When people try to calm others who are afraid of flying some will claim it's more likely you will be killed by lightning than dying on a flight. Is there any truth in this?
The answer is: it depends on where you are, what aircraft you're flying on, how frequently you fly on them, and how often you stand next to tall objects in the middle of a field during thunderstorms (among other factors.)
If you're talking about the recent average chance of dying in a plane crash on a U.S. mainline air carrier per year vs. the recent average chance of getting killed by lightning in the U.S. per year, then, yes, you're far more likely to be killed by lightning. A couple of dozen people are killed annually by lightning in the U.S., but there have been no passenger deaths at all on any U.S. mainline carrier due to an aviation incident (i.e. not counting "passenger had a heart attack at 30,000 feet") since late 2001 [source].
On the other hand, if you're referring to flying daily on a helicopter with a shoddy safety record in a mountainous region where the climate also never results in any convective available potential energy, then you're much more likely to die in an aviation crash.
Real conclusion: Without additional constraints, this is not an especially meaningful thing to compare. If you simply don't fly, your chance of dying as an occupant in an aircraft crash is 0%. If you spend all of your time in a place with no CAPE, your chance of dying in a lightning strike is also (almost) 0%.* On the other hand, if you're flying frequently on a private aircraft with shoddy maintenance or you have a habit of standing near tall objects in the middle of large, open fields during thunderstorms, you'd best have good life insurance.
* There are a few non-thunderstorm possible causes of lightning, such as volcanic eruptions, but these probably represent a statistically-insignificant number of lightning deaths.
According to this ATAG report there were 37.4M commercial flights in 2014. There were 20 A1 accidents per Aviation Safety. So if you randomly pick a flight, your chances of boarding one which will get into a hull loss accident is one in two million.
According to the NOAA between 1959-1994 on average 90 people were killed by lightning. The 1959 population of the USA was 178M, 1994 population was 260M, taking the mean the chances of killed by lightning is 1:2.43M -- about the same as the flights.
Yes and no. (but mostly yes)
Considering the USA, because it is easier to find statistics, during 1 year (1999. ok, that's old, but in the newer report I could not find exact numbers).
- Lightnings According to @chx's answer, ~90 people are killed by lightning every year.
- Flights 691 people died in a plane accident. Source National Transportation Safety Board page 30. However, 628 died in private aircrafts. Apparently the remaining 33 died in commercial flights.
So yes, if you consider commercial flights, which is probably the common meaning, but no if you consider all flights.
That could be very different in other countries.