USAF Kc135 crash Bishkek
It seems that Boeing believe that it will take them 2 years to do the full top-down assessment of the rudder and FCAS and to prototype any modifications required, so it looks like the underlying issue will be with the 135 community for quite some time to come.
As the 135 has been in service for more than a few decades....why is this considered a new problem?
Join Date: Jul 2006
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Probably because this is either the first time this particular problem cropped up after in-flight recorders with sufficient data-paths to diagnose post-crash were introduced - or it was the first time it wasn't squashed so early on by the pilots that it never came to anyone's attention.
Thankyou for posting the link downsizer.
Hmm... Dutch Roll. I am interested if this is really a pure aerodynamic Dutch Roll or, more of an "inertia coupling"? The 135 could have been carrying 90t of fuel in a 45t airframe. This cause does not sound good at all!
Hmm... Dutch Roll. I am interested if this is really a pure aerodynamic Dutch Roll or, more of an "inertia coupling"? The 135 could have been carrying 90t of fuel in a 45t airframe. This cause does not sound good at all!
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Typical USAF report. Establish a tech problem with the aircraft, establish that there were no failure indications for the crew to diagnose, establish that there was no training in place to diagnose such a failure yet still find a reason to shift some blame on to the crew.
Ref: Investigation board determines cause of KC-135 crash in May
"Upon takeoff, a flight control system malfunction, the board found, generated directional instability, causing the aircraft's nose to slowly drift from side-to-side or "rudder-hunt." This condition, not fully diagnosed by the crew, progressed into a more dangerous oscillatory instability known as a "Dutch roll." The board identified that a poor layout of key information in the inflight manual and insufficient crew training contributed to the mishap by detracting from the crew's ability to act on critical information during their troubleshooting to turn off either of two cockpit switches which may have eliminated the malfunction.
Having not recognized the Dutch roll condition, the crew initiated a left turn to remain on-course along the planned route of flight and used a small amount of left rudder to coordinate the turn. The use of rudder, while in a Dutch roll, increased the aircraft's oscillatory instability. The ensuing large side-to-side movements of the aircraft varied the crew member's foot pressure on the rudder pedal which caused inadvertent fluctuations in rudder position. These fluctuating rudder movements, coupled with slight right rudder use while rolling out of the turn, compounded the Dutch roll severity and produced extreme airframe stress that caused the KC-135's tail section to separate from the aircraft. The subsequent, uncontrollable descent resulted in an in-flight explosion."
