After doing routine maintenance, a ground crew dropped a stepladder on an active runway. And then three aircraft landed, passing by it at high speed! Also, this stepladder couldn’t be at a worse point along the length of the runway. It was approximately 200 metres after the touchdown zone of runway 33.
The incident happened at Birmingham Airport (EGBB), on the 8th of September 2020. It happened at 22:27, so night time at this time of the year in Birmingham. Two technicians had been doing maintenance on the runway approach lights for runway 33, work requiring the stepladder. They also needed to check all runway centerline lights, in both directions. The crew were in contact with ATC, who kept track of their position and any oncoming aircraft traffic.
ATC informed the crew that there would be a gap of around one hour in air traffic, starting from 21:30. So after making the appropriate preparations, they went out at 21:33. They first went to work on the runway approach lights, unloading the stepladder from the back of the truck. This is a 2.2m (7ft) A-frame ladder, mostly of aluminium construction. The work on the approach lights took around 15 minutes.
Having finished this work, the technician returned the ladder to the truck, securing it with an elastic bungee. Then the crew had to inspect the runway lights. Unbeknownst to them, the end of one of the hooks of the elastic bungee had broken off. They drove down the entire length of the runway, dropping the stepladder after the touchdown zone. That ladder fell on the runway at 21:54. After driving to the end, they drove back along the runway, stopping at each centerline light.
A Forgotten Stepladder On A Runway
The technicians intended to check each centerline light, in both directions. If they had, they would eventually find the dropped the stepladder on the runway. Unfortunately, a technical fault with their equipment (a torque wrench) forced them to stop short of where the ladder fell. They left the runway, returning a few minutes later. Then at 22:18, ATC informed the technicians that the next inbound aircraft was 20 nautical miles out.
The technicians left the runway, still oblivious of the missing stepladder. Three aircraft were now on approach, with a separation of 4nm. The first was EI-DPC, an ASL Airlines Boeing 737-800. The second was G-GDFR, also a 737-800, belonging to Jet2. The third was G-OOBA, a TUI 757-200.
The first 737 landed without reporting anything. The second aircraft told ATC that they may have seen something on the runway, but weren’t sure what. The crew of the first aircraft then radioed, to say they too may have seen something just after the touchdown markers. ATC then asked the third aircraft, now on final, if they wanted to continue. The crew of G-OOBA said they did. At the same time ATC requested for an Airfield Safety Unit (ASU) vehicle to prepare for a runway inspection.
The ASU vehicle took the runway immediately after the third aircraft (G-OOBA). They found the stepladder on the runway at 22:31. The ladder had been there for 37 minutes. By this time, the two technicians had realized that the ladder was missing from their truck. But they assumed that another technician had borrowed it! Before they could find that technician, the tower informed them about what the ASU found on the runway.
The British Air Accident Investigation Board AAIB report goes into extraordinary detail, regarding the truck, the stepladder, the bungee and how they came together on the runway. They traced the movements of the truck and the technicians, using CCTV at the airport. They issued recommendations about how to affix (and how NOT to affix) items on an airport vehicle with an open truck bed. But the AAIB also made recommendations regarding how ATC handled the matter.
According to then-current rules, there should be a runway inspection if no aircraft movements have taken place for a certain amount of time. Also, in unusual situations such as suspected FOD on the runway and an aircraft inside 4nm, ATC should ask the crew’s intentions in a neutral way. ATC asked “Are you happy to continue?” instead of “Request your intentions?”.
But of course the main issue here is the dropping of the stepladder on the runway. Analysing its position on the runway, the 737s’ wheels got to within 0.2m (8”) and 2.29m (7.5’) of it! They would have hit it doing around 120kts or more.
The (AAIB) released their report on the incident last week. They rated this as a serious incident. Just yesterday we saw what kind of damage a bit of gravel managed to do on a 747. A stepladder on a runway? The consequences of a collision with such an object are simply unthinkable.