Agusta AW139
Join Date: Jun 2011
Location: below sea level
Age: 44
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I performed the inspection on one of our ships,
Found that the screw hole is much lower than the rigid hydraulic line.
In my opinion the finding on the H/C which did have chaffing on the hydraulic line is typically an example of Murphys Law (caught on the right time).
1. The screw which had been installed was too long.
2. Somebody has been leaning/standing on the rigid hydraulic lines causing them to bend a little downward causing the outer line to vibrate against the screw.
regards,
Dragstay.
Found that the screw hole is much lower than the rigid hydraulic line.
In my opinion the finding on the H/C which did have chaffing on the hydraulic line is typically an example of Murphys Law (caught on the right time).
1. The screw which had been installed was too long.
2. Somebody has been leaning/standing on the rigid hydraulic lines causing them to bend a little downward causing the outer line to vibrate against the screw.
regards,
Dragstay.
Join Date: Apr 2008
Location: Texas
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AW139 RPM increasing issue!!!
Troubleshooting question: If you choose to help, greatly appreciated.
ONLY in cruise, one of our 139's RPM switch set at 100% at straight level flight momentarily bumps up 2% percent with no pilot assistance.
Collective wiring rang out good
LVDT's on order yet no test box
Any starting points?
ONLY in cruise, one of our 139's RPM switch set at 100% at straight level flight momentarily bumps up 2% percent with no pilot assistance.
Collective wiring rang out good
LVDT's on order yet no test box
Any starting points?
Join Date: Aug 2007
Location: NZ
Age: 71
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We have had Tq surges in the cruise with ALT hold engaged, and that caused momentary Rrpm to 102. It was a faulty bleed valve. But at the same time we would also have an overspeed to 102-103 on raising the collective moderately quickly as on lift off to the hover.
If 1 or 2 Tq is spiking at the same time, swap the bleed valve over and see if the other engines Tq spikes, if it does, problem solved.
Regards
Mick.
If 1 or 2 Tq is spiking at the same time, swap the bleed valve over and see if the other engines Tq spikes, if it does, problem solved.
Regards
Mick.
You could try cleaning the bleed valve filter first. Much easier than changing the valves over side to side. Many bleed valve issues are caused by a partially blocked filter.
If no change, then sure, go ahead and swap side to side to help troubleshoot.
If no change, then sure, go ahead and swap side to side to help troubleshoot.
Join Date: Nov 2000
Location: Abroad
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Icing
Hi, does anyone know what the flight manual of the AW 139 says about flying in icing conditions?
I know its approved to fly in known icing conditions but is it approved to fly in moderate icing or only light icing?
Txs
I know its approved to fly in known icing conditions but is it approved to fly in moderate icing or only light icing?
Txs
Join Date: Aug 2001
Location: Cornwall
Age: 75
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Flight in icing conditions
This from the RFM, Supplement 71, Ice Protections System (IPS)
No IPS, No clearance at all.
G.
TYPE OF OPERATIONS
Instrument Flight Rules (IFR) Day/Night in known icing conditions
Instrument Flight Rules (IFR) Day/Night in known icing conditions
No IPS, No clearance at all.
G.
Join Date: Nov 2000
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Txs....soo known icing? Is that light, moderate or severe? Thats the question....
No aircraft I know ( fixed wing or rotor) are approved to fly in severe icing.
Anyone know what the certification stated? Or can you asume
known icing= moderate icing?
No aircraft I know ( fixed wing or rotor) are approved to fly in severe icing.
Anyone know what the certification stated? Or can you asume
known icing= moderate icing?
GENERAL INFORMATION
The IPS is designed to allow full icing operations by automatically deicing
MR blades and anti-icing TR blades. The functioning of the system
is controlled automatically (with two independent Channels A and
B) in relation to the severity of the icing conditions encountered at any
time. An additional cockpit indicating panel shows the status of the IPS
and additional IPS Master Warning and Caution lights (Figure 3) are
provided for both pilot and co-pilot positions.
Main Rotor Ice Protection is provided by electrical heating of the MR
blades (sequential heating of six leading edge zones along the blade
span). Tail Rotor Ice Protection is provided by continuous heating of
the leading edge of the four blades.
Electrical power is provided by two Main Gearbox mounted AC generators.
Electrical power to the blades is controlled by a control box and
distributed through distribution boxes and slip rings. Atmospheric
information is provided to the control box by Outside Air Temperature
Sensors and Ice Detectors sensors (Liquid Water Content - LWC). The
Ice Detectors and windshield heating are active at all times with the
IPS ON.
The MR de-icing system works in AUTO by allowing a small amount of
ice to accrete on each leading edge zone and then sequential heating
of each zone causes the ice to be shed. It is normal, therefore, to see
an increase in torque required that will cycle up and down in accordance
with the heating cycles. Part of the torque increase (2 – 3%) is
due to the power required by the AC generators which also supply the
TR anti-ice function when the IPS is set to AUTO mode.
The torque variation, due to ice, can be expected to be around 5 ÷
15%, depending on OAT, LWC, and Water Droplet size (Mean Volumetric
Diameter - MVD) when the system is working in icing conditions.
Higher torque increase may be experienced in more severe
icing conditions (higher LWC, larger MVD), but such conditions do not
occur frequently in the atmosphere.
No rotor unbalance is to be expected as a consequence of ice shed,
because of the symmetric 5 MR blades heating and the continuous TR
blades heating.
Ice shedding from the MR will be experienced during system functioning
in ice and this can occasionally be seen and heard, with small
pieces of ice striking the windscreens.
With the IPS selected ON and in AUTO mode on the overhead panel
(See Figure 1), an encounter with ice is indicated by the ICING caution
illumination on the MFD CAS, when OAT is less than +4°C and LWC
values being shown on the IPS Panel ICE SEVERITY window (See
Figure 2). Icing is also indicated by a build up of ice on visible aircraft
structure, e.g. unheated area of windscreens, wiper arms, SLD
marker.
The SLD marker is a composite sphere, installed on the right side of
the fuselage, in view of the pilot through the lateral screen. It is
designed to help the pilot visually detect if SLD conditions are encountered.
The sphere has a black central circle with yellow and red rings
around it. Ice accretion can be easily seen on the black marker.
A MANUAL mode is provided, selectable by the pilot, that overrides
the normal control system and applies the maximum possible heating
to the MR blades.
Different types of ice will form on the aircraft depending on the icing
conditions. The main types of ice are Glaze and Rime. Glaze ice is
clear and will tend to form at higher sub-zero temperatures (0°C to -
5°C) and is more likely with higher LWC and larger droplets. This type
of ice can generate high drag increase to occur due to the shape that
forms. Rime ice is white and opaque and tends to form at lower temperatures
with smaller droplets. Rime ice forms in a more streamlined
shape and causes a smaller increase in aircraft drag. It is possible to
have a mixture of both, which is know as Glime or Mixed Ice.
Flight in Freezing Rain or Freezing Drizzle is not permitted because it
is not covered by the current Airworthiness Rules for any type of aircraft.
Freezing Rain and Drizzle (also known as Supercooled Large
Droplets - SLD) consists of supercooled water droplets of sizes
greater than the EASA/FAA CS/Part 29 Appendix C, atmospheric definition
used for Certification. These conditions, although rare, have a
serious effect on any aircraft’s performance. Pilots must use normal
operational planning and techniques to avoid flight in these conditions.
If encountered inadvertently, the conditions must be vacated immediately.
PILOT ACTIONS IN CASE OF SEVERE ICE ENCOUNTERS
Severe icing conditions are indicated by some or all of the following:
• High PI rise (>30% above normal for flight condition)
• Steady increase in base PI with heating cycles
• High LWC (>1.5 g/m3)
• Heavy amounts of water streaming across windscreens
• Evidence of SLD (ice forming on sides of aircraft, SLD
Marker)
• Increase in vibration
• Tendency for significant speed loss.
Actions:
• Reduce speed to 80 KIAS
• Select 102% NR
• Use up to 110% PI
• Check for system failures
• Select MAN
— if PI reduces Select AUTO, and use MANUAL to
reduce subsequent PI rise.
— if PI does not reduce, or rises steadily, select AUTO
and do not select MAN again (possible runback ice)
• Change altitude – severe ice conditions are usually near the
top of the clouds
• Consider vacating icing conditions if severity does not reduce
The IPS is designed to allow full icing operations by automatically deicing
MR blades and anti-icing TR blades. The functioning of the system
is controlled automatically (with two independent Channels A and
B) in relation to the severity of the icing conditions encountered at any
time. An additional cockpit indicating panel shows the status of the IPS
and additional IPS Master Warning and Caution lights (Figure 3) are
provided for both pilot and co-pilot positions.
Main Rotor Ice Protection is provided by electrical heating of the MR
blades (sequential heating of six leading edge zones along the blade
span). Tail Rotor Ice Protection is provided by continuous heating of
the leading edge of the four blades.
Electrical power is provided by two Main Gearbox mounted AC generators.
Electrical power to the blades is controlled by a control box and
distributed through distribution boxes and slip rings. Atmospheric
information is provided to the control box by Outside Air Temperature
Sensors and Ice Detectors sensors (Liquid Water Content - LWC). The
Ice Detectors and windshield heating are active at all times with the
IPS ON.
The MR de-icing system works in AUTO by allowing a small amount of
ice to accrete on each leading edge zone and then sequential heating
of each zone causes the ice to be shed. It is normal, therefore, to see
an increase in torque required that will cycle up and down in accordance
with the heating cycles. Part of the torque increase (2 – 3%) is
due to the power required by the AC generators which also supply the
TR anti-ice function when the IPS is set to AUTO mode.
The torque variation, due to ice, can be expected to be around 5 ÷
15%, depending on OAT, LWC, and Water Droplet size (Mean Volumetric
Diameter - MVD) when the system is working in icing conditions.
Higher torque increase may be experienced in more severe
icing conditions (higher LWC, larger MVD), but such conditions do not
occur frequently in the atmosphere.
No rotor unbalance is to be expected as a consequence of ice shed,
because of the symmetric 5 MR blades heating and the continuous TR
blades heating.
Ice shedding from the MR will be experienced during system functioning
in ice and this can occasionally be seen and heard, with small
pieces of ice striking the windscreens.
With the IPS selected ON and in AUTO mode on the overhead panel
(See Figure 1), an encounter with ice is indicated by the ICING caution
illumination on the MFD CAS, when OAT is less than +4°C and LWC
values being shown on the IPS Panel ICE SEVERITY window (See
Figure 2). Icing is also indicated by a build up of ice on visible aircraft
structure, e.g. unheated area of windscreens, wiper arms, SLD
marker.
The SLD marker is a composite sphere, installed on the right side of
the fuselage, in view of the pilot through the lateral screen. It is
designed to help the pilot visually detect if SLD conditions are encountered.
The sphere has a black central circle with yellow and red rings
around it. Ice accretion can be easily seen on the black marker.
A MANUAL mode is provided, selectable by the pilot, that overrides
the normal control system and applies the maximum possible heating
to the MR blades.
Different types of ice will form on the aircraft depending on the icing
conditions. The main types of ice are Glaze and Rime. Glaze ice is
clear and will tend to form at higher sub-zero temperatures (0°C to -
5°C) and is more likely with higher LWC and larger droplets. This type
of ice can generate high drag increase to occur due to the shape that
forms. Rime ice is white and opaque and tends to form at lower temperatures
with smaller droplets. Rime ice forms in a more streamlined
shape and causes a smaller increase in aircraft drag. It is possible to
have a mixture of both, which is know as Glime or Mixed Ice.
Flight in Freezing Rain or Freezing Drizzle is not permitted because it
is not covered by the current Airworthiness Rules for any type of aircraft.
Freezing Rain and Drizzle (also known as Supercooled Large
Droplets - SLD) consists of supercooled water droplets of sizes
greater than the EASA/FAA CS/Part 29 Appendix C, atmospheric definition
used for Certification. These conditions, although rare, have a
serious effect on any aircraft’s performance. Pilots must use normal
operational planning and techniques to avoid flight in these conditions.
If encountered inadvertently, the conditions must be vacated immediately.
PILOT ACTIONS IN CASE OF SEVERE ICE ENCOUNTERS
Severe icing conditions are indicated by some or all of the following:
• High PI rise (>30% above normal for flight condition)
• Steady increase in base PI with heating cycles
• High LWC (>1.5 g/m3)
• Heavy amounts of water streaming across windscreens
• Evidence of SLD (ice forming on sides of aircraft, SLD
Marker)
• Increase in vibration
• Tendency for significant speed loss.
Actions:
• Reduce speed to 80 KIAS
• Select 102% NR
• Use up to 110% PI
• Check for system failures
• Select MAN
— if PI reduces Select AUTO, and use MANUAL to
reduce subsequent PI rise.
— if PI does not reduce, or rises steadily, select AUTO
and do not select MAN again (possible runback ice)
• Change altitude – severe ice conditions are usually near the
top of the clouds
• Consider vacating icing conditions if severity does not reduce
Regards
Aser
Surprised that there is no mention of icing on the horizontal stabiliser,as it can make pitch control `interesting` in some helos..
It is heated by the exhaust stream pretty much across the whole span, as you can tell by the amount of exhasut soot that collects on it! 
So it probably doesn't get any ice forming on it, same with the fin.
So it probably doesn't get any ice forming on it, same with the fin.
Join Date: Jun 2008
Location: Canada
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De-icing???
Well,I can tell you that we do not wait to fly in this conditions
the system still do not work at this time and we don't know if it is gone be usable this Winter.We don't know how much ice we will get on the horizontal stab and the vertical fin,but we know that if we have ice on it,it is a no go for take-off.The slip ring problem is supposed to be fixed,so will see,but we all anticipate serious problem and some epic flights if it works.
the system still do not work at this time and we don't know if it is gone be usable this Winter.We don't know how much ice we will get on the horizontal stab and the vertical fin,but we know that if we have ice on it,it is a no go for take-off.The slip ring problem is supposed to be fixed,so will see,but we all anticipate serious problem and some epic flights if it works.
Join Date: Nov 2005
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Hi nooby-spot on with the BOV filters to clean 1st.
The other thing I would/have done after cleaning BOV filters is checking BOV closure point. I have found over time that making a mark on hex adjustment shaft-then move 1 full turn in & out and then return to original position. Yet to confirm from PWC but this has affected BOV closure behaviour.
Also I would suggest "matching" BOV closure point to within 0.5% Ng of #1 & #2...again affecting this behaviour in cruise.
If you go to trouble of swapping after all that-once removed check the valve for smooth travel by moving with your fingers.
Good luck
The other thing I would/have done after cleaning BOV filters is checking BOV closure point. I have found over time that making a mark on hex adjustment shaft-then move 1 full turn in & out and then return to original position. Yet to confirm from PWC but this has affected BOV closure behaviour.
Also I would suggest "matching" BOV closure point to within 0.5% Ng of #1 & #2...again affecting this behaviour in cruise.
If you go to trouble of swapping after all that-once removed check the valve for smooth travel by moving with your fingers.
Good luck
Join Date: Oct 2004
Location: California
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Glass Windshields or Acrylic?
Wondering what percentage of 139's have glass or heated glass windshields?
We do have plain glass and have busted 4 each ( 1 RH, then 2 LH and just now the second RH) in the space of 14 months and 103 flt hours.
PPG says FOD impact, but we only go airport taxiway to airport taxiway 99.99% of the time. Always hangared.
Anyone with glass seen any micro chipping or such and not had window shatter.
PPG says that the specification for airworthiness is 10% damage depth and still OK, ie 0.012" is limit for damage on each layer of 0.125 glass. I measured our last FOD crush mark and got around 0.007", but optical micrometer will get more accurate data when returned to PPG.
Fly to Philly tomorrow to let AW investigate and determine if we have a freak airframe with a weird frequency or vibe and/or flexing nose section. Owner will not fly in again until cause is found.
Anyone got any info on glass windshield reliability, care to respond.
Thanks in advance
KC
We do have plain glass and have busted 4 each ( 1 RH, then 2 LH and just now the second RH) in the space of 14 months and 103 flt hours.
PPG says FOD impact, but we only go airport taxiway to airport taxiway 99.99% of the time. Always hangared.
Anyone with glass seen any micro chipping or such and not had window shatter.
PPG says that the specification for airworthiness is 10% damage depth and still OK, ie 0.012" is limit for damage on each layer of 0.125 glass. I measured our last FOD crush mark and got around 0.007", but optical micrometer will get more accurate data when returned to PPG.
Fly to Philly tomorrow to let AW investigate and determine if we have a freak airframe with a weird frequency or vibe and/or flexing nose section. Owner will not fly in again until cause is found.
Anyone got any info on glass windshield reliability, care to respond.
Thanks in advance
KC
Join Date: Jun 2012
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There was an issue with ppg glass windows on Bell mediums a little while ago, our fleet had three or 4 new ppg glass windshields crack, two cracked with the aircraft just sitting on the ground.
I believe it came down to a run of mis-formed windows, they were not contoured to match the airframe and when installed were put under constant stress.
I would check to see that the windshields fit properly when installing the next ones.
I believe it came down to a run of mis-formed windows, they were not contoured to match the airframe and when installed were put under constant stress.
I would check to see that the windshields fit properly when installing the next ones.
Join Date: Oct 2004
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Oh yeah, we are down on shimming and trimming and radiusing inside edges after 4 of these. Third window (2nd LH) took 3 attempts to get a window that didn't arrive with defects or would actually fit in airframe contour of opening without rocking from corner to corner.
Coincidentally our first one happened in our hangar overnight too. That has the "experts" stumped
Cheers
KC
Coincidentally our first one happened in our hangar overnight too. That has the "experts" stumped
Cheers
KC