The KI-209A does not have an OBS resolver inside the indicator to provide selected course information to the GPS. Instead, it has a Sine/Cosine potentiometer. To see the Sine/Cosine potentiometer and properly calibrate to it, it requires more than the +/- 10 degrees of adjustment that a KLN-90B has. The KLN-89B and KLN-900 has +/- 180 degrees of adjustment. Therefore, the KI-208A and KI-209A are limited to the KLN 89B and KLN 900.

No. The Bendix/King KLN-94 Color IFR GPS is not a slide-in direct replacement for the KLN-90B IFR GPS. The mounting rack and connector are different. They do use the same KA-92 GPS antenna. The KLN-94 does directly replace the KLN-89B IFR GPS.

The KI-209A does not have an OBS resolver inside the indicator to provide selected course information to the GPS. Instead, it has a Sine/Cosine potentiometer. To see the Sine/Cosine potentiometer and properly calibrate to it, it requires more than the +/- 10 degrees of adjustment that a KLN-90B has. The KLN-89B and KLN-900 has +/- 180 degrees of adjustment. Therefore, the KI-208A and KI-209A are limited to the KLN 89B and KLN 900.

Yes, the KLN-90B is compatible with GPSS as long as it has updated to the most current software level?

Click here to view a document containing the different database coverage areas.

In most cases, Honeywell offers two options for GPS database updates: - Card/cartridge replacement - Computer download

Users can order a subscription and have a database card/cartridge delivered to a given address every 28 days. If an update is not required as frequently, users can simply order a database card or cartridge direct from Honeywell Wingman Services. Click Hereto go to the Wingman website.

The GPS database Internet download option is available for most receivers. The update is downloaded to a laptop computer. The laptop is then interfaced to the GPS inside the aircraft via the PC interface kit (P/N 050-03213-0000). Certain GPS receiver software as well as laptop performance requirements must be met in order to properly utilize Internet downloading and the computer interface. Please view the following document for complete instructions on computer updating. GPS_download.pdf

Please Note: The KLN-35A and KLX-135A GPS units can only be updated via computer as they do not have externally accessible databases.

A normal Annunciator Control Unit (ACU) includes a control and relay assembly. The control portion includes lighted annunciations (words) as well as a switch assembly to activate a relay. The relay assembly provides the electrical transfer of information between a conventional nav (VOR/ILS/GS) and GPS to one Course Deviation Indicator (CDI).

The ACU units can be complete with control and relay built into one assembly or they can be separated depending on the part number. Some GPS systems and CDIs include internal relays. Therefore, only a control with switch is required. In this case, you would only purchase the Control Head. Some installations use different custom sizes and styles of annunciator switches. Therefore, in this case, only a remote relay is purchased without a control assembly.


In addition to variations in switches, relays, and sizes, ACUs are engineered to be compatible with specific GPS systems by different manufacturers. Variations in power input and bezel orientation are available as well.

For IFR GPS approach certification, GPS status annunciations are required to be in the pilot's field of view. These annunciations (or lights) indicate active switches such as the NAV/GPS and OBS (if applicable) modes. Other annunciations or alerts might include the following:

TERM - light that will signal pilot when operating within 30 miles of departure or arrival airport (i.e. Terminal area)
APR - light that signals pilot when the GPS is engaged in Approach mode
MSG - light that signals pilot that the GPS has generated a Message alert that should be viewed on the GPS
WPT - light that signals pilot that the GPS has generated a Waypoint alert that should be viewed on the GPS
INTG - light that will signal pilot when the GPS receiver detects a position error or is unable to calculate the Integrity of the position

Some annunciator units and annunciator control units or ACUs have a variety a these switches and annunciators depending on the GPS system to be interfaced with or the aircraft installation. However, there are certain annunciations such as MSG and WPT that are standard for all annunciators required.

No. Although they are similar in appearance and function, the KLN-90, KLN-90A, and KLN-90B are not direct replacements for the KLN-88. The KLN-90 series receivers use a different mounting rack, antenna, and larger connector.

While they are not direct replacements, the KLN-90 series GPS systems are the ideal replacement system for the KLN-88. Both the KLN-88 and KLN-90 series units operate through a unique knob functionality.

Negotiating the exchange price of a unit only limits the allowable repair cap for the core unit. Southeast Aerospace's exchange transactions are based on the return of economically repairable core unit. Once the core is received and evaluated, the core repair cost incurred by SEA cannot exceed 80% of the original exchange price. That is, it cannot cost SEA more than 80% of the original OH/SV exchange price collected from the customer. Therefore, when and if an SEA exchange price is discounted, there is a risk that additional charges may be assessed once the core is returned and evaluated.

For more information, please refer to these other Exchange FAQs

As of October 2010, Honeywell does not have any plans to incorporate WAAS into these units. No further details are available.

However, Honeywell is manufacturing WAAS sensors for their APEX GPS series. This series DOES NOT include any of the following: KLN-89B, KLN-90B, KLN-94, KLN-900 or GNS-XLS.

See this PDF document for a detailed listing of currently available IFR GPS systems and a brief comparison.

Yes, this is a total "plug and play" upgrade. The KLN-90B uses the same rack and has the same connector pin-outs as the KLN-90A. The database cartridge style is also the same. The KLN-90B has several upgraded features including certified IFR approach capability, digital OBS and an internal back-up battery pack for continuous operation in the event of aircraft power spikes.

As per the Instructions For Continued Airworthiness, there are no periodic service requirements for the KLN-90B. This unit is manufactured to allow "on condition maintenance". The unit monitors the internal battery and displays a message if the battery is in need of replacement. The typical life of the battery is about 5 years but can vary. Southeast Aerospace evaluates each unit and replaces the battery as needed during maintenance. Not every unit serviced needs a battery replacement at time of service.