EC120
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Aha !
That explains why generator switch was on when machine came back from a flight by a Eurocopter pilot then...
As I just pressed all three buttons and then started, I actually turned it (the gen) off for the start and then back on when I saw no charge after the start.
Owner once told me that a 'general parameter' yellow caution warning that comes and goes is due to him doing the same once and starting without the generator on - does that sound right ?
That explains why generator switch was on when machine came back from a flight by a Eurocopter pilot then...
As I just pressed all three buttons and then started, I actually turned it (the gen) off for the start and then back on when I saw no charge after the start.
Owner once told me that a 'general parameter' yellow caution warning that comes and goes is due to him doing the same once and starting without the generator on - does that sound right ?
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BIG thanks to all for input on this issue. Did an EC flight yesterday and had to shut down and start up again immediately. Used the techniques you passed on and all went well. Carefully monitored battery voltage which never dipped below 20V and start settled nicely at 700 degrees.
Going on Eurocopter's own ground school shortly so hopefully confidence will grow in this machine.
Probably hot start next I fly but I guess I'll have no excuse now...
Going on Eurocopter's own ground school shortly so hopefully confidence will grow in this machine.
Probably hot start next I fly but I guess I'll have no excuse now...
Join Date: Jul 2002
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EC120-track&balance
Hi all,
I am looking for some input on track & balance as it comes up on our pride and joy!
My personal experience is a lot of R-44, some R-22 and some Bell-47 and 206.
On the EC120 I am basically new.
Of course we always go with the EC-manual, but anyone who does track & balance knows, that there is still a lot of "Black Arts"/"Witchcraft"/"Magic Hands" involved!
So here it comes:
Until now I always extracted from the manual, that T&B would be done in the following sequence:
a) Balance on ground or hover
b) Track on ground or hover - adjust with pitchlinks
c) Track in flight - adjust with tabs/readjust pitchlinks for hover
d) Check balance again
e) Start all over if you have to...
Now I am curious what you have to say about the EC120 or any EC for that matter:
a) and b) are pretty much the same, but at c) there is no adjusting for Track, but for vibration.
I understand, that sometimes you might get a smoother ship if the blades do not track perfectly (wake aerodynamics I guess...), but what I do not understand is, why one would not at least try to get all the blades into line before diverging again (if necessary...).
Matter in case: On blade is obviously climbing a little at max cruise, but instead calling for some trimtab action to bring it down in line, the vibration graph is asking to push the blade UP even further (with the trimtab)!!
I understand that not always everything looks "logic" at first sight, but this gets me,
Manual says to visualize the track and do trimtab adjusments according to the graph. Now all the blades are dead-on on the ground and in hover and are still within tolerance in flight, but of course one always wants to go as smooth as possible.
"Logic" tells me to "pull" the blade down with the trimtab - manual says "push it up". If it where for the pitchlinks, no problem I just try it out, but those trimtabs definitely have a limited "bending"-lifetime. I don't want to bend them the wrong way just for a trial....
Any "oldtimers" (nothing to do with age actually, ) out there with some hardcore experience in this matter?
I guess any A-Star, Squirrel, Ecurielle, etc. will do as the ships have basically the same rotor!
Thanks,
3top
I am looking for some input on track & balance as it comes up on our pride and joy!
My personal experience is a lot of R-44, some R-22 and some Bell-47 and 206.
On the EC120 I am basically new.
Of course we always go with the EC-manual, but anyone who does track & balance knows, that there is still a lot of "Black Arts"/"Witchcraft"/"Magic Hands" involved!
So here it comes:
Until now I always extracted from the manual, that T&B would be done in the following sequence:
a) Balance on ground or hover
b) Track on ground or hover - adjust with pitchlinks
c) Track in flight - adjust with tabs/readjust pitchlinks for hover
d) Check balance again
e) Start all over if you have to...
Now I am curious what you have to say about the EC120 or any EC for that matter:
a) and b) are pretty much the same, but at c) there is no adjusting for Track, but for vibration.
I understand, that sometimes you might get a smoother ship if the blades do not track perfectly (wake aerodynamics I guess...), but what I do not understand is, why one would not at least try to get all the blades into line before diverging again (if necessary...).
Matter in case: On blade is obviously climbing a little at max cruise, but instead calling for some trimtab action to bring it down in line, the vibration graph is asking to push the blade UP even further (with the trimtab)!!
I understand that not always everything looks "logic" at first sight, but this gets me,
Manual says to visualize the track and do trimtab adjusments according to the graph. Now all the blades are dead-on on the ground and in hover and are still within tolerance in flight, but of course one always wants to go as smooth as possible.
"Logic" tells me to "pull" the blade down with the trimtab - manual says "push it up". If it where for the pitchlinks, no problem I just try it out, but those trimtabs definitely have a limited "bending"-lifetime. I don't want to bend them the wrong way just for a trial....
Any "oldtimers" (nothing to do with age actually,
) out there with some hardcore experience in this matter?I guess any A-Star, Squirrel, Ecurielle, etc. will do as the ships have basically the same rotor!
Thanks,
3top
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Not evrysing only somesings!
There is a lot of "curious" translation in the Manuals!
Sometimes outright wrong! You would think EC could afford a professional translater.....
It seems non of the pilot gang here is involved in Track & Balance!
3top
There is a lot of "curious" translation in the Manuals!
Sometimes outright wrong! You would think EC could afford a professional translater.....
It seems non of the pilot gang here is involved in Track & Balance!
3top
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3 Top
I may be teaching your granny to suck eggs but...
Just double check the orientation of your vertical accelerometer , if it were 180 deg out i.e. upside down the phase angle you read will 180 degrees out and therefore give rise to the (at face value) strange discrepancy of de-tracking the rotor to achieve a lower vibe level.
It does depend on the values you are talking about but by and large3 bladed rotors such as on the 350/355 /120 etc have less tendency for abiguity than 4 , 5 and 6 bladers IE A large track spread normally DOES equate to large 1P vibes.
Whereas a 4 blader you can have a big 2 and 2 split with very low 1P and high 2P as per the 412 with its built in +20 -20 +20 -20 theoretical perfect track.
All these rules of thumb are of course out the window when you get an atypical blade in the pack
Have fun
Wunper
I may be teaching your granny to suck eggs but...
Just double check the orientation of your vertical accelerometer , if it were 180 deg out i.e. upside down the phase angle you read will 180 degrees out and therefore give rise to the (at face value) strange discrepancy of de-tracking the rotor to achieve a lower vibe level.
It does depend on the values you are talking about but by and large3 bladed rotors such as on the 350/355 /120 etc have less tendency for abiguity than 4 , 5 and 6 bladers IE A large track spread normally DOES equate to large 1P vibes.
Whereas a 4 blader you can have a big 2 and 2 split with very low 1P and high 2P as per the 412 with its built in +20 -20 +20 -20 theoretical perfect track.
All these rules of thumb are of course out the window when you get an atypical blade in the pack
Have fun
Wunper
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wunper,
thanks for the "eggs"
No chance on the wrong direction of the sensor, just checked both manuals (EC and ACES, our electronic dynamic balance equipment), both coincide with the sensor conector pointing up, and it always did while doing t&b.
But at least I am not alone for "logic" here!
As soon as I get back in the air with the ship I will post what is the game!
Thanks again,
3top
PS: Sure would be hard to pair a 3 blader!
thanks for the "eggs"
No chance on the wrong direction of the sensor, just checked both manuals (EC and ACES, our electronic dynamic balance equipment), both coincide with the sensor conector pointing up, and it always did while doing t&b.
But at least I am not alone for "logic" here!
As soon as I get back in the air with the ship I will post what is the game!
Thanks again,
3top
PS: Sure would be hard to pair a 3 blader!
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EC120 Fenestron Issues
Following all the goo on the African Aviation site regarding the EC120 roll over in Durban, some interesting questions have been raised.
It seems that the crux of the matter is that the EC120 involved was engaged in a training sortie and the good old Tail Rotor Control Failure exercise was being carried out. This is where it all ended up as a pile of paper work for the insurers and Civil Aviation to sort out. Apparently the guys ended up with a violent onset of uncontrollable yaw so rapid that they elected to keep it in the air for a while in the hopes of getting the beast under control rather than dumping early and possibly bending the skids. But alas keeping it in the air meant lots of whirly whirly and then the ultimate decision to dump the machine resulting in the roll over. From what I can gather the guy did a good job as he managed to get it onto the ground quite level but the right aft section of the skid dug in (had a bit of rain over the previous couple of days) causing the dynamic roll over situation. He estimates the rate of rotation to be in the region of 120-160 deg per sec as things got rather blurred.
The CAA have pulled ratings based on "fenestron issues" that they say the guys don't know about. Sounds like they are hinting at differences between conventional and Fenestron systems, but they wont provide the information.
So the BEEEEG ? - are there any guys out there that have this information on hand so the rest of the guys (instructors) that escaped the CAA sword can continue training and at least be a little more versed in the finer aspects of this "fenestron issue" that is causing such a stir on the African Aviation site.
It seems that the crux of the matter is that the EC120 involved was engaged in a training sortie and the good old Tail Rotor Control Failure exercise was being carried out. This is where it all ended up as a pile of paper work for the insurers and Civil Aviation to sort out. Apparently the guys ended up with a violent onset of uncontrollable yaw so rapid that they elected to keep it in the air for a while in the hopes of getting the beast under control rather than dumping early and possibly bending the skids. But alas keeping it in the air meant lots of whirly whirly and then the ultimate decision to dump the machine resulting in the roll over. From what I can gather the guy did a good job as he managed to get it onto the ground quite level but the right aft section of the skid dug in (had a bit of rain over the previous couple of days) causing the dynamic roll over situation. He estimates the rate of rotation to be in the region of 120-160 deg per sec as things got rather blurred.
The CAA have pulled ratings based on "fenestron issues" that they say the guys don't know about. Sounds like they are hinting at differences between conventional and Fenestron systems, but they wont provide the information.
So the BEEEEG ? - are there any guys out there that have this information on hand so the rest of the guys (instructors) that escaped the CAA sword can continue training and at least be a little more versed in the finer aspects of this "fenestron issue" that is causing such a stir on the African Aviation site.
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EC120 T&B
Not sure if this helps but I will give it a shot. We operate 3 EC120's our high time ship is coming up on 4,000 hours and #2 is close to 3,500. We almost never do a track and balance. If you are trying to get rid of a vibration that you cannot seem to fix with T&B, adjust the RRPM. We have found that the hammers are tuned to a specific RRPM. As little as a 2 RRPM difference in this equation makes a HUGE difference. Ours are smoothest at 409-410 RRPM. It does not seem that this would make a big difference but it does. If all else fails try this and see if it works. Hope this will will smooth things out for you.
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I see no one is interested in the query here - have I stood in the proverbial doggy doo
and chased valuable comment away.
Sounds like the poor guys in Durbs are desparate for some info on the Fenestron Aero D.
and chased valuable comment away. Sounds like the poor guys in Durbs are desparate for some info on the Fenestron Aero D.
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Canthover
I have no experience with the aerodynamics of the EC120 and it's fenestron, however lots of previous with the Gazelle. The Gazelle has a history of fenestron issues but after some exhaustive testing, fenestron stall as it is known was concluded as a non event and more likely just a combination of human error at the controls. In my view this was smoke and mirrors to protect the manafacturer and a situation where the fenestron can stall under certain conditions does exist. In fact on one of my many Instructor upgrades I attempted to prove this with vector description. I couldn't be proved wrong but didn't feel the need to make a huge ass of myself taking on Aerospatiale!
The interesting part of your post for me is that the crew were executing tail rotor control failure techniques, these if got wrong can lead to unusual airflow and dynamics around the shroud which could lead to a stall situation, it's very easy to say that as I wasn't there and can't say exactly what the handling Pilot was doing at the critical moment. None the less, I can add that tail rotor malfunction practice was written out of the Gazelle training guide as it was considered to risky to practice.
I have no experience with the aerodynamics of the EC120 and it's fenestron, however lots of previous with the Gazelle. The Gazelle has a history of fenestron issues but after some exhaustive testing, fenestron stall as it is known was concluded as a non event and more likely just a combination of human error at the controls. In my view this was smoke and mirrors to protect the manafacturer and a situation where the fenestron can stall under certain conditions does exist. In fact on one of my many Instructor upgrades I attempted to prove this with vector description. I couldn't be proved wrong but didn't feel the need to make a huge ass of myself taking on Aerospatiale!
The interesting part of your post for me is that the crew were executing tail rotor control failure techniques, these if got wrong can lead to unusual airflow and dynamics around the shroud which could lead to a stall situation, it's very easy to say that as I wasn't there and can't say exactly what the handling Pilot was doing at the critical moment. None the less, I can add that tail rotor malfunction practice was written out of the Gazelle training guide as it was considered to risky to practice.
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What would be the "Issue" on the Fenestron?
If they got into trouble, something must have been stuck! Maybe they where freezing the pedals to each other, in a stress situation like this sometimes people do the weirdest things - if the student freezes the pedals there is no way to correct anything.
I never had a Fenestron stall, though I run out of pedal plenty of times - but that does not mean that the Fenestron is stalled, but just giving all it has.
That EC quit doing stuck-pedal training is more likely to the inherent danger of roll over if you do it wrong or something goes wrong.
I was lucky enough to do some training with a factory instructor and when he showed us "stuck-pedal" he was surprised how fast the EC120 comes around when applying collective to straighten out for a straight run-on. He said it was his first time to do that in a 120.
He also said the 120 was the lowest inertia helicopter he ever flew!
He didn't pick up on my invitation to fly a R-22 with him to show him a "no"-inertia helicopter!!
It seems rather curious, that SA EC120 guys where not able to stop the rotation with full pedal application.
When I check out people in the EC120 I let them "run away" sometimes in a hover to get them on the watch for the TR, as the Fenestron lags quite a bit over a regular TR and anticipation is the name of the game.
It is not so hard to keep the helicopter level and turning around itself fairly fast. This of course gets the students attention and a "big eyes" look towards me. After I tell him to do something to recover they step on the pedal (I will block the wrong side, as I don't know what the 120 does if accelerated beyond more or less neutral pedal position) and it takes up to 3 complete turns to stop the rotation.....
Anyone close to the guys to ask about the posibility of "pilot-froozen-pedals" in the case at hand?
3top,
If they got into trouble, something must have been stuck! Maybe they where freezing the pedals to each other, in a stress situation like this sometimes people do the weirdest things - if the student freezes the pedals there is no way to correct anything.
I never had a Fenestron stall, though I run out of pedal plenty of times - but that does not mean that the Fenestron is stalled, but just giving all it has.
That EC quit doing stuck-pedal training is more likely to the inherent danger of roll over if you do it wrong or something goes wrong.
I was lucky enough to do some training with a factory instructor and when he showed us "stuck-pedal" he was surprised how fast the EC120 comes around when applying collective to straighten out for a straight run-on. He said it was his first time to do that in a 120.
He also said the 120 was the lowest inertia helicopter he ever flew!
He didn't pick up on my invitation to fly a R-22 with him to show him a "no"-inertia helicopter!!
It seems rather curious, that SA EC120 guys where not able to stop the rotation with full pedal application.
When I check out people in the EC120 I let them "run away" sometimes in a hover to get them on the watch for the TR, as the Fenestron lags quite a bit over a regular TR and anticipation is the name of the game.
It is not so hard to keep the helicopter level and turning around itself fairly fast. This of course gets the students attention and a "big eyes" look towards me. After I tell him to do something to recover they step on the pedal (I will block the wrong side, as I don't know what the 120 does if accelerated beyond more or less neutral pedal position) and it takes up to 3 complete turns to stop the rotation.....
Anyone close to the guys to ask about the posibility of "pilot-froozen-pedals" in the case at hand?
3top,
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Eagle,
thanks for the input! We just got a service bulletin about that and did adjust the RRPM, which now is running right in the specified range.
We did also a head inspection. On one of the dampers a rod end is pretty much at the limit, so this might have given a part of the rather rough ride, but I still believe it is the climbing blade.
I will track&balance tomorrow and put the blades in line.
We'll see how it goes.
One more question, do you guys T&B heavy or light?
A) Heavy, the machine has more inertia to dampen any vibration, but one has to pull more AOA to keep flying.
B) Less weight doesn't dampen as well but the bird will go faster for the max continous power data collection.
3top
thanks for the input! We just got a service bulletin about that and did adjust the RRPM, which now is running right in the specified range.
We did also a head inspection. On one of the dampers a rod end is pretty much at the limit, so this might have given a part of the rather rough ride, but I still believe it is the climbing blade.
I will track&balance tomorrow and put the blades in line.
We'll see how it goes.
One more question, do you guys T&B heavy or light?
A) Heavy, the machine has more inertia to dampen any vibration, but one has to pull more AOA to keep flying.
B) Less weight doesn't dampen as well but the bird will go faster for the max continous power data collection.
3top
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To be honest I am not sure, but I will guess light. We get about 115 knots at max cont. 113 knots if it is really hot. We have a fairly heavy ship at 2600 pounds empty.
nose mount for EC120
Anyone flown or seen a EC 120 with a nose mount for a ultramedia type camera gimbal?
I've seen the one that is attached to the skid but am after something that puts the camera further forward.
Mickjoebill
I've seen the one that is attached to the skid but am after something that puts the camera further forward.
Mickjoebill
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Nose Mount for EC120B
I have never heard of a "skid" mounted gimbal. The only one that I know of is the factory mount just forward of the skid and offset to the left side. I do not believe there are any other options available. Here is a photo of ours.
Jeff
Jeff
Thanks.
The factory mount as I understand it isn't ideal for 15 inch + gimbals being utilised for filming.
We need the gimbal further forward, usually on some kind of pole mount.
cheers
Mickjoebill
The factory mount as I understand it isn't ideal for 15 inch + gimbals being utilised for filming.
We need the gimbal further forward, usually on some kind of pole mount.
cheers
Mickjoebill