SPECIAL AIRWORTHINESS INFORMATION BULLETIN
Aircraft Certification Service
Washington, DC
U.S. Department of Transportation
Federal Aviation Administration
CE-09-13

February 23, 2009

This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) alerts you, an owner or operator, of certain Piper PA-46 series aircraft, of possible cracks in the engine mount where both the nose landing gear (NLG) trunnion and the NLG actuator attach. This condition is addressed in Piper Service Bulletins (SB) 1103C and 1154C and Piper Service Letter (SL) 1001. This SAIB emphasizes the importance of compliance with Piper service information.

Note; the information provided below is for reference only. See the latest version of the Piper service information for current information. Also, this SAIB does not address PA-46-310P and PA-46-350P aircraft modified by STC ST00541SE, conversion from piston to turboprop propulsion.

At this time, this airworthiness concern is not an unsafe condition that would warrant AD action under Title 14 of the Code of Federal Aviation Regulations (14 CFR) part 39.

Background

This SAIB is a result of reported cracks being found in the engine mount, both where the actuator for the nose landing gear attaches, and at the pivot where the NLG trunnion attaches. The picture below shows the general area.
ILLUSTRATION (Figure 1)

Below are descriptions of the areas where problems occur, what service information is available, and a summary of reported problems.

LG actuator attachment
There are two types of cracking to be aware of at the NLG actuator attachment. The first type, and the subject of Piper Service Bulletin (SB) 1103C, is cracking around the circumference of the “foot” (the metal tube where the actuator bolt attaches). Some aircraft have a one-piece machined foot and do not have this problem. See pictures below (from Piper SB 1103C) showing pictures of both welded and machined configurations.

The “foot” cracks only occur on some early engine mounts where the “foot” is made up of two parts; a metal disk welded to a metal tube. The cracks have been found in the welded area between the disk and tube.
ILLUSTRATION (Figure 2)

Actuator Cluster
The second type of cracking is in the actuator cluster weld, which attaches the “foot” to the engine mount tubing and is the subject of service bulletin 1154C. This second type of cracking occurs in the welded joints where the foot attaches to the engine mount tubes (cluster weld). See picture below.
ILLUSTRATION (Figure 3)

NLG trunnion attachment (pivot)
Piper Service Bulletin 1154C and Service Letter 1001 both address cracking in the engine mount where the NLG trunnion attaches. See the appropriate bulletin for your aircraft.

Piper Service Information
Below is a list of current Piper Service information and applicability to specific model and serial numbers.
ILLUSTRATION (Figure 4)

Service Difficulty and Accident Incident Data
Forty-nine reports of damaged engine mounts and/or collapsed nose landing gear were identified as of late 2007. These reports came from the National Transportation Safety Board’s accident database and the Federal Aviation Administration’s Service Difficulty and Accident-Incident databases.

Of these, 12 appeared to be associated with damage in the area of the NLG actuator attachment and 9 in the area of the trunnion pivot. Twenty-four contained insufficient information to determine any relationship to this SAIB, and the remainder did not apply.

Engine Mount Part Numbers
Model
 S/N Range
 P/N Mount Original
 P/N Mount New
 Comments
PA-46-310P
 All
 84010-002
 84010-002
 See Note (1)
PA-46-350P
 4622001-4622189
 89137-02
 89137-041
 See Note (2)
PA-46-350P
 4622190 and up
 89137-041
 89137-041
 See Note (2)
PA-46-500TP
102460-002
 102460-036
 See Note (3)
PA-46R-350T
N/A
 N/A

(1) 84010-002 engine mounts may have either machined or welded feet. Visual verification is required.
(2) 89137-041 engine mounts may have either machined or welded feet. Visual verification is required.
(3) -036 may be identified by a one-piece machined NLG actuator attachment. The -002 has separate tubular feet.

Recommendation

After reviewing the above data, we recommend that you inspect the engine mount where the nose landing gear trunnion and actuator attach. You should perform this inspection following the appropriate Piper service information SL 1001, SB 1103C, and/or SB 1154C, as appropriate, for the model and serial number of your aircraft and the configuration of your engine mount

For Further Information Contact

William O. Herderich, Aerospace Engineer, FAA, Central Region, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, GA 30349; phone (770)-703-6082; fax (770) 703-6097; email: william.o.herderich@faa.gov