Years ago flew a light twin single pilot Essendon to Albury. It had weather radar. Was somewhat mystified to notice all the mountains usually on the right (east) were displayed on the left (west) side of the radar screen.
On the way home back to Essendon, same weird display. Wrote it up in the maintenance release. The techs discovered the wiring to the radar was faulty and rectified the defect. That aircraft had been like that for months and not only did all the other pilots know about it (or maybe they never used the radar) but if they did, they didn't have the guts to snag it on paper.
Flew an Aero Commander for an Essendon operator Security Express. One of the pilots warned me the ADF only had five miles range. He was dead right.so I snagged it. The MR reply was Ground Tested Serviceable. Flew it again next day and same problem. Talked to the LAME who had signed it off as serviceable.
He said the ADF had been like that for months and all the pilots of Security Express were aware of it but had given up complaining verbally. Challenged the LAME why he had written "ground tested.. serviceable" when clearly he had not worked on it. He said he had contacted the aircraft owner who told him to sign it off as serviceable without looking into why the range was so poor. I don't know who owned that Aero Commander but he should have been hung out to dry by DCA.