Watching rented iTunes movies on iPhone 4 while on plane

Sorry if this has been posted before but I cant seem to get a straight answer here. I have an iPhone 4 and tomorrow I am taking a 6 hour flight. I planned on renting several movies tonight and then watching them at various times on the plane, with the iPhone in airplane mode. I have heard (its all over the Internet) that you cannot start a rented iTunes movie from the iPhone 4 in airplane mode. I am told that Apple cannot start the 24 hour clock unless the phone is connected via Wifi or 3G. So they say you have to start playing the movie in the airport and then pause it, and then resume it in the air. Is this true???? This seems absolutely ridiculous and it defeats the purpose of me wanting to use the phone in the air. Plus, the flight is long, so presumably I would have to start playing 3-4 movies in the airport, and then resume them in the air.
Is it true? Can you start an iTunes rented movie on the iPhone 4 while its in airplane mode??? Or do I really have to start each and every movie while in the airport??????
iPhone 4 iOS 4