Yes, however one connector pin needs to be jumpered. One basic difference between the older KI-525A units and the newer units is the OBS resolver. The older units contain a 30 Hz resolver only. The newer style units contain a 30 or 400 Hz resolver. Therefore, if you are replacing an older unit with a newer unit, you must jumper pin a to pin S in the bottom connector. For example, this will allow the new style -07 unit to be used in place of the -00,-01 and -04 units which are no longer in production. Furthermore, if you are replacing a -00 or -04 unit without bootstrap synchro with a -07 unit with bootstrap synchro, the synchro is simply not connected and does not function. However, this is a very easy connection if one plans to use the snychro in the future with systems that require a heading input. For a complete breakdown of the different KI-525A part numbers, please see the bottom of the KI-525A page.

No. Although, the KI-825 uses the same two 41 pin type connectors that the KI-525 has, there are several wiring differences between them. Also, the KI-825 has a third 50 pin connector that is used for the expanded features of the KI-825 such as Nav/GPS switching. The KI-825 utilizes a configuration module to store settings and parameters that must be programmed into the KI-825 to use the additional functions and features of it.

None, they represent the same unit. Original King Radio part numbers were 9 digits. For example, 066-3056-01. During the Bendix and King merger (i.e. Bendix/King), a new part numbering system was created that converted these 9 digit part numbers to 12 digits. Therefore, 066-3056-01 became 066-03056-0001. Despite this numbering change, units that were originally from the King Radio design still have the 9 digit part number format on the unit dataplate. The 12 digit format for King units appears to be used for catalog and internal Honeywell purposes only. Therefore, any unit that has a zero in its third to last number (i.e. XXX-XXXX-X0XX) has a 9 digit part number (i.e. XXX-XXXX-XXX) on its dataplate / ID Plate.

On select DG and HSI instruments, the selected heading is marked by an orange heading bug that can be moved to any point around the perimeter of the compass card. As the aircraft's heading changes, the bug rotates with the compass card altering the pilot to the difference between the selected heading and the actual aircraft heading. The heading bug may also be coupled to the autopilot thus producing off heading signals.

For the most part, the system wiring and connections are the same. The only wiring change needed pertains to the HSI unit. The KI-525 contained a Power flag instead of the standard Heading (HDG) flag as with the KI-525A. Therefore, pin P must be added to the existing KI-525 harness for the HDG flag in the KI-525A.

If the HSI is being upgraded to the -07 version of the KI-525A, then there is another pin that must be jumpered. Please see the KI-525A FAQ for more information on this matter.

The original KCS-55 system contained the KA-51A slaving accessory. This still can be utilized in the KCS-55A however it is recommended to upgrade to the KA-51B due to the age and lack of availability of service parts for the KA-51A. If the KA-51B is added, then a connector change would be required.

In January 1989 Bendix/King changed from a nine digit to a twelve digit part numbering system. The new, larger 12 digit numbers allowed for the inclusion of software version into the last two digits of the part number for certain units in which software changed frequently such as EFIS and TCAS processors. Therefore, the two digits immediately preceding the software version indicate the hardware version of the unit.

Different software versions imply different operational features and/or interface capabilities and software modifications imply software repairs (bug fixes) to insure proper operation of these features and interfaces. Software version upgrades frequently require hardware modifications to the unit. Such hardware modifications accompanying software version upgrades do not necessarily change the hardware version of the unit.

The Century NSD-360A is vacuum driven while the KCS-55A is electrically driven.

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 75% of the original exchange price. That is, it cannot cost SEA more than 75% 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

Certain versions of the KI-525A include a bootstrap heading synchro transmitter. This synchro outputs a voltage per degree of heading rotation. This output is provided to be a source of slaved heading information for external systems such as autopilots, flight directors, stormscopes or any other device that might need a magnetic heading reference.

The term "boostrap" refers to the amplified repeated heading from the system heading reference and synchro transmitter.

A slaved compass system, when installed in an aircraft, is continuously corrected by the remotely connected magnetic direction sensing device (usually a flux valve). An un-slaved system is corrected manually by using a knob on the panel mounted unit to set the compass card.

See example images below. The NSD360 is an un-slaved compass system; it has a knob on the bottom right side to set the compass card. With this particular model, the knob is a push button that needs to pushed & turned at the same time to set the card. On the other hand, the KI-525A is a slaved compass system without a manual compass card set button.