A-87-122
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: CONDUCT A DESIGN-ENGINEERING INVESTIGATION OF THE PRIMARY CONTROL SYSTEMS INSTALLED IN GROB G102 AND G103 SERIES SAILPLANES AND G109 SERIES MOTORGLIDERS TO DETERMINE THE ADEQUACY OF GROB'S MANUFACTURING/QUALITY CONTROL PROCESSES AND DESIGN STRENGTH SPECIFICATIONS. THE INVESTIGATION SHOULD INCLUDE A STRESS ANALYSIS OF CRITICAL COMPONENTS SUCH AS BELLCRANKS AND A METALLURGICAL EVALUATION OF GROB'S WELDING AND MATERIAL/HEAT TREATMENT STANDARDS. ANY DEFICIENCIES DISCOVERED IN THE DESIGN OR MANUFACTURING PROCESSES SHOULD BE CORRECTED. ANY COMPONENT PART AFFECTED BY SUCH DEFICIENCIES THAT DOES NOT CONFORM TO THE TYPE CERTIFICATE DESIGN STANDARDS SHOULD BE REDESIGNED AND/OR REMANUFACTURED AND, WHEN AVAILABLE, INSTALLED IN ALL APPLICABLE GROB AIRCRAFT OPERATING IN THE UNITED STATES.
In plain language (FlightFinder summary)
The FAA is asked to investigate the design and manufacturing quality of primary control systems in Grob G102, G103, and G109 series aircraft, including stress analysis of parts like bellcranks and metallurgical evaluation of welding and heat treatment. Any discovered deficiencies must be corrected, and affected components that don't meet design standards must be redesigned or remanufactured and installed in all relevant Grob aircraft operating in the U.S.
This plain-language summary is written by FlightFinder to explain the recommendation above. It is not the official wording — the verbatim NTSB text is quoted above.
Details
| Status | Closed - Acceptable Alternate Action |
|---|---|
| Mode | Aviation |
| Closed | Aug 29, 1989 |
| NTSB number | ATL87IA067 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).