Lightning strikes were common during the piston and early turbine powered era when weather radar was not available. Weather radar was required to be fitted to all RPT turbine aircraft in Australia in 1963 as an aftermath of the breakup of a Vickers Viscount over Botany Bay the previous year.
Once airborne in weather there was no way of locating and avoiding storm cells and adverse weather encounters with turbulence,icing,lightning and/or hail were not uncommon.
Evidence of this can be seen on the DC3 aircraft still flying today which have numerous indentations about the windshields and on the fuselage in line with the propeller plane of rotation.
Hail was by far the greatest worry. Fortunately the slower speeds of the era enabled survival from these encounters as with turbulence as well.The same encounters at four times the speed of today's aircraft would result in impact forces sixteen times as severe.
Weather radar helps avoid all these risk factors including lightning. Nevertheless lightning strikes still occur even well away from storm cells and modern aircraft cope well with this.
Lightning can be from cloud to cloud, cloud to ground, or vice versa, I am told by some experts.In practice it matters not which way it goes. What is of interest is if an aircraft is in it's path.
My impression gained from quite a few in the piston era is that cloud....aircraft....cloud are not as severe as and aircraft becoming betwixt the cloud...
ground or vice versa event. We have all seen lightning travel across the sky for long distances in a bluish spidery pattern and it is not surprising that encounters with this type is difficult to avoid and is relatively common.In my experience although spectacular they are a far cry from the other kind.
Strikes between ground and cloud seem to have more zing in them and are much more spectacular.The kind of thick orange tinged strike which moves vertically between ground and cloud when it transits through an aircraft leave a lasting impression on the optic nerve (hence keep a low profile) and memory, as well as significant damage to some parts of the airframe,generally at the exit points. This kind of strike generally resides beneath and in close proximity to the storm cell. Generally weather radar enables avoidance of these areas and so this kind are less frequent.
The principle of the Faraday's Cage protects the occupants of a hollow container (the aluminium tube);that is, that the electric charge travels to the outside of such a vessel.
Modern aircraft cope well with strikes overall especially when you consider all the electrics,glass screens etc. Being struck in a gasoline fuelled aircraft is not appealing although there are very few mishaps attributed to ignition to fuel vapours. There is some evidence that some turbine aircraft were lost in this way as a result of using JP4 fuel. This type of fuel is no longer used by airlines to my knowledge.
Static discharge wicks are just that and dissipate the static charge built up by the friction of air moving over the surfaces during flight.
All the above is based on personal observation and I do not lay claim to expert knowledge on the matter.
ON THE GROUND STAY INDOORS WHEN LIGHTNING IS ABOUT!!