A check: These checks are performed every 400–600 flight hours or 200–300 flight cycles and depend on the aircraft type. One aircraft cycle includes one round of takeoff and landing.
Whether flying at night or during the day, pilots need to see some kind of horizon. They use this to determine the airplane's attitude. At night pilots will turn their gaze from outside to inside and use the artificial horizon. The artificial horizon is normally a simply globe split into two hemispheres.
Private jets do not go through TSA because they have their own security protocols and regulations. Private jet terminals have expedited security checks where passengers are personally known and their identities are thoroughly verified beforehand.
The simple answer is yes, pilots do, and are allowed to sleep during flight but there are strict rules controlling this practice. Pilots would only normally sleep on long haul flights, although sleep on short haul flights is permitted to avoid the effects of fatigue.
On many aircraft types, pilots can open the side windows in the cockpit. The main reason for this is not for ventilation or vision; it is related to aircraft safety law.
A lot of airports have restrictions on night flights because of noise issues. Also some smaller domestic airports close at night. There are a few that leave late at night in order to take advantage of the time difference in the arrival city. There aren't more because there isn't much demand for them.
Visual IllusionsThe lack of visual cues can lead pilots to lose any sense of depth perception. There is often the temptation to 'duck under' the correct approach path, making the airplane lower than it should be.
Air accident investigations and aircraft safety inspections are now more effective, while improvements in manufacturing technology and better quality control are also making aircraft safer.
Flying is considered very safe due to modern technology, improved aircraft equipment designs, and enhanced pilot, mechanic, and air traffic control training. There are fewer planes in the air than cars and trucks on the road with much more space between them, further leading to safer travel conditions.
Your odds of being in an accident during a flight is one in 1.2 million, and the chances of that accident being fatal are one in 11 million. Your chances of dying in a car crash, conversely, are one in 5,000.