DAKAR - The crew of Dana Air flight 9J-922 from Abuja to Lagos sent out a mayday call on June 3. There was engine trouble, and minutes later the plane crashed into a crowded Lagos neighborhood, killing all 153 passengers and more on the ground.
The fourth plane crash to kill more than 100 people in Nigeria in the past decade, it occurred less than 24 hours after a Nigerian cargo plane missed the runway at Ghana's Kotoka International Airport and crashed into a bus, killing ten.
Despite two deadly crashes, African aviation experts say air travel in some parts of the continent is getting safer, although aviation regulation and oversight remain a key challenge for most sub-Saharan African countries.
The most dangerous places to board
The U.N.-affiliated International Civil Aviation Organization says Africa had the fewest scheduled commercial flights between 2001 and 2010, but an accident rate that was four to five times that of other continents.
When disaster strikes, observers often look to factors like inclement weather, electricity cuts, decrepit infrastructure, old aircraft, and pilot error, but aviation experts say the root problem lies with the poor policing of African commercial aviation.
They also say West and Central Africa are particularly dangerous places to board a commercial flight.
"Frequently, the authorities that are charged with overseeing aviation have very little authority," says William Voss, president of the Washington-based Flight Safety Foundation. "They have inadequate staffing, they are overridden frequently from political levels, and there are a lot of issues with political will. You will have politically influential operators appealing to higher levels of government, and that is the sort of thing that was corrected in Nigeria."
Voss, who has worked extensively in West Africa, echoes fellow aviation experts who have described Nigeria as a "model of reform" since 2006, when the country reached a turning point. Following a series of crashes over a two-year period - including one in Port Harcourt that killed 107 people, many of them schoolchildren - the country revamped infrastructure and passed a civil-aviation law that created a relatively autonomous safety regulator.
Lagos-based Arik Air and Air Nigeria have since become members of the prestigious International Air Transport Association (IATA), which requires passing rigorous international safety audits, and in 2010 the U.S. Federal Aviation Administration awarded Nigeria category-1 standing, its top safety rating that allows domestic carriers to fly to the United States.
Such qualifications are essential for carriers that want to join the lucrative international market, and experts say the economic pressure has prompted reform in other African countries.
According to Tom Kok, director of the London-based AviAssist Foundation, Nigeria is now one of 10 African nations that rate higher than the global minimum standards for aviation safety.
"This unfortunate accident in Nigeria may lead to the simple assumption that things are not well-organized in Nigeria," he says. "But it is very important to remember that in countries with stellar aviation-safety records, like Australia or Canada or the United States, accidents unfortunately still happen."
In 2011, he adds, Africa saw a record-low in plane accidents.
Flying below the regulatory radar
But the problem is far from solved: In countries where political agendas are topped by healthcare and education concerns, aviation safety is often a low priority, and the EU blacklist of nations deemed too unsafe to operate Europe-bound flights remains dominated by African countries, including the Democratic Republic of Congo, Benin and Angola.
And even in Nigeria, which has seen a proliferation of regional and domestic carriers in recent years, the pressure to turn a profit in an increasingly crowded marketplace compels some companies to cut corners. Dana Air, for example, which was launched by a pharmaceutical company in 2008, purchased the 22-year-old Boeing MD-83 involved in Sunday's crash from an American airline.
It is not uncommon for African airlines to purchase second-hand aircraft from more developed nations, and experts have said that even old planes, if properly maintained, can safely operate almost indefinitely. But lax, inadequate or financially under-resourced government regulation means that some carriers do not follow the kind of standard safety procedures that would require employees to report negligence and malfunctions, and government regulators often cannot afford to keep enough qualified inspectors to ensure compliance.
Unfortunately, experts say, a commitment to aviation safety tends to follow tragedy, rather than precede it.
Although an ongoing investigation has yet to determine exactly what caused flight 9J-922 to crash, the MD-83 model is currently being phased out of service in the United States due to poor fuel efficiency.