If I recall correctly the Air India bombing was not an inside job, rather a result of the suitcase being checked on with a bomb it.  At that time baggage screening for bombs was rudimentary and they allowed bags to be checked when the passenger wasn't on the plane.  Fortunately that has all changed.  

The Narita bombing was the same....I believe that it is accepted to be a failed attempt by the same bombers to bring down a second Air India plan.  The bomb exploded early.