Chinook RTB
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Chinook RTB
I'm currently working on a new RTB system for the chinook, briefly, I planned to fit two fixed automatic blade tracking camera's to the aircraft, one at 12 o'clock to track the forward rotor, and one inside the cabin looking at the rear rotor 10:30 position. I'm well aware of the cross coupling between rotors, problems caused by the fuselage and the translation of adjustments from one axis to the other. I also planned to track and balance the fwd rotor first, and then track and balance the rear relative to it, again due to the aerodynamic effects caused by intermeshing rotors.. However, the powers that be have decided that I ought to use a trackerless solution, and aim for a single adjustment, one flight solution. I feel that this will not achieve the desired results on this aircraft, but as yet have not met anyone who can back up my argument.
Does anyone have experience of this aircraft, or can anyone give me advice on other companies attempts at "trackerless" RTB on this aircraft?
Does anyone have experience of this aircraft, or can anyone give me advice on other companies attempts at "trackerless" RTB on this aircraft?
I'm not sure if I've fully understood the question, but think so.
I fly the EC-155 fitted with full M'ARMS and this incorporates an RTB function. On a single flight the following aquisitions are carried out through a menu on the pilots panel:
FPOG, Hover, 100 kts and Max Continuos Power cruise (about 155 kts).
The flash disc is then downloaded into a ground station (curiously, not the main M'ARMS ground station but a portable one, but that's a different story!) where a program they call 'steady copter' analyses the data and makes adjustment calculations.
This is significantly different to the BHL IHUMS system I'm used to where the tracking is done by camera and adjustments are suggested automatically on a rolling 9 flight basis. The ECF system just uses accelerometers and requires specific pilot input.
I don't have the detailed facts to immediate hand, but can get them (including the operators manual on pdf for the program) if you want to e-mail me.
Cheers.
I fly the EC-155 fitted with full M'ARMS and this incorporates an RTB function. On a single flight the following aquisitions are carried out through a menu on the pilots panel:
FPOG, Hover, 100 kts and Max Continuos Power cruise (about 155 kts).
The flash disc is then downloaded into a ground station (curiously, not the main M'ARMS ground station but a portable one, but that's a different story!) where a program they call 'steady copter' analyses the data and makes adjustment calculations.
This is significantly different to the BHL IHUMS system I'm used to where the tracking is done by camera and adjustments are suggested automatically on a rolling 9 flight basis. The ECF system just uses accelerometers and requires specific pilot input.
I don't have the detailed facts to immediate hand, but can get them (including the operators manual on pdf for the program) if you want to e-mail me.
Cheers.
Flytest, have you had any dealings with "helitune.com"?
Syc
Syc
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Sycamore,
Yes, I know the guys very well, and I also know how they do it... the right way. Unfortunately, due to internal politics, I have to prove that the trackerless method, and the single tracker method are a crock of ****. I am hoping somebody out there will already have attempted either of these methods, and be able to give me some feedback on the shortcomings... either that or I will have to bow to the superior wisdom of our systems boys (who wouldn't know the difference between an intermeshing rotor and a pile of Kangaroo dung), and waste several thousand whole earth pounds, just to be able to say "I told you so".
Beancounters.. ya gotta love em!
Yes, I know the guys very well, and I also know how they do it... the right way. Unfortunately, due to internal politics, I have to prove that the trackerless method, and the single tracker method are a crock of ****. I am hoping somebody out there will already have attempted either of these methods, and be able to give me some feedback on the shortcomings... either that or I will have to bow to the superior wisdom of our systems boys (who wouldn't know the difference between an intermeshing rotor and a pile of Kangaroo dung), and waste several thousand whole earth pounds, just to be able to say "I told you so".
Beancounters.. ya gotta love em!
Flytest, there was a time when a pole.a paint-brush,and a tin of white emulsion was enough; though maybe you might give it another try out the side door of a Wokka!!
Syc
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Flytest
I hope your beancounters aren't Pruners!
I have HUMS RTB configuration experience on Chinooks. I have no wish to fuel a pissing contest on this rich topic and I agree with your sentiments on this thread, I hope you find the following helpful.
There are plenty of good Chinook RTB sweats out there with the all the fleet operators and they are the people you would have to convince in any form of system evaluation.
I assume you intend to develop/demonstrate a system that satisfies the following criteria:
1. System can be proven sufficiently robust & capable of starting & finishing any depth of RTB sequence i.e. aircraft fresh out of Phase maintenance or from Major servicing, not just in service tweaking. There is huge scope for variation right here.
2. System can be used by the average unit RTB engineer/crew chief & therefore not reliant upon heroic “guru” intervention to get results.
3. System can produce consistent results over a fleet of helicopters which regularly conduct heavy lifts with a large spread of airframe and blade hours.
The system is only as good as the procedure that is employed in its use and how the operator chooses to interpret and conduct that procedure this can give point 2 a lot of mileage.
Short of circus tricks involving smoke and mirrors you are simply not going to achieve any of the above with a trackerless system or for that matter a single tracker system.
With the Chinook you need all the help you can get, by and large it is not a difficult helicopter to track and balance but it can be quirky especially if the fleet have high blade hours like most fleets do allowing maximum spread of blade (in)compatibility and Tab (in)effectiveness. The only way you are going to weed out a blade problem such as this is with good quality track & lag data. For good quality track data on a Chinook you require two trackers each optimised for its relevant rotor.
At risk of preaching to the choir track data is the RTB operators best friend , it’s a visual pattern kind of thing that people can relate to more readily than polar plots, and that is what they like to do when the chips are down RTB troubleshooting and they are not getting the results they would like to see in vibration terms.
All the highly experienced Philadelphia RTB men would be the first to admit this.
Lots of luck!
Wunper
I hope your beancounters aren't Pruners!
I have HUMS RTB configuration experience on Chinooks. I have no wish to fuel a pissing contest on this rich topic and I agree with your sentiments on this thread, I hope you find the following helpful.
There are plenty of good Chinook RTB sweats out there with the all the fleet operators and they are the people you would have to convince in any form of system evaluation.
I assume you intend to develop/demonstrate a system that satisfies the following criteria:
1. System can be proven sufficiently robust & capable of starting & finishing any depth of RTB sequence i.e. aircraft fresh out of Phase maintenance or from Major servicing, not just in service tweaking. There is huge scope for variation right here.
2. System can be used by the average unit RTB engineer/crew chief & therefore not reliant upon heroic “guru” intervention to get results.
3. System can produce consistent results over a fleet of helicopters which regularly conduct heavy lifts with a large spread of airframe and blade hours.
The system is only as good as the procedure that is employed in its use and how the operator chooses to interpret and conduct that procedure this can give point 2 a lot of mileage.
Short of circus tricks involving smoke and mirrors you are simply not going to achieve any of the above with a trackerless system or for that matter a single tracker system.
With the Chinook you need all the help you can get, by and large it is not a difficult helicopter to track and balance but it can be quirky especially if the fleet have high blade hours like most fleets do allowing maximum spread of blade (in)compatibility and Tab (in)effectiveness. The only way you are going to weed out a blade problem such as this is with good quality track & lag data. For good quality track data on a Chinook you require two trackers each optimised for its relevant rotor.
At risk of preaching to the choir track data is the RTB operators best friend , it’s a visual pattern kind of thing that people can relate to more readily than polar plots, and that is what they like to do when the chips are down RTB troubleshooting and they are not getting the results they would like to see in vibration terms.
All the highly experienced Philadelphia RTB men would be the first to admit this.
Lots of luck!
Wunper
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Wunper,
The system I am involved with is a full HUMS system, I am putting together the RTB package for it. I was under pressure to utilise a trackerless / single tracker system because it was percieved to be "easier". My argument was yes it is easier in terms of hardware production, however it simply would not do the job, and by that I mean, it would not satisfy the points that you have made.
I have limited chinook experience, but I was confident in my argument, I was just hoping that someone with a bucketload of Chinook experience would read my thread and back it up.. so thank you for taking the time to post.
The men from El Monte, Ca claim to have achieved a single tracker solution for Chinook. Of course I am sceptical, but never say never??
Anyway, many thanks again.
The system I am involved with is a full HUMS system, I am putting together the RTB package for it. I was under pressure to utilise a trackerless / single tracker system because it was percieved to be "easier". My argument was yes it is easier in terms of hardware production, however it simply would not do the job, and by that I mean, it would not satisfy the points that you have made.
I have limited chinook experience, but I was confident in my argument, I was just hoping that someone with a bucketload of Chinook experience would read my thread and back it up.. so thank you for taking the time to post.
The men from El Monte, Ca claim to have achieved a single tracker solution for Chinook. Of course I am sceptical, but never say never??
Anyway, many thanks again.
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heedm
Been there and done that; unfortunately with a single tracker system in the intermesh zone you are looking at the forward rotor in absolutely the wrong part of the disk to see any meaningful track response in forward flight regimes, i.e. right when it matters most in terms of Tab correction response on THE rotor that has the vibration stranglehold over the whole aircraft. (The tracker should at least be in the advancing sector ideally in the 12 o'clock location for each rotor)
Net result would be a system that does not provide adequate solutions to points 1, 2 and 3 referred to in my earlier post.
Wunper.
Been there and done that; unfortunately with a single tracker system in the intermesh zone you are looking at the forward rotor in absolutely the wrong part of the disk to see any meaningful track response in forward flight regimes, i.e. right when it matters most in terms of Tab correction response on THE rotor that has the vibration stranglehold over the whole aircraft. (The tracker should at least be in the advancing sector ideally in the 12 o'clock location for each rotor)
Net result would be a system that does not provide adequate solutions to points 1, 2 and 3 referred to in my earlier post.
Wunper
.
Last edited by Wunper; 29th Jul 2003 at 06:18.
