We operate a Cessna 172S with 155a radios.
As I understand the above we can purchase an exchange 165a and this will be a slide in replacement.
We don’t have a HSI so maybee we can exchange Com 1 and use this as the primary radio
Is this an Easa minor mod? is there any way to do this paper work on our own?
Yes you require an minor change approval for this and a logbook entry, and offcourse correct form with the KX-165A.
You can apply for this yourself. Search on EASA Form 32.
Be sure to first find out for yourself if you have the knowledge, or willing to spend time to gain this knowledge to answer the questions EASA might ask you.
The 165A comes in 760 @ 8.33 flavours so make sure that you get the correct version.
And 8.33 kHz in 28 Volt only!
We have a VOR test frequency on the field so testing requires only that you push the plane out of the hangar. I did mine yesterday, and found it 5 degrees out. I’d like to get it spot on, even though the plane is operated VFR
This current condition classifies as out of tolerance (maximum 4 degrees out), which is offcourse no problem for VFR. To test correctly it would require to test at 30 degrees interval, as the error might differ on different radials. Therefore it should be adjusted suchs that it averages around 0 and doesn’t exceed 4 degrees on any radial. A good tester would also test receiver sensitivity.
This current condition classifies as out of tolerance (maximum 4 degrees out), which is offcourse no problem for VFR. To test correctly it would require to test at 30 degrees interval, as the error might differ on different radials. Therefore it should be adjusted suchs that it averages around 0 and doesn’t exceed 4 degrees on any radial. A good tester would also test receiver sensitivity.
I don’t believe FAA requires such a 12 point test to “correctly” meet FAR 91.171 (the context of the discussion) but I am no expert. For my VFR purposes, getting it aligned with the airport VOR test frequency will be fine. In ten years I’ve never actually used a VOR receiver for anything other than as a curiosity item, and as a panel filler. Its fun to play with, but I wouldn’t use it for VFR navigation.
I think Silvaire is referring to a US-style VOR check facility, which is a transmitter at an airfield which transmits a signal with a constant radial, and you tune your NAV receiver to that, and the bearing card (or HSI course pointer) and the to/from flags should indicate correctly.
Yes my £20 man is good value. I think he bills the fixed costs to his big customers 
But in the grand scheme of flying, it is very easy to check one’s equipment many times per year. All you need to do is to set a VOR as a DCT, fly towards it with the autopilot for a bit, and check the radial. In the UK, VORs are regularly “turned” to deliver the current magnetic bearing (not necessarily so in the USA, I believe). Also ILS (LOC/GS) get tested many times. The annual radio check is done only once, whereas anybody flying IFR for real is flying approaches so often in VMC that the equipment is checked on more or less every flight.
A very good point about the KX165A being 24V only. Some people install a 12V to 24V inverter just for that…
What country requires a 406MHz ELT radiation test, for private GA?
Testing the RX sensitivity is a good one. Watch the video here. I don’t think you will easily find this fault unless you inject the signal into the 50 ohm coax. You probably won’t find this problem just by standing next to the plane, which is how the sensitivity is normally checked. These breaks in one of two antennae (LOC or GS) are common enough, but you need to know exactly what signal level the instrument should flag at, and it’s not easy to check that unless you go out to an open field site, with the correct gain antenna on the tester.But such a fault is easily found in-flight.
It is very easy to check one’s equipment many times per year. All you need to do is to set a VOR as a DCT, fly towards it with the autopilot for a bit, and check the radial. In the UK, VORs are regularly “turned” to deliver the current magnetic bearing
Ummmm… I’ve never flown an aircraft with an autopilot and there’s a fair chance I never will
How do you check the radial, or in other words what do you use as the ultimate source of calibration when you’re heading directly to the VOR on AP and checking the radial? Mag compass? GPS? I’m over a lake? 
(I think I’m making my lack of expertise quite clear now)
I think Silvaire is referring to a US-style VOR check facility, which is a transmitter at an airfield which transmits a signal with a constant radial, and you tune your NAV receiver to that, and the bearing card (or HSI course pointer) and the to/from flags should indicate correctly.
Yes, correct. The one I use should read 0 degrees to, 180 degrees from.
How do you check the radial, or in other words what do you use as the ultimate source of calibration when you’re heading directly to the VOR on AP and checking the radial? Mag compass? GPS? I’m over a lake? (I think I’m making my lack of expertise quite clear now)
See this document: https://www.faa.gov/air_traffic/publications/atpubs/aim/aim0101.html
I don’t believe FAA requires such a 12 point test to “correctly” meet FAR 91.171 (the context of the discussion) but I am no expert.
I should have written decent I suppose. The document above also describes the influence of receiver sensitivity.
But in the grand scheme of flying, it is very easy to check one’s equipment many times per year. All you need to do is to set a VOR as a DCT, fly towards it with the autopilot for a bit, and check the radial. In the UK, VORs are regularly “turned” to deliver the current magnetic bearing (not necessarily so in the USA, I believe). Also ILS (LOC/GS) get tested many times. The annual radio check is done only once, whereas anybody flying IFR for real is flying approaches so often in VMC that the equipment is checked on more or less every flight.
True, however it does not test all, such as flag warning and receivers sensitivity. It just gives a rough indication, a single error flag would be unable to be check this way. The test equipment will be set a different RF levels, showing exactly what you filmed. The test sets use a calibration factor for wireless measurements.
What country requires a 406MHz ELT radiation test, for private GA?
At least Netherlands, Germany, France, and UK require full avionics and pitot static testing each year, or other year. These typically include COM, NAV, Transponder (including mode S), DME, ADF, MB, ELT (including 406 MHz decode), ALT, encoder, ASI and VSI to be tested with calibrated test equipement.
As well as ELT manufacturers such as Kannad and Ameri-King require testing. For N flyers, do not forget to renew your NOAA ELT registration every 2 years! This is a mandatory for you 406 MHz ELT’s. See: https://beaconregistration.noaa.gov/rgdb/forms/elt.pdf
That’s an interesting FAA doc, Jesse. It is only advisory, but more to the point is appears hugely outdated. I have never heard of anybody in the USA flying over designated terrain points to check their VOR receiver. Also such points don’t exist outside the USA.
A GPS will display the GPS track, which is a magnetic track, and if you set a VOR station as a DCT waypoint and fly towards it, accurately, that should match the VOR reading. IME in Europe it always does, within a degree or so. That is AFAIK how American pilots do it too, every 30 days.
That’s an interesting FAA doc, Jesse. It is only advisory, but more to the point is appears hugely outdated.
The use of an ‘I see a lake’ calibration source did make me smile. Obviously the most practical calibration standard for in flight check of VOR receivers would be GPS, as Peter describes.
Checking the VOR against a GPS bearing is no approved method of conducting the FAA VOR.
I do it myself, but only to convince myself that the equipment is good.
As there are practically no VOTs and no designated checkpoints in Europe, the only way to comply “officially” is to check the two VOR receivers against each other. That’s what I put in the record.
