What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The pilot experienced symptoms of electrical failure on a return trip home from a day trip with a friend. Approaching ktmb (tamiami) it was noted the garmin radios were flickering, occasionally going dark, and re-powering on again. Attempts to call tamiami were not successful. According to the foreflight app on the ipad, the traffic at tamiami was very heavy. The pilot then diverted to Homestead airport X51 which showed only one aircraft in the pattern. The pilot noted the alternator amp gauge was near zero, though no alt warning light was on he stated. He squawked 7600 on the garmin transponder, but it was also showing signs of power loss. The pilot followed the checklist for electrical failure, and concluded by turning off the battery to save power. Realizng a loss of electrical power would mean losing the ability to extend the landing gear normally, he put the gear handle down and reportedly saw nothing, and no gear extended (the battery switch was still off at this time). The pilot was able to call someone in the office on the ground at Homestead and did a fly-by asking if the gear appeared up or down. Ramp agent rivero in his report indicated the gear was up. At this time, the pilot flew to the west and climbed, then referenced the emergency gear extension checklist. The checklist begins wih "ensure battery and alternator switches are on" and at this point the pilot realized the master was off on his first attempt to lower the gear normally. Following the checklist, he turned the switches on and used the normal gear extension handle first. This time, the pilot said the gear came down and he momentarily saw three green lights before 'everything went dark.' Because he saw three green lights, he did not procede with the rest of the emergency gear extension checklist, believing the problem was solved and the gear was down.
On the phone again for a second fly-by, the ramp agent stated that now the gear was 'indeed down.' The pilot then proceeded to do a soft field technique landing and everything seemed normal until the sound of scraping as the back of the airplane contacted the runway surface. Once the aicraft was stopped in the grass to the left of the runway, proper checklists were followed and the pilot and passenger were evacuated uninjured. Post flight examination revealed the alternator belt had come off the pulley but did not break. The nosewheel was down and locked so there was no damage to engine or propeller. Main gear were folded, showing signs of extension but never locking into place. Damage was limited to inboard flap corners, and tail tie down.
In the investigation conclusion, it appears there was just enough battery voltage left to drop the gear with the hydraulic pump normally and lock the nosewheel into place, but not the main gear. Pilot stated he saw all three green lights prior to losing all electrical power. Pilot followed all checklists according to the manufacturer. Of note, the electrical failure checklist does not instruct the pilot to extend the gear with the emergency lever to save power, nor does it refer the pilot to any landing gear procedures.
As the FAA filed it
THE PILOT EXPERIENCED SYMPTOMS OF ELECTRICAL FAILURE ON A RETURN TRIP HOME FROM A DAY TRIP WITH A FRIEND. APPROACHING KTMB (TAMIAMI) IT WAS NOTED THE GARMIN RADIOS WERE FLICKERING, OCCASIONALLY GOING DARK, AND RE-POWERING ON AGAIN. ATTEMPTS TO CALL TAMIAMI WERE NOT SUCCESSFUL. ACCORDING TO THE FOREFLIGHT APP ON THE IPAD, THE TRAFFIC AT TAMIAMI WAS VERY HEAVY. THE PILOT THEN DIVERTED TO HOMESTEAD AIRPORT X51 WHICH SHOWED ONLY ONE AIRCRAFT IN THE PATTERN. THE PILOT NOTED THE ALTERNATOR AMP GAUGE WAS NEAR ZERO, THOUGH NO ALT WARNING LIGHT WAS ON HE STATED. HE SQUAWKED 7600 ON THE GARMIN TRANSPONDER, BUT IT WAS ALSO SHOWING SIGNS OF POWER LOSS. THE PILOT FOLLOWED THE CHECKLIST FOR ELECTRICAL FAILURE, AND CONCLUDED BY TURNING OFF THE BATTERY TO SAVE POWER. REALIZNG A LOSS OF ELECTRICAL POWER WOULD MEAN LOSING THE ABILITY TO EXTEND THE LANDING GEAR NORMALLY, HE PUT THE GEAR HANDLE DOWN AND REPORTEDLY SAW NOTHING, AND NO GEAR EXTENDED (THE BATTERY SWITCH WAS STILL OFF AT THIS TIME). THE PILOT WAS ABLE TO CALL SOMEONE IN THE OFFICE ON THE GROUND AT HOMESTEAD AND DID A FLY-BY ASKING IF THE GEAR APPEARED UP OR DOWN. RAMP AGENT RIVERO IN HIS REPORT INDICATED THE GEAR WAS UP. AT THIS TIME, THE PILOT FLEW TO THE WEST AND CLIMBED, THEN REFERENCED THE EMERGENCY GEAR EXTENSION CHECKLIST. THE CHECKLIST BEGINS WIH "ENSURE BATTERY AND ALTERNATOR SWITCHES ARE ON" AND AT THIS POINT THE PILOT REALIZED THE MASTER WAS OFF ON HIS FIRST ATTEMPT TO LOWER THE GEAR NORMALLY. FOLLOWING THE CHECKLIST, HE TURNED THE SWITCHES ON AND USED THE NORMAL GEAR EXTENSION HANDLE FIRST. THIS TIME, THE PILOT SAID THE GEAR CAME DOWN AND HE MOMENTARILY SAW THREE GREEN LIGHTS BEFORE 'EVERYTHING WENT DARK.' BECAUSE HE SAW THREE GREEN LIGHTS, HE DID NOT PROCEDE WITH THE REST OF THE EMERGENCY GEAR EXTENSION CHECKLIST, BELIEVING THE PROBLEM WAS SOLVED AND THE GEAR WAS DOWN.
ON THE PHONE AGAIN FOR A SECOND FLY-BY, THE RAMP AGENT STATED THAT NOW THE GEAR WAS 'INDEED DOWN.' THE PILOT THEN PROCEEDED TO DO A SOFT FIELD TECHNIQUE LANDING AND EVERYTHING SEEMED NORMAL UNTIL THE SOUND OF SCRAPING AS THE BACK OF THE AIRPLANE CONTACTED THE RUNWAY SURFACE. ONCE THE AICRAFT WAS STOPPED IN THE GRASS TO THE LEFT OF THE RUNWAY, PROPER CHECKLISTS WERE FOLLOWED AND THE PILOT AND PASSENGER WERE EVACUATED UNINJURED. POST FLIGHT EXAMINATION REVEALED THE ALTERNATOR BELT HAD COME OFF THE PULLEY BUT DID NOT BREAK. THE NOSEWHEEL WAS DOWN AND LOCKED SO THERE WAS NO DAMAGE TO ENGINE OR PROPELLER. MAIN GEAR WERE FOLDED, SHOWING SIGNS OF EXTENSION BUT NEVER LOCKING INTO PLACE. DAMAGE WAS LIMITED TO INBOARD FLAP CORNERS, AND TAIL TIE DOWN.
IN THE INVESTIGATION CONCLUSION, IT APPEARS THERE WAS JUST ENOUGH BATTERY VOLTAGE LEFT TO DROP THE GEAR WITH THE HYDRAULIC PUMP NORMALLY AND LOCK THE NOSEWHEEL INTO PLACE, BUT NOT THE MAIN GEAR. PILOT STATED HE SAW ALL THREE GREEN LIGHTS PRIOR TO LOSING ALL ELECTRICAL POWER. PILOT FOLLOWED ALL CHECKLISTS ACCORDING TO THE MANUFACTURER. OF NOTE, THE ELECTRICAL FAILURE CHECKLIST DOES NOT INSTRUCT THE PILOT TO EXTEND THE GEAR WITH THE EMERGENCY LEVER TO SAVE POWER, NOR DOES IT REFER THE PILOT TO ANY LANDING GEAR PROCEDURES.