Primary finding
Probable cause
the flight crew's improper procedures and actions (failing to contact system operations/dispatch, failing to use all available aircraft and company manuals, and prematurely resetting the ground control relay circuit breakers) in response to an in-flight abnormality, which resulted in the inadvertent in-flight activation of the ground spoilers during the approach to landing and the airplane's subsequent descent rate and excessively hard ground impact in the runway approach light area. Contributing factors in the accident were ValuJet's failure to incorporate cold weather nosegear servicing procedures in its operations and maintenance manuals, the incomplete procedural guidance contained in the ValuJet quick reference handbook, and the flight crew's inadequate knowledge and understanding of the aircraft systems.
Investigator assessment
Analysis narrative
After takeoff, pilots (plts) had difficulty retracting landing gear (LG), & manually bypassed LG anti-retraction system to retract gear. While climbing, they realized cabin pressurization (CP) & takeoff warning (TW) systems were still in ground mode. (There was evidence nosegear shock strut was underserviced/underinflated for cold/winter weather operation; & strut did not extended sufficiently to actuate ground shift mechanism, to release landing gear lever anti-retraction mechanism, & to shift aircraft (acft) systems to flight mode.) Using quick reference handbook (QRH) procedures, plts pulled Ground Control Relay circuit breakers (C/Bs), then noted CP & TW began operating in flight (flt) mode. En route, the flt was uneventful. Plts decided to reset C/Bs just before touchdown. They made a normal approach to runway, & on short final approach, Captain reset C/Bs. At that time, ground spoilers activated, & acft descended rapidly, striking ground tail first in runway approach light area. Abnormal procedure in QRH stated 'GROUND CONTROL RELAY C/Bs (if pulled) . . . RESET . . . .' This was listed in 'Approach and Landing' section of procedure. Acft operating manual (AOM) stated 'Reset Ground Control Relay circuit breakers during taxi . . . .' Plts stated they had not referenced AOM, nor did they notify company of in-flight irregularity. (See: NTSB/AAR-96/07 for detailed info)
Source record
Factual narrative
For detailed information concerning this case, see the National Transportation Safety Board Blue Cover Report (NTSB/AAR-96/07). -