MAP you'd be soon getting close to VNE?
On a R44 the margin required between maximum manifold pressure and conducting a hover OGE is 6". Best rate of climb is 53kts. So say the charts say at 3000ft density altitude , 25 deg OAT the max MAP is 26" Assume the pad is at 3000ft AGL I can safely land if the chopper will maintain straight and level at 53kts and 20" of manifold pressure i.e the max MAP of 26" less the 6" of margin for an out of ground effect hover and 53kts is best rate of climb..right?
Ok here's the bit I don't get ..the theory manual says having confirmed the maximum manifold pressure off the charts confirm this by increasing the collective to the maximum without observing a drop in RRPM. What it doesn't say is what flight condition I should be in when when checking this ..I presume straight and level as a climb will reduce RRPM and I presume I start at VNO?
The thing that seems erroneous about the instructions in the theory manual is if I pull max MAP in straight and level then I imagine I would soon be outsde the limitations within the 44's flight manual ..which says never exceed 100kts IAS when operating at max MAP.. ..which makes sense to me as I'd imagine with low fuel, low weight if you pull max MAP you'd be soon getting close to VNE?
Edit:
sorry, I misread the initial post. The instruction is to increase the collective TO the charted MAP limit, not beyond. It would be possible to do this without exceeding any limits by climbing, but I don't quite see the point of doing it in any case?
All that aside, I find the "53kt powercheck" (shouldn't it be 55kts for the R44?) questionable at best and hardly accurate.
If in doubt, I would rather do an OGE hover check than rely on this 6"-calculation, which is not even in the RFM.
sorry, I misread the initial post. The instruction is to increase the collective TO the charted MAP limit, not beyond. It would be possible to do this without exceeding any limits by climbing, but I don't quite see the point of doing it in any case?
All that aside, I find the "53kt powercheck" (shouldn't it be 55kts for the R44?) questionable at best and hardly accurate.
If in doubt, I would rather do an OGE hover check than rely on this 6"-calculation, which is not even in the RFM.
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The procedure varies from aircraft to aircraft.
Pulling max torque (constant) or other limiting factor EGT etc. and then recording the remaining corresponding T&P's is pretty much standard and, as the other dude mentioned, this is often done as a climb.
It can provide good feedback if you do this each day you fly and record the results so that trends can be observed.
Pulling max torque (constant) or other limiting factor EGT etc. and then recording the remaining corresponding T&P's is pretty much standard and, as the other dude mentioned, this is often done as a climb.
It can provide good feedback if you do this each day you fly and record the results so that trends can be observed.
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I was taught;
- 50kts S&L. Note MP.
- Use placard to determine MAP.
- The difference determines your options.
- Pull the MAP you calculated briefly to verify power is there / ERPM does not drop.
If you use 50kts for the site recce it's easy to accomplish in the dead or downwind legs of your approach.
- 50kts S&L. Note MP.
- Use placard to determine MAP.
- The difference determines your options.
- Pull the MAP you calculated briefly to verify power is there / ERPM does not drop.
If you use 50kts for the site recce it's easy to accomplish in the dead or downwind legs of your approach.
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Presumably the check pilot will want to see whether you can get into and out of a vertical situation. go to as quoted here,
Then think, is that enough? no of course not.
before you fly your instructor will want to see you check the P chart to find your OGE ceiling for that day and load.
now your landing pad will want to be below that so that you have a margin to climb vertically with.
prove the P chart by checking the OGE at hover + say 2" in a clear area above a safe EOL height and landing area.
One inch will give you a time to climb over most obstacles before you have to reduce from max power limit, and allow a bit more if you are close to trees, long grass etc, hence the +2".
otherwise just go in there give the collective a jerk and if you hit the trees in the overpitched state and live, it will make a good bar story.
cheers tet
If in doubt, I would rather do an OGE hover check than rely on this 6"-calculation, which is not even in the RFM.
before you fly your instructor will want to see you check the P chart to find your OGE ceiling for that day and load.
now your landing pad will want to be below that so that you have a margin to climb vertically with.
prove the P chart by checking the OGE at hover + say 2" in a clear area above a safe EOL height and landing area.
One inch will give you a time to climb over most obstacles before you have to reduce from max power limit, and allow a bit more if you are close to trees, long grass etc, hence the +2".
otherwise just go in there give the collective a jerk and if you hit the trees in the overpitched state and live, it will make a good bar story.
cheers tet
