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Reliability of the C-5M Emergency Escape Slides

By MS. SUSAN G. GOTTA, AMC Test and Evaluation Squadron, Joint Base McGuire-Dix-Lakehurst

Airmen aboard the Lockheed Martin C-5M Super Galaxy, the largest cargo transport aircraft in U.S. Air Force service worldwide, expect the emergency escape slides will deploy as designed in the unthinkable event of an emergency that requires aircrew evacuation.

Recently, a test team from the Air Mobility Command Test and Evaluation Squadron (AMCTES), located at Joint Base McGuire-Dix-Lakehurst, New Jersey, completed an evaluation of the emergency escape slides deployment procedures aboard the C-5M aircraft. Testing the effectiveness of the slides helps ensure they will function as expected, if necessary.

“This request from AMC’s Aircrew Training Division at Scott Air Force Base was prompted by three separate incidents in 2017 when AMC C-5M aircraft experienced ground emergencies requiring the deployment of multiple escape slides,” said Air Force MSgt Robert Bello, AMCTES lead test director on the C-5 emergency escape slide operational test. “Those three emergency landings resulted in three [of five] slides failing to inflate as expected.”

Bello added that the main objective of this test was to isolate tactics, procedures, and training that could be contributing factors in the slide failures. Mechanical and equipment factors were not within the scope of this Tactics Development and Evaluation (TD&E).

In accordance with the test plan, this TD&E was executed in two phases, beginning in November 2017 at Dover Air Force Base, Delaware, with test participants from the 436th Airlift Wing at Dover providing support. Testing continued in December at Travis AFB, California, with support from the 60th Air Mobility Wing.

“At each test location, AMCTES test directors observed qualified aircrew personnel deploy all five emergency escape slides in accordance with Air Force tactics, procedures, and training under operationally representative conditions,” said Bello.

In service since the early 1970s, the C-5M is fitted with five emergency escape slides to provide rapid egress from the aircraft during a ground emergency. Four slides are installed in the troop compartment, and one slide is installed in the relief crew compartment. The test plan called for the five emergency escape slides aboard the C-5M to be deployed three times each using one aircraft at Dover and three aircraft at Travis, for a total of 30 intentional slide deployments.

Aircraft safety manuals detail how each of the slides are contained in a rigid case attached to the fuselage by a metal bar. When the aircraft doors are opened in an emergency, evacuation procedures dictate that the slide case is to be positioned on the sill and then the entire slide case is to be tossed out the escape door. A lanyard attached to the door is designed to automatically discharge the air reservoirs that inflate the slide.

“This operational test was conducted in addition to, and separate from, the annual functional checks routinely conducted on all safety equipment,” said Mr. Kerry Lloyd, 436th Air Wing Operations Support Squadron Aircrew Flight Equipment (AFE) manager at Dover AFB. “[For the AFE checks], each and every slide is removed from the plane, manually inflated in the shop, and inspected at least once per year. We check every inch of the slide for cracks, make any required repairs, then re-pack each slide before returning it to use.”

All five of the slides are packed in cases that are different sizes and shapes, each specific to where they are located on the plane. The re-packing process is done by hand and typically requires several personnel to fold and work the slide back into the cases.

“Hopefully, it doesn’t need to be used,” said Lloyd, “but if it does, we do everything possible to ensure that it works.”

The unique aspect of this AMCTES operational test was that the slides were deployed on the planes simulating an actual emergency, instead of during annually scheduled slide inspections like that done by the AFE shops.

“Aircrew were observed following recommended procedures and training to toss out the cases, pull the lanyard, and inflate the slides,” said Bello. “Secondary measures were followed if the slide did not inflate, just like in an actual emergency situation.”

Aircrews receive Emergency Egress Training every three years as directed by Air Force Instruction 11-301, Aircrew Flight Equipment Program, and in accordance with Technical Order 1C-5M-1. An overarching goal of this evaluation was to determine whether those procedures and training adequately prepare aircrew for an emergency.

“Some of the test participants were documented forcefully shoving the slide cases out of the doors, while others were tossed or dropped with less force. This may have affected how fast the slides deployed or whether they deployed at all,” continued Bello.

Of the 30 deployment scenarios tested, there were five instances where issues prevented the successful, full deployment of the escape slides. AMCTES test directors analyzed all raw data collected at the two test sites and made 23 recommendations to improve functionality and enhance deployment procedures of the C-5M emergency escape slides, thus increasing personnel safety aboard the aircraft. Test directors made specific recommendations in four areas: enhance aircrew procedures and documentation; improve human factors associated with the slide equipment design and its configuration aboard the aircraft; update maintenance guidance and training materials; and investigate hands-on slide deployment training exercises for aircrew.

This type of AMCTES evaluation provides a measure of assurance for the rigorous adherence to all safety protocols aboard the C-5M Super Galaxy.

Final published report details are available through the AMCTES Operations Division at Joint Base McGuire-Dix-Lakehurst.