Is it possible to kill people indirectly with the Death Note? Rule X in the Death Note states:


  
  Whether the cause of the individual's death is either a suicide or accident, if the death leads to the death of more than the intended, the person will simply die of a heart attack. This is to ensure that other lives are not influenced.
  


However, Rule XXVI states:


  
  Even though only one name is written in the Death Note, if it influences and causes other humans that are not written in it to die, the victim’s cause of death will be a heart attack
  


Besides the fact that I find these 2 rules to be contradicting (correct me if I'm wrong), it still made me curious: Is it possible to kill people indirectly with the Death Note?

For example, writing a heart surgeon's name during a operation, or a pilot's name while mid-flight.
People who name is not written in the note shall not die due someone else that will die due his name being in the Death Note, both rules can be boiled down to that. That is what the If the death leads to the death of more than the intended means. As long as the death of the person leads to someone else dead, or the conditions prior death can cause death to others, they will die of a heart attack. 

There's no contradiction, both rules says the same just in different ways.

In the example you made: both will die in such way that nobody else dies. The surgeon will step back of the table and die, the pilot will die when he's not piloting. Of course, this is mere supposition and details could escape.

Light made some experiments trying to kill in such impossible ways (like a Japanese prisoner died in front of Eiffel Tower), those died on hearts attacks.