Peter,
I am not sure about Europe, but in the US, a purchase of a single bundle of Garmin database products is permitted to be used on all GTN750/650/G500/G600 in the same aircraft.
Here you get a bit of a discount -
If I read it correctly, you pay €485 instead of €718, for the two databases.
Opinions will vary but I would say €718 is a lot of money unless you actually want two GPSs. As a comparison, the KLN94 is $410 i.e. €302, which is similar to the single unit (GNS or GTN are probably the same) of €359.
Unfortunately Garmin block the crossfill unless you buy the current database for both boxes.
I may be missing something but I don't see a physical keypad
! should have said (and meant to say) pop-up qwerty AND pop-up num pad
OK - I see. But for IFR flight plan entry, one doesn't usually need numbers.
The only time I recall using numbers was for waypoints in RNAV SIDs or STARs which contain names like ZH412 - but entering these individually is supposedly, ahem, illegal....
the G4 has an extremely accurate fuelflow measurement and will show: Fuel flow and fuel used
It is a lot more accurate then the Shadin
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Okay .. you do need to do the math yourself but that is in line with the big boys... When preparing for landing the crew of 777´s need to calculate the landingweight themselves as well :-)
How can the G4 be more accurate than say a Shadin?
All the fuel totaliser systems I know of use the same transducer - the Floscan 201 or 201B
The accuracy is in fact limited by the overnight evaporation fuel loss from the fuel tank, by the fuel temperature (GA fuel is sold by volume but the power developed is by mass, and avgas expands ~ 0.1%/degC) and by the accuracy of airport bowsers. So when I plot the errors I get, they have an annual variation because the loss is bigger in the summer
The x axis is time, over about 6 years. The first 5 samples date back to when the avionics shop (a 145, 21 etc company) wired up the transducer with unshielded cable and I was getting a constant ~6% error... The other two big errors (+7% and -6%) are bowsers with a bad meter, one on the IOM and one in Crete.
To the best of my knowledge Shadin uses a system based on pressure.
The G4 has an "inline" system.
I have a Shadin as well and indeed the G4 values are usually slightly better and are more accurate as far as I can judge.
To the best of my knowledge Shadin uses a system based on pressure.
Shadin use the Floscan 201 turbine flowmeter - see my pic above.
I had a quick look at the Insight site - sensors.
They use the Floscan 201 sensor - they even call it "201" - but packaged in a box so you can't see it.
I think the reason why everybody uses the same sensor is because it is in widespread use in GA and getting the approvals is thus easy. It does have accuracy problems with flow turbulence if the pipework before it is not smooth but (a) it can be solved easily enough and (b) most pilots never notice anyway.
I have a Shadin as well
I would be really interested to know how exactly your system is done. You either have two Floscan sensors, one after the other, or you have just one Floscan sensor feeding both the Insight and the Shadin indicators (which needs to be done very carefully because a power-down on either will bring down both, due to the open-collector output of the sensor, and few if any avionics shops will know how to do that).
A few years ago I met a TB20 owner who had such a system (a Floscan sensor feeding both a Shadin Microflo and some older indicator) and he was 100% sure he had two sensors. Until by chance I saw his plane in a hangar, opened up, and had a look...
When two instruments share a single 201, I recommend adding an isolation diode. Many of the 1984 and later Bonanzas use the same device for the ships FF gage and when a Shadin or JPI is installed, they merely tap into the signal.
I am not a fan of the Insight equipment. The owner is a jerk, knows everything, and has no need to listen to anyone. He refused to add digital readout for at least 5 + years and lost most of the business to JPI.
