Sparks-Schreder HP-140V N704B

Summary

On 18 September 1992 at about 23:15 local time, a Sparks-Schreder HP-140V registered N704B, operated by Malcolm D. Jessop, was involved in an accident near Avenal, 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

18 September 1992 at 23:15

Classification

Accident

Location

Avenal, California, United States

Coordinates

35.8906, -120.0697

Aircraft

Sparks-Schreder HP-140V

Registration

N704B

Category

Glider

Operator

Malcolm D. Jessop

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX92LA393

1 person died.

THE LOSS OF PITCH AND YAW CONTROL DUE TO THE SEPARATION OF THE RUDDERVATOR CONTROL CABLE FROM ITS CLEVIS FORK DUE TO IMPROPER INSTALLATION.

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

Read the full NTSB narrative

THE GLIDER WAS SOARING WITH 2 OTR GLIDERS AT 4000 FT. THE OTR PLTS SAID THE ACDNT PLT RADIOED HE HAD A CTL PRBLM JUST BFR THE GLIDER ENTERED A SLOW ROTATING LEFT SPIRAL THAT CONTD TO GND IMPACT. THE PLT HAD NO PARACHUTE. THIS WAS A KIT BUILT GLIDER THAT USED A V-TAIL RUDDERVATOR FOR PITCH & YAW CTL. POST-ACDNT EXAM SHOWED THAT A CTL CABLE BTN THE MIXING BELL CRANK & THE CTL STICK FLOATING BEAM ON THE LEFT SIDE HAD PULLED OUT OF ITS CLEVIS FORK SHANK. THIS PRECLUDED PITCH OR YAW CTL OF THE GLIDER BY THE PLT. DETAILED EXAM OF THE LEFT & RGT SIDE CABLES & FITTINGS BTN THE MIXING BELL CRANK & THE FLOATING BEAM REVEALED THAT THE MIXING BELL CRANK CLEVIS FORK FITTINGS HAD BEEN PROPERLY SWAGED WITH A KEARNEY TYPE SWAGING TOOL. EVIDENCE SHOWED THE FLOATING BEAM END CLEVIS FORK FITTINGS HAD BEEN IMPROPERLY SWAGED WITH A NECOPRESS TYPE TOOL. DETAILED REVIEW OF MAINT RECORDS DISCLOSED NO RECORD THAT THE CABLES HAD BEEN CHGD OR MDFYD SINCE ORIGINAL INSTLN. CABLES (WITH TERMINAL FITTINGS ALREADY SWAGED ON) HAD BEEN SUPPLIED TO THE GLIDER BUILDER IN KIT FORM.

Quoted verbatim from the NTSB record.