Anatomy of a POH
Learning where to look
“I don’t remember” may not be the words a candidate ever wants to say during a checkride. But, as an examiner, I don’t see an occasional admission of ignorance as a bad thing. My invitation, “Let’s look that up to see if the standby airspeed indicator is required for our flight,” will show me if she can find key information when necessary. A candidate who opens the pilot’s operating handbook (POH) to the right section and quickly finds the answer has proven herself to be a problem solver who can respond to the curveballs that aviation occasionally provides.
Sometimes, though, painful silence follows, broken only by the rustle of POH pages as the candidate furiously flips all around the document as if its organization had no rhyme or reason. Not being familiar with a POH often means the exam doesn’t have a happy ending. As CFIs, it’s incumbent upon us to ensure our students are.
The Pilot’s Handbook of Aeronautical Knowledge (PHAK) explains that an aircraft manufacturer develops a POH that contains general information about an aircraft model. The airplane flight manual (AFM) is also developed by the manufacturer but is specific to an individual aircraft, must be approved by the FAA, and contains instructions for operating the aircraft safely. According to the PHAK, for most general aviation aircraft built within the last 50 years, the POH is also designated as the AFM and follows a predictable format. The first six sections are:
General: This section gives an overview of the airplane including the interior and exterior dimensions, engine and propeller make, fuel and oil types, and capacities. It typically ends with abbreviations used within the document as well as helpful conversion charts.
Limitations: These are the rules, like weight, center of gravity (CG), and airspeed limits, for operating the aircraft safely, and adhering to them is mandatory. It may include a “Kinds of Operation Equipment List” that details exactly which items are allowed to be inoperative in various phases of flight. For example, the Cessna 172S POH shows that the standby airspeed indicator is not necessary for VFR flight but is required for IFR flight.
Emergency procedures: Cabin fires, engine failures, inadvertent icing encounters, and spins are problems that require immediate action. Pilots should memorize many of these remedies and at least know the first few important steps for the others. Some POHs start with emergency checklists followed by amplified procedures—which no one will read in an emergency—that can contain important factors for a successful outcome. For example, in the Piper PA–32R-301 Saratoga POH the engine-out checklist is silent on propeller position, but the amplified procedures warn that failing to pull the propeller back to low rpm means that the glide performance will not live up to the advertised 9:1 ratio. Read the amplified procedures ahead of time and consider amending emergency checklists accordingly.
Normal procedures: The Cessna 172S model begins the “Normal Procedures” section with a summary of important airspeeds followed by a sample preflight inspection routine. Because my own airplane has had many modifications over its 50-something years, some of the normal procedures are outdated. I use this section as a basis for creating a checklist for preflight and flight operations that includes tests for the airplane’s new equipment.
Performance: While you may have loaded a performance profile into your electronic flight bag, pilots need to ensure that the profile matches the POH so knowing how to use the performance charts is important. By routinely making performance predictions and comparing with in-flight performance, CFIs can guide their students to use appropriate safety buffers and help them see that such estimates are useful.
Weight and balance: Look at the envelope for your airplane and you’ll see that the CG position, or balance point along the longitudinal axis, is often between 6 and 12 inches wide so your aircraft needs to be loaded precisely. Beyond the loading graph and envelopes that POHs contain, an AFM must contain an updated weight and balance form that is signed by a licensed FAA mechanic. As aircraft gain and lose equipment over the years, their empty weight and CG positions can change significantly. Ensure you’re using the most updated information.
Breaking out the POH isn’t just an exercise for student pilots. I find a winter day with low weather is the perfect time for me to brush up on my own airplanes. Staying familiar with procedures allows me to fly my airplane more safely and reminds me where information is when I am on the receiving end of a curveball.
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