Captain reported losing the Heads Up Display on short final.
Synopsis
Captain reported losing the Heads Up Display on short final.
Narrative
Planned and flew a visual approach backed up by ILS14 to SRQ in great VMC. HUD was in NP mode on Aircraft X. Last valid call I remember was 'plus 100'. At approximately minimums (200 AGL); HUD indications shimmered; then blinked; and then filled display with all kinds of data/warnings; to include what I believe was the attitude lines of the unusual attitude recovery mode; largely blocking all direct view through the HUD and making it impossible to use and difficult to look through. At approximately 150 ft. AGL (estimated by looking out window); GPWS flare call outs began to count down 50;40; etc like aircraft wanted me to flare. I was way too high for that. FO (First Officer); Pilot Monitoring stated 'That's not right' and asked me what was going on. I said I lost HUD and was proceeding visually. I was able to 'Fly through the HUD' ignoring its information to a normal landing. He said he saw no other indications.I have no idea [of the cause]. HUD was inop from 200 ft. down. I talked to another Captain; and he told me to treat it like a failure and put in AML which we did. We both understood that 5G is not supposed to be on yet; so elected to treat as failure. Maintenance could find no faults in subsequent checks and signed it off. Next leg was no problem. Delayed flight about an hour. Maintenance stated that they have gotten several reports on different aircraft this week similar to this; but do not know the cause.It is quite possible that 5G testing is going on that we do not know about. Also; quite possible it is just a glitch; another software issue; other interference; or just broken. I suggested to Maintenance that they begin tracking these odd events by airport as well as aircraft. Had it been a low IMC approach; I would probably had to exercise a missed.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.