Every two years, the world's aerospace industry descends on this town in the London exurbs in the heat of summer.
Military delegations and civilian groups spend tens of billions of dollars on the hot, big-ticket items displayed in over 105,000 square meters of exhibition space.
And no displays received more interest this year than those of the latest drones.
This year, 107,000 delegates schmoozed at 1,500 stands at the week-long event, which traces its beginnings back to the 1920s. Combining the raw business climate of the global arms market and the excitement of an air show, more than $72 billion in contracts were signed before the trade fair ended.
An as yet undetermined chunk of that was spent on drones, or 'Unmanned Aerial Vehicles' in the parlance of the arms industry.
"We don't call them drones, because there's always a man in the loop, we prefer UAV or UAS (Unmanned Aerial Systems)," said Michael Toscano at a pre-Farnborough conference at Britain's Defense Academy.
Toscano is president of AUVSI, the industry association representing drone makers and suppliers. There are a lot of them.
"The military developed unmanned systems to save lives, private business wants to develop them to make money," Toscano says.
UAVs are the fastest-growing sector in the aerospace industry, according to a recent study by defense consultancy The Teal Group.
Current global sales are between $6.6 billion a year this is expected to almost double to $11.4 billion a year over the next decade. Over the ten-year period $89 billion dollars worth of drones are expected to be sold at air shows like this one and others in Dubai, Singapore and Paris where the world gathers to buy arms.
The surging market in the global sale of UAVs occurs at a time when these systems are becoming a common tool not just in the military but for civilian use as well.
The speed with which drones have become tactical weapons of choice, rather than surveillance tools, has alarmed senior military commanders and theorists. Some, like a former chief of Britain's Royal Navy, question their legality. Others ask whether their use challenges the basic chain of command that goes into critical military decision making.
Those concerns haven't stopped nations cutting deals for existing systems and trying to develop their own. The US and Israel are the main manufacturers and purveyors of all things drone, while Asia is the fastest-growing market in the world. Overall spending on UAVs in Asia is expected to reach around $700 million by 2016.
With a potential market that big, it's no wonder so many countries were selling their drones at Farnborough.
One morning during the festival I watched a salesman from Elbit Systems, one of the major players in Israel, in action.
Eli Dotan was surrounded by a scrum of Nigerian officials. They were led by a 'Mr. Umar,' who was asking about Elbit's Hermes system.
The Hermes, Dotan told him, has flown 40,000 combat missions. There are two models. The 450 and the top-of-the-line 900 series, which Elbit boasts in its website has "class leading payload capacity of 350 kilograms" and is "capable of performing missions for area dominance, persistent intelligence, surveillance, target acquisition and reconnaissance."
The 450 is a good starter model. The Nigerians kept ogling the top-of-the-line 900. The salesman smiled and answered questions but kept emphasizing the 450 might be the place to begin.
Relationship established, cards were exchanged. The scrum moved on. GlobalPost chased after it.
What does Nigeria want the drone system for? Internal security? African Union operations in other parts of Africa?
Mr. Umar, who his assistant says is his country's defense minister but who may not have been officially appointed yet, smiles a wide Nigerian smile, referring to Col. Abubakar Umar, who is reportedly a leading candidate vying for the ministerial post.
"You know, my government says I cannot talk to reporters," Mr. Umar laughs, then gestures at the enormous hall crammed with aerospace equipment. "This is a business environment."
Back at Elbit, Eli Dotan explains, he doesn't expect to make sales at Farnborough. Sales come later and there are a lot of them.
"We are competing on the worldwide market with great success," he says.
But the market right now is tough. Austerity budgets are a global phenomenon, and that means military procurement budgets are being slashed. UAV is the paradigm of a 'more bang for your buck' kind of weapon system.
How much does the Hermes cost? The answer is not so simple, Dotan says. There isn't single sticker price.
"It's like buying a Buick or a Cadillac," he says. "They are both automobiles but the difference in price comes from what's inside them."
What will the system be used for? Surveillance, that's one set of equipment to be loaded in.
Attack? That's more gear.
Do you want state of the art anti-jamming systems — which Elbit also makes — or deflection systems to protect your Hermes from attack?
All of these add to the sticker price.
The cost also depends on human factors. The Hermes is unmanned in the air, but on the ground there are many people involved in running the system. The cost of training them and providing oversight — all of this is subject to negotiation.
If the Nigerian military buys a Hermes, will Elbit train Nigerian operators? Will they go to Israel for training or will Israeli experts go to Nigeria?
It all depends. Each contract is individually designed.
OK, so if the Nigerian government buys a first-class machine with a training period, how much does it cost? Dotan shrugs and avoids giving a direct answer again.
"We are competitive," he says. "We lease systems, we sell them. People have less money than before. We must be creative."
The British sales pitch from Thales deals with all these issues, salesman Andy Murphy explains.
"We don't just sell the platform, we sell the system. A UAV platform is like a model aircraft, it's the system that makes each unit unique."
What is a constant is Thales' after-sales service.
Murphy adds, "We train them up. Countries buy it and run it with their civilians to extract intelligence, then the British military lands it."
It's not just the Israelis or the major American and British aerospace giants hustling drones.
In a corner of Hall 3 is a netted-in area, like an enormous batting cage, but instead of a pitching machine winging balls at guys trying to groove their swings, ALPI, an Italian drone manufacturer is giving a flying demo of its tiny Sixton.
It looks like a metallic insect, takes off vertically and maneuvers easily.
But this is a serious piece of war technology. Massimo Petrusa, speaking in charmingly accented, fluent English, explains the Sixton has seen combat in Afghanistan. The Sixton is small, and the whole system can fit into a backpack weighing around 55 pounds.
The actual flying piece weighs only 4 pounds. It requires just a single operator and adds eyes and ears in the sky for special forces units on patrol in hostile areas.
But Petrusa's pitch today is about the civilian uses for the Sixton.
During the recent earthquakes near Bologna and Ferrara the little machines were flown into damaged buildings to send pictures back to emergency services that were used to determine the internal structural damage and carry out risk assessment.
Alpi also makes more traditional looking drones. How much do they cost?
"We are 10 percent cheaper than the Israelis," Petrusa laughs.
Price and portability is a good sales pitch. The Turkish sales pitch was that the equipment — which looked very similar to the Israeli equipment — was actually made in a Muslim country with full trade relations with other Muslim Middle East countries.
So better to buy Turkish and not risk offending your people's sensibilities.
The rapid proliferation of drones has some military men asking serious questions about their use and just how effective they actually are.
"We're lucky, in a sense, in that we've been fighting against a primitive enemy in remote places. But that's not what war is really like," says Admiral Lord West, former chief of Britain's Royal Navy and top security adviser to Prime Minister Gordon Brown. "They are a lovely way of not risking your own lives and that makes it highly attractive."
The attraction is great for politicians, like President Obama, who can sit in the White House and pick targets.
"Drones have been effective in the FATA (Federally Administered Tribal Areas of Pakistan)," West acknowledges. "We have killed some very senior terrorists."
But he is deeply concerned that drone use is leading to military decisions being made by people not psychologically aware of what their actions mean.
West added, "If you've been in the infantry you know what war looks like or if you've been on a ship like mine, and seen it blown apart and seen what that does to people. It affects the way you think about war."
West's ship, the Ardent, was sunk during the Falklands War.
It's not just politicians with no military training making strategic decisions in secure offices. West talks about "strategic corporals" sitting in Portakabins in Nevada "making decisions about assassinations that should come from much higher up the chain of command."
The corporal, "goes home after a shift to his condo or whatever it is and thinks, 'I wiped out a terrorist.' They are not sufficiently aware of how bloody and horrible war is."
West adds, "I'm not at all convinced about the legality of using them."
In that respect, West is not alone among the military. Professor Noel Sharkey, chair of the computer sciences department at Sheffield University and a specialist in the ethics of battlefield robotic systems, says the military are much more concerned about ethical and legal issues related to UAV than the civilians in government.
Sharkey claims the use of drones pose a fundamental challenge to existing laws of war for several reasons.
"There is no transparency in the decision making that goes into targeting. The targets have no chance for self-defense and no chance to surrender. All of these go against the laws of war," Sharkey says.
The Sheffield professor acknowledges the difficulty of bringing drones within existing legal frameworks like the Geneva Conventions because, as he puts it, "a drone is not a weapon, it is a weapon-carrying platform."
Lord West notes that during his time as Britain's naval chief and then security adviser in the British cabinet, drones, were used primarily as reconnaissance and surveillance tools. It's only in the last few years there has been a dramatic increase in their use as offensive weapons.
Sharkey points out the Obama administration has pushed the envelope on legality.
"In Libya," he says, "the president did not seek congressional approval for their use under the War Powers Act because, the administration claimed, there were no troops involved."
Obama was stretching the point, in Sharkey's view.
"There were troops involved but they were 7,500 miles away. The drones acted as their avatars."
Both Lord West and Professor Sharkey believe that rules of engagement need to be codified, and quickly.
"Otherwise it's going to lead to disaster," Sharkey claims. "There are 51 countries with drone systems."
The professor adds that it is widely believed only five countries — the US, Israel, Russia, China and Iran — currently have drones with weapons systems.
Sharkey says Turks use Israeli-built Harpy but that technically isn't a drone it doesn't fly. It is rocket-launched, hovering and reacting when it is painted with an enemy's radar by firing missiles at the radar signal source.
But, he hastens to add, it is only a matter of time before other countries begins selling armed drones around the world, and some wonder if that has not already happened.
For the moment, the five keep the weapons systems to themselves although Britain uses American Reaper drones for its attacks in Afghanistan. The craft are flown by RAF pilots based in Nevada.
In the hopes of defining a clear set of rules of engagement with unmanned systems, Lord West calls on the Anglo-American military commanders to thrash some ideas out and then "hold a NATO conference to set standards."
Meanwhile back at Farnborough, Stephen McKeever, secretary of science and technology for the state of Oklahoma says he's all for discussions on rules about drones and their use.
"Any new technology has the potential to be abused," he says.
Oklahoma has gone all-in on drones as a business. It's a matter of policy set down by Republican Gov. Mary Fallin when she was sworn in 2011.
It is creating a statewide military-educational-industrial complex in the hopes of becoming the global research and testing center for unmanned systems.
Tim Reynolds of University Multispectral Laboratories in Ponca explains that with airspace in America overcrowded, one of the few places in the US where you can test-fly drones is the empty spaces of Oklahoma.
"What we've done is turn the state into a test bed," Reynolds says. We are allowed to fly from the ground to 40,000 feet."
Reynolds adds, "There are parts of some military bases where we can drop ordnance. We've been testing dropping mortar rounds from UAVs as opposed to missiles. You have to get close to your target. It's real 'whites of their eyeballs' stuff."
But he is also keen to point out the civilian uses of training people to use unmanned systems.
"If you want to inspect a bridge, you can take three weeks building scaffolding underneath it and send a team of men in to look or you fly one of these things under the bridge and take pictures," he says.
For all the UAV industry talks up the civilian use of unmanned systems, there is no doubt that controversy will continue to surround drones. The next generation, already being tested, will be truly "unmanned," according to Noel Sharkey. Totally autonomous, completely pre-programmed for any eventuality.
The reason for eliminating the human operator — even if he or she is on the other side of the world — is that drones are operated by radio frequency, and radio frequencies can be jammed. An autonomous drone doesn't receive any signal. Once it is up in the air it follows its mission through.
These new drones will be bigger. The US Navy is currently testing the X47B, built by Northrop Grumman. It's a carrier-based fighter drone and Sharkey believes the US Navy is looking to the X47B or a similar unmanned vehicle to replace the hugely expensive F-35 system.
This could lead to a new series of issues, Sharkey says.
What ethical and legal safeguards can you program into a completely autonomous machine's operating algorithms?
It doesn't matter that such a machine is years away, he says. "We need to start talking about the rules now."