Boeing 737-800 Memory Items Pdf

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Tommie

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Aug 3, 2024, 4:07:42 PM8/3/24

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When something goes wrong while flying on the Boeing 737, we use the QRH (Quick Reference Handbook). We just have to find out the correct NNC (Non Normal Checklist) and then we just read it and execute it.

But for an engine fire, severe damage or separation, the aircraft is not safe and some actions are necessary rapidly to secure the engine and the aircraft it-self. As soon as we reach 400ft AGL, we complete the memory items.

An engine fire is obvious and easy to detect. You get the fire warning bell associated with the engine fire light in front of you and finally the engine fire switch for the affected engine illuminates. On the newest versions of the 737-800 and 737 MAX, the engine start lever illuminates red as well. Once you have identified the problem, it is best to cancel the warning, it will shut the annoying bell.

It is important to complete the memory items and to pull the engine fire switch because this closes both the engine fuel shutoff valve and the spar fuel shutoff valve and prevent from a massive overboard fuel leak.

"A runaway stabilizer condition can be recognized by continuous uncommanded movement of stabilizer trim, or if stabilizer trim is occurring in a manner that is not appropriate for current flight conditions. During manual flight or flight with the autopilot engaged, automatic stabilizer trim can be commanded by the Speed Trim System or autopilot trim. Since commanded stabilizer trim can occur automatically, the pilot needs to consider the existing flight conditions to determine if a runaway stabilizer condition exists. For example, some stabilizer trim movement can be expected to occur during speed, altitude, or configuration changes."

"During a runaway stabilizer condition the crew should maintain airplane pitch control through the use of the control column, main electric stabilizer trim, and thrust levers. The control column must be held firmly before the autopilot (if engaged) is disengaged to maintain airplane pitch control and retain any elevator commands from the autopilot. After the autopilot and autothrottle are disengaged, use the control column and thrust levers to establish appropriate pitch attitude and airspeed. If uncommanded trim motion continues, it may stop when the control column is displaced in the opposite direction and the control column cutout is activated. Use main electric stabilizer trim to reverse any stabilizer trim movement and to reduce control column forces. Sustained use of main electric stabilizer trim may be needed. It is important to note that even though the steps in the Runaway Stabilizer checklist are sequential, these steps can be accomplished simultaneously. If uncommanded stabilizer trim movement continues, place both STAB TRIM cutout switches to the CUTOUT position. Manual stabilizer trim should then be used for the remainder of the flight."

Following the Lion Air accident, on 7 Nov 2018 the FAA issue an Emergency AD (2018-23-51) and Boeing issue an Ops Manual Bulletin (TBC-19) for MAX Runaway Stabilizer procedure directing operators to existing flight crew procedures" to address circumstances involving erroneous angle-of-attack sensor information.

FAA Emergency AD 2018-23-51 - SUMMARY: We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-8 and -9 airplanes. This emergency AD was sent previously to all known U.S. owners and operators of these airplanes. This AD requires revising certificate limitations and operating procedures of the airplane flight manual (AFM) to provide the flight crew with runaway horizontal stabilizer trim procedures to follow under certain conditions. This AD was prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer. We are issuing this AD to address the unsafe condition on these products..

This AD requires revising certificate limitations and operating procedures of the airplane flight manual (AFM) to provide the flight crew with runaway horizontal stabilizer trim procedures to follow under certain conditions.

Comment summary: Several commenters, including BALPA, NATCA, ALPA, Boeing, the Allied Pilots Association, the JEMOG, Ethiopian Airlines Group, A4A, and SWAPA, requested that the FAA modify the emergency and non-normal procedures contained in the proposed AD. These comments covered several of the proposed checklists, with an emphasis on the Airspeed Unreliable and Runaway Stabilizer checklists. The comments included requests to make small changes involving typographical errors, to add information to checklists, to simplify checklists, to shorten or reduce the number of memory items, and to develop checklists for certain specific failure cases. Three commenters, including BALPA and Ethiopian Airlines Group, recommended providing a combined Airspeed Unreliable and Runaway Stabilizer checklist for certain specific failure conditions.

FAA response: The FAA has made several changes to the checklists, taking into consideration not only comments provided in the context of the NPRM, but also in response to the outcomes from the FAA FSB evaluation. The inputs from the FAA FSB were the result of collaboration with other CAAs during the JOEB. The JOEB conducted an extensive evaluation of the proposed procedures and training conducted by a wide variety of crews, including line pilots with levels of experience ranging from high to low and regulatory pilots from four separate CAAs during the NPRM comment period.

The AFM procedures specified in the proposed AD were the result of procedural development conducted by FAA test pilots, human factors, and operations personnel (along with other engineering and operational experts from other CAAs and from Boeing), which considered a myriad of similar aspects as the procedures were developed and evaluated. Additionally, the procedures were evaluated during FAA certification, including human factors evaluations to determine compliance to 14 CFR 25.1302, and system safety assessments to determine compliance to 14 CFR 25.1309. The FAA convened a team of test pilots, operational pilots, and human factors experts during the development of the AFM procedures specified in the proposed AD. The FAA convened a similar team to consider each procedural comment made during the NPRM comment period and to determine if changes were warranted to improve safety.

A4A and SWAPA expressed concern that there are too many recall items in the Runaway Stabilizer non-normal procedure, and included a suggestion for how to reduce the number of steps. The suggestion included combining some recall items to achieve fewer numbered steps, but with multiple embedded actions in each recall item, such that the suggested changes would result in the same number of required flightcrew actions. The FAA agrees that it is desirable to minimize recall items when appropriate. The recall steps in the non-normal procedures required by paragraph (h) of this AD reflect flightcrew actions required to address a runaway stabilizer condition. Based on the FAA's evaluation and in coordination with human factors specialists, the FAA determined that the commenters' proposed changes would complicate the recall steps and would increase the likelihood that a critical flightcrew action is forgotten or missed. The FAA considered all of the commenters' requests in the context of crew workload, clarity of instruction, consistency with training objectives, and consistency with other procedures contained in the AFM. The FAA declines the request to combine checklists because checklists must be applicable to all potential failure conditions, not just the specific failure conditions noted by the commenters. Additionally, the failure conditions where a combined checklist might be useful were evaluated by multiple flightcrews, resulting in a conclusion by the FAA that, primarily due to the new MCAS required by this AD, the order and content in which these two checklists were accomplished is not critical to continued safe flight and landing.

Dennis Tajer of the Allied Pilots Association, which represents 15,000 pilots of American Airlines, has said of the FAA review: "I want them to be invasive. I want them to be aggressive. I want them to be obstinate about knowing all of the information, I want them to be more than trust but verify." He went on to say that even if the basic steps do not change, the spartan checklist language could be augmented with instructions such as those contained in Boeing supplemental materials: "It may take two pilots to manually trim the aircraft." "It may require elevator load alleviation in order to manually trim the aircraft." I have to say that I agree that more information in the QRH would be helpful.

US government officials told The Wall Street Journal in late May that the FAA is evaluating the emergency procedures not only for the Max, but also for older generations of the 737 including the NG. A Boeing spokesman responded in a statement "While we are working with the FAA to review all procedures, the safety of the 737 NG is not in question, with its 20-plus years of service and 200 million flight hours."

Note that on the MAX, the MAIN ELEC and AUTO PILOT Stab trim switches now either switch will cut-off both main electric and autopilot stab trim. They are renamed PRI and B/U (primary and backup). The switches are guarded in the NORMAL position (switch up) and CUTOFF is switch down. The QRH procedure is the same for all 737s.

Excessive airloads on the stabilizer may require effort by both pilots to correct the mis-trim. In extreme cases it may be necessary to aerodynamically relieve the airloads to allow manual trimming. Accelerate or decelerate towards the in-trim speed while attempting to trim manually. [This is known as the "roller coaster" or "yo-yo" manoeuvre!]