N999

Destroyed
Serious

MASCARI DISCOVERY S-12 S/N: PAD0003

Accident Details

Date
Saturday, June 18, 1994
NTSB Number
LAX94LA259
Location
SALINAS, CA
Event ID
20001206X01575
Coordinates
36.670185, -121.610137
Aircraft Damage
Destroyed
Highest Injury
Serious
Fatalities
0
Serious Injuries
1
Minor Injuries
0
Uninjured
0
Total Aboard
1

Probable Cause and Findings

THE FAILURE OF THE MUFFLER ASSEMBLY DUE TO PREEXISTING CRACKING IN THE OXIDIZED AREA OF THE WELD, WITH SUBSEQUENT DAMAGE AND SEPARATION OF THE PROPELLER AND REDUCTION GEAR BOX. A RELATED FACTOR WAS THE EXCESSIVE TAXISPEED WHICH RESULTED IN THE AIRPLANE BECOMING INADVERTENTLY AIRBORNE.

Aircraft Information

Registration
N999
Make
MASCARI
Serial Number
PAD0003
Model / ICAO
DISCOVERY S-12

Registered Owner (Historical)

Name
MASCARI DAVID M
Address
1557 MOFFETT STREET
Status
Deregistered
City
SALINAS
State / Zip Code
CA 93905
Country
United States

Analysis

On June 18, 1994, at 1604 hours Pacific daylight time, a homebuilt experimental Discovery S-12 Airaile, N999, collided with a standpipe during an off-airport forced landing near Salinas, California. The airplane was being operated by the noncertificated owner/pilot when it inadvertently became airborne during high-speed taxi tests at the Salinas Municipal Airport, Salinas, California. The airplane was destroyed. The pilot received serious injuries. Visual meteorological conditions prevailed.

Witnesses reported the propeller, muffler, and reduction gearbox separated before the airplane struck the standpipe. Examination of the three-bladed propeller by the Federal Aviation Administration (FAA) revealed one of the propeller blades had separated several inches outboard of the hub.

The airplane then glided into a lettuce field. During the force landing flare, the right wing struck a 6-inch-diameter standpipe separating the right wing tip.

The muffler and dampener plate from the reduction gearbox was sent to the Safety Board's Material Laboratory for examination. The muffler was fractured in the area of a factory weld. The weld area was oxidized. Numerous fractures were found in the dampener. Microscopic examination of the fractures disclosed no evidence of progressive separation. A copy of the Safety Board's Materials Laboratory Report is attached.

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# LAX94LA259