Calum Thomson stands transfixed as an Emirates 777 takes off at Glasgow Airport and roars into the skies directly over his head.
The 18-year-old is no stranger to the airport, having spent the best part of a decade spotting planes in the company of family members.
But today is a special day for Calum.
Airport officials have granted the local plane-spotting community rare access to the Graveyard - a restricted area with a perfect view of Glasgow's runway 05.
Calum is there with his father Tommy and dozens of other members of the Glasgow Airport Spotters Group (GASG).
The event is something of a treat for Calum, who has classic autism. The disorder leaves him prone to hyperactivity, obsessional behaviour and sudden outbursts of emotion.
Glasgow-based Tommy, 48, a keen photographer who takes Calum out spotting almost every day, says the airport is his son's "happy place".
He says: "Calum's autism manifests itself in having to watch, track, photograph and video aircraft, which helps him control his emotions.
"He likes to take pictures of the liveries of aircraft and track them all on different apps.
"He is constantly writing down registrations and flight tracks, which is a bonus because it helps his school and also helps him de-stress."
Tommy says plane-spotting has helped Calum "in more ways that I can probably describe".
"When Calum's in a meltdown, it's like a whirlwind going off in his head - you can't speak to him or reason with him," he says.
"The airport helps take things back to normal - he's more relaxed, he's more calm and the biggest bonus is his social interaction (with other spotters).
"It helps him learn how to talk to people, how to interact with people and around his peers as well."
Calum and his father are far from alone in their passion for the hobby.
GASG boasts more than 1,000 members, many of whom are also part of the group Scottish Aviation Photographers (SAP).
GASG administrator Tommy Donachie, 41, from Renfrew, says: "We have a broad range of members.
"You have plane-spotters, pilots, ground crew and you have people from all over the world who are just interested in aviation.
"A big percentage are people who actually work in the airport."
'I wanted to be a pilot'
Tommy Donachie, like many others in the forum, developed an interest in plane-spotting at a young age.
"My dad used to bring me down here," he recalls as he surveys the airfield from the Graveyard.
"Growing up in Renfrew in the 80s, the planes then were a hell of a lot noisier - they used to shake the houses, which got my attention.
"I wanted to be a pilot but I didn't quite get the grades.
"Then I got into cycling and would cycle around the airport. I put a camera in my bag and it developed from there."
One highlight for him was the day the world's biggest passenger plane stopped off at Glasgow.
He says: "The A380 came here in 2014 - you had thousands of people all around the fence. It was the busiest I have ever seen the airport."
Glasgow Airport facts and figures
- The airport has about 90,000-100,000 flight movements per year
- Notable visitors have included the A380 and Tui Dreamliner 787-9. The space shuttle Enterprise did a fly-over at Glasgow in the 1980s
- There are two flight schools and two general aviation companies based there (Signature and Gama)
- The Scottish Air Ambulance Service is also based at the airport
Unusual flight movements
Fellow administrator Kevin McGonigle says group members alert each other in advance to interesting or unusual flight movements, especially those which involve the biggest aircraft.
He says: "Everybody likes what we call the heavies - the likes of the Emirates and the Virgin jumbo that come in.
"Getting yourself into a good position for a good shot of the aircraft is really what it is all about - and the good shots you can get because of weather phenomena.
"It's like a hunt - we are always watching for different things and it's good to catch things that we don't see a lot of."
Kevin acknowledges that some might see aviation enthusiasts as geeks but says the hobby is not as "anoraky" as people might think.
He adds: "I used to have a wee chuckle at the guys on bridges that like to take the names of a certain haulage company's trucks, and obviously you have people that like trains.
"But each to their own. I like to think everybody out there has a wee bit of geek in them - and it just so happens our inner geek is aviation and photography."
The opening of the graveyard marks a growing warmth in relations between the plane-spotting community and officials keen to maintain the security and safety of the airport.
For GASG administrator Michael McQuade, a Glasgow-based office worker, both sides can benefit from a closer relationship.
He says: "They can offer us access to areas that we can't get to ourselves so we can get different shots like we are today, looking straight down the runway.
"On the other hand, they know that we know the ins and outs of the airport.
"If something doesn't look normal, they ask us to report it. I think that's working for both sides."
PC Alan Sneddon, from Borders Policing Command at Glasgow Airport, has been working with the group for the past year.
He too believes a good relationship between the parties is beneficial.
He says: "It is always beneficial for the police to have an extra set of eyes in and around the airfield.
"I know that they are there 24 hours a day and they are willing to supply information to the police, so it is an opportunity for us to develop community liaison links with them and develop intelligence links with the group members and other members of the public."
Airport officials are considering granting the plane-spotters access to other restricted areas of the airport in the future.
Ronald Leitch, head of aerodrome operations at the airport, said it was keen to further develop links with the community.
"We have developed good relationships with the many enthusiasts who visit the airport, and this is particularly true of our Police Scotland colleagues based at the campus and our own security teams," he said.
"Those who do visit often act as an additional set of eyes from a security perspective and on occasion will provide helpful information on any behaviour they deem unusual or out of place around the airport's perimeter."
In the meantime, Tommy says he will continue to take Calum along to the airport as often as he can.
"As long as it keeps helping him, I'll keep bringing him, and I'm quite sure other autistic kids and adults out there would benefit from it," he says.
"He loves anything to do with aircraft - he's there, he's happy. What parent wouldn't be happy if their kid's happy? So it's easy - it's a no brainer."