Airworthiness Directive · Amendment 39-15360 · Cessna Aircraft Company Models 525, 525A, and 525B Airplanes
Cessna Aircraft Company Models 525, 525A, and 525B Airplanes
This AD applies to the following airplane models and serial numbers that have a cockpit mounted pilot relief tube installed and are certificated in any category:
| Models | Serial No. |
|---|---|
| (1) 525 | 0001 through 0637. |
| (2) 525A | 0001 through 0347. |
| (3) 525B | 0001 through 0152. |
We are adopting a new airworthiness directive (AD) for certain Cessna Aircraft Company (Cessna) Models 525, 525A, and 525B airplanes. This AD requires you to inspect the lower wing skin structure, forward wing spar, lower fuselage skin, fairings, and the external fairing frames for corrosion; repair any damage found; apply a corrosion inhibitive sealant to the fuselage fairings before reinstalling; and disable the cockpit mounted pilot relief tube. This AD results from leaking of the cockpit mounted pilot relief tube, which caused corrosion of the airplane structure. We are issuing this AD to detect and correct any damage from corrosion of the airplane structure. Corrosion of the airplane structure could cause structural degradation and lead to structural failure of the airplane with consequent loss of control.
To address this problem, you must do the following, unless already done:
| Actions | Compliance | Procedures |
|---|---|---|
| (1) Inspect the lower wing skin structure, forward wing spars, lower fuselage skin, fairings, and external fairing frames for corrosion | Within the next 90 days after March 11, 2008 (the effective date of this AD) | Follow Cessna Citation Alert Service Letter ASL525-53-04, Revision 2, dated August 19, 2007; Cessna Citation Alert Service Letter ASL525A-53-05, Revision 2, dated July 25, 2007; or Cessna Citation Alert Service Letter ASL525B-53-02, Revision 2, dated July 25, 2007. |
| (2) If corrosion damage is found in the lower wing skin structure, forward wing spars, lower fuselage skin, fairings, or external fairing frames during the inspection required in paragraph (e)(1) of this AD, repair as specified in the applicable service information. If the corrosion damage cannot be repaired within the limits specified in the applicable service information, contact the manufacturer at 1-800-835-4090 for an FAA-approved repair scheme and incorporate this repair | Before further flight after the inspection required in paragraph (e)(1) of this AD | Follow Cessna Citation Alert Service Letter ASL525-53-04, Revision 2, dated August 19, 2007; Cessna Citation Alert Service Letter ASL525A-53-05, Revision 2, dated July 25, 2007; or Cessna Citation Alert Service Letter ASL525B-53-02, Revision 2, dated July 25, 2007. |
| (3) If corrosion on the lower wing skin structure, forward wing spars, and lower fuselage skin was repaired by blending within the limits specified in the service information, do a surface eddy current inspection or a dye-penetrant inspection for cracks | Before further flight after the repair by blending was done as specified in paragraph (e)(2) of this AD | Follow Cessna Citation Alert Service Letter ASL525-53-04, Revision 2, dated August 19, 2007; Cessna Citation Alert Service Letter ASL525A-53-05, Revision 2, dated July 25, 2007; or Cessna Citation Alert Service Letter ASL525B-53-02, Revision 2, dated July 25, 2007. |
| (4) If cracks are found during the surface eddy current inspection or the dye-penetrant inspection required in paragraph (e)(3) of this AD, contact the manufacturer for an FAA-approved repair scheme and incorporate this repair | Before further flight after the inspection required in paragraph (e)(3) of this AD | Contact Cessna Aircraft Company, Citation Customer Support at 1-800-835-4090. |
| (5) Install the fuselage fairings and apply corrosion inhibitive sealant | Before further flight after the inspection required in paragraph (e)(1) of this AD if no corrosion was found; or before further flight after doing the repairs and inspections required in paragraphs (e)(2), (e)(3), and (e)(4) of this AD if corrosion or cracks were found | Follow Cessna Citation Alert Service Letter ASL525-53-04, Revision 2, dated August 19, 2007; Cessna Citation Alert Service Letter ASL525A-53-05, Revision 2, dated July 25, 2007; or Cessna Citation Alert Service Letter ASL525B-53-02, Revision 2, dated July 25, 2007. |
| (6) Determine the type of installation of the cockpit mounted pilot relief tube and disable the relief tube | Before further flight after the inspection required in paragraph (e)(1) of this AD | Cessna Citation Service Bulletin SB525-53-20, dated April 30, 2007; Cessna Citation Service Bulletin SB525A-53-01, dated April 30, 2007; or Cessna Citation Service Bulletin SB525B-53-01, dated April 30, 2007. |
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
