An Air Zimbabwe airplane on the runway of Victoria Falls International Airport, Zimbabwe. (Chen Yaqin/Xinhua)

Air Zimbabwe, a state-owned airline saddled with debts exceeding $330 million, has plunged deeper into crisis after its entire aircraft fleet was grounded due to mechanical problems and the failure by the cash-strapped government to provide funds for vital spare parts.

On Tuesday, all five planes were declared un-airworthy, forcing the flag carrier to hire an aircraft from neighbouring South Africa as managers sought to fulfil some of the scheduled flights.

As the country grapples with a severe economic crisis, Air Zimbabwe has struggled to procure vital spare parts and to pay for mandatory aircraft maintenance checks.

Passengers have been left stranded in recent weeks as the airline’s woes worsened. The only operational plane, an Airbus leased from South Africa, is plying the Harare-Victoria Falls route. From Harare, Air Zimbabwe flies locally to the second city of Bulawayo and the resort town of Victoria Falls, as well as regionally to Johannesburg in South Africa and Dar-es-Salaam in Tanzania.

The failure on Tuesday to take to the skies was unprecedented in the history of Air Zimbabwe, a company which boasted 18 aircraft at the country’s independence in 1980. Economic commentators say decades of mismanagement and corruption have taken a severe toll.

Airline chief executive Ripton Muzenda and Transport Minister Jorum Gumbo were not available for comment. Sources at Air Zimbabwe told African Independent that managers are blaming the Reserve Bank of Zimbabwe for delays in releasing money for aircraft maintenance and spare parts.

The technically insolvent company was kicked out of the International Air Transport Association’s reservation services platform in 2012 for failing to pay member fees exceeding $3.4 million.

In 2011 the airline’s largest aeroplane, a Boeing 767-200, was seized by groundhandling services firm American General Supplies in London over a $1.2 million debt. The aircraft was released after a settlement, although the airline was forced to discontinue its lucrative Harare-London flights. That same year another aircraft, a Boeing 737-500, was impounded in South Africa after Air Zimbabwe failed to pay a $500 000 debt.

As Zimbabwe’s flag carrier chokes in ballooning debt, foreign airlines are taking advantage by introducing new flights to the country.

In recent weeks, South African Airways has deployed a bigger aeroplane on the lucrative Johannesburg-Victoria Falls route. Ethiopian Airlines, Rwanda’s RwandAir and local budget carrier Rainbow Airlines have introduced flights, filling the vacuum left by Air Zimbabwe. Fastjet, Africa’s largest budget airline, last week increased the number of flights on the Harare-Victoria Falls route. Kenyan Airways has also announced plans to enter the fray.

However, foreign airlines are discovering that the Zimbabwean aviation market is fraught with immense difficulties.

This week, Australian carrier Qantas Airways told travel agents in Harare to stop selling tickets for its flights after the International Air Transport Association warned that it has become increasingly difficult to move funds out of the country.

The airline revealed that it is owed a “substantial” amount for tickets sold in Zimbabwe. A shortage of foreign currency means that it is not easy to repatriate money.