Cover Photo by Paul Smith/HAI

Helicopter pilots can mitigate these long-term effects of the career.

When you ask a group of helicopter pilots if their career has affected their health, a common response is “What? I don’t hear so good. I’m a helicopter pilot.”

All kidding aside, many pilots see neck or back pain and hearing loss as an inevitable consequence of spending years in the “helo hunch” in a vibrating aircraft. And yes, research does show that being a helicopter pilot can lead to neck and back pain, as well as hearing loss.

But there ARE things you can do to avoid these health issues.

Flight Helmets: The Good and the Bad

While this article will discuss some negative effects of long-term use of flight helmets, let me make it very clear: in my opinion, everyone who is riding inside a helicopter should be wearing a helmet designed for use in helicopters. The positives greatly outweigh the negatives.

The helmet’s primary purpose is to protect the head and eyes during impact in case of an accident or bird strike, and it works. Numerous studies have documented this, including Taneja and Wiegmann’s 2003 study in Aviation Space and Environmental Medicine and Roskop’s 2015 research for the Civil Aerospace Medical Institute.

Having said this, nothing is perfect, and there are some tradeoffs to wearing helmets. While they provide head and eye impact protection, helmets also make the head weigh more in case of impact. Years of use may contribute to neck and back neurological problems. They also do not provide enough hearing protection to completely mitigate hearing loss.

As a physiologist who works with helicopter flight crews, one of my goals is to help crew members retire with the ability to lift their grandchildren and hear them laugh. Unfortunately, this is not always the case.

With the understanding that helmets are necessary for head and eye protection, as well as to provide a platform for communications and night-vision devices, the rest of this article will share what users need to know to prevent future neck and back pain, and hearing loss.

Keep in mind that the degree of pain and hearing loss experienced by the individual pilot will vary, based on factors including the type of helmet, type of airframe, and whether the aircraft is flown with doors on or off. Like so many things in life, physiological damage depends on a time/dose relationship: that is, how much and for how long.

Neck and Back Pain

Unfortunately, no studies have attempted to quantify the amount of neck and back pain experienced by pilots in the civil helicopter industry. However, a 2018 study by John Crowley, “Aircrew Neck Pain Prevention and Management Insights from NATO,” examined several studies from militaries around the world documenting the very same problems. A literature search I just completed brought up 10 similar studies.

Yes, these are military studies, but the bottom line is they examined helicopter pilots and found more reports of neck and back pain than in other military occupations. The reality is, the militaries have the scientists, funding, and desire to examine such issues, and we certainly can extrapolate from their data.

In addition to the weight of the helmet, a few other factors contribute to the incidence of neck problems. While night-vision goggles (NVGs) may only weigh slightly more than 1 lb, that weight is concentrated at the front, making the pilot’s head front-heavy. Aircraft vibration also plays a role, and that varies, depending on the airframe.

The purpose of the flight can play a role too. Turning the head around in an orbit and craning the neck as law enforcement flight crews often do can exacerbate problems. Further contributing to back problems, most helicopters put flight crews (mainly those sitting up front) in an unusual position that does not allow for sitting up straight, the “helo-hunch.”

When considering neck pain, no one single factor is to blame. Helmet weight, NVGs, and aircraft vibration all contribute, but the combination of them is the real culprit.

As I mentioned, retiring with neck and back pain is a concern for pilots. However, I am also concerned that neck and back pain could affect the operational fitness of working flight crews. Two possibilities are that inflight pain will challenge situational awareness and will reduce the head’s range of motion.

As with neck problems, numerous military studies illustrate that long-term helmet use is associated with back problems. In 2010, Lt. Paul Sargent, M.D., and Lt. Angela Bachmann, M.D., reported that 82–92% of otherwise healthy young aviators reported back pain, and 44–50% had pain during flight. While this is significant in itself, Sargent and Bachmann’s study, “Back Pain in the Naval Rotary Wing Community,” documented that this pain resulted in decreased concentration (54–66%), hurried flights (16%), and cancelled flights (7%). A study by the Australian Navy had almost identical findings (64% had pain, 55% had trouble concentrating, 16% reported hurried flights, and 7% refused flights).

Neck and back issues bring with them concerns of decreased operational readiness. These include cancelled flights, which can result in lost work days and distraction, as well as hurried flights and attrition.

The Way Out: Exercise

The best way to mitigate neck and back issues is through stretching and exercise. Many individuals do not exercise at all, and even people who exercise regularly often do not exercise their necks. However, the medical papers and presentations I’ve reviewed unanimously conclude that mitigation comes down to exercise. I am not speaking about specific exercises but a well-rounded resistance program that includes the neck. Stretching can provide short-term relief, with the goal of increasing blood flow, and therefore oxygen, to the tissues.

Another major mitigation for back pain is to redesign the seats, but until the military requires this in new purchases, it will not happen. There is, however, one other way to lessen the back pain you may be experiencing: provide additional support to the lumbar, or lower back, region. Lumbar support cushions are widely available and may at least partially mitigate the pain.

Hearing Loss

When discussing hearing-related issues, it is important to understand the difference between loudness and pitch. Loudness is the impact of the sound (pressure) wave on the ear drum, or tympanic membrane, and is measured in decibels (dB). The pitch is the frequency (high vs. low) of the sound and dictates where in the cochlea (inner ear) the sound is picked up. Pitch is measured in hertz (Hz).

We are mostly concerned with low frequencies, between 100 Hz and 1,000 Hz. In helicopter operations, this noise is continuous and at high intensity. It originates from several sources, including but not limited to engines, driveshafts, transmissions, and rotor blades. Frequencies affecting crew members come from the tail rotor blades (96–100 Hz), main rotor blades (10–20 Hz), and blade slap (20–1000 Hz).

The US Surgeon General has established 85 dB as the maximum level of continuous unprotected exposure to steady-state noise for 8 hours. As the dBs increase, the amount of permitted exposure decreases (the time/dose relationship). To avoid noise becoming hazardous, it should be no greater than 85 dBs if continuous, or it should be an impulse/impact noise no greater than 140 dBs.

As with the neck and back pain, hearing loss can also lead to operational compromises. The obvious challenge is hearing and understanding radio communications. Another is the loss of ability to hear sound changes in the engine.

I have not found any studies that illustrate hearing-loss issues as related to helicopter operations. A 1990 study on tank gunner performance and hearing impairment published in the Army RD&A Bulletin correlates hearing loss with incorrect commands heard by gunner, target identification, and wrong targets killed. Regardless of the focus of the study, one can see how hearing loss can impact helicopter operations.

Adding a secondary layer of protection would be the way to reduce this problem. Many studies show that simply inserting foam-type ear plugs under the helmet makes a big difference. Some prefer the convenience of communications ear plugs (CEPs), which provide hearing protection and can also connect to comm systems.

Think Long-Term Health

While flying in helicopters can produce negative physical effects such as neck and back pain and/or hearing loss, there are steps you can take to mitigate most of the effects. I realize exercising and wearing hearing protection are not popular topics, but before dismissing them, I urge pilots to consider the alternative: pain and hearing loss. By just modifying your lifestyle slightly, it is possible to significantly reduce those issues and avoid partial disabilities and early retirement.

Author

  • From 1988 to 2002, Dudley Crosson was an aerospace physiology consultant for NASA contractors. Since 9/11, he has supported various public safety aviation units. He was also an associate professor at the Florida Institute of Technology and until recently an affiliate professor in aerospace physiology and human factors at the University of Hawaii.

Dudley Crosson

Dudley Crosson

From 1988 to 2002, Dudley Crosson was an aerospace physiology consultant for NASA contractors. Since 9/11, he has supported various public safety aviation units. He was also an associate professor at the Florida Institute of Technology and until recently an affiliate professor in aerospace physiology and human factors at the University of Hawaii.