Flight and navigation instruments.

§ 25.1303 Flight and navigation instruments. (a) The following flight and navigation instruments must be installed so that the instrument is visible from each pilot station: (1) A free air temperature indicator or an air-temperature indicator which provides indications that are convertible to free-air temperature. (2) A clock displaying hours, minutes, and seconds with a sweep-second pointer or digital presentation. (3) A direction indicator (nonstabilized magnetic compass). (b) The following flight and navigation instruments must be installed at each pilot station: (1) An airspeed indicator. If airspeed limitations vary with altitude, the indicator must have a maximum allowable airspeed indicator showing the variation of V MO with altitude. (2) An altimeter (sensitive). (3) A rate-of-climb indicator (vertical speed). (4) A gyroscopic rate-of-turn indicator combined with an integral slip-skid indicator (turn-and-bank indicator) except that only a slip-skid indicator is required on large airplanes with a third attitude instrument system useable through flight attitudes of 360° of pitch and roll and installed in accordance with § 121.305(k) of this title. (5) A bank and pitch indicator (gyroscopically stabilized). (6) A direction indicator (gyroscopically stabilized, magnetic or nonmagnetic). (c) The following flight and navigation instruments are required as prescribed in this paragraph: (1) A speed warning device is required for turbine engine powered airplanes and for airplanes with V MO /M MO greater than 0.8 V DF /M DF or 0.8 V D /M D . The speed warning device must give effective aural warning (differing distinctively from aural warnings used for other purposes) to the pilots, whenever the speed exceeds V MO plus 6 knots or M MO + 0.01. The upper limit of the production tolerance for the warning device may not exceed the prescribed warning speed. (2) A machmeter is required at each pilot station for airplanes with compressibility limitations not otherwise indicated to the pilot by the airspeed indicating system required under paragraph (b)(1) of this section. [Amdt. 25-23, 35 FR 5678, Apr. 8, 1970, as amended by Amdt. 25-24, 35 FR 7108, May 6, 1970; Amdt. 25-38, 41 FR 55467, Dec. 20, 1976; Amdt. 25-90, 62 FR 13253, Mar. 19, 1997]