Medication And Aircraft Maintainers

When thinking about aircraft mishaps and their causes, we tend to focus on the pilot. After all, he's in the driver's seat, there to troubleshoot any problems that may arise, and he's expected to bring the "on-loan" aircraft back to base, in one piece, after a mission. If a mishap occurs, investigators look for causes related to pilot error along with evidence of mechanical failure, weather factors, runway condition and ATC issues. Reviews of data from civilian general aviation, commercial air and military aircraft mishaps show that the two most often cited causal issues are pilot error and mechanical/logistic factors.

Aircraft maintainers--jet engine mechanics, avionics, environmental and life support technicians, dedicated aircraft crew chiefs and others--have direct input into the reliable function of aircraft system components and the overall aircraft. We don't know, however, what role maintainer human factors play in mishaps associated with mechanical issues like engine or flight control failures. The cause of a mechanical-related mishap is often obvious. The part wore out before its service life expired, or it failed due to an unanticipated performance stress, etc. In other cases, human error played a role when someone forgot, overlooked or incorrectly installed or serviced something on the aircraft. Documented cases include incorrectly installed fuel sensors, flight control sensors or engine parts, forgotten tools, and overlooked items in the aircraft forms. So, the question arises: Do some instances of improper maintenance occur due to the influence of maintainer human factors issues, such as self-imposed stress (drug or alcohol use, poor diet, improper rest), fatigue, poor concentration, shift-work problems, inadequate training or lack of motivation?

Aircrew are closely scrutinized by their flight surgeons for illness and monitored while taking any medications. Those who fail the scrutiny are usually grounded from flying duties. In contrast, a maintainer's physician may not make the connection between an illness or medication and the impact on the maintainer's ability to perform his or her job of repairing and inspecting their aircraft with optimum attention and diligence. Compromise of the maintainer's duty performance has the potential for endangering an aircrew and damaging aircraft and equipment.

What We Learned

Because of their important role in safe flight operations, researchers wanted to know if maintainers were returning to regular duty while taking physician-prescribed or self-prescribed medication (for a self-diagnosed ailment) that had a potential to impair their ability to perform critical tasks. Studies of medications such as antihistamines (e.g., Benadryl[R]), which are used to treat allergies and may cause drowsiness, have shown that they reduce scores on various motor skills and thinking performance tests.

In one study, a group of 214 USAF aircraft maintainers representing various specialties completed an anonymous questionnaire regarding medication and duty performance. Of the 83 airmen who recalled treatment by a physician or who had self-medicated during the six months preceding the questionnaire, 39 had taken medication with potential side-effects such as drowsiness. These medications included antihistamines (Benadryl[R], Atarax[R]), certain common cold preparations (Contac[R], Dimetapp[R], Nyquil[R]), pain relievers (Tylenol[R] with codeine), muscle relaxants (Flexeril[R]) and digestive tract symptom relievers (Donnatal[R], Lomotil[R]). About 67% (26) of these individuals returned to work without any reported duty limitation status. More importantly, among the 29 who experienced actual drowsiness side effects, 65% (19) returned to work while on the medication.

What It Means

Apparently, some maintainers in this group returned to their regular duties--servicing, repairing and inspecting various aircraft components--while impaired. Not only was there impairment due to the medications the individuals took but, combined with the symptoms of the underlying ailment, the effect of the medication was likely compounded. Self-medication is most worrisome because maintainers and other non-flying operations personnel don't have the benefit of a physician to help determine if a medication is safe to take while doing their particular job. Even the most seemingly harmless over-the-counter medication can carry hidden risks, including cross-reaction with other medications and exacerbation of pre-existing medical conditions. For example, scientific studies have shown that, as with alcohol, sedating antihistamines may even cause performance impairment in the absence of drowsiness, without the worker realizing it.

To put things in context, however, there have been no documented Class A, B or C mishaps in the USAF directly linking a maintenance error to impairment caused by a prescribed or over-the-counter medication (mainly because we historically haven't looked at the effects of these medications on maintenance personnel). But the safety issue remains: Any medication you take, over-the-counter or prescription, may be detrimental to performance, including attention, memory, vigilance and motivation. Mistakes that result from ground crew human factors create a risk for loss of life or serious injury, and they can be dramatically costly in terms of equipment damage, with direct impact on flight operations during training and combat.

At our base, we discussed these concerns with the appropriate squadron commanders and supervisors, and we published an article in the MAJCOM safety magazine about self-medication. We also briefed the professional medical staff (family practice, primary care and other specialists who may see ground crew personnel) about preventive medicine issues. We emphasized the importance of determining a patient's occupation, the potential for medications to interfere with job functional requirements, discussing and documenting of medication side-effects, and the use of limited duty or quarters recommendations with a follow-up plan to determine fitness to return to duty.

We discussed the benefit of the person's physician, with the concurrence of the person under treatment, talking to the person's supervisor to help limit the impact on the workplace due to illness/injury and treatment. We also discussed the option of using some sort of tracking and documentation system similar to the Personnel Reliability Program (PRP) or AF Form 1042, Medical Recommendation for Flying or Special Operational Duty. With a computer-based interface to the workplace, medical providers can ensure supervisors are aware that a maintainer may not be fully functional to perform critical aircraft maintenance repairs and inspections after a visit to the doctor. Information like the nature and duration of impairment could assist in manning forecasts for maintenance tasks.

The review of selected USAF Class A mishap reports showed that questions of maintainer human factors generally have not historically been considered in maintenance-related mishaps. Furthermore, non-mishap incidents and ground mishaps are not usually investigated or documented so extensively. Adding a maintainer human factor review checklist item to the mishap investigation report template may prevent overlooking a potential element in the cascade of events leading to an aircraft mishap.

By presenting this information, I hope to contribute to the already-vigilant efforts to provide aircraft which are safe and functioning at peak performance. This can best be achieved by ensuring that the folks "turning the wrenches" are fit and at peak performance themselves--and are aware of the limitations caused by illness, injuries and the medications used in treatment. Accomplishing this requires education and guidance from medical support personnel and maintenance leadership. The effort required is justified, since these highly skilled, professional and dedicated individuals form the foundation to the flight mission effectiveness triad: Air Crew, Air Traffic Controllers, and Aircraft Maintainers.

Fix 'em safe!

COPYRIGHT 2001 U.S. Air Force, Safety Agency
COPYRIGHT 2008 Gale, Cengage Learning