Centaurus
13th Nov 2018, 23:10
https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20161205X33941&AKey=1&RType=Final&IType=FA (https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20161205X33941&AKey=1&RType =Final&IType=FA)
In flight loss of control after thunderstorm penetration by Metro on night cargo flight.in USA
For years there was a myth in Australia that all Metro radars were unreliable so no point in snagging them. Some of the time it was because the pilots had never read the handbook for that particular type of radar and therefore did not know how to operate the radar efficiently. On other occasions pilots were reluctant to record perceived faulty radar in the maintenance release for fear of jeopardising their job. Maybe not nowadays but certainly a few years ago.
Most airborne weather radars (older versions especially) are adversely affected by attenuation in heavy rain present in storms and thus cells don't show up. The NTSB report above would indicate that probably this was the case here. Tragic outcome.
. Things haven't changed much since then. Informal discussions with pilots of older turbo-prop aircraft, have revealed surprising mistrust of the installed weather radar - with lack of maintenance, inoperative or inefficient radar cited as the main problem. The following edited report on the Pprune website by a Metro pilot operating into thunderstorm areas between Melbourne and Sydney, graphically illustrated the dangers of flying at night or in IMC without serviceable weather radar.
“The weather forecast indicated heavy storms all the way to Sydney. 50 miles out from Melbourne after using the radar to get around some of the larger paints, the rain must have got through a hole in the nose cone because the radar died completely. Normally this isn’t too much of a problem as the radar in the Metro is notoriously unreliable. When I reached the planned cruising level of 13,000 ft I still couldn’t see outside and so had to simply point the plane in the right direction and cross my fingers. Strange spider-web patterns of St Elmo’s fire were running all over the windows and were quite visible even with the cockpit lights full up. I couldn’t see the instruments properly because the plane was shaking so badly…a few seconds later the plane started to climb rapidly no doubt due to an updraft in the thunderstorm cell…another violent shake had the plane going down equally fast.”
Finally this graphic description of a thunderstorm penetration in a jet transport aircraft was published in Handling the Big Jets by Captain D.B. Davies: “…We encountered the most violent jolt I have ever experienced in over 20,000 hours of flying. I felt as though an extremely severe positive, upward acceleration had triggered off a buffeting, not a pitch, that increased in frequency and magnitude as one might expect to encounter sitting on the end of a huge tuning fork that had been struck violently.Not an instrument on any panel was readable to their full scale but appeared as white blurs against their dark background..From that point on, we had no idea of attitude, altitude, airspeed or heading. We were now on instruments with no visual reference and continued with severe to violent buffeting, ripping, tearing, rending crashing sounds. Briefcases, manuals, ashtrays, suitcases, pencils, cigarettes, flashlight were flying about like unguided missiles. It sounded and felt as if the pods were leaving and the structure disintegrating.
In flight loss of control after thunderstorm penetration by Metro on night cargo flight.in USA
For years there was a myth in Australia that all Metro radars were unreliable so no point in snagging them. Some of the time it was because the pilots had never read the handbook for that particular type of radar and therefore did not know how to operate the radar efficiently. On other occasions pilots were reluctant to record perceived faulty radar in the maintenance release for fear of jeopardising their job. Maybe not nowadays but certainly a few years ago.
Most airborne weather radars (older versions especially) are adversely affected by attenuation in heavy rain present in storms and thus cells don't show up. The NTSB report above would indicate that probably this was the case here. Tragic outcome.
. Things haven't changed much since then. Informal discussions with pilots of older turbo-prop aircraft, have revealed surprising mistrust of the installed weather radar - with lack of maintenance, inoperative or inefficient radar cited as the main problem. The following edited report on the Pprune website by a Metro pilot operating into thunderstorm areas between Melbourne and Sydney, graphically illustrated the dangers of flying at night or in IMC without serviceable weather radar.
“The weather forecast indicated heavy storms all the way to Sydney. 50 miles out from Melbourne after using the radar to get around some of the larger paints, the rain must have got through a hole in the nose cone because the radar died completely. Normally this isn’t too much of a problem as the radar in the Metro is notoriously unreliable. When I reached the planned cruising level of 13,000 ft I still couldn’t see outside and so had to simply point the plane in the right direction and cross my fingers. Strange spider-web patterns of St Elmo’s fire were running all over the windows and were quite visible even with the cockpit lights full up. I couldn’t see the instruments properly because the plane was shaking so badly…a few seconds later the plane started to climb rapidly no doubt due to an updraft in the thunderstorm cell…another violent shake had the plane going down equally fast.”
Finally this graphic description of a thunderstorm penetration in a jet transport aircraft was published in Handling the Big Jets by Captain D.B. Davies: “…We encountered the most violent jolt I have ever experienced in over 20,000 hours of flying. I felt as though an extremely severe positive, upward acceleration had triggered off a buffeting, not a pitch, that increased in frequency and magnitude as one might expect to encounter sitting on the end of a huge tuning fork that had been struck violently.Not an instrument on any panel was readable to their full scale but appeared as white blurs against their dark background..From that point on, we had no idea of attitude, altitude, airspeed or heading. We were now on instruments with no visual reference and continued with severe to violent buffeting, ripping, tearing, rending crashing sounds. Briefcases, manuals, ashtrays, suitcases, pencils, cigarettes, flashlight were flying about like unguided missiles. It sounded and felt as if the pods were leaving and the structure disintegrating.