Bins Separated From The Airplane Ceiling Causing Additional Injuries, Board Says

The NTSB has issued a series of safety recommendations following several survivable accidents that have occurred in the last 3 years in which overhead bins and passenger service units (PSU) on Boeing 737 airplanes became separated from their attachments during the accident sequences.

The board says in its letter to Acting Administrator Michael Huerta that the separation of the bins likely increasing the number of reported occupant injuries, particularly injuries to the head and face. In addition to this occupant safety hazard, the negative-g strap attachment bracket (used as part of the flight crew five-point restraint assembly) failed in two cases, possibly contributing to back injuries to the flight crewmembers. Findings in these investigations (some of which are ongoing) suggest that current crashworthiness test requirements do not provide an adequate basis on which to evaluate how these items will withstand impact forces during survivable accidents.

To address the problem, the NTSB says that the FAA should modify the design and test requirements for the attachment points of passenger service units to account for the higher localized loading that results from the relative motion of the attachment structure, and require that the installation design for overhead bins and passenger service units (PSU) manufactured by Boeing and installed in Boeing 737NG series airplanes be modified so that the PSUs remain attached to the bins or are captured in a safe manner during survivable accidents.

Overhead Bin Failure NTSB Image

The agency should also review the designs of manufacturers other than Boeing for overhead bins and passenger service units (PSU) to identify designs with deficiencies similar to those identified in Boeing’s design, and require those manufacturers, as necessary, to eliminate the potential for PSUs to separate from their attachments during survivable accidents, and develop test criteria and performance measures for negative-g strap assemblies to better evaluate their real-world loading capability during accident sequences.

Once test criteria and performance measures are established, the FAA should, amend 14 Code of Federal Regulations Part 25, as appropriate, to include the newly developed test criteria and performance measures for negative-g strap assemblies. Finally, the FAA should require that negative-g strap attachment brackets manufactured by Ipeco be retrofitted with stronger brackets.

FMI: www.ntsb.gov