Timothy wrote:
… it was only just out of Annual, …
Classic “Waddington Effect” .
Also: Is there not a gear pump running light ? If you have an electro-hydraulic gear system, you NEED to know if the pump is operating when it should not, ie. pumping the hydrualic fluid over-board in the middle of a flight.
An interesting conflict of opinion above and from a maintenance providers perspective I have seen both over and under mantanance in aircraft I have inspected.
Maintenance is usually a function of owner attitude, this can usually be seen in the logbooks long before it becomes obvious in the state of the aircraft.
A few years back a four seat single arrived and it soon became apparent that it was by far the worst mantaned aircraft I had ever seen, in fact it was so bad that I was forced to file more MOR’s on this one aircraft than I had written in the previous thirty years in aircraft maintenance. ( this caught the eye of the CAA who took the unusual step of inspecting the aircraft ).
It was clear from the logbooks that the aircraft had been mantaned well by a reputable company at Blackpool for a long time until the ownership changed a number of times along with the change of mantanece providers and then the aircraft did not go back to the same mantanance shop for an annual for some time eventually ending up in the hands of an independent maintainer at a very small Airfield oop north.
The new owner had been blinded by the new Garmin radio fit and had failed to see that the rest of the aircraft was only just able to make it to its new home ( engine camshaft badly worn & bad crankcase fretting ).
To say the owner was unhappy with the bill to fix fifteen or so years of neglect would be a massive understatement and he never retuned to us. I have no doubt whatsoever that he is telling anyone who will listen that we are a bunch of sharks who ripped him off and that his new maintainence providor are much cheaper ( presented with an aircraft that has new engine, flex hoses , new seat belts , new wheels & brakes as well as a hoast of other new cables, bearings and other stuff ) I have no doubt of this but if that is the cost of turning out a safe aircraft then so be it.
I have never before come across an aircraft that so well illustrated the problems of being the guy who holds the licence and has to certify it as safe, on the one hand you have the owner threatening to take legal action aganst you for all sorts of things ( including the fact that I had made the reports to the CAA that are mandatory on grounds of client confidentiality ) and on the other hand you have an aircraft stuck in your hangar that you simply can’t let fly because it’s highly dangerous state. In the end I was glad to see the back of the aircraft and an owner who in his heart of hearts had realised that he had been sold a lemon because he had not looked past the new avionics and wanted us to fix the problems arising from his lack of caution when buying the aircraft for nothing.
A_and_C wrote:
I have never before come across an aircraft that so well illustrated the problems of being the guy who holds the licence and has to certify it as safe, on the one hand you have the owner threatening to take legal action aganst you for all sorts of things ( including the fact that I had made the reports to the CAA that are mandatory on grounds of client confidentiality ) and on the other hand you have an aircraft stuck in your hangar that you simply can’t let fly because it’s highly dangerous state. In the end I was glad to see the back of the aircraft and an owner who in his heart of hearts had realised that he had been sold a lemon because he had not looked past the new avionics and wanted us to fix the problems arising from his lack of caution when buying the aircraft for nothing.
Been there, done that, got the T-shirt !
I am getting much better at vetting out these types. It’s very often EXACTLY as you described it, expensive avionics fit and no money for the Mx.
That all said, this has nothing to do with Timothy’s hydraulic failure as clearly, the £££ were being directed to the acft’s Mx.
Is there not a gear pump running light ? If you have an electro-hydraulic gear system, you NEED to know if the pump is operating when it should not, ie. pumping the hydrualic fluid over-board in the middle of a flight.
I think the system you are thinking of will show the pump running and will thus indicate there is a leak in the high pressure circuit when the gear is UP. Most SEP retractables drive the pump UP until the gear hits some rubber bungs and, as these bungs compress, a pressure switch trips (c. 1500psi) and that is all that holds the gear in the UP position during flight.
It would not indicate a leak from the reservoir, which sounds like what Timothy had. The only way to detect that is to check the dipstick, which may not be easy. On the TB20 you have to lift up a back seat. From here
It would be nice to have a remotely readable fluid level indication but hey that is way too complicated 
Even for the engine oil level – a far more important thing to measure – the combined brains of the GA industry have only managed to come up with the piece of crap at the end of here
Peter wrote:
It would be nice to have a remotely readable fluid level indication but hey that is way too complicated Even for the engine oil level – a far more important thing to measure – the combined brains of the GA industry have only managed to come up with the piece of crap at the end of here
You do wonder if it is a lack of will as amazingly all gases and fluids are easily seen on sight gauges on Citations. Even to PA46 has hydraulic fluid visible in a compartment sight gauge fairly clearly. It just takes someone to care to make it so.
Timothy wrote:
It turned out that a pipe, or rather a join where a pipe attached to the reservoir, had cracked and the contents of the reservoir had dumped out.
To empty the reservoir in just one flight requires a pump.
Highly unlikely that this was a low or no pressure leak.
My guess is that the pump operated at the beginning and end of a few flights and pressurised it out.
If anyone is really interested, I can ask the engineer the exact location and nature of the leak.
Timothy wrote:
My guess is that the pump operated at the beginning and end of a few flights and pressurised it out.
Hmmm, and the pre-flights did not catch the streaming hydraulic fluid ?
No. I can’t say any more than that. I do a pretty thorough check and there was nothing to be seen.
I am meeting the Chief Engineer tomorrow (he is going to teach me how to milk a mouse or something 
) and so we’ll have the cowlings off. I’ll ask him to point out exactly where the break was.
Ahhh, yes the elusive mouse milk – have fun with that !
If you can, please take a picture of the break spot.
