Nose landing gear failure to extend - Civil Aviation Safety Alerts (CASA) No. 2016-10

Attention:

Owners, operators and maintainers of CL-600-2C10 (Regional Jet Series 700/701/702) aeroplanes

Issuing Office: Continuing Airworthiness
File Classification No. : Z 5000-35
RDIMS No. : 12467149
Document No. : CASA 2016-10
Issue No. : 02
Effective Date: 2017-03-21

Purpose:

The purpose of this Civil Aviation Safety Alert (CASA) is to advise the aviation community of the hazard resulting from the failure of nose landing gear to extend.

This revision of CASA 2016-10 removes reference to defective hardware. Ongoing failure investigation has indicated that the defective hardware is not the likely cause of this occurrence.

Background:

Recently, a Service Difficulty Report (SDR) was received for a CL-600-2C10 (Regional Jet series 700/701/702) landing incident where the nose landing gear (NLG) did not extend. The investigation following the incident found that the NLG doors jammed preventing the gear from extending. The NLG door linkage mechanism became disconnected and prevented the forward doors from opening. When the NLG doors do not open fully, the nose landing gear is unable to extend.(refer to Figure 1)

The investigation found that the NLG drive arm was disconnected from the lock link and one pin (item 66, part number (P/N) 52621-1) was missing a nut and washer (item 68 and 67, nut P/N MS21042L4 and washer P/N NAS620C416L), whereas the adjacent pin had its nut and washer intact. (Refer to Figure 2)

As a result of these findings, Goodrich has issued Service Bulletin (SB) 52200-32-88 and Bombardier has issued SB 670BA-32-055. Additionally, the Illustrated Parts Catalogue (IPC), Aircraft Maintenance Manual (AMM) and Component Maintenance Manual (CMM) have been amended.

Refer to figures 1, 2 and 3, as seen below.

Figure 1: Fly by picture shows the forward NLG doors partially opened.

Figure 2: Illustrated Parts Catalogue (IPC) - NLG Lock Link

Recommended action:

TCCA recommends the inspection and replacement of these MS20142 nut installations on the affected NLG drag brace installations with the corrosion resistant steel (CRES) MS20143 nuts installed with Loctite and torque seal by incorporating Goodrich SB 52200-32-88 and Bombardier SB 670BA-32-055 as soon as possible, if not already done.

The new nut installation also incorporates the use of Torque Seal which provides a visual inspection indication of a loose nut. Torque seal indications of a loose nut require immediate action prior to next flight to correct the situation.

Contact office:

For more information concerning this issue, contact a Transport Canada Centre; or contact Dan Haughton, Continuing Airworthiness in Ottawa, by telephone at 1-888-663-3639, by fax at 613-996-9178 or by e-mail at CAWWEBFeedback@tc.gc.ca.

Original signed by

Rémy Knoerr
Chief
Continuing Airworthiness

THE TRANSPORT CANADA CIVIL AVIATION SAFETY ALERT (CASA) IS USED TO CONVEY IMPORTANT SAFETY INFORMATION AND CONTAINS RECOMMENDED ACTION ITEMS. THE CASA STRIVES TO ASSIST THE AVIATION INDUSTRY'S EFFORTS TO PROVIDE A SERVICE WITH THE HIGHEST POSSIBLE DEGREE OF SAFETY. THE INFORMATION CONTAINED HEREIN IS OFTEN CRITICAL AND MUST BE CONVEYED TO THE APPROPRIATE OFFICE IN A TIMELY MANNER. THE CASA MAY BE CHANGED OR AMENDED SHOULD NEW INFORMATION BECOME AVAILABLE.