Pilot reported landing on a runway where there was a disabled aircraft; although ground personnel advised no landing. Pilot stated the aircraft was far enough down the runway that there was adequate landing distance remaining.

Narrative

I was doing solo pattern work at ZZZ on Date. Midway on my taxi back for a Runway XX takeoff; I noticed a white low-wing aircraft in the run-up area for Runway XX and heard his CTAF request for a radio check from ZZZ Ground Ops. There was no radio check response from ZZZ Ground Ops to his first radio call. As I taxied by his white aircraft; he made a second CTAF radio check call and I responded that 'Aircraft X hears you load and clear;' and he responded with a 'thank you.' My second takeoff was routine. As I remember I was just crossing thru approximately 500 ft. altitude; when the white low-wing aircraft called on CTAF that he was taking off behind me on Rwy XX; I then heard the white low wing aircraft's call that he was departing east; and I continued my downwind leg per normal procedures. I then assumed that he had departed the pattern; and was no longer a traffic factor for my current downwind and set up for my second pattern landing on Rwy XX. As I was on this downwind leg; just as I was approx. line abreast the Rwy XX numbers and was doing a slow descent to set up for the Rwy XX base leg; a CTAF slightly muffled radio call came in; 'Aircraft X..? I need to land in front of you; I have smoke in the cockpit.' My immediate CTAF response was; 'Aircraft X will fly extend downwind; runway is all yours.' I then continued to monitor CTAF and climbed back to 1;000 ft. and flew an extended Rwy XX downwind. I flew extended Rwy XX downwind for about 3 to 4 minutes and the CTAF was quite with no radio calls by anyone. As the aircraft on the runway came into my view during my maneuvers to Rwy XX final; I observed that it was approximately 3/4's of the way down Rwy XX; and stopped on the left side of the Rwy XX center line and just prior to the left side edge grass apron. There was no smoke or fire visible. At this moment I was relieved to not see a crashed aircraft; and no see any smoke and assumed that his 'smoke in cockpit CTAF call' that he had shut down his avionics and therefore was not able to make any additional CTAF radio calls as he executed his emergency landing. I continued my Rwy XX upwind and flew a slight right offset at pattern altitude for Rwy XX; flew just to the right side of Rwy XX; I noticed a single person outside the stopped aircraft. At this time my thought was that he had just rolled out with his electrical system shut down and that he had stopped ASAP on the runway to immediately exit his aircraft to evaluate his own situation. As I was about to turn from downwind to base for a 2nd go around at pattern altitude; a CTAF radio call was made by the Ground Ops maintenance truck that was he was 'about to drive onto Rwy XX.' I then observed the brown maintenance truck drive up to the aircraft; and I was relieved that the pilot of the aircraft not had ground support. Next as I completed cross wind at pattern altitude; and as I was just starting my third down wind; the ground vehicle came on the CTAF and said; 'aircraft in the pattern; this guy landed wheels up; it is going to be a while before we get him moved; you might want to consider landing somewhere else.' I was relieved that no fire or emergency vehicles were present and I replied on the CTAF; 'that with him 3/4's down Rwy XX that I was very comfortable in executing an immediate short field landing.' I then executed a normal short field landing on Rwy XX with my wheels on the ground about 50 to 100 ft. just beyond the Rwy XX numbers and I was decelerated to walking speed well within the first 1;000 ft. of the runway (which is 3;000 ft.) and well before the stopped aircraft which was approximately 3/4's down the runway entirely on the left side of center line; just line abreast with the sock tower approximately 2;500 ft. down from the Rwy XX threshold. As I taxied I stopped on the mid-field [taxiway] to make my 'clear Rwy XX' call I looked back at the white low wing aircraft and did not see any persons present or any support vehicles of any kind. I then proceeded to the fuel area to refuel and then I taxied back to the normal tie down area near hangar and completed my post flight checks.