Another Line of Defence: Luc Vermeulen V35 Bonanza Testimonial

21st December 2020

How did you get started in aviation? 

I was fascinated by aviation from an early age. My late father was a military pilot in the Belgian Army and I remember vividly the typical sound of the rotor blades on his Alouette II Helicopter starting. A couple of times he even passed over our house to say hello.

My first real hands-on flying was in gliders, which I did for many years, but started motor flying when I was about 27-years-old. Eventually I bought a motor glider, which I flew on several long-distance flights from Belgium to Germany and Hungary.

When my mission profile changed (my company is based in Hungary, as are two of my sons), I wanted an aircraft more capable of doing 150Kts and 600 miles, so I bought a Mooney 201. It is a fine aircraft but I felt that 200Hp and loading capability is a bit low when flying in the levels.

When I gained my instrument rating in 2013, a different world opened and I found a V35 Bonanza, which needed some TLC but had a good auto pilot and is a very capable aircraft. Since then I’ve upgraded the airframe with a new interior, tip tanks and some avionics upgrades, a sandel 3500 EHSI, 8.33 radios, and a modern engine monitor. The last major upgrade was TKS Ice Protection.


What do you love most about flying? 

I enjoy the interaction of human and machine and how you can disconnect from earthly matters and focus on the flying experience. The technology available in today’s modern GA is much enhanced in comparison with 30 years ago, but I loved purity and freedom gliding gave; using nature and flying with minimal impact to the environment.

Flying IFR opens another dimension; one where you as the pilot become part of a complex system allowing to travel from A to B in the most efficient way. I love to manage the onboard systems and everything that comes with operational IFR flying. It’s a challenge to remain current but is very rewarding.

From experience level, breaking out of the cloud deck on top, seeing the sun and having a 360 panoramic view for a hundred or so miles in a bright blue sky is fascinating and exhilarating. I feel very privileged to be able to participate in this type of flying operations.


Why did you choose TKS? 

After flying my V35 for about five years, I missed having an anti-icing system on my aircraft. Past experience influenced my decision not to fly on my usual long-distance trips from November onward, as the OAT temps are too low and weather too unstable to plan for effectively. TKS allows year-round flying with a better predictability and CAV’s TKS Ice Protection system is the only effective system available for the V tail Bonanza.

TKS protects the whole airframe, while pneumatic boots do not offer that. If things get really bad on the windshield and impair your view, the windshield TKS spray bar will take care of it. For the Bonanza the TKS panels run over the complete leading edge of the wing and the tail, and seven gallons TKS fluid is more than enough to protect the aircraft in flight if at all required.


How does TKS help you as a pilot? 

TKS Ice Protection increases my dispatch rate and provides additional options when taking tactical decisions while en-route in IFR. In Europe, the minimum ENR altitude is often above 6000 ft and TKS helps to remain within IFR system with radar support when the OAT on the ground is low and the weather is marginal.

For my specific mission of around 600 nm East West over central Europe, the weather will often change mid-flight and if I stay a week, long term weather forecasting can be unreliable. On top of this, I have to cross some mountainous terrain, so TKS provides another line of defense when in IMC.

It is an important tool to have to make a go-fly decision and reduces preflight stress when the weather is not ideal. Still, it’s not a wild card to launch in any weather.


Do you have any memorable experiences of icing? 

Luckily, I’ve not had any scary experiences of icing but there have been several occasions where there was the potential to have to abandon the mission or cancel it.

One time before TKS was installed, I was flying from Hungary to Belgium; the outbound leg was in beautiful 18°C late October autumn weather but during the week, the weather deteriorated significantly and temperatures dropped. On the day of departure, the OAT was 3°C on the ground and it was raining with stratus cloud layers at different levels. Looking at the satellite images, I estimated to be on top at 6000 ft.

I took off with a clear plan B that, if I was not on top and able to see at least 60 miles around the mountainous Hungarian Austrian border west of Vienna, I would turn back. I entered cloud at 2000 ft MSL and remained IMC. At 6000 ft, still in IMC I started to pick up ice and noticed some prop vibrations. Things deteriorated, but I was still climbing, even though vibrations increased at 8500 ft MSL

At 9000 ft I started to see more light and popped out. The prop vibrations continued for another 15 minutes and it took a while for the ice on the wing to sublimate in the sun and return to an expected TAS.

Now that I have TKS, in similar conditions I prime the system before takeoff and leave it on till I am on top. No vibrations, no wing ice and far less stress. Still, my safety margins have not shifted much as the system is not FIKI and I will not file a Flight Plan knowing I will be in potential icing conditions with no possibilities for escape. Only a few weather providers give icing predictions in Europe, so a thorough weather briefing is always required. The reality however, is that once in the air the actual situation is sometimes very different.

Recently I was vectored into a negative temperature -4°C cloud layer over rising terrain in the middle altitudes, and with TKS, this was a non-event; a couple of minutes before entering the clouds I flipped the switch and that was it. Not having TKS would have started a discussion with a very busy approach controller, piling on lots of stress, while potentially collecting ice in the meantime.

On the same trip, on my return leg the OAT at FL100 dropped en route from 12°C to -3°C. I downloaded the satellite radar picture to assess the situation and was unable to avoid entering IMC at some point when passing a weak small cold front. Again I flipped the TKS switch before entering IMC and after a maximum of 20 minutes in the clouds, I was able to proceed in between layers. The aircraft just flew through it without problems: no level change required to avoid ice. It’s as if the icing was never there.


What do you prefer about TKS in comparison to other IPS? 

I have no experience in running a pneumatic boots systems, but most of them come with hot props, which have more potential components that can fail and require more maintenance. A vacuum pump or slip ring not working correctly can cause asymmetric loads on the prop in case ice builds up. TKS’ prop de-ice does not have this problem, as it works with a slinger ring and gravity. In addition, TKS protects areas which remain exposed with a boot system, such as antenna’s, the wing chord and tail areas, where you have run back ice.


What would you say to someone considering installing TKS on their aircraft? 

If you are using your aircraft for longer distances and intend to fly IFR, it’s an obvious choice. My Bonanza was built in 1966 and TKS retrofit was still worth the investment. To find a similar capable modern airframe, that includes TKS would have cost significantly more.

The cost of TKS fluid is often mentioned as a drawback but as the system is only run every month for a couple of minutes and only in potential icing conditions, this cost is minor, particularly in comparison to the peace of mind it gives.

There is weight penalty which for some lighter engine GA models may have an impact on the useful load, but for the Bonanza it transforms it into a safer traveling machine.

Do your homework when finding an installer, check if they have experience with TKS installs. The installation is a major alteration and should be performed in the best of circumstances.

On aviation forums the topic “how to improve the capabilities of your aircraft: TKS or Turbo Normalizing” is often a discussed subject with various opinions. It’s a very personal choice if you prefer Turbo over TKS but I am of the opinion that ice can happen at any altitude. In case I need to go through an icing layer in my approach I am covered, turbo doesn’t offer that protection. Of course, if your finances allow, having both is the best to escape ice when it happens. For now I will stay with an NA IO520; TKS was the right choice for me.