flyera343,
I don't have any more data than that presented in the report that you linked. The data there is rather course with some of it updated at a rate of 1 Hz or less. The sensors on the 777 are located in the EEbay found below the front end of first class, just aft of the nose gear post. From there to the aft galley is approx. 30 meters. The instantaneous center of rotation for the 777 is about 10 meters aft of the EEbay (20 meters forward of the aft galley). The key parameters of interest for calculating the local vertical acceleration at any point along the body are the Nz at the sensor location, the pitch acceleration at the sensor location, and the distance between the sensor location and the point of interest. The data provided shows pitch attitude with a sharp change from -1.2 deg to +3.0 deg in one second. It is hard to infer pitch acceleration from this.
Another way to look at it is how high must the pitch acceration have been to result in negative g at the aft galley? With the aft galley 20 meters behind the ICR (where initial incremental vertical acceleration would have been zero) the pitch acceleration must have been >30 deg/sec^2 in order to result in negative g in the aft galley. The comment from Steward A that "I was strongly hit against the ceiling" indicates that the local acceleration was well below zero (i.e., much more than -1g incremental).
The full negative g event for those unlucky to have been standing in the aft galley did not last much more than 1 second at the most as the pitch acceleration turned negative (nose down) within a second of the event initialization and the elevators were only displaced for one data sample.
Another thing that must be taken into consideration is that for very sharp inputs like this event at high speed there would have been some flexing of the fuselage. The elevators are located very close to the aft galley so the accelerations seen there could have been much different than what is predicted by looking at the sensor data from the front of the airplane and translating back assuming that the structure is rigid.
In my opinion the blame for these injuries falls squarely on the FO who was PF at the time. A potential minor overspeed event was replaced by a very abrupt maneuver. Due to the courseness of the data I cannot tell how far the elevators moved. Limit elevator at this flight condition for the 777 is only 11 degrees.
Lessons learned:
1. Wear your seat belt at all times. Particularly if you are seated aft of the wing! If you are up and about, keep in mind what you are going to grab onto if the bottom drops out - it is sure to come back in a hurry and the further you are from the floor at that time, the bigger chance for injury.
2. Force override of the pilot controls is not the preferred means of disengaging the autopilot!
3. 777 stick force per g target of approximately 40 lbs/g must be respected. Big force = big g = injuries if applied abruptly.
4. Pilots need to realize that on the 777 with the autopilot engaged, moving the pilot controls has zero impact on flight path until enough force is applied to result in an overrride disconnect at which point the manual control laws will respond to the full force being applied. There are only three reasons to touch the 777 controls when the autopilot is engaged:
A. Gain tactile feedback as to what the autopilot is doing.
B. Hold the controls in preparation for disconnect via the disconnect switches.
C. Command immediate disconnect and a large maneuver.