Please review my writing

My topic: Give response to the following questions.
1. Do you think flying is safer today than it used to be?
2. What kind of security you have experienced at airports?
3. Do you feel safe when you fly, or are you a nervous flyer?

My essay:

Nowadays, there are thousands of flights around the world everyday. Many people choose to move by plane because it is very convenient for business. Besides saving money and time, it is safer than other transportation. Although the plane accidents sometimes occurs, the experts always research problems and improve techniques, then they learn from experience and do not repeat mistakes from the past.

The aircraft crashes in the past have partly due to technical errors, the rest due to human. Specifically, some bad guys take advantages of flights to commit illegal acts, such as terrorism. So, checking security before each flights is also important. I went through security at the airport. Everyone has to take off their hats, coats and shoes and let them with their luggage through the security scanner. Then, they were checked the tickets and identity cards before boarding. Perhaps it will cause inconvenience for some people, but it is really necessary for our safety.

I felt a little nervous whenever I took a plane, not because I thought it was unsafe but because I had plane sickness. I remember two years ago was the first time I flied. I felt fine at first. But when the plane took off, my gut was turned upside down and I thrown up vomit. It was an uncomfortable experience that I wanted to forget. So I have only been on the business plane twice. I hope I will not have to fly for work anymore.

Those are all my thoughts and experiences about the plane. How about you? I am looking forward to hearing interesting stories from you.