Agusta AW139
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Hi WDE!
Is this Ontario EMS? We heard rumours about the a/c change/ upgrade. If it is Ontario, good for you guys.
As for dispatch times, I hope reference to flight manual/manufacturer's procedure is priority! I have come across the "scramble start" mentality on certain op's which leads to mission oriented mentality rather than solid aviation standards mentality!
Two minutes from engine start to airborne seems quite drastic. There must be some requirement for oil temperature and internal metals coming up to temp before placing any load on them??? Hope you 139 dudes can advise?
Cheers!
DK
Is this Ontario EMS? We heard rumours about the a/c change/ upgrade. If it is Ontario, good for you guys.
As for dispatch times, I hope reference to flight manual/manufacturer's procedure is priority! I have come across the "scramble start" mentality on certain op's which leads to mission oriented mentality rather than solid aviation standards mentality!
Two minutes from engine start to airborne seems quite drastic. There must be some requirement for oil temperature and internal metals coming up to temp before placing any load on them??? Hope you 139 dudes can advise?
Cheers!
DK
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Using normal battery start procedures, the second engine can be started as soon as the loadmeter is in the green (roughly 20-40 seconds). Using external power, the second engine can be started immediately after the first starter drops out (49% Ng). Using the Quick Start procedure, the second engine can be started after the starting engine Ng reaches 25%, even on a battery start. The only delay for any start is waiting for ENG & XMSN T's and P's. In our GoM environment, the temps are in the green very soon after the starter drops out. Colder climate operations would obviously have to wait longer. NOTE: No shortcuts here...These procedures are straight from the RFM.
As soon as the battery switches are turned on, all avionics are powered-up. There is a RAD MASTER switch that disables some of the avionics to aid in a battery start (RAD MASTER OFF). We use a GPU for nearly every start...RAD MASTER ON...and all avionics are powered-up as soon as the External Power is applied and battery switches are on.
As soon as the battery switches are turned on, all avionics are powered-up. There is a RAD MASTER switch that disables some of the avionics to aid in a battery start (RAD MASTER OFF). We use a GPU for nearly every start...RAD MASTER ON...and all avionics are powered-up as soon as the External Power is applied and battery switches are on.
Last edited by patniven; 12th Mar 2008 at 16:55. Reason: Note
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Starts
And don't forget PW requirement to keep the difference in cycles between No 1 and 2 to less than 10%, means you need to alternate the first engine to be started, a little gem hidden away in the engine maintenance manuals and which I didn't find out until the first 50-hour check. Unlike Patniven, we're starting pretty much all the time on the battery so No 1 has been getting the vote all the time................................
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flungdung
I agree, but only connect the bus tie seconds before starting the No2. It's not been a hugh problem.
I admit that you don't get too many chances before the MAUs have got the better of the batteries, but that's par for the course with a 139.
Red
I agree, but only connect the bus tie seconds before starting the No2. It's not been a hugh problem.
I admit that you don't get too many chances before the MAUs have got the better of the batteries, but that's par for the course with a 139.
Red
heliski22,
Did you try the DCL mode in the ils?
We have found that after reducing speed with IAS mode or using DCL mode, the helicopter always deviates to the right and we end aligned with the taxiway!
Agusta pilot also checked it.
Any other 4-axis user out there?
"Sunset"
Regards
Aser
Did you try the DCL mode in the ils?
We have found that after reducing speed with IAS mode or using DCL mode, the helicopter always deviates to the right and we end aligned with the taxiway!
Agusta pilot also checked it.
Any other 4-axis user out there?
"Sunset"
Regards
Aser
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Aser I have noticed this in a few aircraft, however only on the 3 axis while using the auto level mode while reducing power on the ILS. As you spoke of it was quite a deviation to the right on the ILS.
I agree with Red white and blue. There should be no problem with starting the number 2 first even off the main battery, if you can't you probably need a new main batt or it needs to be deep cycled. The only time you are going to have problems is if you are starting all the time on external power (bad practice) as this will rape the batteries if you don't use them to start. We found this out a year or two ago. To be honest though there is not going to be much of a difference in time between starting with the batt or the EPU.
As for the quick start (which was developed for the EMS industry, I remember something about 3 mins for some reason, something to do with EMS operators in Europe. However, it was quite a while ago I heard this so I may be mistaken)...I have never tried it but if you like I can certainly try it tomorrow and come up with a time for you from seltbelts on to take off. I would estimate around 3-4 minutes if all the system checks have been completed.
I agree with Red white and blue. There should be no problem with starting the number 2 first even off the main battery, if you can't you probably need a new main batt or it needs to be deep cycled. The only time you are going to have problems is if you are starting all the time on external power (bad practice) as this will rape the batteries if you don't use them to start. We found this out a year or two ago. To be honest though there is not going to be much of a difference in time between starting with the batt or the EPU.
As for the quick start (which was developed for the EMS industry, I remember something about 3 mins for some reason, something to do with EMS operators in Europe. However, it was quite a while ago I heard this so I may be mistaken)...I have never tried it but if you like I can certainly try it tomorrow and come up with a time for you from seltbelts on to take off. I would estimate around 3-4 minutes if all the system checks have been completed.
Last edited by platinumpure; 14th Mar 2008 at 04:10.
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Have any of the 139 operators considered replacing the Ni-cad batteries with CONCORDE sealed lead acid batteries ?
They ( CONCORDE ) have numerous STC's for 'other' type / models helicopters but haven't seen one for the 139. Perhaps the right time to put pressure on AW to evaluate and approve
One of the advantages -of sealed lead acids- over Ni-cads is that one will not have any more problems with -defective- battery temp warning systems that warns you for a thermal runaway .
A phenonemon invented by MARATHON, probably triggered by the MARATHON 'bossom buddies' that used to 'parade' around the annual HAI shows in the eighties....
They ( CONCORDE ) have numerous STC's for 'other' type / models helicopters but haven't seen one for the 139. Perhaps the right time to put pressure on AW to evaluate and approve
One of the advantages -of sealed lead acids- over Ni-cads is that one will not have any more problems with -defective- battery temp warning systems that warns you for a thermal runaway .
A phenonemon invented by MARATHON, probably triggered by the MARATHON 'bossom buddies' that used to 'parade' around the annual HAI shows in the eighties....
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Aser,
Just noticed that deviation to the right recently and checked it again last night, same thing. Deviation indicator in the middle of the course needle also flickering left and right off centre by a couple of mm from about 6miles out. As you say, fully coupled and using IAS mode to back off the speed as we came in. We'll run some checks next week but when it auto levels, I like to see it run down the centreline - much warmer feeling!!
Yes, I've tried the DCL mode but rather than claim it doesn't work, I'm going to double-check what the RFM says about using it. I thought I was doing it right but.....................
As for the battery start for number two, I agree it shouldn't be a problem and I'd have done it more often if I'd known about the PW 10% requirement, so I'm just going to start #2 first whenever I can now. I'd prefer to see closer to 24v than 23v (just me being cautious)for #2 so I've even started to carry a hand held - the last thing I want to hear is "Standby" after calling Ground for start at some major airport or other (hate bloody airports, I do).
Is it just me, or do you get accustomed to the higher vibe, or does it settle down after a bit? I feel it increasing through about 142/143 knots (pretty common) but the last couple of trips, I've pegged it at the highest speed IAS mode will allow (e.g., 153KIAS at 4,500 ft) and just left it there, before long I'm wondering where the vibe has gone?
Just noticed that deviation to the right recently and checked it again last night, same thing. Deviation indicator in the middle of the course needle also flickering left and right off centre by a couple of mm from about 6miles out. As you say, fully coupled and using IAS mode to back off the speed as we came in. We'll run some checks next week but when it auto levels, I like to see it run down the centreline - much warmer feeling!!
Yes, I've tried the DCL mode but rather than claim it doesn't work, I'm going to double-check what the RFM says about using it. I thought I was doing it right but.....................
As for the battery start for number two, I agree it shouldn't be a problem and I'd have done it more often if I'd known about the PW 10% requirement, so I'm just going to start #2 first whenever I can now. I'd prefer to see closer to 24v than 23v (just me being cautious)for #2 so I've even started to carry a hand held - the last thing I want to hear is "Standby" after calling Ground for start at some major airport or other (hate bloody airports, I do).
Is it just me, or do you get accustomed to the higher vibe, or does it settle down after a bit? I feel it increasing through about 142/143 knots (pretty common) but the last couple of trips, I've pegged it at the highest speed IAS mode will allow (e.g., 153KIAS at 4,500 ft) and just left it there, before long I'm wondering where the vibe has gone?
Last edited by heliski22; 15th Mar 2008 at 21:44.
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Aser
Did the DCL thing a couple of times today. It did the decel to 80kts fine but the same as you each time, off to the right but came back in to the centreline over the numbers. I let it continue to ALVL, otherwise it would have been aligned with the grass to the right side at DH.
PM me with some contact details, please.
22
Did the DCL thing a couple of times today. It did the decel to 80kts fine but the same as you each time, off to the right but came back in to the centreline over the numbers. I let it continue to ALVL, otherwise it would have been aligned with the grass to the right side at DH.
PM me with some contact details, please.
22
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AW 139 Cat A Ops
"1. The optimum Nr for rotor performance is 100% (any more or less and the rotor is LESS efficient)
2. In order to meet the RFM Cat A performance standards, any OEI flight during take off and landing must be conducted with the remaining engine at maximum power.
3. To ensure that this is so, the collective lever must be raised until the Nr droops. This will bring the remaining engine up to maximum power. If the remaining engine is NOT at maximum power then the performance promised in the RFM cannot be guaranteed.
4. If the starting point was 100% Nr then this would mean that when the Nr was 'drooped' to say 98% then the rotor was working at a less efficient speed so the Nr is set to 102%. Thus, when the Nr is drooped it will droop to 100% where it should remain until Vtoss is achieved.
Comment!
2. In order to meet the RFM Cat A performance standards, any OEI flight during take off and landing must be conducted with the remaining engine at maximum power.
3. To ensure that this is so, the collective lever must be raised until the Nr droops. This will bring the remaining engine up to maximum power. If the remaining engine is NOT at maximum power then the performance promised in the RFM cannot be guaranteed.
4. If the starting point was 100% Nr then this would mean that when the Nr was 'drooped' to say 98% then the rotor was working at a less efficient speed so the Nr is set to 102%. Thus, when the Nr is drooped it will droop to 100% where it should remain until Vtoss is achieved.
Comment!
1. Type specific 
2&3. Obvious, and applicable to any type
4. Gobbledygook
2&3. Obvious, and applicable to any type
4. Gobbledygook
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212man
It's 'Guess The Question' time. The question you answered is not the question being asked - apologies for sounding a bit like Donald Rumsfeld.
The statement posted was in response to the much asked question
"Why do we select 102% Nr for Cat A ops but not for Cat B Ops - or for that matter during OEI ops"
The only answer I can find that fits the published info is the one given. Apologies if you find it gobbledegook. If you tell me which bit you don't understand the I will try to explain further. Other 139 guys seem to get it but maybe you are not familiar with the type.
G
The statement posted was in response to the much asked question
"Why do we select 102% Nr for Cat A ops but not for Cat B Ops - or for that matter during OEI ops"
The only answer I can find that fits the published info is the one given. Apologies if you find it gobbledegook. If you tell me which bit you don't understand the I will try to explain further. Other 139 guys seem to get it but maybe you are not familiar with the type.
G
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AW 139 Cat A Ops
"1. The optimum Nr for rotor performance is 100% (any more or less and the rotor is LESS efficient)
2. In order to meet the RFM Cat A performance standards, any OEI flight during take off and landing must be conducted with the remaining engine at maximum power.
3. To ensure that this is so, the collective lever must be raised until the Nr droops. This will bring the remaining engine up to maximum power. If the remaining engine is NOT at maximum power then the performance promised in the RFM cannot be guaranteed.
4. If the starting point was 100% Nr then this would mean that when the Nr was 'drooped' to say 98% then the rotor was working at a less efficient speed so the Nr is set to 102%. Thus, when the Nr is drooped it will droop to 100% where it should remain until Vtoss is achieved.
100% Nr is only for Cat B because there is no need for extra power to ensure best Cat B performance in the entire envelope.
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Bpaggi
It depends what is your flight condition or flight profile. For Cat A operations optimum NR is 102% as pubblished
With respect the aircraft does not know whether you are flying Cat A or Cat B so the type of profile selected cannot affect the rotor efficiency. It is either more efficient at 102% or not. If it is more efficient then why not use it for Cat B ops and for OEI landings? I suspect, but I don't know (and I wish I did) that the helicopter is designed to fly at 100% because that is the most efficient Nr.
In order to meet the RFM Cat A performance you have to stick to RFM procedures that are quite clear. FADEC will take care of the power once you take care of the pubblished procedures
The FADEC (actually it's not a FADEC but I know what you mean) will only deliver if you put the collective in the right place. As the RFM invites you to adjust collective during the response to engine failure it may not be in the right place to get max power from the remaining engine. 'FADEC' wont help you then.
Not true, collective has to be kept at the same position of a standard AEO maneuvre unless a droop is necessary to achieve transational lift to accelerate to Vtoss
Well the only practical way I know that you can be sure the remaining engine is at max power is to pull until the NR droops. Exactly how much droop would depend on the circumstances.
The starting point for Cat A can only be 102%. The droop is allowed up to 90% and is not meant to achieve a better efficiency but to convert the huge M/R inertia into transational lift, once you have achieved Vtoss you have to recover your 102% NR setting.
Agree
100% Nr is only for Cat B because there is no need for extra power to ensure best Cat B performance in the entire envelope.
Surely any wise pilot who believes that 102% Nr endows the machine, in some way, with better performance, would select 102 for every take off - A or B.
I am not sitting here thinking I know all the answers that's why I'm enlisting Ppruners help and advice but if it's not published by AW then I have to be sceptical. If AW say 102 is good for Cat A but not for Cat B then I have to look deeper for an answer. It cannot be performance, it must be technique. Somebody show me otherwise and I'll be a happy man.
G
With respect the aircraft does not know whether you are flying Cat A or Cat B so the type of profile selected cannot affect the rotor efficiency. It is either more efficient at 102% or not. If it is more efficient then why not use it for Cat B ops and for OEI landings? I suspect, but I don't know (and I wish I did) that the helicopter is designed to fly at 100% because that is the most efficient Nr.
In order to meet the RFM Cat A performance you have to stick to RFM procedures that are quite clear. FADEC will take care of the power once you take care of the pubblished procedures
The FADEC (actually it's not a FADEC but I know what you mean) will only deliver if you put the collective in the right place. As the RFM invites you to adjust collective during the response to engine failure it may not be in the right place to get max power from the remaining engine. 'FADEC' wont help you then.
Not true, collective has to be kept at the same position of a standard AEO maneuvre unless a droop is necessary to achieve transational lift to accelerate to Vtoss
Well the only practical way I know that you can be sure the remaining engine is at max power is to pull until the NR droops. Exactly how much droop would depend on the circumstances.
The starting point for Cat A can only be 102%. The droop is allowed up to 90% and is not meant to achieve a better efficiency but to convert the huge M/R inertia into transational lift, once you have achieved Vtoss you have to recover your 102% NR setting.
Agree
100% Nr is only for Cat B because there is no need for extra power to ensure best Cat B performance in the entire envelope.
Surely any wise pilot who believes that 102% Nr endows the machine, in some way, with better performance, would select 102 for every take off - A or B.
I am not sitting here thinking I know all the answers that's why I'm enlisting Ppruners help and advice but if it's not published by AW then I have to be sceptical. If AW say 102 is good for Cat A but not for Cat B then I have to look deeper for an answer. It cannot be performance, it must be technique. Somebody show me otherwise and I'll be a happy man.
G
3. To ensure that this is so, the collective lever must be raised until the Nr droops. This will bring the remaining engine up to maximum power. If the remaining engine is NOT at maximum power then the performance promised in the RFM cannot be guaranteed.
Not true, collective has to be kept at the same position of a standard AEO maneuvre unless a droop is necessary to achieve transational lift to accelerate to Vtoss
" SINGLE ENGINE FAILURE, RECOGNIZED AT/AFTER TDP (CONTINUED TAKE OFF)"
1. [...].Mantain 0º while using collective to droop NR to minimum of 90% and set 2.5min. power.
Yes, "quite clear"
Anyway... if you are taking off at any Tq. above 80% I don't think you need to use collective, the "droop" will be automatic. If you are very light you may need to use collective to drop NR and use all the power the engine can give (if you need it).
Geoffersincornwall, how is it in the sim at MGW ? I'd like to go there some day.
EDIT: I think the rotor is more efficient at NR 90% than 100% at 2.5min power , in the transition to Vtoss. No?
Regards
Aser
Last edited by Aser; 20th Mar 2008 at 16:56.
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A stimulating experience
The sim as a fantastic tool but as with any such device will only deliver according to the software. It is supposed to be accurate but how do you know when the only real aircraft training is done using the OEI training switch - which is a great tool in itself.
I'm currently doing a customer's TR course and due to their location have cranked up the OAT to 35 - 40 degrees. At that temp and with no wind the machine does the job with no fuss. A higher MTOM will be interesting but we are waiting to hear officially about that.
Enjoying the job very much but wish that the flow of information was a little better. Physically I am near the centre of the AW world but info-wise I could be the other side of the world. That's the trouble when you are not important enough.
Hope to see you one day.
G
I'm currently doing a customer's TR course and due to their location have cranked up the OAT to 35 - 40 degrees. At that temp and with no wind the machine does the job with no fuss. A higher MTOM will be interesting but we are waiting to hear officially about that.
Enjoying the job very much but wish that the flow of information was a little better. Physically I am near the centre of the AW world but info-wise I could be the other side of the world. That's the trouble when you are not important enough.
Hope to see you one day.
G
Geoff, you are right - I am not familiar with the type and maybe the quote would appear more logical in a wider context.
What I would say is this: For a CAt B procedure, the only pre-requisite is the ability to hover IGE AEO. Nothing is guaranteed in the way of OEI performance either for a rejected take off or continued (or attempted continued!) Take off. Therefore, it would make sense to operate the aircraft at the most efficient Nr when AEO, which seems to be 100%, as this is the only flight regime being recognised by the RFM.
For a CAt A procedure, everything is predicated on the subsequent OEI performance, so it would make sense to operate such that in the event of an engine failure, the aircraft then enters the optimum OEI conditions. It would seem that the natual Nr decay for this type (as quoted) is about 2%, therefore setting 102% for AEO ops would place the aircraft at 100% in the transition to OEI.
Of course, at the end of the day it all depends what you do with the lever after the failure and I'm assuming the quoted decay is the normal result of leaving the collective position alone.
I hope this ties in with your dilema?
What I would say is this: For a CAt B procedure, the only pre-requisite is the ability to hover IGE AEO. Nothing is guaranteed in the way of OEI performance either for a rejected take off or continued (or attempted continued!) Take off. Therefore, it would make sense to operate the aircraft at the most efficient Nr when AEO, which seems to be 100%, as this is the only flight regime being recognised by the RFM.
For a CAt A procedure, everything is predicated on the subsequent OEI performance, so it would make sense to operate such that in the event of an engine failure, the aircraft then enters the optimum OEI conditions. It would seem that the natual Nr decay for this type (as quoted) is about 2%, therefore setting 102% for AEO ops would place the aircraft at 100% in the transition to OEI.
Of course, at the end of the day it all depends what you do with the lever after the failure and I'm assuming the quoted decay is the normal result of leaving the collective position alone.
I hope this ties in with your dilema?
