Air North Brasilia Crash in Darwin (Merged)
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Excellent posts, PT6. We thank you.
How do you know that the prop has feathered?
Is takeoff permitted with an autofeather inoperative? Do you test the autofeather prior to every takeoff, or once only at the start of the day?
How do you know that the prop has feathered?
Is takeoff permitted with an autofeather inoperative? Do you test the autofeather prior to every takeoff, or once only at the start of the day?
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I am trying to understand something here... how would autofeather kick in if the engine has not actually failed? I am under the impression from talking to ex Air North pilots that the 'dead' engine has it's power pulled back to around 10% torque. The airplane will surely not autofeather since the engine is still running.
Can someone clarify please?
Can someone clarify please?
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FDG135. Yes Auto-feather is tested after every start. It arms at 64 Deg. power lever angle as levers are advanced. Call is Auto-feather Armed. Otherwise call is Auto-feather not armed. I can't remember the MEL but I believe dispatch is allowed without Auto-feather operative subject to a few conditions which may have included a weight reduction penalty. Not sure on this one. It may have been a no-go item. Prop is considered feathered when prop rpm drops to 10%. Same as on the Saab 340B WT. Same props. They do not stop rotating in feather just go to a min. drag angle.
Auto-feather will operate when torque drops to less than (now I am stretching my memory) something like 40% as long as there is significant torque at the other prop. I can't recall the actual figures. I have never seen this system fail during a take-off. In my experience it always armed (provided someone remembered to turn on the switch!). Pulling back the power lever would cause an auto-feather if it was turned on and armed. It can Auto-feather with the engine running.
Auto-feather will operate when torque drops to less than (now I am stretching my memory) something like 40% as long as there is significant torque at the other prop. I can't recall the actual figures. I have never seen this system fail during a take-off. In my experience it always armed (provided someone remembered to turn on the switch!). Pulling back the power lever would cause an auto-feather if it was turned on and armed. It can Auto-feather with the engine running.
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PT6..I dont fly a Bras but I reckon you might be wrong about auto feather working by reducing power on one engine...
In similar aircraft it also relies on both power levers being above "X%" Tq and above a certain PLA.. hence why zero thrust is used to simulate the feathered eng..
In similar aircraft it also relies on both power levers being above "X%" Tq and above a certain PLA.. hence why zero thrust is used to simulate the feathered eng..
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AFX & Rudder Boost
The B1900 requires both power levers to be set above 90% N1 to arm AFX. Retarding a power lever below that setting disarms the AFX hence the need to set zero thrust on the failed side when simulating ‘engine failed & prop feathering’.
A more sinister issue with the B1900 (I don’t know about the EMB120) is failure of rudder boost as this would require considerably greater rudder pressure by the pilot to control the aircraft. In other words, failure of rudder boost will increase minimum control speed. If my memory serves me correctly FAR 25 sets maximum rudder pressure of seventy pounds at VMCa.
AFX and rudder boost are both pre-flight check items, and are required for dispatch.
A more sinister issue with the B1900 (I don’t know about the EMB120) is failure of rudder boost as this would require considerably greater rudder pressure by the pilot to control the aircraft. In other words, failure of rudder boost will increase minimum control speed. If my memory serves me correctly FAR 25 sets maximum rudder pressure of seventy pounds at VMCa.
AFX and rudder boost are both pre-flight check items, and are required for dispatch.
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PT6,
I have not flown a Bras.
Whats the point of having the micro switches ?. Wouldn't it stand to reason that with the Auto FX switch on and both levers up would be required to have the system operative ?.
I do not believe the prop will feather if you pull the power lever back in normal operations with Auto Feather armed, I believe it would have to be an actual failure:
Here: SmartCockpit - Airline training guides, Aviation, Operations, Safety
Page 11, 62 degree PLA...
B200 and Metro 23, from memory both the power levers need to be up to arm the system.
I have not flown a Bras.
Pulling back the power lever would cause an auto-feather if it was turned on and armed. It can Auto-feather with the engine running.
I do not believe the prop will feather if you pull the power lever back in normal operations with Auto Feather armed, I believe it would have to be an actual failure:
Here: SmartCockpit - Airline training guides, Aviation, Operations, Safety
Page 11, 62 degree PLA...
B200 and Metro 23, from memory both the power levers need to be up to arm the system.
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I think you will find that the power levers have to be advanced above 63 degrees PLA to arm the AUTO FX, and for it to operate, there has to be a significant drop in TQ, which activates the system.
Auto FX used to be left on throughout the flight, but after a few unintentional auto FX's at cruise power due lost of TQ signal, most operators changed their SOP's to switch off after take off and on before landing.
Auto FX is one of the take off warnings, so I think from past memory it was a no go item
Auto FX used to be left on throughout the flight, but after a few unintentional auto FX's at cruise power due lost of TQ signal, most operators changed their SOP's to switch off after take off and on before landing.
Auto FX is one of the take off warnings, so I think from past memory it was a no go item
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AFX and rudder boost are both pre-flight check items, and are required for dispatch
To check the Auto feather before flight the Autofeather switch is placed in "test" not "arm" because it only normally arms at greater than 90% n1 as said above..the system only works if one engine is running at high power while the other drops below the set figure..depending on model of 1900..if both powers drop together neither prop will feather. I can't find a reason why pulling one power lever back while the other is up wouldn't cause an actual autofeather if the side you pull back is still running..you might need it to like some sort of FCU failure where the engine rolls back but doesn't shut down.
With the PW100 series the Autofeather depends on an oil pump I'm told, and if this fails the prop fails into fine..high drag/windmilling (never flown one can't confirm)..unlike the pt6 which eventually goes into coarse with loss of oil px
Grandpa Aerotart
If its anything like a Bandit (E110) AFX system to test it you held down a spring loaded switch while advancing both power levers up to a certain tq setting and then reduced one - it auto feathered - advance that power lever and it un feathered then repeat on the other engine. Armed for takeoff, and with the power levers above whatever the PLA was, if the system sensed a fall in tq/oil press, or however it worked, below a certain level with the thrust lever still fwd it auto feathered the prop on the failing engine.
So merely reducing power on one engine to simulate engine failure would NOT cause autofeather - on training flights it was a manual system - I'd be surprised if the EMB120 works much differently.
I haven't flown a Bandit since 1994 so all this is purely from memory.
So merely reducing power on one engine to simulate engine failure would NOT cause autofeather - on training flights it was a manual system - I'd be surprised if the EMB120 works much differently.
I haven't flown a Bandit since 1994 so all this is purely from memory.
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Oh yes I have had a re read and the power levers must be up past a microswitch for afx to be armed..reducing power by pulling the lever back disarms afx so won't cause prop to feather at low power settings on pt6..cheers CC
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PT6 Auto feather
Josh, Chimbu and co you are all correct. With power levers advanced and auto feather armed both AFX lights illuminate. If one power lever is intentionally retarded that prop wil NOT feather. That is why you have to simulate that it has feathered by using 10 - 12% TQ. If you had an FCU roll back with both levers advanced and AFX armed the affected prop will feather.
It frightens me that some people, posting here, don't seem to grasp this basic understanding of the aircraft sytems that they are flying. Or perhaps thay are not flying and a little bit of Knowledge is dangerous. Api noon Chimbu.
Groggy
It frightens me that some people, posting here, don't seem to grasp this basic understanding of the aircraft sytems that they are flying. Or perhaps thay are not flying and a little bit of Knowledge is dangerous. Api noon Chimbu.
Groggy
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The system in the 120 is a more refined version of the 110. Looking up some hand written notes, the system has mechanical feathering by the condition lever or electric feathering vis the electric feathering pump. This pump is activated by the electical feathering switch, the Auto Feather System, the fire handle, or the prop aux pump test button.
The electrical feathering solenoid is activated by the electrical feathering switch, the Auto Feather system, the Fire Handle orthe Flight low pitch micro switch.
The daily check of the Auto FX system is to use the prop aux test button to run the blades out of feather position and then use the electric feather switch to run the blades back to feather. This test checks the proper operation of both the electric pump and the electric solenoid valve.
Auto FX is armed when
The Auto FX will activate if the torque of one engine is < 23.6% with a 1/2 second delay.
The electrical feathering solenoid is activated by the electrical feathering switch, the Auto Feather system, the Fire Handle orthe Flight low pitch micro switch.
The daily check of the Auto FX system is to use the prop aux test button to run the blades out of feather position and then use the electric feather switch to run the blades back to feather. This test checks the proper operation of both the electric pump and the electric solenoid valve.
Auto FX is armed when
- Auto FX switch is on
- Power lever angle is greater than 62 degrees
- Torque on both engines > 62%
The Auto FX will activate if the torque of one engine is < 23.6% with a 1/2 second delay.
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Auto FX, Uptrim, V1, VR all very nice and technical but when are we going to get real. Train it in the SIM..! Thought we were supposed to have learnt that lesson in Tamworth.
Thought we were supposed to have learnt (sic) that lesson in Tamworth.
Clearly not, based on the number of asymmetric training fatalities since the Metro at Tamworth, and some bloody close goes, three at least that I am aware of, which also involved Metros.
Tootle pip!!
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Is it too dangerous?
If it is too dangerous to carry out these procedures in RPT aircraft with only the crew aboard, then let's stop pretending that these aircraft have the magic ability to perform these manouvers with a full load of passengers aboard.
Either the aircraft cannot do it safely, or the crew training should improve.
Either the aircraft cannot do it safely, or the crew training should improve.
Not so straightforward as that Bushy, I'd say.
While I agree most aircraft can perform assymetric drills and recoveries without incident, the sad fact is that in a significant number of cases (ie. enough so that most of us can name people we know who've been killed in them - or perhaps that's being a bit too general; I know I can, anyway) aircraft and lives are lost.
For every one that spears in, there'd be what, 5 more who scare themselves? Dunno, but it'd be up there somewhere. If modern sim training can do the job realistically enough, then there's a good argument for using it, particularly when you can offset the cost of doing it in the sim against hours not flown in the actual aircraft.
Also, you can take things further in a sim than in the real case, so arguably the training's better. I'm fairly old school in regard to my own training in various types, ie most emergency training done in the real thing, but I don't see the point in doing potentially dangerous stuff airborne when you could do it (hopefully cost-effectively) in a simulator.
So it's a furph to ask 'Is it too dangerous?'. The question is, is it dangerous enough that we should mandate use of alternative means of training where they are reasonably available?
While I agree most aircraft can perform assymetric drills and recoveries without incident, the sad fact is that in a significant number of cases (ie. enough so that most of us can name people we know who've been killed in them - or perhaps that's being a bit too general; I know I can, anyway) aircraft and lives are lost.
For every one that spears in, there'd be what, 5 more who scare themselves? Dunno, but it'd be up there somewhere. If modern sim training can do the job realistically enough, then there's a good argument for using it, particularly when you can offset the cost of doing it in the sim against hours not flown in the actual aircraft.
Also, you can take things further in a sim than in the real case, so arguably the training's better. I'm fairly old school in regard to my own training in various types, ie most emergency training done in the real thing, but I don't see the point in doing potentially dangerous stuff airborne when you could do it (hopefully cost-effectively) in a simulator.
So it's a furph to ask 'Is it too dangerous?'. The question is, is it dangerous enough that we should mandate use of alternative means of training where they are reasonably available?
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The use of Simulators should be mandatory.
I did 19 years on the F-28, NO simulator, although they were available, all 10 hours of endorsement requirement for both F/O and Command, all renewals with only a DME homing being done in the Frasca. Other bases of Ansett did make use of the one in Indonesia.
Went to TAT in France, into the Sim, like a breath of fresh air, learnt a lot in just the short time we were there. Similar in Belgium with DAT.
With the Lear also the majority was also in the Simulator, who wants do do NIGHT stalls and high rate descents over the water, in the storms, half way
to Kuching at 0200. Scared me spitless, the cadets even worse.
Larger A-310, all work done in the Sim, likewise the F-100 for various operators.
For my sins I have 3000 hours as a Simulator Instructor, it is the greatest aid to training, regrettably it can be the destroyer of any or all if misused by the Airline or the Instructor at the panel.
There is no sense to me in shutting down or failing any system on a perfectly servicable aircraft. There are too many tragic results in the system from GA, Airlines and our own RAAF from the accidental/deliberate failure of syatems and regrettably the ego or some of the check/trainers can be a factor, more easily survived in the Sim.
I dont know the cost of a Brasilia Sim, it has got to be cheaper than this tragic loss.
Be safe out there, I drive a Bus full of kids, that can be tough, no Sim there, all done live!!!!
I did 19 years on the F-28, NO simulator, although they were available, all 10 hours of endorsement requirement for both F/O and Command, all renewals with only a DME homing being done in the Frasca. Other bases of Ansett did make use of the one in Indonesia.
Went to TAT in France, into the Sim, like a breath of fresh air, learnt a lot in just the short time we were there. Similar in Belgium with DAT.
With the Lear also the majority was also in the Simulator, who wants do do NIGHT stalls and high rate descents over the water, in the storms, half way
to Kuching at 0200. Scared me spitless, the cadets even worse.
Larger A-310, all work done in the Sim, likewise the F-100 for various operators.
For my sins I have 3000 hours as a Simulator Instructor, it is the greatest aid to training, regrettably it can be the destroyer of any or all if misused by the Airline or the Instructor at the panel.
There is no sense to me in shutting down or failing any system on a perfectly servicable aircraft. There are too many tragic results in the system from GA, Airlines and our own RAAF from the accidental/deliberate failure of syatems and regrettably the ego or some of the check/trainers can be a factor, more easily survived in the Sim.
I dont know the cost of a Brasilia Sim, it has got to be cheaper than this tragic loss.
Be safe out there, I drive a Bus full of kids, that can be tough, no Sim there, all done live!!!!
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Yes thats true. Harry was not well before but seemed to have dropped the will to push on.
One of the other sons (Shane's Brother) is a LAME and ex Air North, and still in the industry back down here.
Funeral this Friday.
J
One of the other sons (Shane's Brother) is a LAME and ex Air North, and still in the industry back down here.
Funeral this Friday.
J