Us fix wing arent much better our old Tonkas would be lucky to do 10FH without some glitch 
How many staff / UAS sorties per aircraft per day at a typical location? Define that & you might get a better idea? Even an achieved output of 5 hrs per airframe per working day would seem to be very high to me? That would give at least 30 working days before the 150 hr “re-check” inspection.
I wonder what oil analysis has been done to check for more than normal wear & tear ? That said, if the engines have been operated at a higher than specified RPM setting for a considerable, any oil analysis would probably be “the same” anyway unless there had been excessive wear on bearings, etc, that would show up.
I appreciate that this may be a dumb question to most, but is the 150 hours per airframe or per type?
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Has to be per airframe - you would get a huge imbalance of airframe hrs across the fleet otherwise = impossible to safely detect abnormalities.
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No idea where the 150 hours has come from.
Tutors can still fly but no cadets or UAS Student solos to mitigate risk.
Apparenty 140FH madecit way onto cadet central via an email from a Wing Aviation Officer who was probably told to him by the local aurcraft spotter lol
Most probably,
Came from OC of the Local AEF…
I’d like to think they wouldn’t just pull random numbers out of thin Air.
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Good, which confirms the 140fh and not 150fh which is also doing the rounds, either way still not clear on how much data they need to make a decision to let cadets loose with the tutors. Some better comms has just been released so guess we just have to sit it out, which is a shame as may miss the summer spell 
TBH it is what it is…
…wouldn’t be a summer without something to pause and complain about
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So i thought i would take a look at the maintenance schedule on the Lycoming O-360 engine
looking at this operators manual (page 98 onwards) it suggests the oil and filter is changed either every 25 or 50 hours depending on the filter type.
150 hours seems even an higher achievement now given the oil and filter will be changed between 3-6 times during this “bedding in phase”
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From what I’m hearing this issue might effect us for quite a while yet, or certainly has the potential to. Certainly we’re look at months rather than days or week for a return to RAFAC AEF or UAS solos.
The amount of evidence required to tip the ‘safety scales’ is pretty high. So we’re going to need many aircraft that have been modified to hit 150h, then have very very detailed inspections. Currently the risk is remote whereas to fly cadets it needs to be improbable.
I can’t argue with what they are doing. Flying cadets needs to be to be as safe as possible. It sounds like they are 98% sure this will fix the issue. But without statistical evidence they can’t be 100%, so cadets can’t fly. And until that time, fair enough.
(And for what it’s worth, @Torphoon it is 150h post modification per aircraft!)
And this, I think, is the fix:
Known since 2015??!!
I am happy to be corrected but got my data straight from the maintainers so dont know why why the difference ? Anyhow in scheme of things 10 hrs probably wont make much difference. Also the maintainers says this is an inspection interval but I am assuming maintainers arent involved with duty holders RA. Out of interest have you seen first hand where the 140/150 hrs befores cadets get to go flying has come from as I not seen in writting at duty holder level whether its a culumanation on 1 airframe or a collective.
Silly question here but what is the risk?
I get that the hazard is the oil leak but is it so severe that there is catastrophic failure? (Ie engine failure) or simply low oil level leading to increased wear?
I would like to hope the latter else why has this only been noticed now?
And if so what is learnt in 150hrs thsn cannot be learnt in a weeks worth of flying by monitoring the oil levels?
Not seen, but heard. Essentially 150 hours post modification they are looking for a build up of ‘sludge’. They are pretty sure it’s this build up that is causing the seal to fail. The modification should stop this build up. They believe that without the modification you’d see this build up by the 150h mark. So if they have 20 airframes that have been running post-modification for at least 150h with no build up, then in theory, problem solved.
And it doesn’t mean 150h up, cadets go flying. It means once an aircraft gets to 150h and is inspected, if all is well then that’s a bit more evidence that the modification has worked. So you need many aircraft to get to 150h to get lots of evidence.
That is second-ish hand information, and this isn’t my area of expertise, so I might be paraphrasing slightly on things there.
The risk is you end in an aircraft who’s cockpit is completely covered in oil, so you can’t see. Then the engine fails because you have no oil. On the Impact vs Likelihood scale this is way up there on the Impact line…
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No worries i got my gen from one ofvthe maintainers and having been a maintainer sometimes there are different figures for different mod. States but 10hrs propably wont make mych difference Still sounds like finger in the air from those assessing the fault as there are other techniques that will establish why the seals are failing, and analysis to establish if at all the oil or the seal is the cause. My contact hasnt told me what the fix is exactly but what bassically on the same lines, just that they are just frustrated as we are as it has messed up there work schedules and they enjoy flying the cadets.
I know the issue is also being looked at by 1710 NAS, so I guess things might change quite rapidly too given the multiple inputs!
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Thanks.
I confess I’ve not paid full or detailed attention a d believed thus was a minor leak seen under the aircraft.
If indeed the risk is oil on the cockpit viewing panels i get it
There’s not been too much to pay attention to. I don’t know about the rest of you, but we’re still waiting for official confirmation through the proper lines of communication that flying is even paused.