Case Study: United States Air Force Honeywell ADT-222 Test Set Replacement

Like the original Sperry ADT-222A, many Honeywell ADT-222B test sets have reached the end of their supportable life cycle. These legacy units have been hindered over the past several years by parts obsolescence, availability of replacement parts and repair capabilities. Many end users have found them increasingly more difficult and costly to repair and re certify.

In October 2014, the United States Air Force required a replacement to their legacy Honeywell and Sperry ADT-222B test sets. They had 20 test sets, 12 of which were deemed unserviceable and being used to cannibalize for working units. These units were integrated into the for air data controller for the Electronic System Test Stations (ESTS) system. The system is used to test aircraft air data computers and provide accurate pneumatic pressures to the aircraft air data computer system over a remote bus. The Honeywell assets had been manufactured in the 1980’s and had become nearly impossible to support due to obsolescence and available parts.

A competitive, full and open solicitation was released for a newer and supportable replacement test set. The primary objective of this program was to replace the ADT-222B, while providing a “plug and play” drop in replacement. This meant that the replacement had to be capable of communicating remotely over the IEEE-488 bus using the legacy Honeywell 1975 protocol.
Raptor Scientific (TestVonics, Inc.) proposed a derivative to our USAF approved ADC-2500 Series Air Data Calibrator, a low technical risk approach. The ADC-2522 was uniquely designed to support the ESTS ADTC program. Over the course of 14-month engineering evaluation, our team successfully developed and qualified the ADC-2522 to fully replace and emulate the Honeywell ADT-222B.

The ADC-2522 is a high precision air data test set calibrator and can precisely control and measure Altitude and Airspeed pressures. It meets and/or exceeds all the performance characteristics set forth by Tinker AFB for the Honeywell ADT-222B and ADT-222C. The ADC-2522 can be operated using local controls including the 10.4-inch touchscreen display with intuitive graphical user interface. It can also be operated remotely through RS-232 or IEEE-488. Because of this, the ADC-2522 is qualified to the same National Stock Number (NSN: 4920-01-105-0016) as the Honeywell ADT-222B (P/N: 4047505-421).

Since 2016, twenty (20) of these units have been in continuous operation in USAF facilities. There have been zero reliability issues reported and the USAF has full capability to support and calibrate these units using existing calibration standards.

Since then, our ADC-2522C and ADC-2550V3 derivatives have been used to replace the Honeywell ADT-222B and ADT-222C. They have the same ranges and accuracies and feature additional interfaces like RS-232, USB, VGA and RJ-45. The most notable difference between the ADC-2522 and the ADC-2550V3, is that it does not include the Honeywell Sperry IEEEE-488-1975 interface and software emulator. Customers replacing their test set with the ADC-2550V3 are opting to update their ATE to command remotely over IEEE-488.2 or RS-232 using our SCPI communications protocol.

• ADC-2550V3 Air Data Calibrator

Looking for a replacement for your Sperry or Honeywell ADT-222A, ADT-222B or ADT-222C test set? Contact Raptor Scientific for more information.

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