NTSB Safety Alert SA-027 - Check Your Restraints

Check Your Restraint s

Carefully f ollow restraint system maintenance and

replacement guidan ce to prevent death and injuries

The problem

 General aviation aircraft restraints degrade due to age, UV exposure, and repeated use.

 Although restraints are required to be inspected annually, degradation of their capability

can be difficult for aircraft owners and maintenance personnel to detect.

 Some aircraft are only equipped with lap belts and do not have shoulder harnesses ,

which can prevent occupants from impacting the airplane interior during a crash .

Related accidents

The NTSB has investigated several accidents in which restraint systems did not perform to their

design standar ds because they had degraded or in which shoulder harnesses were not installed

on the aircraft . Occupants often sustain serious or fatal injuries during accidents when a

restraint fails or is not used , and n umerous studies by the NTSB and others have shown

improved survivability and decreased injuries when shoulder harnesses are installed and used

in aircraft . The following accident summaries illustrate some common —and preventable —

accident scenarios related to these issues :

 A commercial pilot died when his Taylorcraft F-19 airplane impac ted terrain after takeoff

and his shoulder harness failed. The passenger’s restraint system remained intact , and

she sustained serious injuries. Examination of the pilot’s shoulder harness revealed

features consistent with a previous overload tensile failure , which reduced the capability

of the shoulder harness to provide adequate occupant protection . (NTSB accident

number ANC05FA070 )

 A commercial pilot of an aerial application flight sustained serious injuries following a wire

strike in a Piper PA -36-285 airplane . Examination of the pilot’s restraint s showed signs of

wear and degradation , and the lap belt failed inboard of the adjustment buckle .

(CEN09LA023 )

 A private pilot and his passenger died during a ditching following a loss of engine power

in a Beech A36 airplane . The airplane was not equipped with shoulder harnesses . The

cause of death for both occupants was attributed to drowning with complications due to

blunt force trauma. The installation and use of shoulder harn esses would have

significantly increased the occupants’ chances of survival by reducing the severity of the

SA-027 December 2013 , revised December 2015 blunt force trauma the occupants experienced, possibly allowing them to escape .

(LAX06FA129 )

What can pilots and aircraft owners do?

 Know the history of the restraints in your airplane. Have the restraints examined by a

mechanic or the manufacturer to verify that the y meet required specifications . Replace

the belts if the examination deems it necessary .

 If your airplane was desig ned without shoulder harnesses, install them if possible .

What can maintenance technicians do ?

 Understand aging restraint systems and know the signs — cut or worn edges, damaged

stitching, broken threads, UV damage, and/or any excessive wearing — that indicate a

restraint system does not meet its original design standards .

 Inform owners o f the available options to replac e restraint systems on their aircraft .

 Encourage owners of aircraft not equipped with shoulder harnesses to install them .

 Know that aircraft used for agricultural operations experience additional stresses and

environmental factors that can result in increased wear over time.

Interested in more information?

The reports for the accidents referenced in this safety alert are accessible by NTSB accident

number from the NTSB’s Aviation Accident Database & Synopses web pag e at

www.ntsb.gov/aviati onquery/index.aspx. Each accident’s public docket is accessible from the

NTSB’s Docket Management System web page at http://dms.ntsb.gov/pubdms/.

The FAA’s Policy Statement, “ Methods of Approval of Retrofit Shoulder Harness Installations in

Small Airplanes ,” provides information related to acceptable methods of approval of retrofit

shoulder harness installations . This information can be accessed through the FAA’s website at

www.faa.gov .

“Acceptable Methods, Techniques, and Practices —Aircraft Inspection and Repair ” (FAA

Advisory Circular 43 .13-1B) contains inspection guidance for safety belts in chapter 9 ,

section 9-46(b) . This information can also be accessed through the FAA’s website at

www.faa.gov .

In 2011, the N TSB conducted a study titled, “ Airbag Performance: General Aviation Restraint

Systems .” This study can be accessed through the NTSB’s websit e at www.ntsb.gov.

This NTSB safety alert and others can be accessed from the NTSB’s Safety Alerts web page at

http://www.ntsb.gov/safety/safety -alerts/Pages/default.aspx .