The Kilimanjaro International Airport (JRO) is placed very handily for Arusha which makes it a better landing site for visitors on Safari to the Serengeti or other Northern National Parks. For Flying into Tanzania direct flights are generally easier and cheaper into Dar, however this is often offset by the cost and time of transiting by Bus, to Arusha, which is an 8 hour drive, or by internal flights, which at peak season can be expensive.
To fly straight into Arusha you can generally get flights with KLM or Qatar Airways, though these premium airlines are often quite expensive compared to the other flight providers:
Kenya Airways often provide cheaper flights, though you will generally end up with a stopover in Nairobi. If this is the case you will need to book a hotel in the city for your overnight as there is no accommodation at the airport – you will also need to check with your local travel advice office in case Nairobi has any security issues for foreign visitors.
Ethiopian Airlines is another good choice for flying into Northern Tanzania. Your flight will stop in Addis Ababa, but the airport there is relatively modern and an acceptable place to wait for a few hours.Visitors from Europe could also consider Condor Flugdienst, who fly from Frankfurt. This midrange airline has good standards and while they are not the cheapest, they are very reasonable.
Visas for most travelers are available at the border or the airport after landing, however please be aware that your airline may refuse to transport you if you have not purchased a visa and do not have a return flight – this is especially important for those who are traveling to Tanzania and returning only after touring other destinations, or via a different carrier. An additional requirement for entry into Tanzania is an up to date certificate of immunisation against Yellow Fever. While the disease is almost eradicated in the country, the Tanzanian government is still doing their utmost to stopping its spread, hence this requirement.