Inglês/Português
<< compressed-air starter | compressibility | compressibility burble >>
Back to: "C"compressibility
- Fonte1
- INTERNATIONAL CIVIL AVIATION ORGANIZATION. Manual of aircraft accident and incident investigation. Part III: investigation. 1st ed. Montreal, 2014. (Doc. 9756)
- Fonte2
- AGÊNCIA NACIONAL DE AVIAÇÃO CIVIL. RBAC 23: requisitos de aeronavegabilidade: aviões categoria normal, utilidade, acrobática e transporte regional. Brasília, 2013. Disponível em: http://www2.anac.gov.br/biblioteca/rbac/RBAC23EMD61.pdf. Acesso em: 23 jun. 2014.
- Nota adicional1
- Operating limitations. The Airplane Flight Manual must contain operating limitations determined under this part 23, including the following— (a) Airspeed limitations. The following information must be furnished: (1) Information necessary for the marking of the airspeed limits on the indicator as required in §23.1545, and the significance of each of those limits and of the color coding used on the indicator. (2) The speeds VMC, VO, VLE, and VLO, if established, and their significance. (3) In addition, for turbine powered commuter category airplanes— (i) The maximum operating limit speed, VMO/MMOand a statement that this speed must not be deliberately exceeded in any regime of flight (climb, cruise or descent) unless a higher speed is authorized for flight test or pilot training; (ii) If an airspeed limitation is based upon compressibility effects, a statement to this effect and information as to any symptoms, the probable behavior of the airplane, and the recommended recovery procedures; and (iii) The airspeed limits must be shown in terms of VMO/MMOinstead of VNOand VNE. (b) Powerplant limitations. The following information must be furnished: (1) Limitations required by §23.1521. (2) Explanation of the limitations, when appropriate. (3) Information necessary for marking the instruments required by §23.1549 through §23.1553.
- Contexto
- Advancing blade stall is encountered under similar flight conditions as retreating blade stall: high airspeed, high density altitudes, and high gross weights. At high advancing blade Mach numbers in the area of the blade tip, airflow compressibility effects due to the formation of localized upper surface shock waves shift the centre of pressure aft. Sharp rises in drag associated with the shock waves produce a disturbed airflow. Vibrations are felt throughout the helicopter. The nose of the helicopter tends to pitch down and the helicopter tends to roll in the direction of the advancing blade stall. Under certain conditions, the helicopter may suffer structural damage. Some new rotor blade designs counter this advancing blade effect with the outer portion of the blade being swept aft, or with blade twist to reduce the angle of attack at the blade tip.
- Subárea1
- Aerodynamics
- Português
- compressibilidade