A feedback system for a flying control member in a cockpit of an aircraft having servo mechanism for adjusting the flying control surfaces in accordance with movement by a pilot of the flying control member, comprising: sensing means operable to monitor variation in the power transmitted through the servo mechanism during an aerobatic manoeuvre involving movement of the aircraft in the roll axis and/or in the pitch axis by monitoring parameters which vary with said variation in power; a computer operable by the sensing means to generate signals based on the monitored values of said parameters and corresponding to said variation in power; and, tactile means (13, 14, 15, 16, 20, 21, 22, 23, 26) operable by the signals to impart to the flying control member a tactile response representative of said variation in power; wherein the computer is programmed to generate said signals at each of spaced cruising altitudes upon performance of the same aerobatic manoeuvre at airspeeds in a range of airspeeds increasing from an airspeed close to the stalling speed to the maximum permitted airspeed at that altitude, and the tactile means are operable by said signals to impart, to the flying control member, tactile responses which increase from a weak value upon performance of the same aerobatic manoeuvre at one end of said range of airspeeds to a strong value upon performance of the same aerobatic manoeuvre at the other end of said range of airspeeds; whereby the nature of the tactile response upon performance of the same aerobatic manoeuvre at any of said spaced cruising altitudes provides the pilot with an estimate of the airspeed of the aircraft relative to the stalling speed and/or the maximum permitted airspeed at that altitude. sensing means operable to monitor variation in the power transmitted through the servo mechanism during an aerobatic manoeuvre involving movement of the aircraft in the roll axis and/or in the pitch axis by monitoring parameters which vary with said variation in power; a computer operable by the sensing means to generate signals based on the monitored values of said parameters and corresponding to said variation in power; and, tactile means (13, 14, 15, 16, 20, 21, 22, 23, 26) operable by the signals to impart to the flying control member a tactile response representative of said variation in power; wherein the computer is programmed to generate said signals at each of spaced cruising altitudes upon performance of the same aerobatic manoeuvre at airspeeds in a range of airspeeds increasing from an airspeed close to the stalling speed to the maximum permitted airspeed at that altitude, and the tactile means are operable by said signals to impart, to the flying control member, tactile responses which increase from a weak value upon performance of the same aerobatic manoeuvre at one end of said range of airspeeds to a strong value upon performance of the same aerobatic manoeuvre at the other end of said range of airspeeds; whereby the nature of the tactile response upon performance of the same aerobatic manoeuvre at any of said spaced cruising altitudes provides the pilot with an estimate of the airspeed of the aircraft relative to the stalling speed and/or the maximum permitted airspeed at that altitude.