Tag Archives: Preventions of Aviation Safety Disasters

Did AF 447 use correct Turbulent Penetration Procedures?

The second issue seems to be flight crew training when in heavy turbulence and when the pitot-static system is not operating.
Basic Instrument flying procedures in convective turbulence recommend a shift of instrument scan to attitude instruments and a disregard for pitot-static instruments, such as airspeed, vsi and altimeter. The procedure is to keep the wings level and the nose level with the attitude instruments. As the acft bounces along through the area of heavy turbulence and as the pitot-static system is affected by rain, ice and the pressure variations encountered in heavy turbulence, scan on the attitude instruments allows the crew to keep the acft straight and level.

Also, the power is monitored so that it remains at cruise power settings, neither more nor less and this keeps the airspeed relatively constant.

The crew should have slowed the acft to turbulent penetration airspeed prior to penetrating an area of turbulence or upon penetration. This speed allows the wings to accept g loadings due to turbulence but not be moving fast enough to over stress the wing g limits.

I wonder if in fact AF training covered these areas and if they allowed flight crew to practice all of these procedures?

Getting into heavy turbulence is to be avoided, but knowing these procedures is critical to survival in the event that convective weather is encountered.

Other procedures include all of the various heaters and engine ignition circuits should be placed on.

Using automation in these circumstances is not a good idea because the programming for automation usually involves smooth air and one g flight.

Could reliance on automation in these circumstances indicate a weakness in training proficiency on the part of this airline and this crew? Is this the second issue for AF, AB, BEA and all other airlines following this investigation?