The question raised in this brief but pointed forum post—whether the elevator trim stall demonstration required for the Certificated Flight Instructor (CFI) practical test should be performed with or without flaps extended—touches on a recurring source of confusion in flight instructor training that has real operational consequences. The elevator trim stall (also called a trim stall or "out-of-trim" stall) is one of the required maneuvers under the Airman Certification Standards (ACS) for the Flight Instructor–Airplane certificate, and it exists specifically to demonstrate what happens when an airplane is trimmed for a slow-airspeed, nose-high configuration and power is abruptly increased, causing a rapid pitch-up that the pilot must recognize and counteract. The lack of a single, universally cited answer online—and the applicant's explicit uncertainty about what a Designated Pilot Examiner (DPE) will expect—reflects a broader pattern in CFI training where the letter of the ACS leaves room for interpretation, and candidates are left to reconcile guidance from instructors, online forums, and examiner preference.
For working CFIs and CFI candidates, this is not a trivial procedural detail. The trim stall demonstration is designed to simulate a real-world scenario: an airplane trimmed nose-up for slow flight or approach configuration (often with flaps and reduced power, mimicking a go-around or balked landing setup) that suddenly receives a large power addition. Without flaps, the maneuver can still demonstrate the pitch-up tendency from trim and power coupling, but it arguably fails to replicate the actual accident scenario the maneuver was created to address—historically, stall/spin accidents during go-arounds or balked landings where pilots, distracted by reconfiguring flaps and power, lost control after failing to counteract trim-induced pitch forces. Most standardized guidance, including FAA guidance embedded in the Airplane Flying Handbook, frames this maneuver in the context of a landing configuration, which implies flaps should be extended to accurately replicate the go-around scenario the maneuver was built to teach. However, because the ACS task language itself does not explicitly mandate flap configuration, and because aircraft-specific limitations or instructor preferences vary, DPEs and instructors sometimes diverge on execution, feeding exactly the kind of forum uncertainty seen in this post.
This matters beyond test-day mechanics because CFI candidates are not just being evaluated on rote maneuver execution—they are being evaluated on their ability to teach the underlying aerodynamic principle and risk scenario to future students. An instructor who cannot articulate why the maneuver is flown with or without flaps, and what real-world scenario it replicates, has missed the deeper teaching point the ACS is testing for. This connects to a broader trend in flight training standardization: the FAA's shift from the older Practical Test Standards (PTS) to the ACS was explicitly intended to tie maneuvers more closely to the underlying risk management and aeronautical decision-making rationale, rather than treating them as checklist items. Ambiguity in execution details like flap configuration undermines that goal when instructors and DPEs aren't aligned, and it places outsized weight on individual DPE preference during the practical test—a dynamic CFI candidates everywhere navigate not just for trim stalls but for other loosely specified maneuvers (e.g., steep spirals, chandelles, lazy eights) across the Commercial and CFI ACS documents.
The practical takeaway for CFI applicants and instructors precepting them is to consult their specific DPE ahead of the checkride when possible, review the applicable Airplane Flying Handbook language on elevator trim stalls (which frames the maneuver as replicating a go-around/balked landing scenario, generally implying a flaps-extended, landing-configuration setup), and, most importantly, be prepared to brief the underlying accident scenario and aerodynamic rationale regardless of which configuration is flown. This kind of pre-checkride diligence—reaching out to examiners, cross-referencing FAA source documents rather than relying solely on secondhand forum accounts—remains a best practice not just for this maneuver but across the entire spectrum of practical test preparation, particularly as ACS documents continue to evolve and examiners exercise judgment in areas where the written standard leaves room for interpretation.