Hetfield,
Very rare indeed but reading & refreshing my memory of the Iranian Air Force 747 accident on the approach into Madrid on the link on post# 108 doesn't fill me full of confidence.
This aircraft, by coincidence was ex TWA & the sister ship of the ill fated TWA off Long Island which "appeared to suffer an in-flight explosion of the centre tank" caused by shorting fuel pumps or USN cock-up depending on the version you subscribe to.
The B738 incidentely is a lightning magnet & (not just my opinion but confirmed by "ginger-beers" ) seems to suffer a disproportianete number of strikes compared to other types (before winglets too, so not that)
Don't know if it is relation of wing-span to length / where the composite bits are located/ poor bonding ? really no idea, but it attracts lightning like no other type I have flown & is several scales worse than the 733/4/5 for instance.
Incidentally I wasn't suggesting that a lightning strike caused this, merely stating that what I saw, in duration & intensity, looked more like a lightning discharge than an explosion. Difficult to say anything with any degree of certainty concerning the poor quality of cctv anyhow.
Edited to say, having read the post above about the exercises
Itavia DC9 over the Med / Iran Air Airbus / TWA (maybe?)/ a TU154 not so many years ago ? indeed why not, but in that case we will wait 20 ? 30 ? or how many years ? for the truth.