Investigation Summary
The flight was operating as a scheduled regional service under 14 CFR Part 135. During the final approach to Runway 21R, the captain attempted to expedite the landing to accommodate a departing DC-9 on the same runway and to achieve a short-field landing. To do this, he engaged the 'beta mode' of the propellers while still in flight—a regime intended only for ground operations to provide reverse thrust or rapid deceleration. Because the engines' flight idle fuel flow settings were higher than normal and slightly mismatched, entering beta mode at low speed created a massive, asymmetric drag profile. At approximately 60 to 70 feet above the ground, the aircraft yawed and banked violently to the left (reaching 80-90 degrees) before rolling back to the right and impacting the ramp. The investigation was hampered by the absence of both a Cockpit Voice Recorder (CVR) and a Flight Data Recorder (FDR), which were not required for this aircraft type at the time.
Final Conclusions
The NTSB determined the probable cause was the captain's inability to control the airplane while attempting to recover from an asymmetric power condition at low speed, caused by his intentional use of the beta mode in flight. Contributing factors included an unstabilized visual approach, the presence of a departing aircraft on the runway, the desire for a short-field landing, and higher-than-normal flight idle fuel flow settings. The severity of injuries was attributed to the lack of fire-blocking material in the passenger seat cushions.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
David Sherer, aged 45.
First Officer
Shawn Manningham, aged 26.
Systems & Failure Modes
Propeller Beta Mode
A propeller pitch range intended for ground use to provide reverse thrust or taxi control; using it in flight causes high drag and can lead to uncontrollable yaw if power is asymmetric.
Fire-Blocking Seat Cushions
Materials designed to resist ignition and slow the spread of fire; their absence in the C-212 contributed to the fatalities from smoke and burns.
Interesting Facts
- 01The aircraft was a CASA C-212-CC, a military design converted for civil use.
- 02The captain had been cited twice previously for unsafe flying and had a license suspension in 1979.
- 03The aircraft was not equipped with a CVR or FDR as they were not legally required for its configuration.
- 04Nine victims died from smoke inhalation and burns; investigators noted fire-retardant seat cushions might have saved them.
- 05Three people on the ground were injured when the aircraft struck ground support vehicles.
Safety Actions & Advisories
Fire-Retardant Materials Mandate
Source ↗The NTSB recommended that the FAA require all aircraft operated under 14 CFR Part 135 to be equipped with fire-blocking materials in seat cushions, similar to the requirements for Part 121 carriers.
CVR and FDR Requirements
Source ↗Following the investigation's difficulty in determining exact engine parameters, the NTSB reiterated recommendations to require Cockpit Voice Recorders and Flight Data Recorders on multi-engine, turbine-powered commuter aircraft.
Beta Mode Warning
Source ↗The NTSB recommended that the FAA require manufacturers to install a positive means to prevent the intentional or inadvertent selection of the beta range in flight on aircraft where such use is prohibited.
Known Controversies & Unanswered Questions
DC-9 Culpability Discrepancy
Reference ↗The NTSB final report listed the presence of a departing DC-9 as a contributing factor in the probable cause, yet the analysis section of the same report stated the DC-9 departure met separation standards and did not contribute wake turbulence.