A-06-063
NTSB Safety Recommendation — Aviation
Recommendation text
TO THE FEDERAL AVIATION ADMINISTRATION: Require a design review of CF6-80 series high pressure turbine (HPT) stage 1 disks that incorporate chamfered blade slot bottom aft corners that includes a stress analysis and finite element model emphasizing the blade slot bottom aft corner to determine whether sufficient material property margin exists to ensure that cracks do not occur. If the design review of chamfered HPT stage 1 disks finds that this design does not provide sufficient material property margin, then a redesign or material change should be implemented.
In plain language (FlightFinder summary)
The FAA is asked to mandate a design review of CF6-80 series high-pressure turbine stage 1 disks with chamfered blade slot bottom aft corners, including stress analysis and finite element modeling focused on that corner, to verify adequate material property margin against cracking. If the review shows insufficient margin, a redesign or material change must be implemented.
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 Action |
|---|---|
| Mode | Aviation |
| Closed | Sep 23, 2009 |
| NTSB number | ENG06IA018 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).