The CNN reported the other day that all international flights bound for the Murtala Muhammed Airport, Lagos, are routinely diverted to Kotoka International Airport, in Accra, Ghana, following poor weather conditions and delays in installing new Instrument Landing System, which is used to check visibility.
After six hours into its flight to Lagos, an America’s Delta Airlines, returned to Atlanta, its point of departure. Apart from financial loss to the airlines, delayed flights, and inconveniences to airline and airport workers, the slogan, “Safety First,” has become a casualty of obvious administrative lapses.
The Ministry of Aviation admits that “These developments are greatly regretted. We will like to let the public know that the authorities at the (Murtala Muhammed) Airport, Lagos, were at the process of replacing the old Category 2 ILS with the newly procured Category 3 system that allows for the clearest visibility landing.”
An aircraft captain says, maybe tongue in cheek: “We have instrument landing system in all Nigerian airports. They are functional, but they are exposed to vagaries of maintenance. And this is not peculiar to Nigeria.”
The following narrative is the synthesis of discussions held with aircraft captains, and an Air Traffic Controller. While the pilots are guided by the ILS, the ATCs guide the pilots.
By the way, Air Traffic Control is the sequencing and control of aircraft traffic from, within, and to, an airport station.
They must be in constant communication with all aircraft around the airport.
The standard requirement is that all commercial aircraft must fly under instrument flight rules, which means the operation of an aircraft is based on the navigational instrument of the aircraft and of the airport.
In the process of landing an aircraft, there are precision and non-precision approaches. But on a day with clear skies, when the weather is CAVOK, an acronym for Ceiling And Visibility Okay, a pilot may ignore the instrument chart, and fly to the runway visually.
But he must advise the airport’s Air Traffic Control that he is now flying VFR, or by Visual Flying Rules. Precision Approach Procedure is achieved in an airport that has an instrument landing system.
This means lateral and vertical guidance for descent profile and AZIMUTH for the aircraft. These two are called localiser and glide slope. AZIMUTH means that the aircraft is within the area approved for landing by the landing instrument.
A landing instrument is a device that guides an aircraft, and its pilot, to a point of at least 1,000 to 1,500 feet landing area of an airport’s runway. The glide slope guides an aircraft up to three categories.
The first category, designated as “1,” is 200 feet above the airport’s elevation level; “2,” is 100 feet above, and “3,” 50 feet above. Now, “3A” and “3B,” are regarded as “RVR,” or Runway Visual Range; and “3C,” is the zero feet, or no visibility, zone.
Nigeria’s international airports have not been calibrated to Category 3C for visibility. They have only been calibrated to Category 1, with 200 feet above airport elevation level, and forward visibility of 800 metres.
An airport’s elevation level is the height of the airport above mean sea level in that geographical area. The elevation level of Lagos is 132 feet, so an aircraft using the Murtala Muhammed Airport cannot be below 332 feet.
But if the pilot is able to go below 100 feet, without the aid of a landing instrument, he may see the runway, though he runs a risk, in the prevailing harmattan weather in Lagos, where visibility has dropped.
If anything goes wrong, he will “just buy the land,” the parlance used by pilots to say, the aircraft will crash. So, an aircraft pilot can choose to fly if he is prepared to face the consequences, if anything goes wrong.
But generally, a pilot will likely not fly if the weather around the airport is bad, or below published minimum. But if he chooses to fly, he goes into the approach place to look for the runways available at the take-off airport.
He also checks the published minimum weather of the vicinity of the closest airport, known as alternative airport. Such alternative airport should usually not be more than a maximum of 15 to 20 minutes, or between 100 and 120 miles, or even less, from the take-off airport.
The implication for a pilot that chooses to fly out of the airport that has been declared closed is that he cannot bring his aircraft back to land in that airport if he loses an engine, and has to land immediately.
When the weather at the take-off airport has dropped below published minimum, the airport will be closed, and all airports intending to send aircraft to that take-off airport will be told that it is closed.
If an aircraft wants to take-off from Lagos airport that has been declared closed, his closest alternative, or emergency landing, airports are Ibadan, in Nigeria, and Cotonou, in Benin Republic.
A landing aircraft must comply with the regulations by filing a flight plan that shows destination, alternative airport, and 30 minutes to hold over at the alternative airport.
There will be complications to landing at Cotonou, because the aircraft will be crossing international borders, which means that passengers will have to undergo customs and immigration protocols, which they had no plans for.
But British Airways airline uses Accra, Ghana, as its alternative airport to Lagos because of their colonial and historical ties, and because Kotoka Airport has suitable landing and take-off facilities.
Nigeria has the following weather conditions: thunderstorm and rain, harmattan, and dust haze. In a thunderstorm, rain or the prevailing cloud may have covered more than seven-eighth of the sky. That causes real dark cloud at the take-off airport.
Thunderstorms produce high and gusty winds, which sometimes are beyond the capability of many aircraft. Rain conditions reduce visibility, especially during the approach to the landing of an aircraft.
At this point, the pilot must compare published visibility minimum and published cloud based minimum, as compiled for the International Civil Aviation Commission by JEPPESEN, which seeks to maintain universal operational standards all over the world.
If you are coming to land in a thunderstorm condition, the odds against you are rain, low cloud base, and gusty winds. A pilot checks his aircraft manual, and the “approach plate,” to confirm and determine if it is safe to land at that intended, but troubled, airport.
An approach plate is the document that a pilot would study, interpret, and execute, during an approach to the landing phase of his flight. Everything that pertains to prescribed procedures for landing at that intended landing airport is despatched in the approach and landing plates.
A member of the Air Traffic Controllers Union is of the cynical opinion that greed is making Nigeria’s state actors to compromise the integrity of landing and taking off from Nigerian airports.
He points out that lighting on the tarmac, victim of the failing power supply, is run by the Federal Airports Authority of Nigeria, instead of the National Airspace Management Authority. He adds that the Centre taxiway of the MMIA has not been operational in the last 20 years.
All these make you feel that those who run Nigeria’s aviation sector put air passengers on suicide mode.
