Just when he thought bad weather was going to force him to turn his turboprop around and miss giving an important presentation, EGNOS saved the day. General Aviation pilot Julian Scarfe shares his experience of flying with EGNOS.
“I was recently invited by France’s Directorate General for Civil Aviation (DGAC) to travel to south Paris and give a talk on proportionate regulation for General Aviation. As the co-owner of a 1966 Twin Comanche, it seemed like the appropriate way to travel was to fly myself to Toussus Le Noble airport – just a short taxi ride away from the meeting venue. The only problem with this plan was that Toussus Le Noble is no longer a customs airport, meaning a stop at Le Touquet in northern France was necessary to clear customs en route.
“The timing was tight. Taking off from my home airport of Cambridge when it opened, I had only about an hour to spare to arrive in time for my presentation in the early afternoon. I woke up early as I often do before an interesting trip and checked the automatic weather reports at Le Touquet. Although the general weather forecast for the day was good with clear skies and fair visibility, the temperature had been dropping overnight towards the dewpoint of 11°C, and at 6:00 AM the temperature was 12°C. When temperatures hit the dewpoint, fog is inevitable.
“The last report I received before setting off was that at Le Touquet visibility was 1100 metres with broken cloud at 100 ft. This by itself was not a problem, but my heart sank when I read the Notices to Airmen (NOTAMs): Le Touquet’s instrument landing system (ILS) was out of service. I was just about to send a message to the event organiser with apologies for my absence when I realised that Le Touquet also has a GPS approach that, with the help of EGNOS in the form of LPV, has a decision height of 250 ft – almost as low as the ILS. So I set off, carrying sufficient fuel to fly to Le Touquet, hold for several hours if necessary, and fly back to Cambridge if a landing at Le Touquet proved impossible.
Bad weather ahead
“The flight as far as the Channel was uneventful. As I was handed to Lille Approach I was informed by the controller that the weather at Le Touquet was ‘pretty bad’, with a visibility of 1400 metres and overcast cloud at 200 ft. I knew this was right on the margin for an LPV approach. On the one hand, the approach and runway lighting might just be visible from the 250 ft decision height. On the other hand, it might not be… When I told the controller that I would fly the approach, he warned me that I might need to hold at the initial approach fix TUKVI because an aircraft ahead of me, a larger state aircraft, was also attempting the approach.
“In the event, no holding was necessary, and I was cleared for the approach. I asked if the preceding aircraft had made a successful approach. ‘No,’ the controller told me, ‘he has gone around on a missed approach.’ Hearing this, I adjusted my expectations to being
unable to see the lights and missing the approach too – an important mental discipline for instrument flying.
“As with most approaches in fog, the conditions feel a little strange – one flies in clear air above the thin cloud layer, in my case entering the top of it at about 650 ft in the descent. One then must rapidly adjust to instrument flying for about a minute, as the view outside disappears into the fog. The needles of the LPV indication were delightfully stable and, as I descended into the gloom, I felt confident in the guidance system, even though I knew it might not lead me low enough for a landing.
A successful experience
“At 270 ft in the descent to the decision height of 250 ft the approach and landing lights suddenly came into view. It is difficult to express in wordsthe beauty a pilot sees when these lights come appear. Even at a time of relatively high workload, I couldn’t help but smile.
“The landing was uneventful in the reasonable visibility below cloud. On the tarmac, I taxied in to a deserted apron, walked in to show my passport to the customs officers, and paid my landing fee, which included a €5 extra charge for the approach lights – worth 100 times that to me on this occasion!
“As I was leaving, to my surprise, I heard the engines of an aircraft going around off the approach again, most likely because it was not equipped to benefit from an EGNOS-enabled LPV approach.
“This was my first experience flying an LPV approach to minima. I found it to be identical to flying a traditional ILS, except that on my equipment the indications are displayed in cyan rather than green, and perhaps that the LPV indications are a little more stable than the ILS. In the years before the EGNOS safety of life service was operational, I would not have had the opportunity to spend the rest of that day enjoying the conference and an evening in Paris.”
EGNOS and aviation
Aviation is a key market segment for European GNSS. EGNOS, which was designed for aviation, has revolutionized the way we fly. It has created more access to small airports, increased safety and facilitated business across Europe. Across the commercial, regional, general and business aviation sectors and from airports to OMES and pilots – everyone is benefiting from EGNOS. You can learn more about all of these benefits here.
Source: European GNSS Agency (GSA) (http://www.gsa.europa.eu).