indicated airspeed on new Mini install

[tominidaho]

I just got finished with a total panel re do on my Rans S-7S, now the only round gauge is my hour meter. With 1530 hours on it I am emotionally attached to it. The panel is carbon fiber (not labeled or finished yet but here's a picture anyway). I now have a little over 3.5 hrs on the Mini install, and there seems to be a pretty major discrepancy with the ind. airspeed. Keep in mind I know my plane pretty well, and since the mini install I seem to have "lost"at least 15 mph off both the top end and the low end.

I followed the procedure for calibrating the airspeed indications, and am pretty sure I did so correctly. But then I see where it clearly states"the Mini does not provide any means to correct indicated airspeed", the procedure I followed apparently is just for "correcting the true airspeed that it displays in the PFD data box, when the Mini is equipped with a magnetometer". All I want and need is a fairly accurate INDICATED airspeed, just like my old traditional ASI. I like everything else about the Mini and am having lots of fun getting to know it better... but when I am showing barely 90 mph when I know I'm going over 105+ it's disconcerting. FWIW, in practice my Mini will be used as an ASI and ROC meter, all the other features are nice, but I plan to continue using my IFLY 700 as my primary nav tool, it's not like I fly IFR or need any backup. I'm not crystal clear what a magnetometer even is, or why I would need one (what do they weigh?? I'm into light) but if it is the only way I can get my indicated airspeed ( don't really care about true, and have the IFLY for ground speed) readings more accurately I'll consider it.

[GRT_Jeff]

We've found some of the earlier Air Data modules are reading low in some conditions and they require a hardware modification to fix the problem. You can go to the SET MENU, AHRS Maintenance page and scroll down to the AD Serial Number. We can check that number in our records to see if it is the updated version. If it needs to be updated, you can have us do it, or we can send you a replacement Air Data module to swap out.

[Bobturner]

Double check that you are set up for mph not knots. The 15% lower numbers sure sounds like knots.

[tominidaho]

I'll check that AD serial # today, looks like another good WX day.

That was my first thought, I was seeing knots! But unfortunately I am pretty I have it set up for MPH. That is what the displays says anyway. I'll double check that today.

I am real pleased with the easy legibility, I was a little concerned having all that info in that small area, I didn't want to need my reading glasses to make it out! No problem at all there.

Note: that pushrod on the right that goes under the panel leads to a firewall mounted MECHANICAL master switch , meant for a race car.
Lighter and no wiring or switches needed, best of all if left on, NO power draw from a coil, so idiot proof. That PEX valve in the radiator hose allows coolant to flow through a heat exchanger with a muffin fan, so I have two heaters, the usual muffler heat muff and the hot water one. Just in case anyone was wondering.

[tominidaho]

My AD s/n appears to be: 155.

I only had a brief time in the cockpit, work interfered and I didn't get to go flying, but for sure my main flight display seems to indicate MPH. I assume this means just that, that it is set up for MPH and not to indicate knots. On my initial setup I changed it over from the knots to mph as it came showing knots, I don't suppose there is anyway it could displaying knots, while claiming to be showing MPH?

[GRT_Jeff]

I checked the data for SN 155 and it is not the updated version, so that could be the problem. We'd have to compare it with another pitot input, or measure voltages in the circuit to confirm.

If it's set to MPH it's MPH, and it will indicate "MPH" by the airspeed.

[tominidaho]

Right about now I guess I should mention I've been flying this exact model of plane since '94. 3,000 hrs now, so though of course anything is possible (as in my two other old style ASI's lying to me all those years!) to see the degree of change I am now seeing is a good indication something is not quite right. If needed I can pull it and send it back if that is the way to go? That wouldn't be a big deal on my end, it's easy enough to do.

I have never swapped out a air data module, so I don't really know what's involved and if it's something I can or should do.

[Marc]

The pitot block module on the Mini is customer replaceable. It has two screws on two corners of the block. Remove those and pull the module out.

Installations is simply line up the connector to match the contact pads. Insert the Pitot block and install the screws.

Give us a call or email to support so we can make arrangements.

[tominidaho]

Wiil do, I can for sure handle that and would prefer to keep my hands on it. Thanks