“Tom and Connor stepping out together in London was a big deal,” a source tells PEOPLE. “It was the same weekend that Scientology does their annual gathering called the International Association of Scientologists (ASI).”
The event is one that “Tom has attended numerous times in the past,” says the insider.
“This appears to be the first time Connor has gone,” the source adds.
On Saturday, the 57-year-old actor and his son were spotted heading to a private helicopter in London. Once inside the vehicle, Tom — who learned how to fly a helicopter for his role in the Mission: Impossible franchise — was seen showing Connor, 24, some aviation basics.
“Connor and Isabella grew up in the church of Scientology, they’ve been members since they were kids,” the source tells PEOPLE, adding the siblings “are completely dedicated Scientologists just like Tom.”
Connor and Tom’s shared commitment to Scientology has made their bond strong over the years.
“Connor has been able to remain close with Tom because of Scientology,” the source adds.
A source previously told PEOPLE that “Connor has a pretty simple life” in Clearwater, Florida.
“He lives in his own home in a Scientology community. His life is deep-sea fishing. He has a lot of friends and seems very well-liked.”
Connor’s sister, a fashion designer who goes by the name Bella, lives in London with her husband Max Parker, whom she married in 2015.