# Proposed AD 98-NN-57-AD: Boeing Model 737 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Comment period closed
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 29, 1998, 63 FR 57953
- Comments due: December 14, 1998
- Docket: 98-NN-57-AD
- FR document: 98-28969
- Official PDF: https://openairdocs.org/files/sha256/73/e8/73e8a33c8afac1a9810f2ca915422398c7dbe15c9442deb8c13fd09180f22793 (from https://www.govinfo.gov/content/pkg/FR-1998-10-29/pdf/98-28969.pdf)
- Federal Register: https://www.federalregister.gov/documents/1998/10/29/98-28969/airworthiness-directives-boeing-model-737-series-airplanes
- Page: https://openairdocs.org/proposed/98-NN-57-AD

## Summary

This document proposes the adopting of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737 series airplanes. This proposal would require a one-time inspection of the main landing gear (MLG) axle flange to detect cracking, and follow-on corrective actions. For certain airplanes, this proposal also would require replacement of the original brake mounting gasket with a more durable aluminum-nickle-bronze gasket, and installation of new shear studs, if necessary. For certain airplanes, the proposal would require modification of the mounting flange holes of the torque tube. This proposal is prompted by reports of cracking in the axle flange and by reports of deterioration of the brake mounting gasket. The actions specified by the proposed AD are intended to prevent fracture of the MLG axle and separation of the wheel from the MLG, and consequent reduced controllability of the airplane.

## Notices in this docket

- Oct 29, 1998: Notice of proposed rulemaking (NPRM). (first notice), FR document 98-28969, comments due Dec 14, 1998 (https://www.federalregister.gov/documents/1998/10/29/98-28969/airworthiness-directives-boeing-model-737-series-airplanes)

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