Any medium transport aircraft (B727, MD80, A320 etc) on a routine domestic flight of around 4hrs will almost never have a Vref lower than about 110kts. IIRC, the Vref for this approach was around 140kts. The speed was unmonitored for about 100 seconds as it dropped below 100kts. So along with pitch, the "space" on the airspeed tape between the bugged speed or Vref and the actual speed would also provide a warning.
Great post, fdr.
Last edited by PJ2; 29th January 2013 at 07:40.