PA Pilot Posted May 24, 2006 Report Share Posted May 24, 2006 We replaced the alternator belt on the ship a couple of month ago with the spare that Lycoming ties up in the engine compartment. The old one was missing 8-10 inches of teeth. The "new" belt has now thrown some teeth, and the local A&P who swapped belts said that it felt somewhat stiff to him, possibly because it got a free ride in a hot engine compartment for four years. The maintenance shop we use has asked us to fly the ship to their facility, which is about a 1 1/2 hour flight assuming no headwinds over some mountainous (for Pennsylvania, anyway) terrain. I have some qualms about making the flight, not so much because of the missing teeth per se, but because the rubber in the belt itself may not be in good condition. I'm not even sure whether the a/c can legally be considered to by airworthy. I'm a low hours (150) helicopter pilot and so I'd like to get the thoughts of others with more experience. Quote Link to comment Share on other sites More sharing options...
delorean Posted May 24, 2006 Report Share Posted May 24, 2006 I wouldn't do it....that extra belt is there to get you home. Like you said, it's been baking on top of the engine for 4 years in bent up position. It's not so much the fact that you might lose your alternator and fly off the battery--you can do that all day no problemo as long as you keep the lights off. It's the fact that when that belt lets loose, it could get thrown up into the drive belts, and dislodge them. It happened to a student of mine in his brand new R44RII coming back from the factory.....ended up cutting the tail off and getting in a BIG fight with Frank Robinson. Those alternator belts should be replaced at least every 500 hrs. I've had two alt belts come off, and at least four or five alternators go out. ALWAYS land and check if you get an alternator light. If it looks freyed or the alternator bearing is frozen, cut it off. -Jonathan Quote Link to comment Share on other sites More sharing options...
Witch Posted May 25, 2006 Report Share Posted May 25, 2006 Question:If the belt is cut off, can the engine be started and the bird flown to the nearist field for repair? I'll keep the lights off and be ready for an auto if necessary. Thanx Later Quote Link to comment Share on other sites More sharing options...
Goldy Posted May 25, 2006 Report Share Posted May 25, 2006 PA- I second Deloreans opinion...the real risk is shedding the belt..not losing the alternator. How bout if the belt flies off and ends up wrapped in your tail rotor?? Oh what fun that could become. I would rather fly with no belt and use my handheld radio...In reality, just order in a new belt and replace it before you fly it. Just too many reasons not to fly it in a degraded condition... Witch-- Take a look at the checklist..start engine, engage clutch, engage alt, so yes, the engine is running with alt off...the engine runs without it, so no need to auto. You will lose some things, like your low RPM horn...gee...is RPM important on a Robbie ?? I wouldn't go near the bird knowing I'm going to shred a belt enroute. Goldy Quote Link to comment Share on other sites More sharing options...
joker Posted May 25, 2006 Report Share Posted May 25, 2006 OK, I 'third' the opinions before me. Only you can set the standards by which you fly. Start with high standards now in your career before its too late. If you were out in the desert, miles from anywhere, then yes this might be a 'calculated' risk that you would take. However, as you are not in 'dire straits' then you have no need to lower your standards. Replace the belt, and then at least you are knowningly taking off with a serviceable system. That way, you can also point out any wear and tear that might happen. The issue of the belt departing the aircraft and causing damage is also possible. Delorean, I query your point about flying off the battery. Regarding the complete loss of electrical power in an R22 (not so in the 300CB), I believe this is a more serious situation. As well as the usual stuff, you will lose the tachs, govenor and the low RPM horn as well as the other electrical equipment. I don't know if the drive belt tension actuation is powered from the bat / alt circuit too, or from the mags directly. Of course the aircraft will function with out all these (drive tension notwithstanding), but can you?! Joker Quote Link to comment Share on other sites More sharing options...
Goldy Posted May 25, 2006 Report Share Posted May 25, 2006 Ok Joker- I'm gonna go way out on a limb here, if I can recall, the tachs will remain, they are both driven without the alternator ( via sensors directly on the main rotor gearbox and mags ). Also remember, we would not have a complete loss of electrical power...you still have the 25AH battery fully charged. It will be discharging every minute..but I think you would have 30-60 or so minutes before it all went to crap. ( turning off all non-essential stuff of course..) HOWEVER with all that being said...you don't fly a ship in that condition. I don't have 1000's of hours, but I would hope even the really old timers ( as opposed to just being old ) would agree as well. Goldy Quote Link to comment Share on other sites More sharing options...
joker Posted May 25, 2006 Report Share Posted May 25, 2006 Goldy, Thanks for the reply. I very open to correction too, as its been a long time since I looked at the R22 schematics. However, I don't think you're right about the tachs. Here's a quote from the R22 POH. "Continued flight without functioning alternator can result in loss of electoronic tachometer, producing a hazardous flight condition" You're right, the sensor is on the shaft, but it is still powered by electronic source...hence the reason for the CBs. Re. the battery: This I wouldn't like to guess how long left in flight. Of course it depends on the age and the quality of the battery, regardless of whether you have turned off the non-essential equipment. Then it depends on what essential requirements have that you don't have control over...i.e. tachs, governor, horns and bells, fuel gauge, drive belt tension (if applicable), etc..etc.. [i know that you could actually pull CBs for these] Yes, 30-60 minutes would be a plausible estimate, but there are too many variables, to take a chance in this aircraft. This is as opposed to say the 300CB where, yes, you could fly all day without a electrics! I think we are all agreed that this would not be a wise flight, though! Joker Maybe just for interest, someone could list the CBs and their Amp ratings in the R22. POH doesn't have this. And if someone could find out about the 'drive tension system' too. Quote Link to comment Share on other sites More sharing options...
justfly Posted May 25, 2006 Report Share Posted May 25, 2006 I will NOT second, third, fourth... (how many opinions are we up to??? ) but will instead disagree with my learned colleagues regards flying the R22 sans alternator. In addition to the quote from EMERGENCY PROCEDURES joker has supplied, we have... Section 2 - LIMITATIONS (page 2-8 R22 POH) "Alternator, RPM governor, low rotor RPM warning system, and OAT gage must be operative for flight."Remember we MUST have a G.O.A.L. (Governor - OAT - Alternator - Low rotor rpm warning system) to fly the R22. Forgive me gentlemen if I misunderstood you. It sounds like we all are in agreement with PA Pilot's original question, to NOT make this flight with the degraded belt. (the SYSTEMS DESCRIPTION for the TACHOMETERS is on page 7-17) Quote Link to comment Share on other sites More sharing options...
relyon Posted May 25, 2006 Report Share Posted May 25, 2006 I've had two in-flight alternator failures in R22s. The first occurred enroute while the ship was being ferried to be exchanged for another and was caused by something in the alternator (probably a diode). The light began to flicker and didn't go out after cycling the switch, so all radios and lights were turned off. No problem making it to the destination and landing there 1.7 hours later. For the majority of the flight only the tachs, gauges, governor, and intercom were drawing current; the comm was turned on only when needed, then switched back off. There was more than enough left in the battery to start the engine again after shutdown. The second occurred in the traffic pattern and was caused by a belt. Ironically, it happened when I was prepping a student for solo and going over emergency procedures. Not more than thirty seconds after I'd asked "what would you do if the alternator light came on?" the light comes on! No noise of any sort, but both of us got a wiff of burning rubber, so it didn't take much thought connect the two and make an informed guess as to what had happened. After landing and shutdown, we found just a few cords remaining of the belt. There's generally more battery capacity available then many realize. The battery is rated at 30AH to begin with and, unless it's really cold or really old, is usually good for at least 20AH if it can start the engine to begin with. From looking at the ammeter discharge rate with the alternator out, it appears that the tachs, gauges, governor, and intercom collectively use 2-4 amps. Chances are you'll be out of fuel long before the battery quits provided the electrical load is managed. In a worse case scenario, turn the master switch off and control the throttle manually. The only things drawing power then are the tachs and the clock. I seriously doubt the combined current draw in that case is more than a few hundred milliamps. Bob Quote Link to comment Share on other sites More sharing options...
flingwing206 Posted May 25, 2006 Report Share Posted May 25, 2006 Hm. The old belt shed teeth. The new/old belt is shedding teeth. If you throw the alternator belt in the R22, you can possibly throw the drive belts. The limitations section of the POH says a functioning alternator is required for flight. Safety-critical systems run off of the alternator. I'm sorry, what was the question again? Quote Link to comment Share on other sites More sharing options...
PA Pilot Posted May 25, 2006 Author Report Share Posted May 25, 2006 Thanks, folks. I appreciate the sanity check. I decided not make the flight, especially because some of the terrain is stuff I wouldn't want to autorotate in to... Bob Quote Link to comment Share on other sites More sharing options...
delorean Posted May 25, 2006 Report Share Posted May 25, 2006 If you have a good battery, you will run out of fuel before you run out of battery....as long as you keep the lights off. The GPS sucks a lot of power and so do the radios when you xmit. But, I should have prefaced that with "this is to limp it home" only. Keep in mind that the tach is wired around the master switch. So if you started getting low on battery power, and decided to switch the master OFF, the tach would still work (provided that you had the clutch switch to ENGAGE, or the ALT switch to ON.) You would lose the low rotor RPM system & the governor.......but as long as you have the tach, you don't NEED either of those. Don't worry about the clutch.....if it's fully engaged, it's fine. That motor shouldn't readjust for more than a second or two during an entire flight. Quote Link to comment Share on other sites More sharing options...
Huey Posted May 25, 2006 Report Share Posted May 25, 2006 Rule #1Pushing the limits will get you killed. Quote Link to comment Share on other sites More sharing options...
Goldy Posted May 25, 2006 Report Share Posted May 25, 2006 Rule #1Pushing the limits will get you killed. OK, let me recap what we've all been saying. There is a difference between what is possible and what is intelligent. None of us advocate actually flying this thing, just that it would be possible, with various limitations. PA-- I think we all agree you did the right thing, and you are now a better pilot for it ! Now on to the next thread ! Goldy Quote Link to comment Share on other sites More sharing options...
Witch Posted May 26, 2006 Report Share Posted May 26, 2006 OK, so howabout this scenerio: You're flying around the badlands of Utah and suddenly, without warning, the alternator belt decides to fling itself into the vast wasteland. You land-the prudent thing to do at this juncture-and find the belt has escaped its confines. Being in a severe mode of panic because you have no food, a half-empty can of Red Bull, and no survival skills whatsoever, you decide to activate the ELT. Question: How long until you are rescued from this desolate, barren planetscape? Also, will you get into trouble by some governmental authority for activating the ELT? Later Quote Link to comment Share on other sites More sharing options...
jdrockin Posted May 26, 2006 Report Share Posted May 26, 2006 Just a thought from working as an auto mechanic, but if the old belt was shedding teeth and the "new"/different belt was shedding teeth, perhaps there is more to this problem than just a bad and weathered belt... Quote Link to comment Share on other sites More sharing options...
PA Pilot Posted May 26, 2006 Author Report Share Posted May 26, 2006 Just a thought from working as an auto mechanic, but if the old belt was shedding teeth and the "new"/different belt was shedding teeth, perhaps there is more to this problem than just a bad and weathered belt...I agree with that. It may be just because it's brittle or may be something in addition. When we replace it, the plan is to check cooling fan balance and some other things (I just drive 'em, I don't fix 'em, so I'm not sure of the details) to make sure there's not another cause. Bob Quote Link to comment Share on other sites More sharing options...
Brianmech72 Posted May 26, 2006 Report Share Posted May 26, 2006 From an automobile standpoint its interesting to me that its a toothed belt and not a V belt. Why would they do that? I agree with that. It may be just because it's brittle or may be something in addition. When we replace it, the plan is to check cooling fan balance and some other things (I just drive 'em, I don't fix 'em, so I'm not sure of the details) to make sure there's not another cause. Bob Quote Link to comment Share on other sites More sharing options...
Guest pokey Posted May 26, 2006 Report Share Posted May 26, 2006 Brian? i'm quite sure its a toothed V-belt Right everyone? PaPilot, where in Pa are you? i'm just across the Delaware ( 5 miles) in NJ Quote Link to comment Share on other sites More sharing options...
PA Pilot Posted May 26, 2006 Author Report Share Posted May 26, 2006 Brian? i'm quite sure its a toothed V-belt Right everyone? PaPilot, where in Pa are you? i'm just across the Delaware ( 5 miles) in NJCorrect, it is a V-belt with teeth. We're at Brandywine (N99). Bob Quote Link to comment Share on other sites More sharing options...
Guest pokey Posted May 26, 2006 Report Share Posted May 26, 2006 I used to go into Brandywine alot years ago. Is Bob Mertz still around? We almost made it to the helicopter show this past year, but my friend stood still too long that day & the wife nabbed him. Who does the work on your ships? you just have the robinsons? Quote Link to comment Share on other sites More sharing options...
PA Pilot Posted May 26, 2006 Author Report Share Posted May 26, 2006 I used to go into Brandywine alot years ago. Is Bob Mertz still around? We almost made it to the helicopter show this past year, but my friend stood still too long that day & the wife nabbed him. Who does the work on your ships? you just have the robinsons?I don't think I know Bob Mertz, although the name sounds familiar. We've been using Pocono Air Ctr. for maintenance (we bought the R22 from them). We're just some whackos who fly for fun -- the R22 is a five-way partnership, and we've formed another four-way to get a Raven II. I'm a convert from fixed-wing... Quote Link to comment Share on other sites More sharing options...
Guest pokey Posted May 26, 2006 Report Share Posted May 26, 2006 lol @ fun lovin' whackos ! i just fly for fun too, have a 269B model. Is pocono air Bob Strenz? If you OR yer "whacko" friends ever fly over to N40, stop in & say hi,,,, great restaurant they have here too, (closed tuesday & wednesday tho) Mertz used to have a shop at brandywine, then he got himself into "trouble" so i hear & last i seen him was about 5-6 years ago, he moved off the airport, but walking distance,,, he has/had ALOT of lycoming & continental engine parts,, his son was "kinda" into helicopters. Quote Link to comment Share on other sites More sharing options...
PA Pilot Posted May 26, 2006 Author Report Share Posted May 26, 2006 lol @ fun lovin' whackos ! i just fly for fun too, have a 269B model. Is pocono air Bob Strenz? If you OR yer "whacko" friends ever fly over to N40, stop in & say hi,,,, great restaurant they have here too, (closed tuesday & wednesday tho) Mertz used to have a shop at brandywine, then he got himself into "trouble" so i hear & last i seen him was about 5-6 years ago, he moved off the airport, but walking distance,,, he has/had ALOT of lycoming & continental engine parts,, his son was "kinda" into helicopters.I've flown in to N40 several times (always in fixed-wing though) and I agree about the restaurant -- really, really good burgers. Pocono Air is Mark Boyer -- in addition to selling/maintaining Robinsons, he used to run the FBO at MPO -- he now operates out of N30. He and his wife are doing the R44 transition training for our partnership. Quote Link to comment Share on other sites More sharing options...
Guest pokey Posted May 26, 2006 Report Share Posted May 26, 2006 BTW,,, MY advice on the belt, dont fly it. And the advice of replacing it every 500 hours wether it needs it or not? YIP ! That pesky "extra" belt?-- i hate to see them when i do "pre-heat, 4 years, baaawwk!- serve well-done, baaaawk" ! Quote Link to comment Share on other sites More sharing options...
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