Turbofan Engine Malfunction Recognition and Response Final Report

Introduction

On 13 December 1994 a Jetstream 31 turboprop crashed at Raleigh Durham, resulting in fatal injuries to 15 passengers and two crew. It was determined by the NTSB that the pilot had mistakenly assumed that an engine had failed and subsequently failed to respond appropriately. The AIA, at the request of the FAA, subsequently undertook a project to identify the issues related to the accident and identify corrective actions. The results of the AIA/AECMA project were published in 1998 (Reference 1). Key findings of the AIA/AECMA Project Group included:

• 
  Although the vast majority of propulsion system malfunctions are recognized and handled appropriately, there is a shortfall in some pilot’s abilities to recognize and handle propulsion system malfunctions. The shortfall from initial expectation is due to improved modern engine reliability, changing propulsion system failure characteristics (symptoms), changes in flight crews’ experience levels, and related shortcomings in flight crew training practices and training equipment.
  

• 
  Industry has not provided adequate pilot training processes or material to ensure pilots are provided with training for powerplant malfunction recognition. This shortfall needs urgent action to develop suitable text and video training material which can be used during training and checking of all pilots for both turboprop and turbofan powered airplanes..
  

• 
  The training requirements related to “Recognition and correction of in-flight malfunctions” are found in Appendix C of 14 CFR Part 63 for Flight Engineers. The disposition of the flight engineers recognition training requirements to pilots of airplanes where no “Flight Engineer” position exists is not apparent. However, the expectation does exist that the pilots will perform the duties of the flight engineer.
  

• 
  The review of simulator capabilities shows that the technology exists to better produce realistic propulsion system malfunction scenarios. However, at the moment, realistic scenarios are often not properly defined nor based on airframe or powerplant manufacturers’ data. Rather, the scenarios are often based on the customers’ perceptions of the failure scenario. There is generally no airframe or powerplant manufacturers’ input into realistic engine failure/malfunction scenarios as represented in simulators. Furthermore, the engine failures currently addressed in most training do not cover loud noises and the onset of heavy vibration. Complete and rapid loss of thrust is currently being trained and is probably the most critical from an airplane handling perspective; however, this failure is not necessarily representative of the malfunctions most likely to be encountered in service. There is also evidence that this lack of realism in current simulations of turbofan propulsion system malfunctions can lead to negative training, increasing the likelihood of inappropriate crew response. Review of current simulators indicates that the tactile and auditory representation of airplane response to engine compressor stall/surge is very misleading.
  

• 
  A substantial number of the turbofan accidents reviewed are related to propulsion system malfunctions resulting in high-speed aborts, including above V₁ and V_r. Accordingly, current pilot training may be deficient in addressing the symptoms of the malfunctions, particularly loud noises and the importance of V₁ and V_r speeds. There was only one RTO-related accident identified on turboprop airplane in the database.
  

The AIA/AECMA report included a recommendation that :