CASA Suspends Barrier Aviation Operations
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Exactly. They could then be a contributing factor to an accident.
One stark reminder of the dilemma is the Alaska Airlines MD83
Alaska Airlines Flight 261 - Wikipedia, the free encyclopedia
One stark reminder of the dilemma is the Alaska Airlines MD83
Alaska Airlines Flight 261 - Wikipedia, the free encyclopedia
[O]ne of the worst argued decisions I have had the misfortune to read.
The worst part is that, but for CASA's abject and scandalous failure to fix 206, the regulatory action and litigation would not have been necessary.
Sunfish and others,
Tread wear and tread depth are not measured/evaluated in the same way as for a motor car tyre, visible tread or otherwise has little meaning.
How the serviceability of a aircraft tyre is determined re. wear remaining depends on the manufacturer, there are several different indicators used. even bare canvas being visible does not necessarily mean an aircraft tyre is worn beyond limits.
Sadly, many GA tyres are thrown away with life remaining, at great expense, at an annual/100h inspection, because of a stupidity in Schedule 5.
Serviceability of an aircraft tyre does not depend on the weather forecast for a flight.
Tootle pip!!
Tread wear and tread depth are not measured/evaluated in the same way as for a motor car tyre, visible tread or otherwise has little meaning.
How the serviceability of a aircraft tyre is determined re. wear remaining depends on the manufacturer, there are several different indicators used. even bare canvas being visible does not necessarily mean an aircraft tyre is worn beyond limits.
Sadly, many GA tyres are thrown away with life remaining, at great expense, at an annual/100h inspection, because of a stupidity in Schedule 5.
Serviceability of an aircraft tyre does not depend on the weather forecast for a flight.
Tootle pip!!
Last edited by LeadSled; 12th Jan 2013 at 23:05.
Sadly, many GA tyres are thrown away with life remaining, at great expense, at an annual/100h inspection, because of a stupidity in Schedule 5.
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75 cm of bare canvas can be exposed before an airliner tyre is considered unserviceable.
They wear them down as much as they can as it costs them money to remove tread prior to being recapped.
They wear them down as much as they can as it costs them money to remove tread prior to being recapped.
New Direction, plenty of heavy operators care how many landings they get out of a tyre! From memory the figure was about 40 or was it 70? I can't remember.
Undamaged heavy tyres are retreaded up to about Seven times according to my memory - ultrasonically tested each time of course.
I bow to Leady and Mach as my knowledge of this subject is a bit rusty these days. In my day the drivers would be concerned to have good rubber if they were heading for a few wet runway landings. Dry weather ops? Not so much.
Undamaged heavy tyres are retreaded up to about Seven times according to my memory - ultrasonically tested each time of course.
I bow to Leady and Mach as my knowledge of this subject is a bit rusty these days. In my day the drivers would be concerned to have good rubber if they were heading for a few wet runway landings. Dry weather ops? Not so much.
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It is for that reason I believe a thread decicated solely to debate of defects, correct use of the Maintenance Release, MELs, and when an aircraft can and can't be flown, would be totally appropriate.
When I get time I will transfer this debate to a dedicated thread, leaving the Barrier Aviation thread for matters relating to that issue only. __________________
Tail Wheel
Dunnunda Forum Moderator
When I get time I will transfer this debate to a dedicated thread, leaving the Barrier Aviation thread for matters relating to that issue only. __________________
Tail Wheel
Dunnunda Forum Moderator
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dust cap
most aircraft tyre/wheel "dust caps" when fitted by the manufacturer have a hexagonal head and a part number to be found in the I.P.C. A torque figure is stated in the maintanance/overhaul manual, that is why they are a pressure seal and not a dust cap. the inflation/deflation valve is just that, a valve.
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Hmmm
I would like to say that some of the guys here are close to the mark but not quite.
That is not the case though. I have been flying and certifying aircraft from GA, airline and military disciplines in many countries, and for decades. Some of what is being stated here is nonsense. Many of us can see that.
What we are seeing here is a series of generalisations and naturally many are not really accurate.
We do have parameters, we also have standards, publications, experience and knowledge. The aircraft are maintained iaw a variety of publications and I don't know if I have ever seen anything close to black and white.
I can say that the GA fleet of 1980 was different to the fleet of 2010. Yes, the aircraft are for the most part the very same ones but the publications and procedures have been modified to accommodate them.
I personally don't have an issue with aging aircraft, indeed I am much happier sitting behind a Lycoming engine operated 100 hours beyond the manufacturers recommended TBO than one that has been newly minted or reborn.
Just like we have a wide range of pilot proficiency we have a similar standard with the way aircraft are maintained.
A worn but maintained and serviced machine may not be necessarily any more at risk than a brand new machine. It is the pilots that crash machines all said and done anyway.
Even the military don't throw brand new items at an aircraft, no aircraft I have ever worked on has ever been maintained in that manner.
I have never, ever measured tyre tread or torqued a valve cap. I cannot ever recall seeing such a requirement.
It will be what is written in the records that trips guys up. I would imagine that it is the holes where tasks have been missed rather than the manner in which they were done that would be the issue.
If a job has been certified as being done in an acceptable fashion then chances are it has. If there is a problem at this point then of course further questions should be asked.
Being picky and pedantic does not necessarily make for a safer aircraft... often it just shows up the jerks.
The regulators are aware of that also.
That is not the case though. I have been flying and certifying aircraft from GA, airline and military disciplines in many countries, and for decades. Some of what is being stated here is nonsense. Many of us can see that.
What we are seeing here is a series of generalisations and naturally many are not really accurate.
We do have parameters, we also have standards, publications, experience and knowledge. The aircraft are maintained iaw a variety of publications and I don't know if I have ever seen anything close to black and white.
I can say that the GA fleet of 1980 was different to the fleet of 2010. Yes, the aircraft are for the most part the very same ones but the publications and procedures have been modified to accommodate them.
I personally don't have an issue with aging aircraft, indeed I am much happier sitting behind a Lycoming engine operated 100 hours beyond the manufacturers recommended TBO than one that has been newly minted or reborn.
Just like we have a wide range of pilot proficiency we have a similar standard with the way aircraft are maintained.
A worn but maintained and serviced machine may not be necessarily any more at risk than a brand new machine. It is the pilots that crash machines all said and done anyway.
Even the military don't throw brand new items at an aircraft, no aircraft I have ever worked on has ever been maintained in that manner.
I have never, ever measured tyre tread or torqued a valve cap. I cannot ever recall seeing such a requirement.
It will be what is written in the records that trips guys up. I would imagine that it is the holes where tasks have been missed rather than the manner in which they were done that would be the issue.
If a job has been certified as being done in an acceptable fashion then chances are it has. If there is a problem at this point then of course further questions should be asked.
Being picky and pedantic does not necessarily make for a safer aircraft... often it just shows up the jerks.
The regulators are aware of that also.
Leaddie
You said:
Could you please tell us to what, precisely, in Schedule 5 are you referring?
You said:
Sadly, many GA tyres are thrown away with life remaining, at great expense, at an annual/100h inspection, because of a stupidity in Schedule 5.
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Sunny probably inadvertently gave a very good example of what the regulator would pick up on and then start on some very serious questions.
Something as simple as fitting a valve cap would soon expose some irregularities if any of that was mentioned on the worksheets.
I have never torqued anything to 10 inch pounds and not sure it is even possible. If a guy reckoned he had, and wrote the entry up accordingly, the regulator would be wanting to know how he did it and what equipment he used.
Mention of Aircraft Spruce as a supplier would have the alarm bells ringing very loudly. The regulator would be wanting to see the Form 1 or FAA 8130. Spruce would not normally be a supplier for RPT operations. The regulator would also want to know if the catalogue has been approved as acceptable data for the operation, (Torque figure), - that would be opening another can of worms.
So in just a few simple steps of procuring and fitting a tyre valve cap you may have left yourself open to some real serious interrogation... depending of course on how it was all written up.
This goes back to what I said the other day about it is what is written up that often causes the grief.
In this case a brand new valve cap just appearing would attract much less attention.
I agree that operating wheels with caps missing is not a good look. I have actually handed some caps to Bouraq engineers in Indonesia to fit to the front of their 737. Pretty obvious to some passengers when you are standing at the bottom of the entry stairs.
GA aircraft have a low pressure dust cap which is a little different again.
Something as simple as fitting a valve cap would soon expose some irregularities if any of that was mentioned on the worksheets.
I have never torqued anything to 10 inch pounds and not sure it is even possible. If a guy reckoned he had, and wrote the entry up accordingly, the regulator would be wanting to know how he did it and what equipment he used.
Mention of Aircraft Spruce as a supplier would have the alarm bells ringing very loudly. The regulator would be wanting to see the Form 1 or FAA 8130. Spruce would not normally be a supplier for RPT operations. The regulator would also want to know if the catalogue has been approved as acceptable data for the operation, (Torque figure), - that would be opening another can of worms.
So in just a few simple steps of procuring and fitting a tyre valve cap you may have left yourself open to some real serious interrogation... depending of course on how it was all written up.
This goes back to what I said the other day about it is what is written up that often causes the grief.
In this case a brand new valve cap just appearing would attract much less attention.
I agree that operating wheels with caps missing is not a good look. I have actually handed some caps to Bouraq engineers in Indonesia to fit to the front of their 737. Pretty obvious to some passengers when you are standing at the bottom of the entry stairs.
GA aircraft have a low pressure dust cap which is a little different again.
Last edited by baron_beeza; 14th Jan 2013 at 07:17.
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Just for you breeza.
This is a basic example....the digital ones are much nicer to use.
Park Tool Torque Wrench 1/4" | 0 - 60 Inch Pounds Reading
Park Tool Torque Wrench 1/4" | 0 - 60 Inch Pounds Reading
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Yep, they are available but our torque wrenches have to have calbration certificates and be recertified regularly. We then have to take drag resistance into consideration when using them.
These are screwdriver torque figures, very difficult to measure in reality.
The tyres are checked for inflation every night on airliners, you don't see the engineers torqueing the valve caps on... they would be laughed off the flight line. I have routinely checked inflation of 30 to 40 tyres every night, - just a small part of putting the aircraft to bed.
It is the same as the rocker cover screws on the piston engines where what they want is a calibrated 'tweek' of the wrist. The trick is that the procedure has to have a 'figure' that can be recognised. To the LAME that is translated as a feel... just as screwing on a valve cap is. Using any tool is asking for trouble as overtightening is obviously much worse.
The same applies to the spark plug HT lead nuts, they are just tweaked to a little more than finger tight. We still have pilots that seem to think it is criminal when they manage to undo one during their pre-flight. The reality is that anyone overtightening the nut should be shot...
Again while we torque the spark plugs it is extremely important the caps are not overtightened. They are never torqued using a tool, well not that I have ever seen.
There was mention of tread depth on the tyres also.... I have worked with airlines where would allow wear to go through so many plies, on the last retread you could even allow it to go beyond the retread limit.
The tyres are marked with the number of retreads, if you let the wear go too far then you would lose out on any further retreads.
Talk of measuring tread depth is a little off the mark.
If any mechanic I supervise tried telling me that he had torqued a tyre valve cap I would be very suspicious. I would most certainly be obliged to go and recheck and see just what had been done.
Perhaps some guys do have special little tools that make it impossible to overtorque them, I can't remember seeing them in my time.
When you work in the Islands or Africa you have to be wary of guys marching out with a 1/2 " drive wrench and trying to tweak them to 10 ft lbs, that happens much more often than it should also.
With the modern 'metric' educated youth you also find that they have trouble equating things in real terms. One US gallon is about 4 jugs of beer.
Twenty pounds pull on an arm of 12 inches means nothing at all to these guys. The LAME or supervisors need to be on the ball.
These are screwdriver torque figures, very difficult to measure in reality.
The tyres are checked for inflation every night on airliners, you don't see the engineers torqueing the valve caps on... they would be laughed off the flight line. I have routinely checked inflation of 30 to 40 tyres every night, - just a small part of putting the aircraft to bed.
It is the same as the rocker cover screws on the piston engines where what they want is a calibrated 'tweek' of the wrist. The trick is that the procedure has to have a 'figure' that can be recognised. To the LAME that is translated as a feel... just as screwing on a valve cap is. Using any tool is asking for trouble as overtightening is obviously much worse.
The same applies to the spark plug HT lead nuts, they are just tweaked to a little more than finger tight. We still have pilots that seem to think it is criminal when they manage to undo one during their pre-flight. The reality is that anyone overtightening the nut should be shot...
Again while we torque the spark plugs it is extremely important the caps are not overtightened. They are never torqued using a tool, well not that I have ever seen.
There was mention of tread depth on the tyres also.... I have worked with airlines where would allow wear to go through so many plies, on the last retread you could even allow it to go beyond the retread limit.
The tyres are marked with the number of retreads, if you let the wear go too far then you would lose out on any further retreads.
Talk of measuring tread depth is a little off the mark.
If any mechanic I supervise tried telling me that he had torqued a tyre valve cap I would be very suspicious. I would most certainly be obliged to go and recheck and see just what had been done.
Perhaps some guys do have special little tools that make it impossible to overtorque them, I can't remember seeing them in my time.
When you work in the Islands or Africa you have to be wary of guys marching out with a 1/2 " drive wrench and trying to tweak them to 10 ft lbs, that happens much more often than it should also.
With the modern 'metric' educated youth you also find that they have trouble equating things in real terms. One US gallon is about 4 jugs of beer.
Twenty pounds pull on an arm of 12 inches means nothing at all to these guys. The LAME or supervisors need to be on the ball.
Last edited by baron_beeza; 14th Jan 2013 at 09:36.
Beeza, Now I checked my wheels yesterday and they have plastic caps on the valves. What happens if I "upgraded" these to MS 20813-3B? I guess Aviaquip will have the same part as Aircraft Spruce, but with a release note - at Five times the price.
But hey, I'm building in Experimental category anyway, buttoning up the left wing today in preparation for the start of the fuselage. There are one or Two things I've "upgraded" here and there. I know its not a Boeing, but I don't do hose clamps and rubber for primary fuel lines.
I guess it all comes down to the observation that any fool can ask a question that a wise man cannot answer and a close inspection of any and every aircraft will always produce a non conformance.
Has anyone ever seen the mythical safety net for baggage in a hired aircraft? My best Bunnings ratchet straps obviously don't conform.
How about producing your torque wrench calibration certificate?
....and the certificate of the test equipment that calibrated it?
.....and the certificate of the test equipment that calibrated that test equiment?
...and, Aaaaargh!
But hey, I'm building in Experimental category anyway, buttoning up the left wing today in preparation for the start of the fuselage. There are one or Two things I've "upgraded" here and there. I know its not a Boeing, but I don't do hose clamps and rubber for primary fuel lines.
I guess it all comes down to the observation that any fool can ask a question that a wise man cannot answer and a close inspection of any and every aircraft will always produce a non conformance.
Has anyone ever seen the mythical safety net for baggage in a hired aircraft? My best Bunnings ratchet straps obviously don't conform.
How about producing your torque wrench calibration certificate?
....and the certificate of the test equipment that calibrated it?
.....and the certificate of the test equipment that calibrated that test equiment?
...and, Aaaaargh!
Leaddie
You said:
Could you please tell us to what, precisely, in Schedule 5 are you referring?
You said:
Sadly, many GA tyres are thrown away with life remaining, at great expense, at an annual/100h inspection, because of a stupidity in Schedule 5.
Barrier being grounded
TO CASA Being evil for doing it on day before Christmas
TO Which base is it?
TO All of the bases are grounded
TO Blaming it on a disgruntled ex-employee
TO Nope, its actually Horn Island which is the major problem
TO Media release saying its due maintenance
TO Allegations of a little black book
TO Snag Sheets being inappropriate
TO Maintenance requirements of a GA Fleet
TO Is CASA overbearing in their reading of MRs and "Open Items"
TO Is there a difference between a minor and major defect?
TO Example of tyre treads
TO Tyre Cap Valves
TO Torque tightening and catalogue requirements
TO Dust Caps
I probably missed some subplots in there somewhere...but that seems the progression so far?
TO CASA Being evil for doing it on day before Christmas
TO Which base is it?
TO All of the bases are grounded
TO Blaming it on a disgruntled ex-employee
TO Nope, its actually Horn Island which is the major problem
TO Media release saying its due maintenance
TO Allegations of a little black book
TO Snag Sheets being inappropriate
TO Maintenance requirements of a GA Fleet
TO Is CASA overbearing in their reading of MRs and "Open Items"
TO Is there a difference between a minor and major defect?
TO Example of tyre treads
TO Tyre Cap Valves
TO Torque tightening and catalogue requirements
TO Dust Caps
I probably missed some subplots in there somewhere...but that seems the progression so far?
