What effect does driving convictions have on a PPL? Recently, I was driving some friends around when they started complaining that I was driving "too slow" (basically not over the speed limit). I stated that my reason for being cautious was I did not want to jeopardise my PPL / NPPL (in progress).

I would like to know however, what driving convictions actually do affect pilot licenses or get them revoked?
In the US, driving while under the effects of alcohol and drugs may have a adverse effect on your medical certificate.  Additionally, I have heard (from an FAA inspector) second hand that in one instance, someone who had a driver's license revoked for a large number of speeding and reckless driving circumstances, eventually had a medical certificate revoked.

Arrests, and administrative actions require reporting to the FAA Aeromedical branch within 60 days and failure to do so can not only affect a medical certificate, but also pilot certificates, instructor certificates, A&amp;P certificates, controller certificates, etc.  The penalties for non-reporting are significant.

Addendum:  US pilots are required to make TWO reports relative to substance and alcohol issues.  Part 67 requires reporting notifications, arrest, etc. to the Aeromedical Branch. Part 61 requires a notifying Security at FAA upon conviction  or disposition.

Reference item 8 in the below FAQ which is provided for AME guidance:


  https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/media/SubstancesAbuseDependenceFAQ.pdf


Also, according to FAA documentation, the normal look back on substance abuse is 2 years.