Register

The Human Factor: The Two Challenge Rule

Gemini Sparkle

Key Takeaways:

  • Visual approaches are "seductive," causing pilots, even professionals, to continue unstable approaches significantly more often in visual meteorological conditions (VMC) than in instrument conditions, due to factors like increased manual flying and reduced threat awareness.
  • The "Two Challenge Rule" is presented as a crucial method to counter this temptation, empowering the pilot not flying (PNF) to make two callouts for deviations and initiate a go-around if the pilot flying (PF) fails to correct the instability.
  • Successful implementation of this rule requires establishing clear stable approach criteria (e.g., airspeed, glideslope, vertical speed) and a defined Stable Approach Height (SAH), prompting early intervention and leading to more accurate and safer landings.
See a mistake? Contact us.

As I was talking with Dr. Martin Smith about the research he and his associates at Presage Group were doing on unstable approaches, he commented that visual approaches “were a little more seductive than instrument approaches in terms of continuing with an approach that is unstable.” Dr. Smith said even though all of the participants in the study were professional pilots and most were flying scheduled short-haul passenger service under instrument flight rules, 80 percent of the unstable approaches reported in the study occurred during visual ­meteorological conditions.

The Presage data shows pilots flying an approach in VMC are more likely to be flying the airplane manually, seem less aware of operational and environmental threats, are less likely to view those threats as unmanageable, are less likely to rely on expert knowledge of instruments and procedures and have lower confidence in their companies’ go-around policies. As Dr. Smith said: “That’s some seduction! It’s almost like they’re hand-flying a Cherokee 140 on a CAVU summer day with not a worry in the world.” Dr. Smith worried that due to the normalization of deviance mentioned in my previous article, these ­nonprescribed, deviant behaviors may have become the accepted way to conduct VMC approaches within the industry.

Ready to Sell Your Aircraft?

List your airplane on AircraftForSale.com and reach qualified buyers.

List Your Aircraft
AircraftForSale Logo | FLYING Logo
Pilot in aircraft
Sign-up for newsletters & special offers!

Get the latest stories & special offers delivered directly to your inbox.

SUBSCRIBE