A Muhrim man should not go under the shade during travel or keep a shade or an umbrella over his head. Therefore traveling on airplane or a roofed vehicle is not permitted for a Muhrim man, but it is permitted for women.
Going into a camp or under the roof of stations in middle of the way or in Mecca, Arafat, Mash’ar or Mena has no problem. Also passing roofed markets and tunnels, which have been made for pedestrians, is permitted.
Whenever a shade no effect on preventing one from sunlight and rain, men are permitted to go under that shade. Therefore Muhrim men can use roofed vehicles or airplane from dawn to sunrise or in full cloudy days, but using a shade on rainy nights has atonement.
Passing bridges in the way and staying in the shades of vehicles has no problem.
Ill persons and those whom sunlight harms them severely or is a strong discomfort can use roofed vehicles, but they should pay the atonement (the amount of atonement will be mentioned in the next article).
Whenever a Muhrim goes under the shade because of ignorance or forgetfulness then there is no atonement on him, but if it has been done deliberately or according to a necessity, then it has atonement and the amount of the atonement is one sheep for each Ihram, meaning that one sheep is obligatory for the whole Ihram of Umrah and one sheep for the whole Ihram of Hajj.
It is better to perform Zebh (ritual slaughter) for atonement of Umrah in Mecca and those related to Hajj in Mena, but it is permitted to delay this act and perform it in the homeland. If it is hard to find people who deserve the food, it is better to perform this act in the homeland, but Hajjis should be aware not to forget it.
A Sheep of atonement should be used completely by poor persons and Hajji can use none of that.