Bell 47G N47VS

Summary

On 25 September 1989 at about 17:10 local time, a Bell 47G registered N47VS was involved in an accident near Corvallis, Oregon, United States. 2 people were on board and one had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

25 September 1989 at 17:10

Classification

Accident

Location

Corvallis, Oregon, United States

Nearest airport

Corvallis (CVD)

Coordinates

44.6309, -123.2701

Aircraft

Bell 47G

Registration

N47VS

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Corvallis → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

SEA89LA177

1 person had minor injuries.

STUDENT PILOT'S IMPROPER USE OF THE COLLECTIVE CONTROL WHILE PERFORMING HOVERING AUTOROTATIONS, AND THE INSTRUCTOR'S INADEQUATE SUPERVISION OF THE STUDENT'S ACTIONS, WHICH RESULED IN HARD LANDINGS. IN ADDITION, THE ENGINE MOUNT WAS SIGNIFICANTLY WEAKENED STRUCTUALLY AS A RESULT OF CORROSION.

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

Read the full NTSB narrative

WHILE PRACTICING HOVERING AUTOROTATIONS ON AN ASPHALT TAXIWAY SEVERAL HARD LANDINGS OCCURRED AS A RESULT OF THE STUDENT'S DIFFICULTY LEARNING THE PROPER APPLICATION OF COLLECTIVE PITCH. THE CFI THEN INSTRUCTED THE STUDENT TO MOVE TO A SOD AREA ADJACENT TO THE TAXIWAY FOR THE CUSHIONING EFFECT TO REDUCE IMPACT FORCES ON THE AIRCRAFT. THE CFI SAID HE DID NOT INSPECT THE AIRCRAFT FOR DAMAGE AFTER THE HARD LANDINGS ON THE TAXIWAY. THE STUDENT THEN PERFORMED ONE HOVERING AUTOROTATION ON THE SOD AREA, AND DURING THE SUBSEQUENT HOVER CONTROL WAS LOST. THE AIRCRAFT ROLLED OVER AND IMPACTED THE GROUND. HEAVY SKID IMPACT MARKS WERE FOUND ON THE TAXIWAY. THE ENGINE MOUNT TUBULAR STRUCTURE AT THE BOTTOM MOUNT, AND THE CROSS MEMBER SUPPORT TUBES, WERE FRACTURED. THE WALLS OF THE TUBES WERE OF IRREGULAR THICKNESS, CONTAINED EXTENSIVE CORROSION SCALING, AND IN SOME PLACES COULD BE BENT BY HAND. THE BOTTOM OF THE ENGINE, WHICH IS MOUNTED TO THE TRANSMISSION AND MAIN ROTOR MAST, WAS FREE TO MOVE. LAST ANNUAL INSP. FIVE DAYS BEFORE ACCIDENT.

Quoted verbatim from the NTSB record.