Performance and Perception of Precision Approach and Landing Systems aboard USS Harry S. Truman

Robert P. Benner, NAVAIR 5.1.6.10 Air Traffic Control and Landing Systems, Patuxent River, MD, USA

Abstract

Precision Approach and Landing Systems (PALS) certification flight tests are conducted aboard US Navy aircraft carriers approximately every two years to ensure proper and safe operation of shipboard PALS equipment. A PALS certification clearance is issued by Naval Air Systems Command (NAVAIR) flight test engineers at completion of testing, authorizing use of PALS systems for no longer than 24 months. PALS certification flight tests were conducted aboard USS HARRY S. TRUMAN (CVN-75) 10-14 January 2007.

In August of 2007, communications from CVN-75 indicated that aircrew and CVN-75 personnel were losing confidence in the operation and performance of PALS systems. A white paper, written by the CVN-75 Combat Systems Officer (CSO), asserted that Automatic Carrier Landing System (ACLS) performance was unsatisfactory and recommended PALS certification tests be repeated.

A tiger team was assembled to analyze and respond to the communications from CVN-75. The team concluded that degradation of PALS systems was possible based on loss of aircrew confidence. However, data sent from CVN-75 indicated nominal performance of PALS systems. The tiger team was detached to CVN-75 while the ship was forward deployed, conducting combat operations in support of Operation Iraqi Freedom (OIF), to conduct an investigation and limited certification flight tests of CVN-75 PALS.

The investigation revealed that a combination of degradation of PALS systems, unreasonable expectations of ACLS automatic landing performance, and miscommunication of actual ACLS automatic landing performance led to the loss of confidence in CVN-75 PALS. Cooperation between NAVAIR and CVN-75 personnel led to successful completion of the investigation and certification tests. The investigation and testing provided a better understanding of PALS systems by CVN-75 aircrew, Landing Signal Officers (LSOs), and shipboard maintainers and operators, leading to increased confidence in PALS systems. This paper discusses the events leading up to an emergent request for assistance from CVN-75, methods of determining cause for loss of confidence, and lessons learned from these events.