Originally Posted by
thcrozier
Those were frightenly high frequency phugoids, on the order of 8 seconds bottom to top.
Very good Observation!
Even GA aircraft usually have phugoides around 20s. Airliners typically 40 - 60s. 8s is a clear indications something is totally wrong. You would get a high frequency phugoide if the angle of incidence is very different between wing and tailplane. Which would fit quite well to the assumption that the HS must have experienced a significant excursion.