Things to look out for during R22 preflight?
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Things to look out for during R22 preflight?
Hi,
I was just wondering if anyone has advice on what parts/things to pay special attention to during the R22 preflight, or parts that are not on the checklist. Basically, things most important or likely to break.
Thank you in advance!
I was just wondering if anyone has advice on what parts/things to pay special attention to during the R22 preflight, or parts that are not on the checklist. Basically, things most important or likely to break.
Thank you in advance!
This may seem waaaay basic, but it almost got me. Make certain the fuel caps are on completely and securely. Not long after earning my rating (in the R22), I flew to a nearby airport to give my first passenger rides. After landing, one of the admiring throng asked "whatsat hole?" Hole? WHAT HOLE? It was the open fuel tank, left side. 
My heart skipped a few beats while thinking about the TR being in the path of the departing cap.
This ship had paint marks to line up indicating the cap was completely on, and I would swear I had COMPLETELY tightened it. I'll never know how it came off. The second piece of luck of the day was that the old tractor on the field used for cutting the grass had the EXACT same fuel cap. I moved the stock one to the left side, put the tractor cap on the right side, and as I flew back to base, I periodically reached outside with my right hand and felt that cap to be sure it was staying tight.
In retrospect, I wondered why the cap didn't have a safety chain so it couldn't go more than a few inches from the filler port.
My heart skipped a few beats while thinking about the TR being in the path of the departing cap. This ship had paint marks to line up indicating the cap was completely on, and I would swear I had COMPLETELY tightened it. I'll never know how it came off. The second piece of luck of the day was that the old tractor on the field used for cutting the grass had the EXACT same fuel cap. I moved the stock one to the left side, put the tractor cap on the right side, and as I flew back to base, I periodically reached outside with my right hand and felt that cap to be sure it was staying tight.
In retrospect, I wondered why the cap didn't have a safety chain so it couldn't go more than a few inches from the filler port.
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In retrospect, I wondered why the cap didn't have a safety chain so it couldn't go more than a few inches from the filler port.
Removing the chain means that hopefully the cap will fall off before you get airborne. I always place the cap on the pilot's seat during refuelling.
Back to the original question, check that there are no marks on the cabin roof just under the rotor mast fairing. These would indicate that there has been mast-bumping. Also worth checking is that there is no trace of oil on the inside of the MRGB access door. This would be an indication that the sprag-clutch seal is leaking. Checking that the OAT gauge and the CAT gauge match (first flight of the day only) is always worthwhile.
Because it's a 22 it is most probably in a school.... which means lots of use and abuse. I always taught my students to do a full and proper preflight every time. There are lots of points to mention but your instructor should have pointed these out to you when teaching you the preflight, and should not let you do your own until you are proficient.
As you get to know the machine you'll get more proficient in the preflight and it will go a lot quicker.
Obviously there are the more important ones to check... fuel, blades and everthing connecting to the blades.... which doesn't leave much on a 22... so do a full one anyway.
As you get to know the machine you'll get more proficient in the preflight and it will go a lot quicker.
Obviously there are the more important ones to check... fuel, blades and everthing connecting to the blades.... which doesn't leave much on a 22...
so do a full one anyway.
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Like rotorfan mentioned, the fuel caps are not to be forgotten.
My instructor told me that the spare-part that Robinson sold the most was actually that not-so-important-fuel-cap, if it's true or not I don't know
Other than than that there are some nice tips in the POH.
My instructor told me that the spare-part that Robinson sold the most was actually that not-so-important-fuel-cap, if it's true or not I don't know
Other than than that there are some nice tips in the POH.
On the fuel cap...If it does go missing, go find an old car lying around. A lot of the old type oil caps will fit in an emergency. Better than sitting waiting for the spare part to get to where you are...
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Guilty of the fuel cap situation. During my Instructors course I was 10min into an exercise on airfield, and got a radio message from the tower "Helicopter XX, company message requesting you check your fuel cap" - they had found it on the pad 
. I was new to refuelling the aircraft and thought that perfect little flat on side/top of the fan scroll seemed a sensible place for it - not a good idea, ALWAYS put it on the seat so you notice upon embarkation if you haven't put it back in it's place.
Check the bottom of the rotor mast fairing as previously mentioned for any rippling or dents indicating mast bumping/hard landing, also re:hard-landing check that you can just fit your fingers (small ish) between the bottom of the tail boom and the top of the fan scroll. Whilst there obviously check the fan scroll nut is aligned with the paint strip, if not, don't fly it (overspeed).
A new one, from experience, is when checking the swash plate boot on the main rotor head you should feel a uniform circle of nut heads under the boot (approx 8-10), but you should not feel evidence of any other objects of un-uniformity. Somebody I know felt an unexpected lump in there, the boot was removed to find that after maintenance a bit of locking wire (steel) was left just touching on the thin aluminium plate (held down by the nuts), one part was stationary and the other rotates, and over a short period of use the wire had stripped off a circle of the inner portion of the aluminium plate, leaving what looked like metallic orange peel coiled up under the boot....
Check for smooth operation of the collective lever - if it's not smooth it could be indicative of overspeed (mis-shapen pitch change bearing I believe)
On the safety course they are very keen to emphasise that when belts are in their first hundred hours it is extremely important that you get blades turning in less than 5 seconds, otherwise the unpredictable slippage of sticky new belts could cause the belt to jump out of it's 'V' and become misaligned which has apparently been the cause of some incidents. Apparently on older belts it is more acceptable as they are less likely to randomly stick and jump out of the groove, but that assumes you always know how old the belts are, as the manual says, "blades turning... less than 5 seconds" if not - don't fly it.
. I was new to refuelling the aircraft and thought that perfect little flat on side/top of the fan scroll seemed a sensible place for it - not a good idea, ALWAYS put it on the seat so you notice upon embarkation if you haven't put it back in it's place.Check the bottom of the rotor mast fairing as previously mentioned for any rippling or dents indicating mast bumping/hard landing, also re:hard-landing check that you can just fit your fingers (small ish) between the bottom of the tail boom and the top of the fan scroll. Whilst there obviously check the fan scroll nut is aligned with the paint strip, if not, don't fly it (overspeed).
A new one, from experience, is when checking the swash plate boot on the main rotor head you should feel a uniform circle of nut heads under the boot (approx 8-10), but you should not feel evidence of any other objects of un-uniformity. Somebody I know felt an unexpected lump in there, the boot was removed to find that after maintenance a bit of locking wire (steel) was left just touching on the thin aluminium plate (held down by the nuts), one part was stationary and the other rotates, and over a short period of use the wire had stripped off a circle of the inner portion of the aluminium plate, leaving what looked like metallic orange peel coiled up under the boot....
Check for smooth operation of the collective lever - if it's not smooth it could be indicative of overspeed (mis-shapen pitch change bearing I believe)
On the safety course they are very keen to emphasise that when belts are in their first hundred hours it is extremely important that you get blades turning in less than 5 seconds, otherwise the unpredictable slippage of sticky new belts could cause the belt to jump out of it's 'V' and become misaligned which has apparently been the cause of some incidents. Apparently on older belts it is more acceptable as they are less likely to randomly stick and jump out of the groove, but that assumes you always know how old the belts are, as the manual says, "blades turning... less than 5 seconds" if not - don't fly it.
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Well.. being that hes singled out the 22.. I thought this thread might be for less obvious things (bent tail boom... no windsheild) and more for things you might wanna do for the sake of being exposed to the internet... Blade.. rotor head... spindle.. mast... transmission mount integrity.. etc etc etc...
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heaps
Mate you never stop learning,
things like the upperbearing rotating in the housing, bolts connecting the flex plates all facing the same way, mag base holding nuts loose, locking nuts on the main rotor pitch links loose, alternator bolts loose, broken lockwire, that the spring that holds the mixture lever on the carby in the full rich position should the mixture cable break is not broken, the cowling that covers the cylinders has a piece of wire holding it together, if it breaks or wears through the cowl drops onto the oli return line from the tappet cover and chews a hole in it, loose wires on the back of your alternator, a jumping engine tach probably means you have oil getting past the seal from the engine into the mag and oil is getting on your points and causing your ERPM to misread- next thing the govoner starts overspeeding. never fly a beta 2 that has a heavy weight pulley on the top and a lightweight on the bottom as they are likely to throw the belts, always check carefuly that all the little hat washers that keep the rod ends clear of components are in place, inspect the belts carefully as your life depends on them, look for balling of the material that feathers out the side of the belts, developing longwise splits in the back of the belt. check that the bolts holding the clutch in place between the puleys are looking good, check for loosness of the tail boom without your test causing it to be the problem, look for cracks in the end of the doublers on the tail feathers, listen carefully on start and engagement to the engine and drive system. always check that your belts are in the right grooves after a long engagement or anytime you see the clutch light flicker a bit more than normal, check the thrust washers on the blade bolts for fine cracks.
things like the upperbearing rotating in the housing, bolts connecting the flex plates all facing the same way, mag base holding nuts loose, locking nuts on the main rotor pitch links loose, alternator bolts loose, broken lockwire, that the spring that holds the mixture lever on the carby in the full rich position should the mixture cable break is not broken, the cowling that covers the cylinders has a piece of wire holding it together, if it breaks or wears through the cowl drops onto the oli return line from the tappet cover and chews a hole in it, loose wires on the back of your alternator, a jumping engine tach probably means you have oil getting past the seal from the engine into the mag and oil is getting on your points and causing your ERPM to misread- next thing the govoner starts overspeeding. never fly a beta 2 that has a heavy weight pulley on the top and a lightweight on the bottom as they are likely to throw the belts, always check carefuly that all the little hat washers that keep the rod ends clear of components are in place, inspect the belts carefully as your life depends on them, look for balling of the material that feathers out the side of the belts, developing longwise splits in the back of the belt. check that the bolts holding the clutch in place between the puleys are looking good, check for loosness of the tail boom without your test causing it to be the problem, look for cracks in the end of the doublers on the tail feathers, listen carefully on start and engagement to the engine and drive system. always check that your belts are in the right grooves after a long engagement or anytime you see the clutch light flicker a bit more than normal, check the thrust washers on the blade bolts for fine cracks.
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I was just wondering if anyone has advice on what parts/things to pay special attention to during the R22 preflight
Always time the clutch engagement. I believe the limits are "between 60 and 100 sec", but more importantly, on any given machine it should take the same time on every start. If took 1:20min yesterday and 1:35min today, your belts are about to let go.
If it took 1:20min yesterday and 45sec today, your clutch actuator switches have failed and your belts aren't fully engaged. Both has happened to me.
Only exception is brand new belts(less than 40hrs or so), clutch engagement will take a few seconds more every day until they are stretched.
And, as general advice:
Human perception is a b!tch. We see only what we want to see or expect to see.
If you do the preflight with the attitude that everything is probably alright, you might go through the whole walk-around and "look" at everything, but wouldn't even notice if a tail rotor blade had fallen off. I've fallen into this trap a few times myself, missing things that should be completely obvious.
Instead, before doing the inspection, say to yourself: "there is something wrong with this machine and I'll find it!"
If it took 1:20min yesterday and 45sec today, your clutch actuator switches have failed and your belts aren't fully engaged. Both has happened to me.
Only exception is brand new belts(less than 40hrs or so), clutch engagement will take a few seconds more every day until they are stretched.
And, as general advice:
Human perception is a b!tch. We see only what we want to see or expect to see.
If you do the preflight with the attitude that everything is probably alright, you might go through the whole walk-around and "look" at everything, but wouldn't even notice if a tail rotor blade had fallen off. I've fallen into this trap a few times myself, missing things that should be completely obvious.
Instead, before doing the inspection, say to yourself: "there is something wrong with this machine and I'll find it!"
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Back to the original question, check that there are no marks on the cabin roof just under the rotor mast fairing. These would indicate that there has been mast-bumping.
Instead, before doing the inspection, say to yourself: "there is something wrong with this machine and I'll find it!"
"People are often surprised when their engine fails on take-off, I'm always surprised if it keeps going."
Mindset.
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This also happens if the aircraft falls off its ground handling wheel on one side, like mine did when a friend let go of the wheel handle half way round. The sideways whip in the mast made the fairing hit the roof and crinkled the side of the fairing.
I've seen a dodgy practice hover auto also yield the same result.