On January 17, we undertook one of the most interesting and, in some ways, challenging flights of the trip...the 2,078 NM (2,390 SM) flight from Maun, Botswana/FBMN to St. Helena/FHSH with a fuel stop in Luanda, Angola/FNLU.
Maun, Botswana to Luanda, Angola
The flight from Maun to Luanda was easy and uneventful other than it took us almost an hour to contact Luanda Control after entering Angolon airspace. Evidently Angola does not have any VHF communications outlets in the southwestern part of the country where we entered. It was severe clear and early in the morning so we were not worried about traffic conflicts and just kept trying until we reached them.
Weather for the morning hours was forecast to be excellent which turned out to be the case.
Getting a visa to enter Angola is ridiculously difficult, but they have an exception that allows "crew" to remain in the country for up to 72 hours without a visa. Although we did not intend to overnight in Luanda, just in case something unexpected happened, we wanted the ability to stay over. Thus, prior to leaving home, the Becky and Carolyn got pilot licenses (student level), uniforms, and air crew ID badges so that they could legitimately be counted as crew for this part of the trip. They looked sharp in their second officer uniforms with two stripe epaulets on the shoulders.
Once we landed at Luanda, we were pleasantly surprised by friendly and efficient service and a very nice "VIP" waiting area.
Once again we were the smallest airplane on the ramp, even in Angola. The Luanda general aviation ramp was full of big jets.
We wanted to arrive at St. Helena as close to our ETA as possible because the airport was normally closed on Thursdays and they had opened it especially for our arrival. So we had planned our arrival at Luanda to allow plenty of ground time so we could launch for St. Helena right on time. That all worked as planned and we even had some time to relax in the comfortable waiting area before taking off again.
The St. Helena Airport Controversy
Before describing our flight from Luanda to St. Helena (in a separate post as this one is getting long!), it is worth mentioning that the construction of the St. Helena airport was (and continues to be) very controversial. Google "St. Helena airport controversy" and you can read many views of the airport both pro and con. I will attempt to summarize the issues without taking a side.
Prior to the opening of the airport in 2016 at a cost to the British taxpayers of more than $300 million USD, the only way to travel to and from St. Helena was a five day trip aboard the Royal Mail Ship St. Helena. The "RMS" (as locals called the ship) made the round trip to St. Helena from Cape Town, South Africa approximately once a month. Thus, committing to visit St. Helena involved a minimum of ten days of travel and typically a one month stay. While the time on the ship was reported to be enjoyable, it was expensive and required a big time commitment. Thus, tourism at St. Helena was modest.
St. Helena is Overseas Territory of the United Kingdom. The UK government and taxpayers provide substantial subsidies to the government of St. Helena in order to maintain basic services an acceptable standard of living for the 4,500 residents.
According to this report, the total subsidy is about $35 million USD annually which included a subsidy for the operation of the RMS when it was in service. Furthermore, the RMS itself was nearing the end of its service life and there would be an additional cost to the UK taxpayer of about $80 million USD to replace it. Over the long term, a ship would likely need to be replaced every 20-30 years (the RMS was retired after 28 years in service) while construction of an airport was thought to require less on-going capital investment as compared to a ship which eventually "wears out."
Thus, the economic rationale for building the airport was that it eventually would result in an increase in tourism on the island boosting the economy enough to allow a reduction or, over the very long term, elimination of the subsidy to the St. Helena government. Constructing the airport also would avoid the cost of replacing the RMS at least once and perhaps multiple times over the life of an airport. Cargo would still need to arrive to the island by sea, but the plan was to do that with a pure cargo ship (as opposed to a hybrid passenger/cargo ship like the RMS) on a contract basis. The goal was to reduce or eliminate the UK taxpayer subsidy for the shipping operation.
In the end, a majority of the islanders ("Saints" as they are known) supported building the airport (according to this report) which was consistent with a 2002 referendum on the matter. The UK government agreed to fund the construction of the airport and construction contracts were signed in 2011 and the airport was certified as operational in 2016.
But then the winds started blowing the wrong way - literally.
Wind Shear
Many island airports are susceptible to wind shear problems due the nature of the topography of an island. A volcanic island (like St. Helena) with steep and uneven terrain is even more likely to create undulating air currents which can make approach and landing difficult.
The runway at St. Helena is especially challenged for several reasons. First, the ends of the runway sit on a shear 1,000 FT cliff over the ocean. This rapid change in terrain in such close proximity to the runway combined with almost constant moderate to very strong winds can "mix up" the air substantially causing wind shear. We have flown to island airports with runways perched 100-400 FT above the ocean (most recently Robin Crusoe Island as described here), but a 1,000+ FT cliff is dramatic.
To complicate matters further, there are hills protruding to the east of the runway in the face of the prevailing southeast winds that create additional disturbances. An interesting video animation of the combined effects is shown below.
YouTube link: https://youtu.be/Dndm2z7w8j0
Another graphic from this study illustrating the issue...
The study goes into a lot more detail, but suffice it to say wind shear was known to be a potential issue before the airport opened. After the airport was completed and trial flights arrived, the issue became even more acute as dramatically illustrated when a Boeing 737 in British Airways livery made to first test flight with a large commercial aircraft to the island...
YouTube link: https://youtu.be/vgsdclUEVt4
About 00:18 into the video above during the first (intentional) low pass of the runway, you can see the wings tips flex substantially as it encountered wind shear. On the second approach the crew intended to land, but aborted the attempt due to windshear. On the third approach they landed, but there was a lot of "wobble" on short final approach and the landing appeared to be hard.
After this and other early trial flights, the opening of the airport for regular commercial service was put on hold in order to do more detailed studies of the wind shear conditions. The initial press from this delay was very negative as some people interpreted it as meaning the airport may never be usable for normal passenger flights. Fortunately, these worst case concerns were not realized.
After pausing the opening of the airport for more detailed study of the wind shear conditions and test flights with other aircraft, the airport finally received its first regularly scheduled commercial flight on October 17, 2017. The "solution" to the wind shear issue was a combination of 1.) detailed meteorological studies which allow more accurate forecasting of wind shear conditions permitting rescheduling of flights on particularly tough wind days; and 2.) use of the Embraer 190 aircraft which is better suited to handling turbulent conditions and also has a better ability to land "downwind" on runway 02 which is not as susceptible to wind shear.
Based on reports Josh and I heard from airport officials, the pilots of the Embraer 190 aircraft now operating a twice a week schedule there consider the wind shear a manageable issue and have not cancelled flights solely due to wind shear concerns. However, flights have been cancelled due to low clouds and reduced visibility, especially during the 2018 southern hemisphere winter season.
So, while the airport is not completely "out of the woods" in terms being able to support a highly reliable commercial airline schedule, much progress has been made especially as it relates to the wind conditions.
My take is the issues with low clouds can eventually be mitigated with more precise instrument approach facilities. Right now the approach typically used by commercial aircraft (see below) only allows aircraft to descend to 867 FT above the runway (minimum descent altitude or MDA) as compared to 200 FT or less at a typical commercial airport. If visual contact with the runway is not attained at MDA, the aircraft must "go around" and either try again or divert to an alternate airport. In the case of St. Helena, the closest alternate airport is Ascension Island/FHAW which is 700 NM north. While I am not an expert in instrument approach design, my guess is approaches with lower "minimums" can be designed perhaps requiring special equipment and flight crew training.
Well, that is way more than most normal people would want to know about the St. Helena airport. In the next post I will describe our flight to the airport (spoiler alert...it went just fine with no wind or weather problems) and an enjoyable afternoon we spent touring "behind the scenes" of the airport operations.
