The first revision of the Collins TDR-90 manual is dated October 1973.

Yes, anytime a transponder is removed or replaced an altitude correlation between what the transponder is reporting and what is displayed on the altimeter needs to be performed. This is outlined in FAA CFR Part 91.413. This regulation indicates that following any installation or maintenance of a transponder where data correspondence error could be introduced, the integrated system has been tested, inspected, and found to comply with paragraph (c), appendix E. Furthermore, these references indicate that an integration test between the altitude reporting equipment and transponder system must be conducted.

For complete information, please refer to these FAA regulations or contact Southeast Aerospace Tech Support team at shop@seaerospace.com.

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

Collins Proline I began production in the early to mid 1970s and was very common in many business aircraft in the 1970s and early 1980s. The original instruction manuals for most of the units is dated in 1974. Although production of the Proline continued through the 1980s, it can be assumed that a Proline I unit is 20-30 years old on average.