Cessna Soloy TU206G N9987M

Summary

On 19 February 1993 at about 22:45 local time, a Cessna Soloy TU206G registered N9987M, operated by Hammonds Air Service, was involved in an accident near Cochise, Arizona, United States. 3 people were on board and 3 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 February 1993 at 22:45

Classification

Accident

Location

Cochise, Arizona, United States

Coordinates

32.0598, -109.9102

Aircraft

Cessna Soloy TU206G

Registration

N9987M

Category

Airplane

Engines

1

Operator

Hammonds Air Service

Operating rule

Part 91: General Aviation

Purpose of flight

Ferry

Phase of flight

Not recorded

Route

San Diego → El Paso

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX93LA126

3 people had minor injuries.

THE PILOT'S CONTINUED FLIGHT INTO KNOWN FORECASTED ICING CONDITIONS, IN AN AIRPLANE NOT CERTIFICATED FOR SUCH FLIGHT, WHICH RESULTED IN AN ENGINE FLAMEOUT DUE TO ENGINE ICE/WATER INJESTION, AND THE PILOT'S INABILITY TO RESTART THE ENGINE DUE TO INADEQUATE INSTALLATION OF THE PNEUMATIC AIR LINES ON THE COWL DOOR SEQUENCING VALVES WHICH PREVENTED THE ALTERNATE AIR DOORS TO COMPLETELY CYCLE OPEN. THE INADEQUATE SYSTEM DESIGN LED TO A BLOCKED COMPRESSOR INLET. FACTORS IN THE ACCIDENT WERE: ICING CONDITIONS, INADEQUATE ENGINE AND INDUCTION ANTI-ICING SYSTEM DESIGN, FAILURE OF THE MANUFACTURER TO PERFORM ADEQUATE SYSTEM TESTING TO ENSURE ADEQUATE OPERATION, AND MOUNTAINOUS TERRAIN.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

THE ENGINE FLAMED OUT AFTER ENCOUNTERING FORECASTED ICING. (THE PILOT HAD EARLIER USED ALTERNATE AIR, BUT WAS UNABLE TO MAINTAIN ALTITUDE DUE TO THE POWER LOSS). DURING AIR RESTART, TOT ROSE TO ABOUT 520 DEG, THE ENGINE WOULD NOT ACCELERATE, AND QUICKLY DIED AWAY. A FORCED LANDING WAS MADE IN MOUNTAINOUS TERRAIN. THE INDUCTION SYSTEM HAS NORMAL AND ALTERNATE AIR PATHS. NORMAL PATH HAS TWO RAM AIR SCOOPS DIRECTING AIR TO AN AIR BOX, THEN DOWN TO THE ENG INLET. SELECTION OF ALT AIR PATH DIRECTS ENGINE BLEED AIR TO CLOSE THE RAM AIR SCOOP DOORS, AND OPEN ALT AIR DOOR ON BOTTOM OF COWL. AIR THEN CIRCULATES AROUND ENGINE AND THROUGH A SPRING LOADED DOOR ON REAR OF AIR BOX. ON SITE EXAM FOUND RAM AIR DOORS CLOSED AND COCKPIT LEVER ON ALT AIR. ALT AIR DOOR OPEN AIR LINE WAS FOUND TO HAVE A LOOSE B-NUT FITTING AT THE VALVE. CHECKLIST CALLS FOR ALT AIR DURING AIR START. STC HOLDER COULD NOT PRODUCE ANY ENGINEERING OR FLIGHT TEST DATA TO VALIDATE THAT ENGINE WOULD PRODUCE SUFFICIENT VACUUM TO OPEN AIR BOX SPRING LOADED DOOR DURING AIR START.

Quoted verbatim from the NTSB record.