Our Air Operations team surveys the railway by helicopter and unmanned aircraft systems (UAS or drones).

Inspecting the railway by air improves performance, reliability and safety – with no disruption to train services or work site activities.

Flying drones on or around our infrastructure and people is a specialist and potentially high-risk activity. It is illegal to fly a drone on or near the railway. So we have a framework of approved suppliers and specially trained in-house pilots, who are the only people authorised to fly drones for Network Rail. All our authorised pilots and suppliers have gone through a robust safety and compliance process. They are the only certified drone operators permitted to provide services from or within 50m of our infrastructure. 

What the team does

Operating our high-tech thermal and visual imaging equipment, this forward-thinking, high-flying team surveys the railway by air. This is effective – our equipment identifies the smallest of faults, and our aircraft cover wide areas fast – and a safe option, reducing the need to send people trackside to inspect railway equipment.

The team also works with internal customers across our routes to develop new aerial inspection techniques, using the latest technology to meet specific briefs.

It’s a critical part of keeping the railway running smoothly and safely, as you’ll see on this page. In just one example, in 2014, the air ops team picked up a fault on the East Coast Mainline that could have brought down the wires on all four rails, which would have caused massive disruption.

Here are some of the services we offer

Much of our railway runs on electricity, and faults with electrical lineside equipment, third rail or power supplies can cause delays. As these electrical faults typically produce heat energy, thermal imaging can pinpoint potential damage so we can carry out repairs and prevent disruption.

Aerial surveys also prevent disruption by reducing the need for ground inspections of electrical equipment – these require us to isolate the area (turn off electricity on that part of the line) so our people can work safely. By inspecting from above, our people are safer and trains can continue to run on the line.

Sometimes we want our trackside equipment to produce heat, for example points heaters that melt snow, and on these occasions our helicopter can check they’re working well.

Our helicopter can spot flooding, landslips and high snow drifts after heavy rain and wind, which can cause a lot of damage and disruption to the network. Identifying locations with damage early on means we can assess and repair it much quicker. This can also prevent potentially serious accidents.

In December 2015 the helicopter team discovered landslips and flooding around Cumbria, such as this landslip north of Aspatria (pictured) when route-proving the Cumbrian coast – this and other instances were recorded and reported to the LNW route team and a geo-technical engineer who was also on the flight.

Climate change and weather resilience on the railway

Aerial view of railway


Our equipment’s visual survey capabilities (including zoom, to inspect in detail) – combined with the helicopter’s ability to travel far, fast – are useful for routine vegetation fencing surveys. The equipment can also survey incidents, such as derailments, cable thefttrespass and fires, or project sites: major junctions, level crossings or large-scale renewal work. As part of this, Air Operations can provide detailed high-resolution still photographs.

The team can also provide detailed, accurate location information. All observers on the helicopter have a laser range finder and our ‘Where am I?’ app that can pinpoint the location, engineering line reference (ELR), mileage and grid reference to within five yards – information that can be sent immediately to people on the ground, or stored and sent later.

We have previously worked with the Network Rail helicopter team in hotspot [cable theft] areas and for proactive identification of locations vulnerable to cable theft. Criminals see the helicopter doing the rounds and it acts as a deterrent. It can also give us valuable imagery of any criminal activity.

Richard Godwin, crime manager for LNW route

RouteView is our aerial image hosting system, to which we upload aerial inspection and survey imagery. It’s used by teams across the business when planning projects or maintenance, reducing the need for physical site visits and trackside asset inspections. Inspectors from the Office of Rail and Road (ORR) and Rail Accident and Investigation Branch (RAIB) also have access to RouteView.

Incident controllers often use RouteView to fine-tune their response to incidents. For example, it helped to correctly identify a footbridge described during an emergency call following reports of a suicidal male – without its imagery, the police and MOMs (mobile operations managers, who respond to incidents) could have been sent to the wrong bridge.

Case study: hot spot

In January 2017, national aerial specialists carrying out a six-monthly maintenance thermal survey of the Great Western Mainline from Paddington to the Airport Spur tunnel portal spotted a traction current switch showing heat. After they’d been recording it for a short time, a train entered the section and the switch flared up, arcing excessively and flashing over (see pictures below) until the train came to a stand in the station platform.

The crew informed overhead line staff as soon as possible, who then went to the site to see what could be done to prevent the switch failing.

One of the overhead line technicians on site heard the switch hum and reported this to fault control, liaising with the electrical control room operator (ECRO) at Didcot to operate the switch live to correct the fault, which was that the switch was not closed properly. The ECRO confirmed that the switch had been used for an isolation of the line earlier in the week by a third party.

Once operated, the switch was inspected visually on the ground through binoculars, to make sure it was sitting correctly. The technicians stayed on site to watch two trains go through the section to check if the switch was still arcing, but this had stopped with the switch now closed correctly.

Our crew

Our national aerial survey specialists, pilots and drone operators can be based anywhere in the country from day to day, depending on where they are needed to inspect the railway.

We work all over the country, carrying out many different surveys, without any disruption to train services and we look for any potential faults on the infrastructure. Our job is all about ‘predict and prevent' so our aim is to catch things early before they fail to keep the network running safely and smoothly. I always tell people that we have the best office on the railway!”Chris Ashworth- National Aerial Survey Specialist, Network Rail

Chris Ashworth- National Aerial Survey Specialist, Network Rail

Drones or Unmanned Aircraft Systems (UAS)

We employ professionally trained pilots to safely and remotely inspect the railway and its infrastructure using drones. It’s a difficult and skilled job which requires patience, specialist training and a qualification to fly approved by  the Civil Aviation Authority (CAA).

It is illegal for members of the public to fly a drone on or near the railway. You could be taken to court and face a penalty of up to £2500. Network Rail will always report drone infringements to the police

The law

Make sure you know the law about drones and the railway:

Our top eight most requested surveys

  • Projects (site surveys, scheme layouts, access points and security surveillance)
  • Monitoring overhead line equipment condition
  • Monitoring asset condition 
  • Identifying and locating overheating equipment
  • Identifying earthworks and drainage issues (including landslips)
  • Inspecting structures
  • Identifying and locating encroachment on to the railway
  • Monitoring vegetation control