[PAR] [TLE] Supersonic aircraft [SEP] A supersonic aircraft is an aircraft able to fly faster than the speed of sound (Mach number 1).  Supersonic aircraft were developed in the second half of the twentieth century and have been used almost entirely for research and military purposes.  Only two, Concorde and the Tupolev Tu-144, ever entered service for civil use as airliners.  Fighter jets are the most common example of supersonic aircraft. [PAR] [TLE] Tupolev Tu-144 [SEP] The Tupolev Tu-144 (Russian: Tyполев Ту-144 ; NATO reporting name: Charger) is a retired jet airliner and commercial supersonic transport aircraft (SST).  It is one of only two SSTs to enter commercial service, the other being the Anglo-French Concorde.  The design was a product of the Tupolev design bureau, headed by Alexei Tupolev, of the Soviet Union and manufactured by the Voronezh Aircraft Production Association in Voronezh, Russia.  It conducted 55 passenger service flights, at an average service altitude of 16,000 m and cruised at a speed of around 2,000 km/h (Mach 1.6).
[PAR] [TLE] Supersonic aircraft [ SEP ] A supersonic aircraft is an aircraft able to fly faster than the speed of sound ( Mach number 1 ) . Supersonic aircraft were developed in the second half of the twentieth century and have been used almost entirely for research and military purposes . Only two , Concorde and the Tupolev Tu-144 , ever entered service for civil use as airliners . Fighter jets are the most common example of supersonic aircraft . [PAR] [TLE] Tupolev Tu-144 [ SEP ] The Tupolev Tu-144 ( Russian : Tyполев Ту-144 ; NATO reporting name : Charger ) is a retired jet airliner and commercial supersonic transport aircraft ( SST ) . It is one of only two SSTs to enter commercial service , the other being the Anglo - French Concorde . The design was a product of the Tupolev design bureau , headed by Alexei Tupolev , of the Soviet Union and manufactured by the Voronezh Aircraft Production Association in Voronezh , Russia . It conducted 55 passenger service flights , at an average service altitude of 16,000 m and cruised at a speed of around 2,000 km / h ( Mach 1.6 ) .
How many passenger service flights did the only other counterpart of the supersonic aircraft Concorde complete?
How many passenger service flights did the only other counterpart of the supersonic aircraft Concorde complete ?
55
55