NTSB Targets SR22T Excessive Fuel Flow

Six accidents are attributed to the problem, which resulted in three fatalities


In formal recommendations to the FAA and Cirrus Aircraft, the National Transportation Safety Board (NTSB) is urging action to “identify the cause and reduce the potential hazard” of accidents occurring from excessive fuel flow rates aboard the Cirrus SR22T. The NTSB has identified six accidents in which excessive fuel flow during initial climb—ranging from 42.2 to 50.1 gph—was identified as at least a contributing factor. 

The underlying cause for the excessive fuel-flow condition was established in only three of the six accident investigations. Two of the associated accidents involve “incorrect” selection of the electric fuel pump’s HIGH BOOST/PRIME position while the third was traced to “an improperly adjusted slope controller,” according to the NTSB. Nevertheless, the safety board believes “that all the potential causes for these failures need to be identified to fully address this hazard.”

In its Accident Investigation Report (AIR-22-04), the NTSB acknowledged previous efforts by Cirrus to identify and address the problem as far back as May 2018. They involved Cirrus Service Advisory SA18-02, which reminded pilots that the electric fuel pump’s HIGH BOOST/PRIME position is for “priming prior to engine start and suppressing vapor formation in flight above 18,000 feet with hot fuel. The fuel pump must be set to BOOST—but not HIGH/BOOST/PRIME—for takeoff, climb, landing, and for switching fuel tanks.”

At that time, Cirrus also implemented a software feature that “locks out the high boost function of the pump (if HIGH BOOST/PRIME is selected) until the airplane reaches a pressure altitude of 10,000 ft.” The updated software included an updated crew alerting system message.

Subsequently, Cirrus acknowledged “the lockout feature was not operating as intended,” according to the NTSB, and issued Service Advisory SA19-01, which states “HIGH BOOST/PRIME fuel pump mode should only be required, in flight, above 18,000 feet on hot days with warm or hot fuel to maintain fuel flow in the green arc or to suppress vapor formation.” Importantly, the FAA has not mandated compliance with the service advisories, according to the NTSB.

Ultimately, the NTSB is concerned that incorrect selection of the HIGH BOOST/PRIME fuel pump switch is not the only reason for the high fuel flows. It stated, “Until the Federal Aviation Administration requires implementation of appropriate mitigating actions to prevent the loss of engine power due to excessive fuel flow in the SR22T, additional accidents may occur due to this hazard.”

The NTSB’s April 12, 2022, recommendations urge Cirrus Aircraft to conduct “a functional hazard assessment (FHA) to identify the causes, effects, and severity levels for the SR22T excessive fuel flow hazard condition during takeoff and climb phases of flight.” Once that occurs, the FAA should “work with Cirrus to identify necessary mitigating actions and require their implementation through the appropriate means, such as an airworthiness directive.”

AOPA ASI Announces New VFR-Into-IMC Campaign

“VFR into IMC is among the top five causes of fatal GA accidents, which are largely preventable,” said AOPA Air Safety Institute Senior Vice President Richard McSpadden in announcing a new safety campaign: VFR into IMC: Avoidance and Escape. “And it’s not only VFR pilots who get trapped; about one-third of these accidents involve instrument-rated pilots.”

The campaign runs through December 31 and will focus on outreach to address the most significant cause of weather-related accidents in GA—flying VFR into instrument meteorological conditions (VFR into IMC).

Part of the new campaign is based on ASI research revealing that pilots encounter these conditions every other week on average. “Often thought of a single cause, VFR into IMC plays a role in several other types of accidents including loss of control in-flight (LOC-I) and controlled flight into terrain (CFIT),” McSpadden continued. Campaign events are packaged in a new online resource center at: tinyurl.com/SAF-VFR2IMC.



An FAA Airworthiness Directive (AD 2022-14-12) issued July 27, 2021, which targeted several models of the American Yankee/Grumman line of piston singles in response to an accident involving an airplane “exhibiting bondline corrosion and delamination of the horizontal stabilizers” won’t see a sister AD go into effect, at least not soon.

That’s because the FAA published an April 7, 2022, notice withdrawing a related proposed AD that would have expanded the list of affected aircraft and required inspecting the majority of the airplane structure. The FAA “has determined that there is not an unsafe condition, but instead incorrectly followed maintenance procedures” were involved in the accident. True Flight Holdings is the models’ present type certificate owner.

The proposed AD was published December 1, 2021, In its withdrawal statement, the FAA agreed “that the instructions in the airplane maintenance manual are sufficient to detect the type of damage that is believed to have led to the originating accident, as well as similar damage on the rest of the airplane.” Of course, the FAA reserved the right to revisit this issue later.

The accident resulting in the AD was on January 19, 2021. The event was detailed in our April 2022 cover story, “When Airplanes Break,” written by the accident pilot. “[T]he outboard elevator attach bracket on the horizontal stabilizer detached, causing loss of elevator control and significant damage to the airplane,” according to the FAA. As of this writing, the NTSB has not yet determined a probable cause.


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