The Duncan Download Blog: Business Aviation Advice & Observations

Darrell Cermak, Rotable Inventory Manager

Duncan Aviation Parts & Rotables Sales has built and maintained one of the largest business aircraft parts inventory in the industry. Our team of aviation professionals has the experience, contacts and connections to identify and secure some of the hardest to find business aircraft parts.

Because of our long history and experience with the Hawker aircraft, we know the most commonly exchanged parts and keep an inventory available to meet customer needs.

Below are some of the more commonly exchanged life-limited parts on a Hawker 125 airframe that have been known to not make the next Time Before Overhaul (TBO).

	Sequence Valves (AIR48540-1) Sequence valves are required Overhaul items and have to be overhauled at the required Chapter 5 Interval. However, sometimes they do not make the TBO due to seal failure and contamination of the hydraulic fluid, leading to internal slide and sleeve failure.
	Starter Generators (23080-005 & -064) Starter generators are exposed to a lot of abuse while operating in a constantly vibrating environment with lots of heat. These conditions over time take their toll, leading to problems, such as not coming on line, unable to be paralleled and premature brush wear.
	Maxarets (AC65216 & AC65218) The Hawker 125 series aircraft utilizes an axle-mounted Maxaret to control skid conditions. It is a required overhaul item and needs to be removed at the necessary intervals. It is not uncommon for valve wear and seal failure to cause leaking, requiring removal before TBO. When removing Maxarets, be sure to use the proper Maxaret extraction tool and procedures to avoid unnecessary damage and expensive overhaul costs.
	Valve Refrig Bypass (104968) The aircraft uses this bypass valve to regulate cabin temperature to the desired setting. Due to ever-changing cabin temperatures, this valve is always opening and closing. Failures such as inop, slow to operate and does not modulate result in unwanted cabin temperature ranges.
	Airbrake Actuator (AIR46520-2 & 21-2) Just like the sequence valves, the Airbrake Actuator is a hydraulic unit with many seals. These seals have been known to fail before the next required overhaul interval and may cause the unit to be exchanged earlier.

Parts & Exchanges

 Duncan Aviation is constantly adding to its inventory to ensure customers have a true one-stop shop when it comes to acquiring parts or exchange units. Search our on-line inventory for aircraft parts and inventory availability or chat live with a Parts & Rotables Sales Rep. Our international business aircraft components solutions experts are available 24/7/365 and can handle any business aircraft system problem with immediate parts exchanges.

Duncan Aviation is still a Hawker Service Center

 In light of the recent changes in the industry for Hawker operators, I want to remind you that Duncan Aviation continues to provide comprehensive Hawker aircraft service and support at all Duncan Aviaiton locations around the world. We are an industry leader in Hawker maintenance, structural repair, landing gear/component overhauls, engine MPIs, avionics upgrades, paint and interior. Our experience and capabilities are second to none. For more information about your options as a Hawker operator, contact any one of the many Duncan Aviation Hawker experts.

Darrell Cermak is a Rotable Inventory Manager located at Duncan Aviation’s Lincoln, Nebr., facility. He specializes in the Hawker 125 and Falcon airframes. His aviation career began in 1995.