Estimated reading time 16 minutes, 11 seconds.
Rethinking a maneuver in response to an emergency is one thing. Convincing the piloting world that they need to change a long-held practice is quite another. But Claude Vuichard did just that in developing a new escape from the vortex ring state. Here, Vuichard and former Robinson chief flight instructor Tim Tucker tell us how they brought the Vuichard Recovery technique to the world.
I’ve been a commercial helicopter pilot since 1981, and have spent most of my career performing utility, search-and-rescue, and training flights in the Swiss Alps. It’s a spectacular place in which to earn a living, but it can also be extremely testing on both pilot and machine, and unforgiving in certain circumstances.
It was while working in this environment one day that I suffered a harrowing experience as I got caught in the vortex ring state.
Vortex ring state occurs when a helicopter is drawn into its own downwash, and requires certain flight conditions. These include low forward speed (up to 10 knots for a low disc loading helicopter and up to 30 knots for a high disc loading helicopter); a relatively rapid rate of descent (at least 500 feet per minute for a low disc loading helicopter and up to 1,500 feet per minute for a high disk loading helicopter); and up to 40 percent torque (power setting).
Over 95 percent of vortex ring state accidents are pilot-induced. The remainder are caused by collapsing winds, loss of visual references, or performance problems. Most vortex accidents occur on the approach downwind.
My fateful encounter with vortex ring state took place one day in 1987. I had been working on a logging job with a SA315B Lama on a very steep slope, doing the same thing I’d done many times before. While flying the empty long line in the forest, the strong thermal updraft I was in suddenly collapsed, and the helicopter dropped. I immediately pulled more power, but the helicopter was already in vortex ring state. An escape to the front was not possible due to the slope, but just as I feared the worst, the helicopter stopped its descent — only a few meters away from the trees.
The incident shook me. I didn’t sleep for the next two nights as I replayed it over and over in my mind. I began to think that there had to be a better way to exit the vortex ring state, and I resolved to find it.
Pilots have always been trained to recover from the vortex ring state by lowering the collective and pushing forward on the cyclic. The problem is that due to the tailwind, they are following their vortex ring — and the ground usually meets them before they leave the vortex ring state!
Reasoning that the tail rotor continues to work normally in the vortex ring state, I thought I could use it to help me reach the upwind part of the vortex to the side of the aircraft. If I then supported this with cyclic, the helicopter would reach the upwind part of the vortex very fast.
As a flight instructor, I resolved to put the helicopter into a vortex and put the technique to the test.
I tried it at the next opportunity, and found it worked not only on the Lama, but on all 20 different helicopter types I have flown in my career.
It’s a very straightforward maneuver. As soon as you find yourself in a vortex ring state, you immediately pull up the collective to provide maximum available power, apply counter torque with the pedal to maintain your heading, and push the cyclic in the opposite direction for a 15- to 20-degree bank. For a counter-clockwise main rotor system, you should bank to the right; while a clockwise-turning main rotor system requires a left bank to exit.
The whole maneuver should be done in two seconds. You should reach the required bank of 15 degrees after the first second, and the helicopter should be level again a second later. As soon as the rotor reaches the upwind part of the vortex, the recovery is complete. The average height loss during the recovery procedure is 20 to 50 feet, depending on the duration of the maneuver.
The technique works in all operational conditions— even to prevent entering vortex ring state in collapsing upwinds. It’s my firm belief that it should be trained until it becomes a reflex.
There are a lot of operational situations where the traditional recovery technique just doesn’t work. These include when you’re on final approach with a tailwind; when you have obstacles in front; when you’re at low height over the ground; when you’re hovering out of ground effect, and the updraft collapses; during many hoist operations; and during many underslung operations.
My technique works in all operational conditions — even to prevent entering vortex ring state in collapsing upwinds. It’s my firm belief that it should be trained until it becomes a reflex. As soon as a pilot in slow forward flight and/or hover out of ground effect feels lightness in the seat — normally 0.3 to 0.8 G — they should immediately and reflexively apply my recovery technique to prevent an accident.
Over the years, I have practiced it countless times in training, to the extent that it has become a reflexive response for me. Then, in 1999, when I found myself in a vortex ring state during a night search-and-rescue flight, it saved my and my crew’s lives from what would have otherwise been a fatal situation.
I knew I had a technique that, if applied reflexively, could prevent almost all vortex accidents and save lives. The trouble was, the only people who believed me were the flight instructors I trained over the next 20 years for the Swiss Federal Office of Civil Aviation (FOCA). Through this, the technique spread throughout the Swiss industry, but it remained an isolated island of knowledge. There was no international breakthrough.
Then, almost 25 years after I developed the technique, I joined Tim Tucker, who was then Robinson Helicopter Company’s chief flight instructor, for a flight during a safety course. And everything changed.
In July 2011, I was teaching one of Robinson’s international safety courses in Neuchâtel, Switzerland. After two days of theoretical training on the ground, the course consists of a flight period with each attendee. The flight includes advanced autorotations and recovery from the vortex ring state. When a local pilot says something like, “Let me show you how we do it here!” I’m understandably a little wary.
One of the course attendees in Neuchâtel was a senior flight inspector and examiner from the Swiss FOCA named Claude Vuichard. After demonstrating the traditional recovery technique from the vortex ring state, I gave the controls of the R44 to Claude.
“Can I show you how we do it here?” he asked. Against my better judgment, but in light of the fact he had thousands of flight hours and, like myself, a few grey hairs, I convinced myself to say “OK.”
He proceeded to show me the technique he had developed, which was radically different from the recovery method I had used my entire career. Instead of lowering the collective as I have always done, Claude raised the collective, kept the nose straight with left pedal, and initiated a shallow right bank with the cyclic. The aircraft seemed to just pop up and out of the vortex and the VSI was reading zero. I was amazed! After practicing it three or four times, I was making recoveries from a fully developed vortex ring state with only a 30- to 40-foot loss of altitude.
When I returned to the U.S., I showed the new technique to a few of the other Robinson safety course instructors, and told them to explore and practice it on their own for a month or two. When we reconvened a few months later, we all agreed this new technique, although a little awkward at first, was definitely more efficient in recovering from the vortex ring state.
Over the next year, we refined the teaching technique, determined common student errors, and in late 2012 began teaching the new recovery method in the monthly factory safety course at Robinson. Then, in early 2013, I started including it in all foreign safety courses.
At this time, there was no name for the technique — we just referred to it as “an additional” technique or “an alternate” method — and both the new and old techniques were taught in the course. I also tested it in the 10 non-Robinson make and model helicopters I’m authorized to give practical tests in, and confirmed the procedure worked better in all of them — from a Sikorsky S-76 to an R22.
By the fall of 2013, I became convinced this new method to recover from the vortex ring state was much more efficient, and if implemented across the helicopter industry would prevent accidents and save lives. I decided to try and convince the worldwide helicopter community that there was a better way.
First, I felt selling the technique would be easier if I branded it with a name. I didn’t want to use my name or Robinson’s name because people would think it was just a “Robinson procedure,” when, in fact, it works across the board. It just seemed natural that since Claude Vuichard showed me the maneuver, I should call it the “Vuichard Recovery.”
“At this time, there was no name for the technique — we just referred to it as ‘an additional’ technique or ‘an alternate’ method — and both the new and old techniques were taught in the course.”
In October 2013, I revised the Robinson Helicopter Company’s R22 and R44 Maneuver Guides and formalized the name by stating: “Another recovery technique is called the Vuichard Recovery, after a FOCA inspector in Switzerland.” A few months later I was struck with a terrible thought: I really shouldn’t name something after someone without first getting their permission, so I hurried off an email to Claude telling him what I had done and seeking his OK. Luckily, he consented.
Now began the uphill battle to convince the helicopter world of the benefits of the Vuichard Recovery. I wrote a number of magazine articles, and with the support of the Robinson Helicopter Company, I traveled around the U.S. giving a presentation of the technique at Federal Aviation Administration (FAA) safety seminars, to law enforcement agencies, pilot organizations and just about anybody who requested one.
During a four-year period, Robinson’s Bob Muse and myself included it as part of 29 foreign safety courses in six different continents.
In August 2015, Robinson sponsored the U.S. Helicopter Safety Team’s (USHST) annual summer face-to-face meeting. After a Vuichard Recovery presentation in the classroom, 19 USHST members received an in-flight demonstration in an R66. The team voted unanimously to endorse the Vuichard Recovery and later published a four-page Airmanship Bulletin to help introduce pilots to the technique.
Finally, the technique was included in the FAA’s updated Helicopter Flying Handbook, published in October 2019. It presents the Vuichard Recovery as “the quickest exit from the hazard” of vortex ring state, explaining the technique along with common errors.
Flight schools around the world now teach the Vuichard Recovery, while operators like the Los Angeles Police Department and Los Angeles County Sheriff’s Department rely on it as their preferred recovery technique. It’s quite a change from the days when I’d ask my Robinson safety course class: “How many of you have heard of the Vuichard Recovery?” and no hands were raised. Now, when I ask the same question, every hand goes up. More importantly, four or five times a year, a pilot somewhere in the world contacts me with a tale of thanks.
Eight years from first seeing the technique high above Lake Neuchâtel to reading about it in the FAA Helicopter Flying Handbook is quite extraordinary. It’s a real testament to all in the helicopter community who were able to look past tradition and recognize a safer, better way.
My hat goes off to the FAA for being the first civil aviation agency to officially approve the Vuichard Recovery technique, with its publication in the 2019 Helicopter Flying Handbook. I’m certain this will avoid many vortex accidents and save many lives in the future. I hope that other aviation authorities, including the European Aviation Safety Agency, will follow the FAA’s proactive safety step.
In my opinion, we need to go a step further. I believe the traditional procedure should no longer be instructed. In a critical flight situation, it is impossible to use more than one procedure — and one that does not work in six operational conditions is of limited benefit.
Any vortex near the ground is a very high stress situation. It’s like you’ve been hanging from a crane, but it suddenly drops you. In this type of stressful situation, most pilots will fall back to the routine they were first trained in, even 20 years ago. Therefore, we need to retrain our brains, and make the Vuichard Recovery a reflex.
Since retiring from the Swiss FOCA, I formed the Vuichard Recovery Aviation Safety Foundation to promote not only my vortex ring state recovery technique, but aviation safety in general. The foundation is producing a new trilogy of 15- to 20-minute films detailing how vortex ring state can be avoided, and once in it, how to escape. These films should be available this summer.
Tim Tucker and I regularly receive emails or calls from pilots around the world telling us about their encounters with vortex ring state — and how the Vuichard recovery saved their lives. It really is the most wonderful confirmation that our efforts have made a difference.