AW189
I was told two months ago that de-icing was sorted bar the paperwork. That was shortly after a well-publicised period of cold testing at Sawyer, Michigan.
Too much energy? Not heard that one.
In what respect too much energy?
Too much energy? Not heard that one.
In what respect too much energy?
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Rotor & Wing reported on Friday that the latest AW189 icing tests were only completed in late May.
De-icing systems add to the aircraft's existing power draw (dedicated 45KVA and 25KVA generators required in the case of the AW139, or one of the two 75KVA main generators in the case of the S-92). Not a problem for types such as these with good OEI performance, but a challenge for older models with smaller power margins.
The systems also tend to be temperamental: Sikorsky had to retrofit the initial version of the S-92's RIPS in 2008 due to teething issues (with additional upgrades following in 2009), and similar reliability/troubleshooting issues have been encountered with both the AW139 and H225/EC225. Development of the S-76D's RIPS system also continues to lag behind target.
I/C
De-icing systems add to the aircraft's existing power draw (dedicated 45KVA and 25KVA generators required in the case of the AW139, or one of the two 75KVA main generators in the case of the S-92). Not a problem for types such as these with good OEI performance, but a challenge for older models with smaller power margins.
The systems also tend to be temperamental: Sikorsky had to retrofit the initial version of the S-92's RIPS in 2008 due to teething issues (with additional upgrades following in 2009), and similar reliability/troubleshooting issues have been encountered with both the AW139 and H225/EC225. Development of the S-76D's RIPS system also continues to lag behind target.
I/C
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Not a problem for types such as these with good OEI performance, but a challenge for older models with smaller power margins.
You don't think, these two facts could have the same origine: not enough power
laurenson, if you look back at the 139, you'll find that elevated helideck procedures were one of the last things added to the RFM and I don't think the 139 suffers from a lack of power! And neither does the 189. A lighter airframe than the 92 with the same engine.
The 189 FIPS is different to the 139 FIPS, so it isn't as simple as just adding a certified system to another aircraft.
FIPS has separate, stand-alone AC Generators that do not take too much power from the helicopter. IIRC for the 139 they take about 17hp to run through the MGB.
The 189 FIPS is different to the 139 FIPS, so it isn't as simple as just adding a certified system to another aircraft.
FIPS has separate, stand-alone AC Generators that do not take too much power from the helicopter. IIRC for the 139 they take about 17hp to run through the MGB.
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Your comparison with S-92 is not perfectly right, S92 has a CT7-8A engine (around 2500-2700shp), while the AW189 has a CT7-2E (around 2000-2100shp). Moreover some charts in the FM reveal that the current configuration doesn't allow elevated helideck CAT A take off at MTOW.
So my concern is about a takeoff or an hover in icing condition, how will react my helicopter? and which level of safety will i have?
So my concern is about a takeoff or an hover in icing condition, how will react my helicopter? and which level of safety will i have?
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laurenson-
S-92. 5.26 pounds / HP
AW139. 4.90 pounds / HP (6.8 tonne). 5.04 pounds / HP (7.0 tonne). 7.3% / 4.3% more engine power per unit mass than S-92.
AW189. 4.58 pounds / HP (15% more engine power per unit mass than S-92)
That's a start. Performance charts will be derived from actual performance during flight testing. I've flown the AW139 for a number of years and watched the performance envelope grow. The same will happen with the AW189.
You need mass to place power in context. Transmission and dynamic losses will all be taken into account during flight testing.
S-92. 5.26 pounds / HP
AW139. 4.90 pounds / HP (6.8 tonne). 5.04 pounds / HP (7.0 tonne). 7.3% / 4.3% more engine power per unit mass than S-92.
AW189. 4.58 pounds / HP (15% more engine power per unit mass than S-92)
That's a start. Performance charts will be derived from actual performance during flight testing. I've flown the AW139 for a number of years and watched the performance envelope grow. The same will happen with the AW189.
You need mass to place power in context. Transmission and dynamic losses will all be taken into account during flight testing.
When somebody referred to not enough power, I think we went off on a bit of a tangent.
Is the power (electrical) available at the right time and in the right place?
This is a powerful aircraft with plenty of generating capacity which is not difficult or unusual. What is difficult is designing a way of distributing and managing that power effectively when there is an endless list of competing systems. Worse still, when the aircraft was designed for one principal purpose and then has to be modified for another.
Is the power (electrical) available at the right time and in the right place?
This is a powerful aircraft with plenty of generating capacity which is not difficult or unusual. What is difficult is designing a way of distributing and managing that power effectively when there is an endless list of competing systems. Worse still, when the aircraft was designed for one principal purpose and then has to be modified for another.
jimf671, FIPS is a stand alone system.
It has it's own AC Generators (two of them) that are not used by ANY other system on the aircraft.
It has it's own Power Distribution Panels and dedicated wiring and infrastructure.
It even has its own warning and control panel. It does not take power from any other aircraft system. It is totally self contained so that it doesn't affect any other electrical system on the aircraft.
Even the heated windshields are different between FIPS and non-FIPS aircraft because of the different power supply.
This means that it is HEAVY because you are adding a totally independent electrical system to the aircraft.
So there is no issue with power supply to FIPS on a FIPS aircraft as it has nothing to do with the standard electrical system, nor does it have anything to do with the engine power.
I've been playing with the 139 FIPS long enough to know what to expect on the 189, except the 189 system is simpler (thank goodness!).
It has it's own AC Generators (two of them) that are not used by ANY other system on the aircraft.
It has it's own Power Distribution Panels and dedicated wiring and infrastructure.
It even has its own warning and control panel. It does not take power from any other aircraft system. It is totally self contained so that it doesn't affect any other electrical system on the aircraft.
Even the heated windshields are different between FIPS and non-FIPS aircraft because of the different power supply.
This means that it is HEAVY because you are adding a totally independent electrical system to the aircraft.
So there is no issue with power supply to FIPS on a FIPS aircraft as it has nothing to do with the standard electrical system, nor does it have anything to do with the engine power.
I've been playing with the 139 FIPS long enough to know what to expect on the 189, except the 189 system is simpler (thank goodness!).
Excellent news.
And the rest of the aircrafts electrical systems; my particular interest being SAR role equipment; are they simple and effective?
(Ammunition pre-loaded in Somerset.)
noooby,
While it may not suck electrical power. The weight pf an independent electricql system and the fact that the generators suck engine power will be a significant impact on performance/payload.
The Sultan
While it may not suck electrical power. The weight pf an independent electricql system and the fact that the generators suck engine power will be a significant impact on performance/payload.
The Sultan
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I agree with sultan,
to carry the same payload, the helicopter will require more power, for the additional weight and for the electrical power.
adding a electrical system coudn't be transparent for the helicopter performance and that is more true for OEI performance.
to carry the same payload, the helicopter will require more power, for the additional weight and for the electrical power.
adding a electrical system coudn't be transparent for the helicopter performance and that is more true for OEI performance.
The 139 FIPS system is ~500lbs give or take. The 189 system is a bit lighter and is installed on an airframe with increased load carrying capability over the 139 so shouldn't impact the available load as much.
The total extra load on EACH engine with the 139 is ~15 horsepower, 30hp in total. If you are very hot or very high that could affect your Cat. A perf, but otherwise it isn't enough to worry about. And if you're operating in a hot environment you should probably remove the FIPS anyway (there are summer "kits" for the removal of FIPS components to reduce wear and weight).
For flight at or near MTOW there is a payload decrease, as there must be for any system that is added to an aircraft, but remember the Air Con on the 189 is no longer driven by the Main Gearbox, so there is a driveline hp saving there when compared to the 139, so it would be interesting to see how it all balances out between the two Main Gearboxes on the two machines. I don't have that data I'm afraid!
The total extra load on EACH engine with the 139 is ~15 horsepower, 30hp in total. If you are very hot or very high that could affect your Cat. A perf, but otherwise it isn't enough to worry about. And if you're operating in a hot environment you should probably remove the FIPS anyway (there are summer "kits" for the removal of FIPS components to reduce wear and weight).
For flight at or near MTOW there is a payload decrease, as there must be for any system that is added to an aircraft, but remember the Air Con on the 189 is no longer driven by the Main Gearbox, so there is a driveline hp saving there when compared to the 139, so it would be interesting to see how it all balances out between the two Main Gearboxes on the two machines. I don't have that data I'm afraid!
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And if you're operating in a hot environment you should probably remove the FIPS anyway (there are summer "kits" for the removal of FIPS components to reduce wear and weight).
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S-92. 5.26 pounds / HP
AW139. 4.90 pounds / HP (6.8 tonne). 5.04 pounds / HP (7.0 tonne). 7.3% / 4.3% more engine power per unit mass than S-92.
AW189. 4.58 pounds / HP (15% more engine power per unit mass than S-92)
AW139. 4.90 pounds / HP (6.8 tonne). 5.04 pounds / HP (7.0 tonne). 7.3% / 4.3% more engine power per unit mass than S-92.
AW189. 4.58 pounds / HP (15% more engine power per unit mass than S-92)
I'm not trying to start a fight but right here at the factory, guys who have flown both the 139 and the 189 will tell you the 189 does not have the power margins of the 139. Not saying it is under powered, but it is no ( 6.8) 139.
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Just need to remember too, 5-bladed rotor systems are higher performing (which everyone loves), but require a more complex system to counter icing. Shedding ice which every system has to be able to do as well as prevent it.
S-92 is a basic 4 bladed (UH-60 rotor system) rotor system.
S-92 is a basic 4 bladed (UH-60 rotor system) rotor system.