Accident Cessna 421B N924MD,
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ASN Wikibase Occurrence # 365608
 
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Date:Monday 11 March 1991
Time:19:58 LT
Type:Silhouette image of generic C421 model; specific model in this crash may look slightly different    
Cessna 421B
Owner/operator:Deer Valley Aviation, Inc
Registration: N924MD
MSN: 421B0427
Year of manufacture:1973
Engine model:CONTINENTAL GTSIO-520-H
Fatalities:Fatalities: 0 / Occupants: 6
Aircraft damage: Substantial
Category:Accident
Location:Tucson, AZ -   United States of America
Phase: Initial climb
Nature:Ferry/positioning
Departure airport:
Destination airport:Scottsdale, AZ (KSDL)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
THE PLT (PIC) WAS A PART 135 CHECK AIRMAN & WAS OCCUPYING THE RGT SEAT. A 2ND COMPANY PLT WAS IN THE L SEAT TO GET SOME TIME IN THE CESSNA 421. THE 2ND PLT MADE THE TAKEOFF & THE ACFT WAS 10 TO 15 SEC INTO THE INITIAL CLIMB, WHEN A LOSS OF PWR WAS DETECTED IN THE RGT ENG. A 3RD PLT (SITTING IN THE BACK) CALLED OUT THAT HE SAW FIRE COMING FM THE RGT ENG NACELLE. THE PIC STATED THAT THE 2ND PLT 'APPREHENSIVELY ATTEMPT(ED) THE EMERGENCY PROCEDURES & GAVE THE AIRPLANE TO ME AS (THE) AIRSPEED RAPIDLY DECLINED.' THE PIC SAID SOME PWR LINES WERE DRCTLY AHD & HE ELECTED TO GO UNDER THE WIRES TOWARD A VACANT FLD. THE ACFT COLLIDED WITH THE PWR LINES, THEN IMPACTED THE GND IN THE FLD. AN ON SITE EXAM OF THE ACFT REVEALED THE RGT ENG TURBOCHARGER EXHAUST CLAMP HAD FAILED, ALLOWING EXHAUST GASSES TO FLOW THRU LOUVERS IN THE RGT NACELLE. NO EVIDENCE OF AN ACTUAL FIRE WAS FND. A METALLURGICAL EXAM OF THE RGT ENG TURBO EXHAUST CLAMP REVEALED IT HAD FAILED FM FATIGUE.

Probable Cause: THE FATIGUE FAILURE OF THE RIGHT ENGINE TURBO EXHAUST CLAMP, AND, THE FAILURE OF THE FLYING PILOT TO COMPLETE THE SINGLE ENGINE EMERGENCY PROCEDURES IN A TIMELY MANNER. A FACTOR IN THE ACCIDENT WAS THE FAILURE OF THE PILOT IN COMMAND TO ADEQUATELY SUPERVISE THE CONDUCT OF THE FLIGHT.

Accident investigation:
cover
  
Investigating agency: NTSB
Report number: LAX91LA129
Status: Investigation completed
Duration: 2 years
Download report: Final report

Sources:

NTSB LAX91LA129

Location

Revision history:

Date/timeContributorUpdates
20-Mar-2024 11:55 ASN Update Bot Added

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