View Full Version : H145 makes forced landing
Collective Bias
8th Dec 2021, 08:51
A norwegian H145 makes forced landing after flameout in snowfall. Second engine flamed out during landning. Half of swedens HEMS helicopters (all H145) can not fly in snowfall. Together with new fixedwing service not able to land on certain airports. Don’t get sick in northen sweden….
CB
A norwegian H145 makes forced landing after flameout in snowfall. Second engine flamed out during landning. Half of swedens HEMS helicopters (all H145) can not fly in snowfall. Together with new fixedwing service not able to land on certain airports. Don’t get sick in northen sweden….
CB
Is this due to the installation of inlet barrier filters? If so, are they essential in Norwegian operations?
ShyTorque
8th Dec 2021, 10:08
Problem with many of these anti-ice filters is that falling snow can collect on or around them. When comes loose it can then get ingested as a "mouthful" and the sudden amount of water puts the flame out. We had the same thing on the Puma HC1, over and above icing there were separate, quite restrictive limits for falling snow.
212man
8th Dec 2021, 10:33
Problem with many of these anti-ice filters is that falling snow can collect on or around them. When comes loose it can then get ingested as a "mouthful" and the sudden amount of water puts the flame out. We had the same thing on the Puma HC1, over and above icing there were separate, quite restrictive limits for falling snow.
332 the same: https://assets.publishing.service.gov.uk/media/5422f67d40f0b61346000651/Aerospatiale_AS332L_Super_Puma__G-BTCT_06-94.pdf
Side note is the co-pilot was also the handling pilot when G-TIGK ditched after the lightning strike and TR failure - not many offshore pilots can say they have had a double engine failure AND a TR Failure, in their careers. Thankfully........
Meh! Happened a while ago and there has been a SIN issued just recently.
Inlet Barrier Filters can be hard to substantiate for certification due to the variance of "snow".
On the H145 it is a fairly simple operation to remove the filter for winter. Remove filter and housing assembly, install blanking plate over inlet grid and install screen on firewall.
The H145 does have room for finger trouble of course if it is allowed to develop!
Problem with many of these anti-ice filters is that falling snow can collect on or around them. When comes loose it can then get ingested as a "mouthful" and the sudden amount of water puts the flame out. We had the same thing on the Puma HC1, over and above icing there were separate, quite restrictive limits for falling snow.
Chalk and cheese between 330/332 and H145.
BTW an "anti-ice filter" is part of the fuel system.
And an "Inlet Barrier Filter" has nothing to do with protection from ice - an Arriel engine on it's own has no anti-ice requirement.
not many offshore pilots can say they have had a double engine failure AND a TR FailureExcept for the chap who can up the ante with a total electrical failure to boot, S-76A in the Gulf of Mexico, introduced the BBQ plates.
ShyTorque
8th Dec 2021, 11:19
RVDT
Location: After all, what’s more important than proving to someone on the internet that they’re wrong? - Manson
So it seems. :rolleyes:
Never heard of an 'anti-ice filter' as part of a fuel system - heat exchangers to cool oil with fuel or heat fuel with oil yes - just how would this 'anti-ice filter' work as part of the fuel system?
If you remove the IBF from the 145, are you allowed to fly in falling and recirculating snow?
Protecting helicopter engines from snow is difficult - you can have heated intakes or put complex filtering arrangements or both but if the snow is wet and sticky, it is nigh on impossible to stop accumulations blocking the intakes.
If you allow snow to build up around the intake, then you have the problem Shy Torque mentions, the engines suddenly ingesting a 'mouthful' of snow which can easily put out the flame.
casper64
8th Dec 2021, 12:52
If you remove the IBF from the 145, are you allowed to fly in falling and recirculating snow?
Protecting helicopter engines from snow is difficult - you can have heated intakes or put complex filtering arrangements or both but if the snow is wet and sticky, it is nigh on impossible to stop accumulations blocking the intakes.
If you allow snow to build up around the intake, then you have the problem Shy Torque mentions, the engines suddenly ingesting a 'mouthful' of snow which can easily put out the flame.
Exactly. As far as I understood once IBF are removed, no restrictions. It is only an issue with IBF which can be removed.
wrench1
8th Dec 2021, 12:54
Never heard of an 'anti-ice filter' as part of a fuel system
Some OEMs offer options to install external fuel filters which allow operations at low temps without Prist, etc. These filters are designed to collect ice. For example, Airbus offers one for the AS350 series.
https://www.airbushelicopters.ca/optional-equipment/airframe-fuel-filter-3/
212man
8th Dec 2021, 13:00
Except for the chap who can up the ante with a total electrical failure to boot, S-76A in the Gulf of Mexico, introduced the BBQ plates.
True! Uncontained turbine burst I recall - took out second engine, TRDS and both GCUs?
Wrench 1 - I see your point but that is not an 'anti-ice filter', it is an airframe fuel filter which removes all sorts of particles including ice -pedantry I know but most airframe fuel filters do the same thing.
Never heard of an 'anti-ice filter' as part of a fuel system - heat exchangers to cool oil with fuel or heat fuel with oil yes - just how would this 'anti-ice filter' work as part of the fuel system?
.
Ever seen ice float on oil?
Protecting helicopter engines from snow is difficult - you can have heated intakes or put complex filtering arrangements or both but if the snow is wet and sticky, it is nigh on impossible to stop accumulations blocking the intakes.
.
if intake is reverse of flight direction ice should not be an issue. But the problem now seems to be the ice sealed the IBF and chocked the engines. Not that the engines ingested ice or water for that matter. Those puma example earlier has nothing to do with this.
But the problem now seems to be the ice sealed the IBF and chocked the engines.
Isnt't there a bypass to prevent such situation like in the H135?
skadi
ShyTorque
8th Dec 2021, 15:21
But the problem now seems to be the ice sealed the IBF and chocked the engines. Not that the engines ingested ice or water for that matter.
Must've been chock ice....
FloaterNorthWest
8th Dec 2021, 15:30
Isnt't there a bypass to prevent such situation like in the H135?
skadi
Yes there are. They are either operated automatically by the Helionix or manually by the pilot.
FNW.
wrench1
8th Dec 2021, 16:39
Wrench 1 - I see your point but that is not an 'anti-ice filter', it is an airframe fuel filter which removes all sorts of particles including ice -pedantry I know but most airframe fuel filters do the same thing.
True. But those filters are marketed, requested, and installed more for their "anti-ice" capabilities vs other contaminates. Semantics for sure, but when contracts list those filters under cold weather equipment requirements you can appreciate how they get grouped under that heading in all discussions.
FMS 9.2-5 Rev 6 (current) Inlet Barrier Filter System
GENERAL
The Inlet Barrier Filter (IBF) system is installed to remove foreign objects such as sand, dust or other particles from the engine inlet air stream in order to prevent premature erosion of compressor blades and other engine components.
The IBF system consists of two completely separated filter frames, which are installed so that each engine intake in front of the firewall is completely covered. The filter frame creates two passageways for the air to enter the engine: Through the filter element and via a bypass door.
The filter element allows air to pass through the filter while effectively retaining most foreign matter. The filter element is made of cotton gauze soaked with oil and can be easily replaced and cleaned through a maintenance action. Water entering through the filter can escape through two drain ports at the bottom of each frame.
The bypass doors are installed to prevent excessive performance detriments and engine flame out when the filter element is clogged. The bypass doors are controlled by an electric actuator, which is connected to the essential bus.
Filter element clogging is measured through a static pressure port located in the filter frame. The pressure difference between the filter frame and aircraft static ports is an indication of the degree of filter contamination (clogging). The pressure measurement is presented as a clogging level in percent on the VMS page. This percentage level is calculated from the pressure loss taking into account altitude, airspeed and power setting.
Despite these corrections, slight clogging indication variations can still occur.
IBF SYSTEM OPERATION
The switches for operation of the IBF system are located in the overhead panel.
The IBF system is operated through two separate IBF switches with three switch positions:
NORM, OPEN and CLOSE.
The IBF RECALL switch allows the maximum clogging level that was encountered since the last reset to be displayed by momentarily placing the switch in the RECALL position. Each time a new or cleaned filter is installed, the RECALL value shall be reset to zero (by holding the switch in the RECALL position for more than 15 seconds).
NORM
The IBF system is active, the bypass door is closed. The engine is protected from foreign matter.
When an OEI condition is detected in flight (power split condition), both bypass doors will open automatically.
When dangerously excessive clogging is detected (equivalent to about 140% clogging), the bypass doors will open automatically to protect the engines from being damaged or surging.
OPEN
IBF system is inactive, the bypass door is open. The engine is not protected from foreign matter.
CLOSE
The bypass doors are closed and will not open automatically in case of OEI condition or dangerously excessive clogging.
This mode can be used to override an automatic opening of the bypass doors in case of OEI, to protect the remaining engine.
SAFETY INFORMATION NOTICE No. 3515-S-71 Rev 1
Airbus Helicopters was informed of a HEMS mission in the year 2020 in conditions close to a temperature of 0 °C, during which a sudden engine flame-out occurred on a helicopter equipped with an Inlet Barrier Filter (IBF). The event occurred during flight with the IBF bypass closed. A successful engine restart was performed in flight and the helicopter could safely continue to its destination.
Although fuel or engine related malfunctions could be eliminated as a root cause, the exact reason for the flame out could never be determined. Following this event, Revision 0 of this Safety Information Notice (SIN) was published to raise awareness with flight crews about a potential partial IBF icing when operating at OAT < 3 °C and in visible moisture.
A further incident occurred recently, where a helicopter equipped with IBF was hovered prolonged in falling snow, followed by a long period on ground in snow with the collective lever raised to prevent sinking in. Shortly after take-off, engine #1 flamed out. After the crew managed to land the helicopter safely in OEI conditions, engine #2 flamed out after the engine was switched to IDLE. Both IBF bypass doors were opened well before the flame out.
Investigations to determine the root cause of this recent incident are ongoing. However, partial icing of the IBF engine intake cannot be excluded as a reason for the flame out.
Purpose of Revision 1 of this SIN is to inform flight crews that the following has been decided as a protective measure for helicopters with IBF installed:
Flights in falling or blowing snow shall be prohibited
Flights at or below 5 °C OAT when visible moisture is present shall be avoided. Visible moisture can be precipitation (snow, sleet, ice crystals) or fog/cloud reducing the visibility below 800 m.
Partial icing of the IBF engine intake can occur even when no signs or only light traces of snow or ice are visible on the helicopter (windshield wiper, pitot tube attachment).
A temporary revision of the IBF Flight Manual Supplement (FMS 9.2-5) will be issued in due time to re-define the environmental limitations within which operation with IBF shall be conducted. In the meantime, Airbus Helicopters is further investigating the situation and expects to provide an update of this SIN within the coming weeks.
The standard air intake provides better protection in the case of inadvertent entry in potential icing conditions. Customers wishing to uninstall the IBF during winter time may do so in accordance with the AMM.
AMM 71-64-00,7-1 Removal - IBF System - INLET BARRIER FILTER SYSTEM
Remove the IBF system LH and IBF system RH as follows:
NOTE
The procedures to remove the IBF system LH and the IBF system RH are the same. The procedure that follows gives the removal procedure of the IBF system LH.
Remove the IBF filter assembly AMM 71-64-00,4-2.
Remove the IBF tray assembly AMM 71-64-00,4-3.
If you plan to operate the helicopter without IBF detachable parts installed, do as follows:
CAUTION
THE IBF DIFFERENTIAL PRESSURE SENSORS CAN BE DAMAGED IF STATIC PRESSURE IS ONLY APPLIED TO THEIR LOW PRESSURE PORTS. DO NOT OPERATE THE HELICOPTER WITHOUT INSTALLED ELBOW UNIT ASSEMBLY.
Install the elbow unit assembly AMM 71-64-00,4-13.
Install the cover and the frame (3) on the main gearbox cowling (2) AMM 71-64-00,4-8.
Install the compressor inlet screens AMM 71-31-00,4-2.
Wrench 1 - I see your point but that is not an 'anti-ice filter', it is an airframe fuel filter which removes all sorts of particles including ice -pedantry I know but most airframe fuel filters do the same thing.
No airframe filter on 135 or 145 or 350 (standard) or H500 (standard) for that matter and possibly not originally on B206.
They were initially fitted to older aircraft without fuel/oil heaters on the engine. Theory being if there was ice in the fuel you would get impending bypass indication as a pre-warning.
Plus it allowed operation at lower temps without FSII. FSII is nasty stuff.
biscuit74
8th Dec 2021, 19:02
"Side note is the co-pilot was also the handling pilot when G-TIGK ditched after the lightning strike and TR failure - not many offshore pilots can say they have had a double engine failure AND a TR Failure, in their careers. Thankfully......."
- And that same pilot had to bale out of an aerobatic sailplane due to mis-rigging. Some people have very adventurous lives !
gipsymagpie
8th Dec 2021, 21:15
for helicopters with IBF installed:
Flights in falling or blowing snow shall be prohibited
Flights at or below 5 °C OAT when visible moisture is present shall be avoided. Visible moisture can be precipitation (snow, sleet, ice crystals) or fog/cloud reducing the visibility below 800 m.
Now there's some wonderfully ambiguous English. Does the 800m refer only to fog/cloud or also to precipitation? And noting rain is not in the list of precipitation.
IBF out please!
Never heard of an 'anti-ice filter' as part of a fuel system - heat exchangers to cool oil with fuel or heat fuel with oil yes - just how would this 'anti-ice filter' work as part of the fuel system?
Its not that unusual, as leas not in chilly climates. Maybe the formal name might be different (like airframe fuel filter or something like that), but the ”go by name” is ice filter as the main purpose is to trap ice. We have them on the Swedish NH90 (not standard in all NH90 but a option) and we did have them on our AS332M1.
Probably a bit off topic in this case though, as it seems like its the Inlet Barrier Filter that is the issue here
AHD may have a little logistic issue with this.
Not all aircraft with IBF's are fitted with the "fixed parts" to allow removal of the filters and fit the blanking plates.
It is listed in the SB to retrofit the IBF's with the covers as an "optional part" and listed in the IPC but there was no facility to install it. i.e. Service Bulletin.
They have just released an SB as of today the 9th of December but no listing of the kit price. Why it isn't part of the original IBF kit is beyond me. It is offered as a "product improvement" which is a euphemism for "oops" to "save face" or "Gesicht wahren" maybe depending on where you are standing at the time.
As a spare part the list price is EUR 6775.14 per side with a lead time of 7 months! Some serious margin there in the "cost recovery" and so much for this winter then?
Looks like a flat piece of Alclad and an Alclad frame, 26 odd screws and corresponding bunch of nutplates. My guess is the total material cost might be EUR 200.00 max and I think I could make them myself in about 4 hours!
The SB says it takes about 10 hours to complete the installation.
At the time we purchased an H145 it was not offered or listed and operationally if you have an issue with a filter you would be grounded without having the option to remove the filter and continue operating.
No doubt the filters are well worth it for the added protection to the operation of the engines but I feel that someone has not really thought this through on the operational side at AHD.
Personally I think the kit should be included as part of the original IBF install SB as it would make sense to incorporate it at the time of installation and the retrofit offered as a "commercial incentive" i.e. FOC.
Just spitballing as we do here but I think a few folks may have a case.
Hughes500
9th Dec 2021, 12:37
Crab
Pretty common to see anti ice filters on 500's fuel systems. Installed between fuel tank and engine driven fuel pump
ShyTorque
9th Dec 2021, 15:11
No airframe filter on 135 or 145 or 350 (standard) or H500 (standard) for that matter and possibly not originally on B206.
They were initially fitted to older aircraft without fuel/oil heaters on the engine. Theory being if there was ice in the fuel you would get impending bypass indication as a pre-warning.
Plus it allowed operation at lower temps without FSII. FSII is nasty stuff.
Agusta seem to have this better thought out. The fuel filters are heated by the engine oil, so that fuel with FSII isn’t required.
Agusta seem to have this better thought out. The fuel filters are heated by the engine oil, so that fuel with FSII isn’t required.
Interesting. Only familiar with the PWC powered 109 and a bit on the139. The 109 definitely doesn't have a heated filter and pretty sure the PT6 powered 139 doesn't either as the FMM is basically the same.
They both do have fuel/oil heat exchangers on the accessory gearbox but the engine fuel filter is part of the FMM.
retoocs
9th Dec 2021, 19:09
Did Airbus not do the falling and blowing snow certification for the IBF?
ShyTorque
9th Dec 2021, 19:23
RVDT,
I think you are correct; I was thinking of the Sikorsky S76. Too many types in my logbook and old age creeping in.
However, the later Agusta 109s with the PW207C engines have an anti-ice airframe filter and don’t need FSII.
Did Airbus not do the falling and blowing snow certification for the IBF?
"snow" is a fairly broad generalisation. There are vastly different types.
I spent some time talking to I think it was the guys from Dart at AHI in Grand Prairie TX who had just completed FAA certification on the filter for the AS350B3.
They had been up in Canada and it is actually pretty involved and difficult.
Maybe AHD used the "wrong type of snow (https://en.wikipedia.org/wiki/The_wrong_type_of_snow)"
retoocs
9th Dec 2021, 22:31
"snow" is a fairly broad generalisation. There are vastly different types.
I spent some time talking to I think it was the guys from Dart at AHI in Grand Prairie TX who had just completed FAA certification on the filter for the AS350B3.
They had been up in Canada and it is actually pretty involved and difficult.
Maybe AHD used the "wrong type of snow (https://en.wikipedia.org/wiki/The_wrong_type_of_snow)"
The FAA requires the warm wet snow -4 to 1°C, 1/4 mile visibility, 20 minutes on the ground, 5 minutes IGE, 1 hour flying max safe speed (as fast as you dare in essentially zero visibility). There's also the cold dry snow test, which I think Transport Canada is pushing. Either test requires a good meteorologist and lots of sitting around waiting for the right conditions.
Sikorsky with the S-76 C++ ended up doing both the warm wet snow and the cold dry snow in its certification of the IBF.
gipsymagpie
10th Dec 2021, 06:28
The BK117 (including C2 and D2 with IBF) were certified to FAR29 so those exact conditions in accordance with AC-29 29.1093 would have been used.
Which the crew in question exceeded in the incident from my understanding. I think they were on the ground running for significantly longer than 20 mins.
papiro58km
14th Dec 2021, 17:03
How different/similar is the BK117 engine installation to the H145, same or different engines?
BK117 A1,A3, A4, B1, B2 - Honeywell (Lycoming) LTS 101 in various flavours 650B1, 750B1.
BK117 C1 - Arriel 1E2
BK117 C2, C2e (EC145) - Arriel 1E2
BK117 D2 (H145) Arriel 2E
BK117 D3 (H145 5 blade) Arriel 2E
Arriel Versions all pretty much the same in the inlet depending with or without IBF.
It is listed in the SB to retrofit the IBF's with the covers as an "optional part" and listed in the IPC but there was no facility to install it. i.e. Service Bulletin.
They have just released an SB as of today the 9th of December but no listing of the kit price. Why it isn't part of the original IBF kit is beyond me. It is offered as a "product improvement" which is a euphemism for "oops" to "save face" or "Gesicht wahren" maybe depending on where you are standing at the time.
Not true. It was supplied as optional to the original kit since the beginning. SB is for those that never opt for that option to implement it standalone as some CAMO insist you cannot do partial SB even you already have most of it :rolleyes: