The Duncan Download Blog: Business Aviation Advice & Observations

Contributed by Jerry Cable, Accessory Tech Rep

Challenger landing gear requires a detailed inspection at 60 months for the 600 and 601 and 96-months for the 604 and 605. It must then undergo a 120-month restoration for the 600 and 601 and 192 month for the 604/605.

The reason for these inspections is to check for cracks, wear and corrosion. Years of water, dirt, salt air, fluid and various other electrolytes have taken their toll. The gear is very susceptible to corrosion and even though steps may have been taken to lessen the effects, some corrosion still forms.

Corrosion is normally found throughout the gear but can often be repaired using standard repair schemes available in the CMM or through engineering concessions. Sometimes, however, the corrosion has exceeded the limits of those repair tolerances.

Some of the more severe corrosion found during these inspections is detailed in the following photographs.

	MLG Trailing Link CL600/601 Axle Bore corrosion found in 35% of the restorations we perform.*
	MLG Side Strut Pin CL600/601 Corrosion on OD radius found in 50% of restorations.*
	MLG Hinge Pin CL600/601 Corrosion on the ID mating with brake line swivels found in 70% of the restorations.*
	MLG Oleo Pin CL600/601 Corrosion on the ID found in 65% of the overhauls.*
	MLG Oleo Cylinder CL600/601 ID corrosion found in 50% of the restorations.*
	NLG Main Fitting CL600/601 Corrosion under steering sleeve found in 50% of restorations.*
	NLG Plunger Tube CL600/601 Corrosion, lower band mating with axle found on 75% of restorations.*
	NLG Axle Barrel CL600/601 Corrosion mating with plunger tube found on 75% of restorations.*
	NLG Steering Cuff CL600/601 Corrosion in the ID Bore found in 60% of restorations.*
	NLG Axle Transverse Bore CL600/601 Corrosion found on 50% of the restorations.*
	NLG Steering Rack CL600/601 Tooth damage going to caster mode found during 90% of restorations.*
	MLG Side Strut Rod End CL600/601 Bearing bore corrosion found in 85% of the restorations.*
	MLG Side Strut CL600/601  Bearing bore corrosion found in 85% of the restorations.*

Jerry Cable is an Accessories Tech Rep located at Duncan Aviation’s Lincoln, Nebr., facility. He is a landing gear and accessory components and systems specialist. His aviation career began in 1991.