Our company manual prohibits reading non pertinent material during flight. It’s probably the most often broken regulation.
By far the most popular thing to do during long flights is to read books, newspapers, magazines and Kindles. I’ve seen very, very few cockpits where the captain prohibits it. The standing joke is: “I’m not reading… I’m just looking at the pictures.”
Some pilots knit or crochet. One fellow was building doll house furniture and he would do fine finishing work on the pieces. There was also a guy who wrote country/western songs. Some pilots have businesses or side hustles so they’ll do some paperwork while at cruise.
I know this seems terribly unprofessional to the reader. But modern airplanes don’t need constant supervision like they did in the past. The flying pilot checks the fuel burn on each leg of the flight and keeps track of the navigation and the non-flying pilot is responsible for communications. That means that we’re always listening to what’s happening on the frequency and the airplane. Nobody reads recreationally in congested airspace or bad weather.
This kind of thing can get out of control though so crews need to maintain good awareness of what’s happening. In October of 2009, the pilots of Northwest airlines 188, became immersed in a conversation about a new crew scheduling program and had their laptops open. Nobody was listening to the radio or monitoring navigation. The airplane overflew the destination by 100 miles. A flight attendant noticed that they should have landed by then and notified the pilots. They had been out of contact with Air Traffic Control for almost two hours, which in my opinion, is disgraceful.
Here’s their route:
From Wikipedia: The FAA found that Cheney and Cole were out of radio contact with air traffic controllers for more than an hour and a half “while you were on a frolic of your own.” It cited the pilots for acting in “total dereliction and disregard” for their duties, and were “disengaged and impervious” to the danger their actions posed to themselves, the passengers and the crew. Among other things, the FAA found that the pilots failed to comply with air traffic control instructions and clearances and failed to monitor the plane’s air-ground radios. The FAA found that the pilots operated the plane in a careless and reckless manner, and thus showed they lacked “the degree of care, skill, judgment and responsibility” to hold a pilot’s license.
The FAA stripped the pilots of all of their pilot licenses and they had to start over again as student pilots and re-gain private, instrument, multi-engine, commercial and ATP certificates from scratch.
The captain retired early and the first officer was offered retirement but declined and was dismissed from the airline.
The other issue is fatigue and catnaps. The U.S. Air Force, Australia, Canada, China, Europe, New Zealand and Turkey, allow crews to take a short catnap for up to 40 minutes. It’s called Controlled Rest In Position or CRIP. It’s not allowed by the FAA in the U.S. yet. Studies show that a short nap of even 15 minutes very significantly improves the performance of a fatigued pilot. Qantas and Air Canada and Air France have specific procedures for CRIP and it is regularly practiced.
Consumers are majority against this procedure while about 75% of pilots favor it. I’m among those pilots. I’ve flown with first officers who have dropped off to sleep en-route and had trouble staying awake even during descent and approach. Therefore, if a crewmember needs 15 minutes with their eyes closed, I don’t object. It’s far better to have them alert for the critical segments than alert during cruise.
In my opinion, allowing reading in the cockpit gives the crew a diversion and actually sharpens them up for the descent and landing. Making the copilot stare out the window or at the unmoving dials does nothing but dull the senses until he’s in a stupor. Better to let the crew entertain themselves a little bit while en-route and then have them feeling rested and ready for the approach. I could be wrong though.
Interesting side note; Flight attendants are also prohibited from recreational reading in flight but they do it all the time. I don’t object to it at all.