Aviation accident are always devastating. They precipitate great suffering on those involved and those connected to the event. They are also learning opportunities and, as a discipline, accident investigation has been for a long time focussed on maximising this learning. But for the learning to be complete the results of these investigations must be shared or the lessons may be lost. With this in mind, I’m going to start a new category of posts looking at significant aircraft accidents and incidents that may have some lessons for airport operators.
In the very early hours of October 11, 1984, Aeroflot Flight 3352 was inbound to Omsk Airport after an uneventful flight from Krasnodar. On approach, the flight crew had some trouble contacting air traffic control but they did eventually receive a form of clearance to land. After clearing the clouds and lining up with the runway, the flight crew thought they saw something on the runway and questioned air traffic control but were assured that the runway was “free”. They continued with the final approach and landing.
But not long after touchdown, the flight crew identified vehicles on the runway and attempted to avoid a collision but it was too late. The aircraft collided with three vehicles and a combination of the fuel on-board the aircraft and a significant amount of fuel on two of the vehicles ignited into a fireball. The flight deck was sheltered from this fire (either through separation or distance from the fuel tanks and engines) and they survived with no or minor injuries. Unfortunately, 174 people in the main cabin and four airport workers died. One passenger and one airport worker survived the collision and subsequent fire.
What Happened on the Ground?*
There was a combination of issues within and between the air traffic control unit and the airport operations team. Obviously, I would like to focus on the airport operations team’s actions and failings but to do that I need to acknowledge the actions of the ground controller. I don’t wish to equivocate with respect to the roles that each person played in this tragedy - it is clear that individual culpability varies between those involved.
The vehicles on the runway were part of the airport maintenance team. They were conducting runway drying operations and friction testing due to the rain that had been falling at the airport. The contingent consisted of a four-wheel drive light vehicle with trailer and two larger trucks. One or both larger trucks carried dry air wind machines and both carried approx. seven tonnes of fuel. They entered the runway around 0515 local.
This work was not planned or initiated in accordance with the established procedures at the airport. Important details regarding the works, such as vehicle information, purpose and duration, were not provided to or requested by air traffic control. After initially denying the request, the ground controller permitted the works crew to enter the runway.
What the controller did next is, by far, the most damming part of the incident - the controller forgot to set the runway as occupied and then he fell asleep. Yes, this behaviour is completely unacceptable but there are some other holes in the Swiss cheese that we can look at.
The vehicle contingent that entered the runway had no radio capable of receiving or transmitting on the tower frequency - they could only communicate with the ground controller and couldn’t hear any aircraft that may be inbound. Also, none of the vehicles had warning beacons installed. They did have “flashing lights” but they elected not to use them because they disliked the impact on their sight.
The workers failed to vacate the runway when the runway lights were activated despite this being a documented process. They did notice the landing lights of the aircraft and sought confirmation from the slumbering controller. Obviously, they did not receive a response and so, rationalised the lights as some form of approach system test.
All but one of these workers paid the ultimate price for this behaviour and their manager was subsequently imprisoned for 12 years. I shudder to think what the life of the survivor was like.
The investigation report I read on line was of unknown origin, in Russian translated by Google and quite short for an accident of this consequence. In some other online resources, I noticed that the investigation was carried out by both a government transport agency and the KGB. This was peak Soviet Russia, so my perception of this investigation is heavily influenced by 1980’s action movies.
However, the most interesting thing, to me, in this investigation report is that it could so easily have focussed on the actions of the controller and the works supervisor but it doesn’t. It looks into the system - especially work supervision and resourcing.
It wasn’t as popular a concept at the time but I can see the early application of organisational-accident thinking and the hints of workplace culture. The consideration of the latent failures by management in the equipment of the vehicles and the resourcing of the air traffic services are clear. Commentary outside of the investigation mentions follow up reviews saw many higher-ranking people were removed from their positions as well as the penalties imposed on site managers.
Lessons for Airport Operators
I find two primary lessons for airport operators - equipment standards and operating discipline.
The standards for lighting vehicles vary between states with Annex 14 only requiring marking of vehicles and lighting if used at night or in low visibility (both of these conditions existed during this incident). The lighting standard to be applied is listed, generally, as a 40cd flashing yellow obstacle light.
Some State standards include:
Europe - replicates ICAO in the text and then provides acceptable means of compliance detailing flags, colours and lighting requirements (similar to ICAO).
US - requires lighting for airport operations vehicles on the movement area (manoeuvring area for many other jurisdictions) in the form of a flashing yellow light on the upmost part of the vehicle visible from 360°.
Canada - gets a little more technical with a 40-400cd range, flash timing of 75 flashes per minutes, 360° visibility and peak intensity angles, etc.
Australia - has some slightly confusing requirements. Under one provision lighting is not required if the vehicle is a single conspicuous colour or marked by flags. But in another it requires lights on the movement area. The light must be a flashing or rotating amber/yellow/orange light of the type purchased at automobile accessory stores. It further recommends specifications similar to Canada.
However, after investigating a landing on an occupied runway incident (no collision, thankfully) a couple of years ago, I recommended that vehicles on the runway need to meet higher specifications than these - not merely brighter but more conspicuous. In the end, we, as the aerodrome operator, established the requirement that vehicles on the manoeuvring area must be equipped with at least two amber lights of 400cd flashing in a disruptive manner (ie not synchronised) etc. Thanks to advances in LED technology, compliant lighting was easy to source from local automobile accessory suppliers.
At the very least, this accident highlights the need for appropriate lighting for vehicles that access the runway. In a modern sense, safety management principles should kick in to assess what is appropriate using established standards, best practices and real-world experience.
Maintaining a listening watch is a simple and often effective supporting safety measure. The physiology of the ear enables auditory signals to often cut into our attention - think about hearing your name in a crowded room. Having a method of listening to air traffic helps to build a better picture of operations and increase your situational awareness.
For airport safety officers and work crews, radios with an external speaker, for when you get out of the vehicle, are absolutely essential for maintaining this situational awareness.
I’m a big fan of this concept. It isn’t about military-like discipline with everyone marching to the eat of management’s drum but rather establishing clear performance standards for work and ensuring they are met. I have written on this subject on New Airport Insider with my key take away messages being focus on outcomes, build the processes and continuously improve through feedback.
It is never as simple as someone didn’t follow the rules. You must also ask why they thought that was okay, were they trained in the procedure, had they done it before, is it common place?
It could be that the workers were never trained in the procedure or that they believed management had set a higher or conflicting priority for them. Usually, people want to do the right thing and often factors around them get in their way or move them off course.
More to Come & Feedback Welcome
As I said above, I’m planning on doing more of these reviews and I’ll be looking at accidents with a particularly airport operations flavour and maybe things that haven’t appeared on Air Crash Investigators or Black Box.
And I am always happy to hear about your experiences. In addition to the incident investigation I ran above, I have also been on a runway a couple of times when aircraft have landed. In both of those cases the aircraft failed to make any radio calls and because they were uncontrolled aerodromes, we had no other warning. Let me know if you’ve experienced the same.
Image credit: (cc) Eduard Marmet
* This accident occurred a long time ago in Soviet Russia and using English (such as here and here) or suspect translations of sources (linked above) has produced a few inconsistencies in the accounts of the event. I’ve put together my best guess of what happened to tease out some worthwhile lessons. Please don’t consider this post an authoritative account of the accident.