By Tomas Kellner
A pilot landing in Queenstown, the popular mountain resort in New Zealand, recently stuck a GoPro camera in his cockpit and recorded the last thrilling minutes of his flight. The video, which has since gone viral, shows the plane skirting jagged mountain peaks and piercing a thick blanket of clouds above the runway, before safely touching down.
The flight would be all but impossible if the pilot were not relying on a digital GPS-based navigation system, called Required Navigation Performance (RNP). It was first designed by Alaska Airlines pilot Steve Fulton (pictured above) and developed by GE Aviation.
Fulton, who now works for GE, knows Queenstown well. He served as the test director and rode in the jump seat with Qantas crews when GE rolled out the system at the airport in 2004. GE Reports managing editor Tomas Kellner talked to Fulton about the video, flying in the mountains, and the nerve-wracking night landings in Alaska that gave him the inspiration for RNP.
Tomas Kellner: Steve, what we are seeing in the video?
Steve Fulton: First of all, it’s an amazing video. I got all jazzed about it. What you are seeing is an airplane following precision guidance along a path that was engineered by GE Aviation. Precision guidance is a combination of path definition and guidance computers. The solid cloud cover with the mountain peaks sticking through make for dramatic viewing, but to the informed viewer, it tells another story. Prior to 2004, flights to or from Queenstown would not have been possible in these conditions. The flight in the video and many hundreds like it since 2004 were only made possible with technology that was pioneered by GE.
TK: What would happen on a day like this before RNP?
SF: Queenstown-bound flights would have been diverted, frequently to Invercargill, which is on the coast south of Queenstown. Passengers would then have to board a bus for a 2 hour 15 minute ride back north to Queenstown.
TK: Have you landed at the airport?
SF: Oh yeah. I led the GE Aviation team that opened up this airport to the technology. We signed the contract on Christmas Eve 2003. My first actual trip to Queenstown was in July 2004 to support the initial validation flights in the Qantas Boeing 737 with both the Australian and New Zealand regulators. Qantas began passenger flights to the airport September 4, 2004. I have on the wall in my GE office the navigation charts used by Qantas on the first flight. The charts are a special gift from the project pilot, Cpt. Alex Passerini.”
TK: You are still an Alaska Airline pilot and you’ve flown all over the world. How does Queenstown compare to other destinations?
SF: Those pictures from Queenstown actually look a lot like southeast Alaska. The RNP technology was developed by my team at Alaska Airlines in the early 1990s. It was approved by the FAA for passenger flights in Juneau, Alaska in 1996. That terrain, that scenario, that type of flying is a normal day of work for an Alaska Airlines pilot today at a number of airports in southeast Alaska.
TK: Tell me about those beginnings in Alaska. What was you inspiration?
SF: The inspiration was both frustration and concern. As pilots in southeast Alaska, we were regularly operating in difficult weather conditions with limited navigation aids. We understood that there was very little margin for error. We had training, experience, and the best in that generation of ground-based navigation equipment and the associated aircraft instrumentation. But still, even with all of that, there were times when a pilot could be put in a very tight spot.
TK: Can you give me an example?
SF: Imagine flying into Juneau, Alaska, at night in the early 1990s. Our aircraft was guided towards the airport by a radio beacon that lined us up on a course that was 15 degrees offset from the runway. At given distance intervals approaching the airport, we could descend the aircraft to prescribed altitudes, which we determined by the barometric altimeter. It was critical to not descend prematurely or below the given altitude as there were the Chilkat Mountains peaks in the darkness below you. In the previous 20 years, 120 lives had been lost in three separate aircraft accidents flying this same route to Juneau. We were well aware of this history.
TK: That sounds very stressful. You had no room for error.
SF: That’s just the beginning. The minimum altitude permissible for descent by instruments was 1,000 feet and contact with the approach lights had to be made at 3.4 miles from the airport in order to continue to a landing. The tricky part was that the last portion of the flight to the runway. It had to be done by using visual references, with the route essentially boxed in by high terrain close to the airport.
At that point we were limited to a minimum of 500 feet of altitude until safely through a notch in a ridge prior to the runway. Only then we could descend the final altitude to the runway while making the final 15 degree course change to line up with the runway.
TK: What if you missed?
SF: If a missed approach was required at any point along that last 90 seconds of visual flight to the runway, there was no published escape route. Each pilot had in their mind a plan, but for each of us it consisted of maximum go-around thrust in a climbing 180 degree, minimum radius turn in the darkness until safely above the terrain.
More than once I inadvertently descended into unseen clouds in the darkness and lost visual contact with the runway lights in this portion of the flight where visual contact was essential.
TK: How did you deal with it?
SF: This type of scenario put a lot of stress on a pilot. In Juneau with conditions producing scattered layers of cloud below 1,000 feet, particularly at night, I could feel the stress and a trickle of sweat down my armpits.
Juneau is the capital of Alaska and yet there are no roads to the outside. The community depended on airline service – it had to be reliable and safe and I knew we could make it better than it already was. That was the motivation for RNP. I was frustrated that sometimes we could not get in, which left the city isolated, sometimes for multiple days at a time when the clouds were low.
Fulton has in his GE office the RNP navigation charts used by Qantas on the first passenger flight to Queenstown. The charts were “as a very special gift from the project pilot, Cpt. Alex Passerini, in recognition of the huge accomplishment of this project,” Fulton says. The pilot in the video is flying a similar route.
TK: How did you solve the problem?
SF: I have a background in engineering and prior work experience developing and certifying aircraft avionics systems. I knew what modern airplanes were capable of and in the early 1990s. GPS was also just becoming available for use. With GPS, computers and electronic displays introduced into air transport aircraft in the early 1990s, the airplane performance had significantly outdistanced the existing navigation and operating rules that were set up in the 1940s and 1950s. You had a situation where an airplane was much more capable than what the system was recognizing.
TK: This seems like a good thing.
SF: That gap between actual capability and assumed capability represented unnecessary risk. It represented cost and it represented inconvenience to our passengers and the community. It also represented an environmental cost. We were burning more fuel and making a lot more noise than what we needed to. All those factors were motivators to me.
TK: How does the RNP system work?
SF: The GE Aviation Systems’ flight management computer on the Boeing 737 does the path computation and creates the lateral and vertical path guidance from a stored set of navigation data in an on-board database. The route design and navigation data is created by a team of experts at GE Aviation’s Flight Efficiency Services, which is currently the leading provider in the world for these products. GPS is an important enabler for this navigation technology, but there is a lot more going on.
GE engineers designed this “highway in the sky” approach to Queenstown.
TK: Can you let us inside the cockpit?
SF: There are essentially four basic functions in the aircraft cockpit that make this operation possible. The first is GPS. You have to know where you are in space, and GPS, unlike the ground beacons we had before, give us the ability to determine our position very precisely anywhere on the face of the planet without reference to any other system on the ground.
Then you have to define what path you want to fly and provide some reference to the centerline of that desired path. That path definition, in both lateral and vertical dimensions, is the second piece.
Thirdly, the flight crew needs to know where they are on that path. There is an electronic display in the airplane that’s like a moving map.
The last piece is guidance. Pilots need precise guidance so they can manage the progress of the flight within the specified performance of the route. They can do it manually or they can use the autopilot.
TK: About three minutes into the video you can see a big sunlit mountain emerge from the fog right in front of the plane. To an untrained observer, this seems pretty terrifying.
SF: You are right. People I’ve shown the video to have been quick to pick up on the scene you are talking about. There is a break in the cloud and you see this enormous mountain ahead and to the left. It kind of makes you go, wow, it must be something. But to me, I know that I have instruments inside the airplane integrating information from a variety of sources. I’ve got another view of that mountain on the heads-down digital map display. I know exactly where my desired path is, how the airplane is progressing along that path and that it is tracking nicely, and I can see where I am relative to that mountain.
TK: How do pilots respond to the system?
SF: It’s a pretty big departure of what we’ve had in the past in terms of style of flying. There’re multiple pieces of information the pilots have that confirm that they are on the correct path and that the airplane is performing properly, even though the view outside of the window looks kind of exciting.
But to answer your question, the pilots are well-trained, fully qualified and approved by regulators to fly these procedures. They respond to the system very favorably. Everybody understands that this is the right way to be flying. In the past we did not have the advantage of this type of precise flying. You really were guessing sometimes before this technology. It was an uncomfortable feeling.
TK: The pilot can always take control of the system, right?
SF: Yes, there is no question about that. The pilot is ultimately in command. You are responsible for monitoring the progress of the flight. If at any point along that flight things are not meeting the required performance, you take action and you take the airplane out of there safely. At every point along the approach path, there is a fully engineered safe extraction route available. It’s a comfortable feeling to know that you are not getting into a place where you feel like you are in a box. There is always an out.
TK: Early on you mentioned Qantas, the Australian national carrier, but Australia is pretty flat. What are the benefits of deploying RNP there and where else has GE installed RNP?
SF: Queenstown was the first RNP deployment in the south Pacific and one of the earliest projects for this group within GE Aviation. The terrain gave us an opportunity to demonstrate to the aviation stakeholders in that region how capable and intelligent these airplanes and operations are when we implement all of the provisions of the RNP procedures. Once they got comfortable with the operation in the difficult environments, they began to embrace the technology as an integral component of a larger airspace management system to improve efficiency and environmental performance in a more complex and crowded airspace.
“Everybody understands that this is the right way to be flying,” Fulton says. “In the past we did not have the advantage of this type of precise flying. You really were guessing sometimes before this technology. It was an uncomfortable feeling.”
TK: So RNP is not just about flying in the mountains. It’s also about fuel savings and efficient operations.
SF: That’s right. This is a typical pattern that we have seen repeated in numerous regions around the world. Since 2004, we have completed over three hundred of these route systems across Canada, New Zealand, Australia, China, Malaysia, Peru, Chile, Brazil, and the US. Most of the deployments are in areas where terrain is not a factor – the objectives are operational efficiency and to minimize the environmental impact of air traffic operation.
However, as this video illustrates so well, the projects in the mountainous regions attract a lot of attention. Many of the projects are quite interesting such as Lhasa, and other location in western and southwest China, as well as Rio’s downtown Santos Dumont airport, where you land right by scenic Sugarloaf Mountain.
TK: Are you going to be filming from the cockpit anytime soon?
SF: This video has been an inspiration for me to get my own GoPro camera and take some shots as I fly. Once in a while conditions are perfect to see some things which are truly amazing!