Helio HST-550A N9991F

Summary

On 30 June 1988 at about 20:00 local time, a Helio HST-550A registered N9991F, operated by Perris Valley Skydiving Inc., was involved in an accident near Perris, California, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

30 June 1988 at 20:00

Classification

Accident

Location

Perris, California, United States

Coordinates

Not recorded

Aircraft

Helio HST-550A

Registration

N9991F

Category

Airplane

Engines

1

Operator

Perris Valley Skydiving Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Skydiving

Phase of flight

Not recorded

Route

Perris → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX88FA241

1 person died.

FAILURE OF THE ELECTRICAL STABILIZER TRIM CONTROL THAT RESULTED IN AN UNCOMMANDED FULL NOSE DOWN ELEVATOR TRIM COMMAND.

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

Read the full NTSB narrative

AFTER DROPPING SKYDIVERS THE PILOT ENTERED A DESCENT TO RETURN TO THE AIRPORT FOR ANOTHER LOAD OF JUMPERS. HE WAS RECEIVING RADAR ADVISORIES DURING THE DROP FROM A TRACON CONTROLLER. AS THE AIRCRAFT DESCENDED BELOW 4,000 FEET MSL THE CONTROLLER TERMINATED THE RADAR ADVISORY SERVICE. IMMEDIATELY AFTER THE CONTROLLER DISCONTINUED THE SERVICE HE ASKED THE PILOT TO CHECK FOR A STUCK MICROPHONE SWITCH. THE AIRCRAFT CONTINUED ITS DESCENT AND COLLIDED WITH A CAMPING TRAILER AND BUILDING UNDER CONSTRUCTION IN AN EXTREME NOSE LOW ATTITUDE. THE ELEVATOR TRIM WAS FOUND IN THE FULL NOSE DOWN POSITION. NO OTHER MALFUNCTIONS WERE FOUND.

Quoted verbatim from the NTSB record.