tomjnx wrote:
I guess if your LNA (half) died (i.e. if the sensitivity got 10dB worse but otherwise the radio still worked)
Actually electrical failure of the avionics itself is quite rare. In most cases it are connectors or wiring issues.
When equipment itself fails, that failure is often a common failure. For example, when you have a side lobe suppresion failure at a transponder, most avionics shops would be able to tell you which brand of transponder you most likely have installed, as this is a common issue on one brand only.
Peter wrote:
What does this “radio check” do which is not obvious when flying the plane normally, using IFR avionics?When I was G-reg, 2002-2005, I never had any such check done.
Under G-reg this is or was part of the LAMPS and the previouse version of LAMPS. On some countries there is a difference between testing requirements for VFR and IFR.
tomjnx wrote:
I guess if your LNA (half) died (i.e. if the sensitivity got 10dB worse but otherwise the radio still worked), there’s some chance the radio check might find it, but it’s relatively unlikely you’d notice it flying the plane normally. But I agree there’s not that much point in this radio check, for an owner flown plane.
Most issues found are found before the customer noticed issues. This is a good thing, because you can find issues before the unit fails completly.
On avionics common issues are:
Low sensitivity / low power output, often due to poor coax cables, or coax cables hooked up incorrect.
Frequencies which are out of tolerance (especially on transponder).
One of the datalines of a parallel altitude encoder short or open.
VOR OBS out out of tolerance
ILS CDI indication insufficient
Failed flag circuits
Incorrect programming of transponder / ELT
On the pitot static side most common issues are:
Leakage in the lines. (Plastic “Cessna style” hardware is often overtorqued to a level where it starts leaking, very old hoses which leak, and interior screws into pitot static lines are quite common).
Altimeter out of tolerance (quite common as well)
Altitude encoder out of tolerance
On the above issues the altitude encoder datalines is sometimes reported without testing, as ATC is complaining. Very few pilots notice an out of tolerance VOR or altimeter, even while these can often quite easily detected. Other issues are hard to detect without test equipment. Often performance slowly degrees which makes it much harder to detect.
Altimeters have to work precisely, especially for IFR, transponders have to send out the right codes, frequencies and output of coms have to be within specs… I think that some of these tests make sense. What does not make sense is that i pay + 1200 € for two hours of work (nothing was bad and i had updated all databases myself before)
Peter wrote:
What does this “radio check” do which is not obvious when flying the plane normally, using IFR avionics?
I guess if your LNA (half) died (i.e. if the sensitivity got 10dB worse but otherwise the radio still worked), there’s some chance the radio check might find it, but it’s relatively unlikely you’d notice it flying the plane normally. But I agree there’s not that much point in this radio check, for an owner flown plane.
What does this “radio check” do which is not obvious when flying the plane normally, using IFR avionics?
When I was G-reg, 2002-2005, I never had any such check done.
Jesse wrote:
This is on the low end, for that kind of money evertyhing has to be ok, and without any leaks.
The matter is that in each case, there wasn’t any trouble or leak. So the difference in price is the net profit.
Of course, in 2013, it was among many other things, including a 100h visit, which in the end reached 4-5k€… So I guess they didn’t need/want to bill much on the LSA/ATC test.
In 2017, I will try again with the big workshop :-) Or fly to the Netherlands !! ;-)
Thanks, We also perform them (French test) every now and then, not that often. Al these testing are quite similair in all countries. In the Netherlands the interval is two years, and includes all avionics, similair the the yearly IFR check in Germany.
Again, I think 475 without VAT is quite high, IF everything was working fine and there where no leaks.
It is not fair to compare prices which include leaking finding, with those which are fine.
It is fair to compare pricing of Dutch regulations, with those for German IFR, and for French IFR, as these test are very similair, require the same equipment, and roughly the same amount of time.
Just to be a little bit more specific, in France, there is two series of test.
1) Avionic ramp test (required every two years in order to fly IFR). This is the test of the avionic stack.
2) Tests of ATC chain (required every two years regardless of flight rules). This is the static test.
You can find here the exact content of the tests. Avionic ramp test is descibed from page 23 to page 31. Tests of ATC chain is descibed on page 35.
I paid 475 € (without VAT) for both tests in 2014.
PetitCessnaVoyageur wrote:
I was said the equipment was 30k€, so it couldn’t be a cheap test.
This is true.
PetitCessnaVoyageur wrote:
during a visit at the big workshop: they billed 1,5h @ 75€ excl. VAT.
This is on the low end, for that kind of money evertyhing has to be ok, and without any leaks.
The difference is quite large. 700 is on the high side, and 1200 Euro is extremly expensive IF the systems where without any leaks.
This kind of testing, depending on the aircraft typically take about 1 – 2,5 hours. Where 1 hour is for a very simple aircraft with only altimeter and maybe transponder, and 2,5 hours would be for an aircraft with double altimeters, double airspeed and a full avionics stack. Doing compass swings could add upto about 2 hours.
This kind of hours are realistic hours to do a good job if all systems operate normally and there is no leakage. Troubleshooting avionics and pitot static leaks can be most time consuming. Especially large leakages which are formed by multiple small leaks can take hours to track down and repair.
This year, it was performed by a specialized avionics shop at my base. When I protested (gently), I was said the equipment was 30k€, so it couldn’t be a cheap test.
So I searched for the last test, which was performed in 2013, during a visit at the big workshop: they billed 1,5h @ 75€ excl. VAT.
The difference is huge… And once more, I feel as the “dindon de la farce”.
