Goldenrivett
The initial part of the news seemed to suggest aircraft was at ALT. However you are right the AC was in OP CLB. My comments were for ALT mode. I don't have anything against VS0 mode rather in RVSM I thought everybody uses it in last few thousand feet to reduce ROC to avoid nuisance TA/RA. Just to recap the event the AC was climbing through FL373 to FL380 when he noticed the speed .81M and ROC 3000 and went to select Mach of .76. It is not clear if ALT* was engaged. If it was not the ROC would further increase to bring the speed back. Anyway with only 700 feet to go the SPEED ALT* should have engaged. At this point he disconnected the ATHR by bringing it to idle and also applied speed brakes. So by now he had done everything that should have been done. By selecting VS0 nothing more would have been achieved because the thrust was idle and FG in ALT capture mode. If the AP was kept engaged the problem should have settled. The workload increase was due to AP disconnection. If speed brake was in full position with AP ON the disconnection of the AP could cause the speed brakes to extend full from half. This would increase the VLS and the drag leading to alpha floor.
Last edited by vilas; 20th Jun 2014 at 05:33.