This SAR helicopter landed safely, and the casualty made it to hospital. Yet somebody still lost their life.
That’s not how most accident reports start.
In March 2022, a UK Search and Rescue Sikorsky S-92 landed at Derriford Hospital in Plymouth with a critically ill patient on board.
The approach was stable, the landing was normal, and the helicopter wasn’t damaged.
Yet one person lost their life and another was seriously injured.
The cause?
Something I always found challenging to manage around public infrastructure:
Helicopter downwash.
It’s a sobering reminder that even when the flight itself is conducted safely, the hazards we create on the ground can still have devastating consequences.
Let’s take a look at what we can learn from this.
💥 Accident Overview
The Search and Rescue S92 aircraft and crew were based in Newquay Airport in Cornwall:
The crew had just completed a rescue of a casualty in a river near Tintagel:
They determined that the casualty needed to get to hospital quickly, so the crew considered two options.
1️⃣ Treliske Hospital in Cornwall was a similar flying time away, however it required an additional ambulance transfer from the helipad to the Emergency Department.
2️⃣ Derriford Hospital in Plymouth offered a faster overall journey because the patient could be moved directly from the helipad to the hospital on a trolley.
With the patient on board, the crew departed for Derriford Hospital. Both pilots had used the hospital helipad before.
During the short flight, they discussed the approach. A light northwesterly wind meant a westerly landing direction would provide a small headwind.
The commander noted that the helicopter’s downwash would likely be blown towards nearby car parks and public areas surrounding the helipad:
“Our downwash will be going over the car park to the left.”
The commander stated that if they saw anyone who might be affected by the downwash, they would go around and reassess the situation.
The winchman informed him that the patient did need “fairly urgent” medical care.
The crew completed the landing checks at about 500 ft AGL. At this point, the winch operator told the co-pilot that the cars on the left would be his lookout from the left seat (the commander sat in the right hand seat, with a limited view on this).
As they hit 80 kts, the winch operator opened the right hand side door and confirmed that the helipad was clear.
At around 200 feet, the winch operator spotted a person near some cars in the undershoot and pointed them out to the co-pilot.
The co-pilot saw him and assessed that he was simply getting into his car and the doors would be shut before the helicopter landed.
The co-pilot also noticed two pedestrians walking along a footpath beside the helipad, that were deemed far enough away.
As the S-92 continued its approach, descending towards the helipad with 45% power applied, the crew remained focused on the landing area ahead.
Two people standing near the corner of the helipad (position B), stopped to watch the helicopter approach. Moments later, they were blown over. Another person exiting a nearby car was also knocked over (position A). They were likely not visible to the crew
The helicopter landed a few seconds later.
Initially, the crew were unaware of what had happened. It was only after landing, when one of the pilots noticed a bystander running towards nearby ambulances, that concerns began to grow.
The commander and winch operator left the aircraft to investigate.
They soon discovered that two people had been injured by the helicopter’s downwash.
One casualty had suffered a serious head injury and died later on the same day.
What started as a routine medical transfer following a successful rescue, had in less than a minute, turned into a fatal accident.
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🔍 What Caused this Accident?
The investigation stated the main causal factors as:
“The persons that suffered fatal and serious injuries were blown over by high levels of downwash from a landing helicopter when in publicly accessible locations near the DH HLS.”
And:
“Whilst helicopters were landing or taking off, uninvolved persons were not prevented from being present in the area around the DH HLS that was subject to high levels of downwash.”
This wasn’t a case of a pilot making a single bad decision (it usually isn’t).
Instead, the investigation found a series of gaps that had existed for years:
1️⃣ The downwash hazard wasn’t fully understood across the system
The hospital helipad was designed to the standards that existed at the time, but those standards didn’t fully address the risks posed by downwash of larger aircraft.
As a result, the risk to people outside the helipad boundary, particularly in nearby car parks and public areas, wasn’t fully recognised.
2️⃣ Previous incidents that didn’t lead to the right changes
There had been multiple complaints and incidents involving helicopter downwash before this accident.
While each event was investigated, the underlying hazard to people in the surrounding car park was never fully identified.
The existing mitigations remained in place, despite not being effective enough to sufficiently manage this threat.
3️⃣ Different people had different assumptions
The helicopter crew and hospital staff had different understandings of who was responsible for managing people around the helipad.
The commander believed surrounding areas would be secured before arrival, while hospital procedures were primarily focused on keeping people out of the helipad itself.
4️⃣ Safety controls stopped at the helipad fence
The hospital’s safety processes concentrated on hazards inside the helipad boundary.
The risk posed to pedestrians and members of the public just outside that boundary was not effectively assessed or managed, despite those areas being exposed to helicopter downwash.
5️⃣ Poor communication and information sharing
The investigation found that communication between helicopter operators and the hospital was not effective in ensuring all risks were properly identified and managed.
There was no simple mechanism for hospital helipad operators and helicopter operators across the UK to share safety information, lessons learned, or emerging hazards.
From personal experience in the HEMS industry, this can be applied to many other helicopter landing sites as well, not just in this specific case.
6️⃣ A system-level failure
The investigation concluded that the downwash risk around the site was not adequately identified, understood, communicated, or controlled.
The accident did not occur just because a single barrier failed, but because several layers of defence all contained gaps (a bit like how we discuss the Swiss cheese model).
When viewed through that lens, this was less a “downwash accident” and more a “safety management accident”.
💡 So what can we learn from this?
There are quite a few lessons we can take from this horrible accident.
One of the biggest lesson is that accidents don’t always happen because someone didn’t manage a specific threat in the moment.
Sometimes they happen because everyone thought someone else had already managed it.
I certainly discovered this the hard way in HEMS as well, where the healthcare system is responsible at times for aviation based threats.
This introduces an element of risk, as you’re asking another industry with different qualities and expertise to deal with safety critical decisions that affect a different industry (aviation).
But let’s dive a little further:
Previous occurrences are incredibly valuable
Several downwash incidents and complaints had already happened before this accident.
The lesson is simple:
Every complaint, occurrence report, near miss, or piece of feedback is an opportunity to identify a weak signal before it becomes a tragedy.
The goal isn’t just to investigate events.
🔸 Where are the gaps?
🔸 What can we do to improve?
🔸 Has the threat been adequately managed?
On an organisational level: Never assume someone else has mitigated a risk
One of the key findings was that different organisations had different assumptions about who was responsible for managing people around the helipad.
Whenever multiple organisations are involved, it’s worth asking:
Who is actually managing this hazard?
If the answer isn’t crystal clear, there is a good chance nobody fully owns it.
Safety is a team sport
One of the strongest themes from this accident is that safety doesn’t stop at the cockpit door.
Pilots, operators, hospitals, airfields, regulators, and ground staff all held pieces of the puzzle.
Unfortunately, nobody had the complete picture.
The best safety systems are built on collaboration, open communication, and constantly challenging assumptions.
Look beyond the landing area
The helipad itself was clear, but the problem existed outside of it.
As pilots, we naturally focus on obstacles, wires, surface conditions, approach paths, and touchdown points.
This accident is a reminder to think one step further:
Who or what could be affected by my aircraft, even if they aren’t inside the operating area?
The heavier the helicopter, the wider your circle of concern is.
The unfortunate reality: Just because a site is approved doesn’t mean it’s risk-free
The crew had operated into this helipad many times before.
The site was approved, established, and routinely used by large helicopters.
But the threats still existed.
As pilots, it’s easy to assume that risks associated with infrastructure have already been identified and managed.
Why else would they be “approved”?
This accident is a reminder that approvals and procedures are not guarantees that every hazard has been found already.
It’s tricky, on the one hand you need to trust the system, on the other – you are always required to verify it.
Downwash is a hard to predict threat that requires active management
We covered how downwash works here ⤵️
The reality is that a lot of research is still ongoing into perfecting downwash models.
Simplification is always going to be an issue, as it can be more unpredictable than we’re able to understand at the moment.
The only applied solution would be to be overly cautious with spacing from objects you can influence with downwash.
Any doubt = no doubt ✅
💭 Conclusion
What strikes me most about this accident is how normal everything looked right up until the moment it wasn’t.
The aircraft was serviceable, the approach was stable, the crew were experienced.
They had even discussed the downwash risk before arriving.
Yet a person still lost their life.
In the HEMS and SAR world, we often operate in environments where there aren’t a lot of systems around us to mitigate things that can cause harm.
It’s what makes it so challenging.
The hazards that matter the most can sometimes be hard to accurately predict.
You can find the full AAIB report here.
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