Summary
We propose to supersede Airworthiness Directive (AD) 2018-11- 05, which applies to certain Honda Aircraft Company (Honda) LLC Model HA-420 airplanes. AD 2018-11-05 requires incorporating a temporary revision into the airplane flight manual and replacing the faulty power brake valve (PBV) upon condition. Since AD 2018-11-05 was issued as an interim action in order to address the need for the immediate detection of a faulty PBV, we are issuing this proposed AD to address the long- term corrective action. This proposed AD would retain the actions required in AD 2018-11-05, would require replacing the faulty PBV with an improved design part at a specified time, and would prohibit future installations of the faulty PBVs on all Honda Model HA-420 airplanes. We are proposing this AD to address the unsafe condition on these products.