Small Aircraft; Low Wing; 2 Eng; Retractable Gear
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 72.9; Flight Crew Total 290; Flight Crew Type 97
Confusion; Distraction; Human-Machine Interface; Situational Awareness
Aircraft Equipment Problem Critical; Deviation - Track / Heading All Types
Flight Crew Overcame Equipment Problem
Human Factors; Aircraft
Another pilot and I headed to KOSH. I flew the first leg then he flew to (Nebraska); and I flew to (South Dakota); where we stayed for the night. During dinner; we looked into getting an IFR slot for Oshkosh; but alas they were all full for the next day. The forecast was IFR until around noon; so instead we decided to sleep in. The ceiling was something like OVC011; and all airports to the east were varying between 900 ft. and 100 ft. (!) ceilings. I filed KLSE that was reporting OVC080. The plan was to get a bit closer to KOSH and wait there until [the] weather improved.My companion pilot is a retired airline captain; so obviously a very capable IFR pilot; but unfortunately he's not IFR current. I have been doing a lot of IFR flights recently in IMC; and I'm very familiar with the plane; so we made a perfect team: I had the plane; and he had the radios. Pilot flying and pilot monitoring.We get our clearance; and while I'm holding short after I'm done with my checklist; I loaded the flight plan; when I realized that KLSE was not in our database. Before going on the trip; we knew that we had only a 'US west' database (rental aircraft...). We didn't know what the limit what exactly; and given that up until then we had been fine; we forgot about that. So I looked into the ILS 18 in more detail; the approach I was planning to do; to see if it required DME (which we don't have); and to see how complicated it would be to fly without GPS (I have practiced this during my training; but I wanted to take a hard look at it before I ventured in real IMC after having mostly relied on GPS for waypoint identification...). I decided that even if we didn't get vectors; I was proficient enough to fly the whole thing without GPS; so our plan was then to take off; and upon reaching our last waypoint; ODI; let ATC know that we were downgrading to \U. We had more than 5 hours of fuel and our alternate (VFR); which I did verify was in our database.Fast-forward an hour and a half; as we're approaching ODI we were told to expect vectors for the ILS 18. Perfect! Just what we wanted. We briefed the approach; and I loaded all the NAV frequencies I was going to use: ODI in NAV 1; the ILS in NAV 1 STBY as a backup; ILS in NAV 2; and LSE (for the missed approach) in NAV 2 STBY. I ran through my approach checklists; and I was 100% ready. I switched CDI and realize that when going back to NAV 2 the G1000 had lost the course I had set up for the ILS... That's weird; I thought. The other pilot suggested that I use NAV 1 for the ILS; which I thought was a good idea anyway; so I switched my frequencies around. We identified the ILS; and verified my course was set to 180.We got a final vector and cleared for the approach just outside of JONRO; an IF. I disengaged the AP and FD and got stablished; so I began my descent to the next minimum altitude in the approach; and we entered IMC. We finally reach the FAF. I anticipated the GS with power; and started coming down at around 500fpm.Everything was going great. I got my scan going: attitude; speed; attitude; GS; attitude; heading and localizer; attitude; GS; attitude... wait a second; where's the GS? After about a minute inside the FAF I had lost the GS. I immediately ask 'what are the localizer minimums?' I quickly update them in my PFD. While I'm doing that; I'm noticing my localizer is flying away from me; so I try to correct by turning to the left... but deflection keeps increasing even more to the left. What's going on? About 5 seconds later I realize that my localizer needle has a FROM indication (the arrow as pointing down)! I take my right hand from the throttle; turn the course; and realize that it was at like ~300. I put it back to 180; and I recover the GS (incredibly it was still centered despite the chaos); and now my localizer is no longer giving me reverse sensing... so I notice I have a 1-dot deflection to the right; which I corrected immediately.Obviously I got pretty tense; but I continued flying the plane instead of thinking why that happened... we were still in IMC; and I got the plane stabilized again. About another minute later; G1000 starts screaming 'TERRAIN; PULL UP'. What?? Both my needles are centered; and I'm still more than 1000ft above minimums. Right away I remembered something I'd learned recently: if the airport is not in the DB; it's going to think you're flying into terrain. So again; I ignore the distractions and continue flying the plane; while my companion is trying to silence the warnings.We finally break out; and finish with a good landing; despite the alerts going off all the way to touch down.So in the end; it was a successful ILS approach that could have ended much more differently if I hadn't reacted quickly. Granted; if I had gotten full deflection before noticing the course issue I would have gone missed; but still. IFR flying is already hard enough without all this handicap. Accidents are always a chain of events; and this could have easily been the beginning of that chain.I imagine the fact that the ILS was not in the DB must have had something to do with it; but still; even if we had been flying a VOR or anything else; why would the course suddenly change to something else; by itself?
GA pilot reported a problem with the localizer on an approach to LSE in IMC with a G1000 system that did not have the database for that part of the country.