Squeaks in the 170
Posted: Thu Mar 05, 2020 5:57 am
When a 100 holy inspection is carried out ,I am sure that a detailed inspections are not carried out inside the fuselage where the engine frame mounts are bolted to the fire wall . There are fittings that can have exfoliating corrosion . These fittings are riveted to stringers that run horizontally along the airframe . The stringers can also crack or corrode that not very obvious with a torch and mirror . The only indication that you will get when some thing is not right is when the skin of the fuselage in this area appears cracked or smoky rivets . We had a issue like this very recent on a Cessna 172 b series and a 172 R series . However a quick and easy way to check your mounts is use a stethoscope on the effected area and have some one gently rock the spinner around [not turning the prop] . You will hear crackling noise or noises [squeaks] coming from that area indicating movement .
There was a Cessna 172r series and it was used as a instructional example when one guy eyes lit up saying he could here noises . YEA sure !!. It was a good laugh until some one else picked up the stethoscope and had a listen . It had a broken fuse large mount . It couldn’t be seen due to the oil and dirt and bits of sound proofing .
A mic place against the fuselage and a amp can be used instead of a stethoscope.
There was a Cessna 172r series and it was used as a instructional example when one guy eyes lit up saying he could here noises . YEA sure !!. It was a good laugh until some one else picked up the stethoscope and had a listen . It had a broken fuse large mount . It couldn’t be seen due to the oil and dirt and bits of sound proofing .
A mic place against the fuselage and a amp can be used instead of a stethoscope.