KFYV 171753Z 08003KT 10SM SCT015 OVC021 19/15 A2997 RMK AO2 SLP139 60001 T01940150 10200 20172 58004
KFYV 171653Z 34004KT 10SM OVC018 19/15 A2998 RMK AO2 SLP142 T01940150
Everything looked very stable until the turn onto final. Then it was a 2700 fpm descent, followed by a 2700 fpm climb, then a brief 7000 fpm dive, with the commensurate speed changes for each, until the signal was lost less than a minute later.
Whatever happened to destabilize the aircraft, it happened quickly.