like first officer fariq, zaha rirks rie lacked any apparent motive. >> many aspects of the case haved the more they've looked, the less they've found. >> i just don't see any logic. i don't see any reason why he would want to be a rogue pilot. >> zaharie's sister spoke out to channel news asia. >> he did not have that kind of makeup. >> he got married fairly early. great guy, extremely helpful, and always willing to share. >> nick spent zaharie at malaysian airlines during the rigorous days of flight school. 30 years ago. >> we can count our teeth in it, you know, everything was very, very regimented. >> above all, he remembers his friend as a skilled and seasoned pilot who loved to fly. seen here in a video tribute posted by his family. >> crazy about flying. he flies little planes also, builds small toy planes and flies them. he has aviation going through his veins. >> if it wasn't zaharie and it wasn't fariq, what about the other passengers on flight 370? could it have been a hijack? >> explain the fact the radios were shut down possibly systemically, it would explain why there ma