Posts Tagged "P&M"

E-MPD Clevis Pin / Split Ring Installations – Inspection / Replacement

Following maintenance, a clevis pin came out of the RP-4 roll trim system pulley on a QuikR causing a left turn. The split ring securing the clevis pin had come out. It is not known if the ring was disturbed during the maintenance. The split ring which came out was the same “spiral start” pattern as that which has caused trouble before (see Service Bulletin 139). This pattern of ring has no positive stop, so that simple rotation of the ring (e.g. caused by it getting caught on something) will cause it to disengage. Disengagement of the split ring and subsequent clevis pin departure could affect the control of the aircraft.

Manufacturer: P&M Aviation Ltd

Applicability: 2016-011-e

Effective Date: 24 November 2016

Compliance/Action: Compliance is required as follows, unless previously accomplished:

  1. Before further flight, from the effective date of this MPD, inspect all clevis pin / split ring installations on the aircraft in accordance with paragraph 2 of P & M Aviation Ltd Service Bulletin 144.
  2. If the inspection in paragraph 1 reveals any spiral start pattern split rings they must be replaced in accordance with paragraph 2 of P & M Aviation Ltd Service Bulletin 144 before further flight.
  3. Record the inspection from paragraph 1 and any necessary rectification action from paragraph 2 in the aircraft technical log in accordance with paragraph 3 of P & M Aviation Ltd Service Bulletin 144.
  4. Repeat the actions in paragraphs 1, 2 and 3 at each Permit to Fly revalidation. 

Reference Publications: See Here

Read the full Emergency Mandatory Permit Directive Here

P&M Aviation SB 144 Spiral Ring Replacement

1) INTRODUCTION

Following maintenance, a clevis pin came out of the RP-4 roll trim system pulley on a QuikR causing a left turn. The split ring securing the clevis pin had come out. It is not known if the ring was disturbed during the maintenance.

The split ring which came out was the same “spiral start” pattern as that which has caused trouble before (see Service Bulletin 139). This pattern of ring has no positive stop, so that simple rotation of the ring (e.g. caused by it getting caught on something) will cause it to disengage. See A below, showing the ring starting to disengage.

Type C is better having a 90 degree positive stop. Type D is used on the QuikR and GTR washout rod universal joints and the most secure type of ring, having no starting ramps and 2 complete turns through the hole. All type A split rings have been discarded at the Factory.

split-rings

2) ACTION

Split rings of the spiral start pattern “A” above must be removed in all locations and be replaced with stainless steel split pins or rings to pattern C or D. The small 4mm clevis pins used in the RP-4 pulley take a 1/16” split pin, part no. FPSP-002. Larger clevis pins take 5/64” stainless steel 316 split pins, part no. FPSP-005.

The ends of the split pin should be trimmed and curled over so as to minimise the possibility of snagging.

3) Documentation

The aircraft technical log must be signed “ Service bulletin SB144 (split rings) carried out” by a qualified inspector and/or an owner/operator.

4) Continued Airworthiness

At each permit revalidation, the inspector must check the service bulletin has been carried out, that there are no split rings of the “spiral

You can read the full service bulletin here.