Incorporating TEM Into Every Flight


In today’s booming housing market across the United States, homebuyers often have only a day or sometimes only hours to decide on whether or not to make an offer and contract on their new home. Under normal housing market conditions, buyers would be afforded the opportunity to collect and analyze the data, make comparisons between other homes in the area, research the school districts for their kids, and put in a bid lower than the asking price with one or two more competitive buyers. Unfortunately, buyers are not afforded those opportunities in today’s market for various reasons, including tightened homebuilder inventories, commodity prices, and the Federal Reserve’s easy monetary policy. As a result, buyers will inevitably tend to make rushed decisions, leading to potentially overspending on their budget, settling with a less-than-desired home, and forgetting other vital considerations. Most of us do not make good decisions under time pressure, and the same type of situation can happen in the aviation world.

Pilots and aircrews often make numerous decisions with limited time and incomplete information during mission execution. We inherently perform our risk management based on experience levels, training, and proficiency. We have all heard the phrase “aviate, navigate, communicate,” but we must also consider adding the term “mitigate” to our operational perspective. Risk mitigation is complex; the key is having the ability to identify and anticipate what factors could potentially impact our flight and narrow our safety margins. Mishaps often result from a string of mismanaged threats and errors versus any single event. Breaking the chain of events as soon as a threat is identified can make the difference between a mishap and a routine sortie. To help us better understand risk mitigation, the aviation community often defers to the practical and effective model of Threat and Error Management (TEM).

TEM Origins

TEM’s origins came from a partnership between the University of Texas Human Factors Research Project and Delta Air Lines in 1994, during one of Delta’s Line Operations Safety Audits. TEM is a methodology to identify and recognize threats, reduce errors, and prevent undesired states (US). All pilots and aircrews acknowledge that we inevitably make mistakes in the complex aviation environment, and there is no perfect flight.

TEM Terminology

In the context of TEM, a threat is any condition or event occurring beyond or outside the crew’s influence. Threats inherently increase the complexity of the operation and can lead to errors if not appropriately managed. Threats should serve as red flags. Watch out— there could be severe consequences! The Federal Aviation Administration describes an error as a mistake made when threats are mismanaged. Air Mobility Command (AMC) defines errors as actions or inactions that lead to deviations from organizational or operational intentions or expectations. In simple terms, threats are external to the aircrew, and errors are internal to the aircrew. Furthermore, unmanaged and/or mismanaged errors lead to one of three outcomes:

  • Inconsequential Outcomes: the error has no immediate effect on safety (if managed properly);
  • Additional Errors: the error causes another error(s);
  • Undesired States (US): risk or unsafe operational conditions are increased, possibly leading to a mishap. AFMAN 11-290 now refers to undesired aircraft states as “Undesired States (US).”

Threat and Error Management

Active TEM strategies, coupled with sharp Crew Resource Management (CRM) skills, serve as a proactive pathway toward mission effectiveness and safe operations. The appropriate response to threats is: Identify and Prepare. Strategies include the identification of major threat(s) during the crew briefing prior to takeoff and before the descent, then developing tactics to mitigate the known and present danger. Repair includes the application of tools already within the system to protect against errors, such as briefing guides, aircraft checklists, and effective training programs. Effective strategies for error recognition and mitigation include: anticipation of errors (e.g., as discussed during mission planning), appropriate task prioritization, and selecting the appropriate automation level for the situation. Recover addresses related human factors; for example, an aircrew corrects the error before it leads to unwanted consequences. Effective errorcountermeasures include continuous employment of flight path management concepts and communication/coordination techniques such as verbalize, verify, and monitor. The model on the previous page depicts the proper interaction and employment of CRM/TEM skills.

Chain of Events Leading to a US

Threats Errors US
Weather • Excessive Crosswinds

• Turbulence

• Icing/Snow

• Improper crosswind controls

• Below turbulence penetration airspeed

• Failure to review cold-weather operational procedures and brief crew on expectations and duties

• Off-centerline landing

• Reduced stall margins

• Wrong engine/pneumatic configuration for taxi and takeoff

Airfield • Wingtip clearance

• Increased taxi distance
for closed taxiway and/or
runway in hot conditions

• Failure to download
crewmembers to verify/
improper use of marshallers

• Excessive taxi speed to make
mission timing at maximum takeoff
gross weight resulting in abnormally
high heat buildup in tires

• Inside minimum obstacle clearance

• Blown tire(s) during takeoff run

Air Traffic Control (ACF) • Revised clearance given right before
transition altitude on climbout

• Radio congestion, complex
clearances, language difculty,
and runway changes

• Failure to reset altimeters to
29.92 in. Hg

• Misinterpretation/wrong
readbacks or callbacks to ATC

• Resolution Advisory (RA) after

• Taxiway/runway incursion

AMC Operation • Operation with duty time/crew
rest waiver—fatigued

• Incorrect ramp fuel loaded

• Omitted stabilized approach callouts

• Failure to cross-verify fuel
quantity between aircraft and
dispatch paperwork

• Failure to execute go-around
during unstabilized approach

• Landed with less than reserve
fuel requirements

CRM VS. TEM—What is the Difference?

Crew Resource Management (CRM) is similar to TEM but has some significant differences. CRM relates more to managing resources, including Air Traffic Control, fellow crewmembers’ inputs, Air Operations Center, Flight Managers, and Base Operations. TEM focuses on effectively managing threats and maintaining proper safety margins. Due to their symbiotic nature, CRM and TEM are most effective when used together.

Practical Application and Way Forward

Individual aircrew members are at different stages in their careers. Some are first flying assignment lieutenants, whereas others are transferring from one aircraft platform to another; many aircrew members are returning from staff and/or school tours, whereas others fly regularly and proficiently. Regardless of where we are on the spectrum, being aware of the vulnerabilities posed by each flight will help us to anticipate and recognize the compounding effects threats and errors can have on flight safety when unmanaged or mismanaged. Protecting our Airmen from injury or loss of life and preserving our AMC assets from damage ensures we are always ready when the nation needs us.