SE-LLZ had a suiteable indicator (HSI) and the GTN could be installed within the required viewing range. There was a new altitude encoder installed, which is required in most installations.
Basically it depends on the aircraft, mounting location, aircraft on STC, type of indicator, type of altitude indicator, autopilot etc. The pricing gives an idea, but could be either higher and lower depending on the aircraft / equipment.
Jesse installed a GTN650 in the aircraft SE-LLZ for a little bit less than 15k EUR including VAT two years ago.
That included everything such as:
GTN650
Antenna
“Paperwork”
Installation work
No additional annunciator was needed. The GTN650 replaced a King KLN94 and KX155A.
So, what is the actual cost of installing a GTN650 on an EASA aircraft?
In this particular case for automating something once airborne, but I don’t recall exactly what. The owner is a tinkerer and has all kinds of gadgets in his Skyranger. I believe more advanced planes, e.g. a Bristel with retractable gear, use it to disable the gear up switch.
Poor man’s radar altimeter? For what purpose?
FWIW, the UL crowd use the ultrasound sensors used in automobiles to detect ground proximity… Not really relevant, but a nifty solution, I thought.
There are actually numerous contacts which could be used to get the gear up/down status. One doesn’t have to achieve perfection by using the squat switches. Actually I have no idea what that pressure switch is for – it’s probably optional. For example, on the Lancair kits there is an option to not have squat switches and use a pressure switch instead.
The standard TB20 has squats on the two mains gears.
AFAIK it won’t, because then it will also depend on the “pressure operated microswitch”.
Furthermore, how do you know whether the sensitive relay coil will work (without figure 3-10)? How do you know it will be reliable?
It might be ok for you when you’re in an experimental mood, but most customers would probably prefer a simpler, proven solution.
Plus, the pressure switch works in this scenario
I reckon a sensitive relay coil would do it, across one of those switches.
Peter wrote:
when faced with a landing gear wiring diagram like this
Given only this page, using the “ground retraction inhibition switches” would have meant a rather big rewiring of the landing gear logic, plus installing an additional relay, so it’s doubtful it would have been simpler/cheaper than the pressure differential switch.