The third- and fourth-quarter mishap spikes, explained

By Julie Shelley, Communication and Public Affairs, U.S. Army Combat Readiness CenterApril 16, 2021

USACRC Release What Are 3QS 4QS 210413.pdf [PDF - 148.9 KB]

Summer is the Army’s deadliest time of year for Soldier mishap fatalities — both off and on duty.

The longer days, nearly unlimited outdoor activities and more leisure travel during the warmer months naturally raise the risk profile off duty. On duty, however, the situation is more complex.

Extended training due to increased daylight, extreme temperatures and other weather phenomena, and the permanent change of station cycle that ramps up during summer were all identified as possible contributors to mishap spikes during the third and fourth quarters in two recent studies conducted by the U.S. Army Combat Readiness Center.

The first study, which looked at aviation mishaps between fiscals 2015-2019, revealed that 40 percent of all Class A incidents occurred during the fourth quarter, with August as the peak month. Flight hours were relatively consistent throughout the years, so heightened OPTEMPO did not explain the spike.

The second study focused on tactical motor vehicle mishaps beginning in fiscal 2015. As opposed to aviation’s spike, which occurred during later summer, Class A ground mishaps and specifically tactical vehicle accidents trended sharply upward during the third quarters of the study period. In particular, May and June — late spring and early summer — were particularly deadly, with nearly a third of the Army’s on-duty tactical vehicle mishaps reported during these two months alone.

But much like aviation, OPTEMPO was not solely to blame for the third-quarter spike. In fact, the Army drives an average of 5 million more miles during the fourth quarter than the third every year, with 30 percent fewer mishaps. Rather, a confluence of factors makes these quarters a “perfect storm” for risk in the air and on the ground.

Foremost among these factors are leader transitions during PCS season. Approximately 50,000-60,000 Soldiers report to new duty stations every year between April and September, leaving gaps in leadership and a learning curve for the personnel who backfill vacant slots on an acting or permanent basis. This is especially evident when you consider that in 70 percent of tactical vehicle mishaps, leaders do not conduct proper troop leading procedures, and that 80 percent involve shortfalls in driver training. While the issue is somewhat less pronounced on the aviation side due to experienced aviation safety officers and instructor pilots available for advice, new leaders might still be unable to holistically assess unit risk for some time after onboarding.

Environment and fatigue almost certainly also play a role. At least 30 percent of Soldiers involved in third-quarter tactical vehicle mishaps during the study period had been on duty more than 12 hours. An inexperienced acting leader with a lot to get done and longer daylight to do it in might be tempted to slide the training schedule later and later on the clock, often in unpredictable spring and summer weather, at the expense of safety. Again, mandatory crew rest and greater fidelity in weather forecasts help mitigate these hazards for our aviation personnel, but no mission is ever without risk.

In March 2020, the USACRC launched an Army-wide communications campaign targeted to the fourth-quarter aviation spike. Equipped with this information, the aviation community nearly eliminated Class A mishaps the remainder of the fiscal year, with only one incident reported during the subsequent seven months. Building upon this success, the USACRC released a third-quarter tactical vehicle spike communications campaign this spring, available at An updated iteration of the fourth-quarter aviation spike campaign for 2021 will also be available by mid-June.

While the reasons for last year’s fourth-quarter success story involve far more than any single communications effort, there is no doubt informed and engaged leaders make a significant difference every day for Army Safety. To find out more about these campaigns and other tools to help keep your Soldiers safe, visit