The Duncan Download Blog: Business Aviation Advice & Observations

Contributed by Dan Magnus, avionics instruments tech rep

Spoking is a general term used when a radar system fails. You can determine which part of the system is causing the problem based on what appears on the radar display.

The most common type of spoking is caused by the magnetron or local oscillator. This occurs when they lose lock and do not track with each other. This will typically appear on the radar display as a pie shaped patch and will only be present if there is weather to be shown. This would be a receiver transmitter problem.

Another type of spoking comes from the antenna and is caused by noise from the sweep resolver. This will normally show up on the radar display as a very thin line that will start at the apex of the screen and continue to the edges, no matter which range you are on. This will almost always appear in the same spot on the screen.

Intermittent connections on the antenna can also cause the antenna to pitch up or down causing spikes or humps within the return. This is a common problem for the Primus series of antennas.

Winter Radar Service

Also remember, the winter season is a great time to get your radar unit tested and ready to go prior to spring, when thunderstorms are more prevalent and radar is used most. Take advantage of Duncan Aviation’s Winter Radar Promotion and get $100 off radar servicesincluding functional checks, evaluations, repairs and overhauls through March 31, 2014. To redeem, print and include the $100 rebate with each radar unit shipped.

If you have questions about your radar's operation or how environmental testing will help your radar's reliability, contact Duncan Aviation avionics tech reps.

Dan Magnus is an avionics instrument technical representative located at Duncan Aviation's Lincoln, Neb., location. He specializes in ADF, Comms, Control Heads, CVR, DME Gables Control Heads, Receivers, Nav-Comm/Receivers, Radar Systems, GPS, GNS, Transponders and UNS Components and Systems Specialist. His aviation career began in 1976.

Duncan Aviation radar technicians use the term “Radar Season” to describe the time of year when high winds and instability in the atmosphere whip up severe thunderstorms capable of producing tornadoes. At the beginning of Radar Season, when pilots rely heavily on their radar units to perform perfectly, is when many unexpected squawks may be encountered. 

Below are four Duncan Intelligence articles written by Duncan Aviation's Avionics Tech Reps with tips and recommendations about basic radar operation. 

Radar Operation Tips

The Honeywell ART 2000 and ART 2100 are high-performance modern radar that is proven reliable. But even simple things like getting in a hurry when shutting down the system can have a huge negative impact on operation over time. » Read More 

Radar Antenna Switch Settings

When replacing an ART-2000 or ART-2100 radar receiver transmitter with a loaner or replacement unit, make sure to check that the antenna switch settings are set to the proper flat plate. » Read More

Weather Radar Tilt Management

Storm season is upon us! The technology of radar is a great tool to avoid severe weather, but it is important to remember its limitations. » Read More

Radar Antenna Alignment Procedures

Seven steps to radar antenna alignment (DA-1203A). » Read More

Winter Radar Service

Also remember, the winter season is a great time to get your radar unit tested and ready to go prior to spring, when thunderstorms are more prevalent and radar is used most. Take advantage of Duncan Aviation’s Winter Radar Promotion and get $100 off radar servicesincluding functional checks, evaluations, repairs and overhauls through March 31, 2014. To redeem, print and include the $100 rebate with each radar unit shipped.

If you have questions about your radar's operation or how environmental testing will help your radar's reliability, contact Duncan Aviation avionics tech reps.

Dan Magnus is an avionics instrument technical representative located at Duncan Aviation's Lincoln, Neb., location. He specializes in ADF, Comms, Control Heads, CVR, DME Gables Control Heads, Receivers, Nav-Comm/Receivers, Radar Systems, GPS, GNS, Transponders and UNS Components and Systems Specialist. His aviation career began in 1976.

Adrian Chene serves as an Avionics Tech. Rep. for Duncan Aviation's Battle Creek, Mich. (BTL) facility, specializing in Astra / Westwind, Challenger, Citation, Embraer, Falcon, Gulfstream, Hawker and Learjet aircraft. He began working in aviation in 1996.

The DGS 65 Gyro contains a Gyro encoder flex card (flex card) mounted inside the gyro capsule at the top of the internal assembly. This flex card is the information collector for the unit and transmits information to the microprocessor.

There are two sets of LEDs and photo transmitters built into the flex card which must operate properly. By monitoring the sequence in which these transmitters turn on and off, the microprocessor determines the direction that the aircraft’s turn.

In recent years, we have determined that older flex cards are reaching their effective life limits and are now experiencing higher failure rates.

There are two primary ways this unit can fail. First if one or both output channels of the flex card fail, the heading change information will not get to the microprocessor and the unit will no detect heading changes. This will result in a heading freeze on the HSI display. This type of failure may also be intermittent.

Second there is a circuit in the unit which monitors the electric current that is being supplied to the LEDs. If the current is interrupted this monitoring circuit with cause the unit to send a flag signal to the HSI display and the red flag will drop in view.

As with the output channel failure, the heading output will freeze. There is no type of temporary repair, bypass or jumper approved by the OEM and doing so is in violation of FAA regulations.

We recommend following the OEM repair manual procedures for repairing or overhauling the DGS 65 Gyro and only using Rockwell Collins Gyro Encoder Flexcard P/N 6342252001.

Gyro Overhaul

Duncan Aviation is an authorized Rockwell Collins Service Center and is able to overhaul most Rockwell Collins gyroscopes. If you ship your gyro directly to Duncan aviation for overhaul, you could receive your gyro back in 3 to 5 days using Duncan's Aviation's AOG service. When shipping your gyro to Duncan Aviation for overhaul, please follow these critical shipping procedures for a business aircraft gyroscopes.

Duncan Aviation has four avionics tech reps at your service to answer your questions or assist in troubleshooting your avionics units, including the gyro.

Contributed by Dan Magnus, avionics instruments tech rep

Typically, the winter months are the time of year that your radar system gets little use. You may be asking yourself, is it necessary for me to run my radar system during the winter season?

Yes!

Our experience at Duncan Aviation has shown that running your radar system during the off season does not shorten its life but may actually extend it and that of the magnetron. There is a higher instance of spoking and intermittent transmitters for customers who have not run their radar systems during the winter months.

We recommend you turn your system on every few weeks over the winter. This simple preventative measure will ensure your radar is functioning properly when you need it and hopefully extend its life.

Winter Radar Service

Also remember, the winter season is a great time to get your radar unit tested and ready to go prior to spring, when thunderstorms are more prevalent and radar is used most. Take advantage of Duncan Aviation’s Winter Radar Promotion and get $100 off radar servicesincluding functional checks, evaluations, repairs and overhauls through March 31, 2014. To redeem, print and include the $100 rebate with each radar unit shipped.

If you have questions about your radar's operation or how environmental testing will help your radar's reliability, contact Duncan Aviation avionics tech reps.

Dan Magnus is an avionics instrument technical representative located at Duncan Aviation's Lincoln, Neb., location. He specializes in ADF, Comms, Control Heads, CVR, DME Gables Control Heads, Receivers, Nav-Comm/Receivers, Radar Systems, GPS, GNS, Transponders and UNS Components and Systems Specialist. His aviation career began in 1976.

Submitted by Jerry Cable, accessories tech rep

Here. Fix This. 

This reminder may sound obvious, but it is amazing how many accessory units are sent into Duncan Aviation with no explanation or only very little instruction. Within the last year we’ve had a starter generator show up with no paperwork. Is it here for the 2,000 hour overhaul or 1,050 bearing change? What about the actuator with a note that simply said “repair.” Repair what? What is the squawk? When does it occur? 

When this happens we run a function test and hope the results identify the issue. However, this isn’t always a guarantee. Not all squawks can be duplicated on the bench. And many times the problem is related to other aspects of the flight or external conditions and may only fail on the bench when these conditions can be recreated. Taking note of the conditions when the component or system fails, is essential to the effective and timely resolution of the problem.

When removing any units from your aircraft, whether it’s an accessory, avionics, instrument, etc., that is to be sent in for repair or overhaul, always identify the squawk or inspection that needs attention. Having the right information about the circumstances surrounding a squawk can save your tech rep many hours of troubleshooting time and yourself a considerable amount of money.

Duncan Aviation provides accessory unit repairs and overhauls for most popular business aviation airframes. All accessory test equipment is calibrated using NIST certificate traceability. This includes three stab actuator test stands and several sets of test equipment unique to Duncan Aviation.

If you’ve ever had to hunt for a specific aircraft part, component or avionics unit, you are well aware of how difficult it is to do a thorough research, locate a reputable supplier, negotiate pricing and schedule delivery. Most of the time, you are under a strict time constraints and need the aircraft part or avionics unit now and you don’t want to deal with all the issues that can complicate the process along the way; issues, such as no available inventory, managing billbacks, no traceability documents and lack of warranty support.

Kassim Khan, co-owner of Aviation Parts & Supply, an aviation parts broker supporting several corporate flight departments, has relied solely upon Duncan Aviation for 18 years to provide the parts needed to serve their customers. “The bottom line is that Duncan Aviation has never let us down,” says Khan.

Read Aircraft Parts on Speed Dial on page 29 of the Fall 2013 issue of Duncan Debrief and find out why Kassim has only one number in his phone when it comes to finding aircraft parts. 

Duncan Aviation maintains a large inventory of aircraft parts for sale. Our streamlined services and competitive turntimes satisfy hundreds of requests throughout the world 24 hours a day, 7 seven days a week. Our many awards testify to the quality of our service.

Duncan Aviation Systems Engineer, Nick Grzebielski will be attending the Aircraft Electronics Association (AEA) U.S. East Regional Meeting at Fort Lauderdale, Florida, presenting a course on Cabin Management Systems (CMS).

A CMS controls all of the powered items in the cabin of an aircraft such as the lighting, cabin temperature, call and even lavatory flush. It also controls the cabin entertainment items such as LCD monitor video select, speaker audio select, volume, head set control, DVD and Bluray players and XM radio. During his course, Nick will cover the basics of CMS getting into the nuts and bolts of installing, interfacing and supporting various cabin management systems. Discussions will include everything from switching to displays, Wi-Fi and more. The session will conclude with time for questions and the critical exchange of pilot and crew debriefs.

In response to the recent explosion of new and exciting CMS entertainment and control options for business aircraft, Duncan Aviation has written a Straight Talk e-book to help guide operators through their many options. Every day, Duncan Aviation Tech Reps field questions on cabin management and entertainment, and these resources cover the most common equipment requested by Duncan Aviation customers and explain what equipment is available and how it can benefit aircraft cabin systems.

To read the Straight Talk About Cabin Management Systems e-book, go to www.DuncanAviation.aero/resources.

For avionics installation support, contact a Duncan Aviation expert http://www.duncanaviation.aero/contact/tech_reps-avionics.php.

Nick Grzebielski is a systems engineer for Duncan Aviation located in Lincoln, Neb. He has designed full-up CMS systems in multiple Part 25 airframes and has recently been involved in the design and certification of multiple Wi-Fi STCs. His aviation career began in 2007.