February 12, 1925, the forecastings of the meteorological institute of Uccle being favorable, the "Princess Marie José" took off Haren with his/her/its three crew members and his/her/its reservoirs to their full capacity of 1500 liters. In spite of his/her/its total weight of 6,5 tons, the biplane tree engines won its altitude of cruise enough quickly to about one thousand meters. After accumulated various delays, following a storm of snow in Dijon, to the strength of the mistral in the valley of the Rhone and to a loss of oil in Alicante, the biplane landed in Oran with four days of delay in relation to the initial timetable.
Edmond Thieffry not wanting to waste more time, decided to start the following day above the first stage of 600 km the desert. All happened well, the plane landing in security in Columbus-Béchar, in presence of a French welcome committee. After an inspection that continued during two days, the "Princess Marie José" take-off toward Gao. It was the beginning of the bad luck. Following a storm of sand having rerouted the plane, the pilot must put his device in order to not to exhaust the last drops of fuel. The plane was discovered, the following day, by two bedouin that, of the saddle of their camel, indicated to the shipwrecked victims the direction to follow to reach the station of Oualen, hardly situated to about ten minutes of flight of their point of fortune landing. While leaving Gao three days later, the plane that was supposed to take the direction of Niamey met in Tilabery where a French civil servant intended to go up on board, in order to indicate the path.

To Niger, the length of the stopover continued during five days for technical verifications. The plane was hardly in flight that his/her/its pilot, Léopold Roger, was obliged to land because of abnormal vibrations. One succeeded once besides in repairing the damage to win Zinder, no without must have made call with the help of the local sultan to clear the track. But the crew was not again at the end of his/her/its pains. A helix having been damaged, it was necessary five days to repair it in a very temporary manner. New immobilization of five days to obtain a new helix then in Strong Lamy. After a stopover in Strong Archambault, the "Princess Marie José" arrived to Banghi where it was necessary to be armed again of patience during eighteen days, in waiting of the arrival of Léopoldville, of a helix of origin routed by boat, with the cargo of the five other biplanes and their pieces of spare, intended to the first lines of Congo. Edmond Thieffries and his/her/its team members finally arrived to Léopoldville April 3, 1925, to the term of 51 days of journey 8.124 km had been browsed in 75 hours and 25 minutes of efficient flight.

April 30 1925 Edmond Thieffries and Jefs Of Bruycker unloaded the boat in Antwerp, Léopold remaining Roger in Africa as foreseen. To their arrival to the station from the North to Brussels, the two aviators were cheered like heroes by the population, the burgomaster Adolf Max having come in person to welcome them. Accomplished mission in spite of all obstacles was proven that one could join Brussels in Léopoldville, but that it was too early to consider of the regular flights.

The beginning in Africa
When Edmond Thieffry arrived to Léopoldville on board of the "Princess Marie José", the five other Handley Page was already on foot of work, since some weeks, for their insertion in the future Congolese network. April 23, 1925, that means twenty days after the arrival of Edmond Thieffry, the first regular link was inaugurated between Léopoldville and Luebo, on a distance of 850 km.

For the first six months of exploitation, the balance settled as follows: 221 passengers, 21.725 kg of mail and 1.666 kg of goods transported. It was already a beautiful result. February 9, 1926, a second section was open to the traffic between Luebo and Gule. One could think of this moment to the relation with the Katanga that became reality, the 20 mai1927, with the opening of the third section doesn't enter Gule and the terminal point of Elisabethville being to 2.275 km of Léopoldville.

The 14décembre, the Sabena created a link secondary Luebo-Tshikapa to go against the Society Forminière. The progress of the expansion program was going to continue quickly with the opening of a Luebo­Lusambo line, April 14, 1928, making from then on possible the traffic between the Kasai and Sankuru. One month later, May 20, the network branched out northbound, with the Léopoldville-Coquilhatville line covering a distance of 735 km and giving correspondence toward Bandundu and Inongo close to the Léopold lake It.

Royal visit
Fn 1928, the Sabena was honored by the visit in Congo of king Albert and queen Elisabeth. The royal couple traveled between June 5, date of his/her/its departure of Antwerp, and August 31, date of his/her/its return in Brussels, either a total course of 26.000 km. On the African roads of the Sabena, he/it added more than 2.500 km, during several stages on board of a Handley Page W8F. In the stopovers of the network, there were various receipts offered by the regimental adjutant Tony Orta, director of the Sabena in Africa.

Fn 1929, the company had in Africa eight Handley Page, capable to transport each ten passengers or a ton of freight. Were added to this respectable fleet, three single-engined Of Havilland DH-50 susceptible to carry away four passengers or 350 kg of goods. During the same year, the Lusambo-Kabalo line was to his/her/its tour bet in service. April 5, 1931, in spite of the economic crisis, one attended the opening of the Mbandaka-Stanleyville line.

In 1924, the planes of the Sabena had done 276.191 km and elated 1.787 passengers, what only gave a rate of occupation of 19%. In 1930, the number of the kilometers browsed cleared, for the first time, the rod of the million with 1.145.836 km. The number of the passengers reached 7.314 units, either the double of 1926, the stagnant occupation rate again to 27%. In 1932, the Sabena network of Congo presented itself as follows: Boma-Léopoldville (350 km), Léopoldville-Port Francqui-Ilebo (700 km), Léopoldville-Stanleyville-Kisangani (1.710 km). during the year 1935, the servicing of Port Francqui was incorporated in line Belgium-Congo while waiting to be re-established, the following year, thanks to a new service Léopoldville-Port Francqui­Luluabourg (Kananga). It is to note that the field of aviation of Port Francqui was closed on the eve of the war.

Elisabethville, 1930. Gaston Pottier, mechanic of side, one of the pioneers, pose owing a Fokker F-VII,

Provision in kerosene of a JU-52 on a track of landed in the Congolese jungle.

February 12, 1925: The "Princess Marie José" and the three flight attendants are ready to leave.

April 30, 1925: Edmond Thieffry and Jefs Of Bruycker, mechanic of side, were acceuillis as hero at the time of their return in Belgium, Léopold Roger, as for him, remained in Congo as pilot.