Kick the Tire, Catch the Wire - Test Certification Trials for Two Emergency Arrestment Systems

Markus Ruedinger, Test Pilot GAF, German Flight Test Center, WTD61, Germany

Abstract

This paper documents the preparation, execution and analysis of two sets of test trials for the certification of two different emergency arrestment systems. The objectives of these tests were first the verification of the manufacturer provided specifications and second to investigate the suitability as emergency arresting equipment for German Airforce (GAF) jet aircraft. The results were later used to define safe engagement parameters and to formulate the final recommendation for the operator.

The engagement trials were conducted with a Tornado (PA200) Strike aircraft equipped with dedicated flight test instrumentation (cameras/instrumented hook). External stores and configuration were varied depending on the required aircraft mass for each test point; masses ranged from 17,000 kg (clean aircraft) to 27,000 kg (external tanks plus heavy under-fuselage store).

The first trials took place in February/March 2010 and the system under test was a mobile engagement system based on a mobile BAK12 arresting system used for deployment operations. The tests were conducted at the German Flight Test Center in Manching (ETSI), where the system was installed temporarily on the main runway which had a total length of 10,000 ft. Emphasis during the test preparation was given to the missed or failed engagement case since high-speed test points were planned and no back-up net barrier was available. Eventually, engagement speeds up to 186 kts GS were reached. Test results are presented as quantitative data concerning hook loads; during the 1st test-set one unexpected hook load exceedance was observed during the high speed test. In addition to that qualitative findings gained during the tests are presented. ¤¤ The second set of test trials was conducted in June 2013. The system under test was a modified 44B2L engagement system. This equipment was adapted and modified to an entire underground system for a CATII instrument runway with specific obstacle clearance requirements on both sides of the runway.

General recommendations are derived for the operator to enable a successful engagement and to take special precautions on modern runways (hook bounces were observed due to runway markings, lighting and runway joints which led to special recommendations especially for runways with touchdown zone lighting systems).

At the end lessons learned are presented applicable for high-risk tests in a complex environment.