On the Design of Flight-Deck Procedures - Intelligent Systems ...

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solution involves “anchoring” a “man-made” waypoint at an arbitrary distance (100 miles typically) on abearing of 347 degrees from FL 11 . 12Guideline #8: The procedures designer must be mindful of the limitations and capabilities ofthe device he or she is designing a procedure for. Devices that are well designed for the humanuser require minimal procedurization. Less robust devices will require more thought on thepart of the designer, and will probably require more complex and lengthy procedures.Electronic checklist displays are highly demanding of compatibility between the procedure and display.The first generation of electronic checklists is currently installed in three air transport aircraft (A-310, A-320, and MD-11). With respect to procedural modifications, these systems are inflexible because thecustomer cannot easily modify the items which will appear on the electronic checklist display, or eventheir order of appearance. For example, one of the procedures in the electrical checklist system is quitecumbersome when performed at a low altitude. To combat this, one airline devised a procedure calledthe “mini checklist.”If engine failure occurs at low altitude and landing is imminent, the ECAM procedure, if sequentially followed,results in turning off various equipment, reactivating the hydraulic system, and then turning ON much of thesame equipment that was just turned OFF. To preclude this, and streamline the procedure, a good technique isto turn ON the green electronic pumps and the appropriate PTU shortly after engine failure in order to reactivatethe affected hydraulic system and eliminate much of the ECAM procedure. It is also a good technique to startthe APU to provide electrical backup. Commonly used terminology is to call for the “mini-checklist” whichconsists only of restoring the hydraulic system and starting the APU as noted above. (If an engine fails duringtakeoff, do not call for the “mini-checklist” until after calling for flaps up).The mini-checklist is a paper checklist which is kept in the cockpit. It lists several items for restoring thehydraulic system and starting the APU. The “mini-checklist,” therefore, is a form of adaptation inhuman-machine systems. A task is “tailored,” or modified, by the human operator to accommodate aconstraints imposed by inflexible devices (Woods and Cook, 1991). This adaptation is required becausethe modified procedure cannot be supported by the existing electronic checklist. The consequences ofsuch inflexibility are that the pilot is required to conduct a procedure (mini checklist) on top of anotherprocedure (ECAM), in order to execute the task. Note that both procedures discussed are performed in ahighly critical and workload-intensive situation -- restoring an essential system after an engine failure atlow altitude.6.1.4 Aircraft Systems and ProceduresA procedure that details how to operate a particular sub-system must be compatible (or correct) in termsof its procedural steps, actions, and flow. The following examples will show how much the proceduraldesigner must be attuned to the engineering aspect of the device (or sub-system). One company’s splitflapprocedure had to be re-written when it was found to be wrong. The problem was traced to the factthat system components that were powered by the standby power unit were different from the standardconfiguration for this model aircraft. The airline apparently did not keep a good record of its ownelectrical system specifications. Such problems, however, are not unique only to airlines. During SpaceShuttle Mission 49, the crew of the orbiter Endeavor tried to deploy a rescued satellite (Intelsat). Theprimary and backup deployment circuits would not send power to the cradle holding the satellite.“Investigation showed that the checklists used in Mission Control and on Endeavor were identical tothose on the other three NASA orbiters. But the problem occurred when circuitry for Endeavor's wiringwas engineered differently and the checklists were not changed to conform with the new orbiter'sdesign.” The problem was finally overcome with the help of engineers in Ground Control (AviationWeek and Space Technology , 1992a, p.79).Likewise, there may be wide differences in aircraft configurations within a given fleet. This sets thestage for the possibility of using an inappropriate procedure in some models. This is particularly true if11 One captain that we interviewed remarked that the 757 (and other glass aircraft equally so) is “a good 'to' airplane, but apoor 'from' airplane.”12 A similar incompatibility that requires a cumbersome procedure is the task of intercepting a jet airway in a 757/767FMS. The procedure requires some 6 steps and two mode changes.32
there are a small number of “odd ball” aircraft within the fleet. In designing procedures for such a mixedfleet, special caution must be taken regarding sub-systems that are invisible to the pilots (e.g., electricalbus configuration).Guideline #9: Management must guarantee that any procedure is compatible with theengineering of the aircraft or any sub-system. Care must be taken when there are subtledifferences between aircraft (especially if these differences are invisible or difficult to detect).Incompatibility can be resolved either by re-engineering or procedure.6.1.5 Cockpit Layout and ProceduresWe have noted instances of incompatibility of procedures with the ergonomic layout of the flight deck.Consider the flap/slat and gear levers, for example. Traditionally, gear and flap/slat levers were mountedin the first officer's area (right side of the cockpit). They were not within easy reach for the captain inthe cockpit of a widebody airplane. In most U.S. airlines the captain and the first officer rotate the dutiesof pilot flying (PF) and pilot not flying (PNF) during a trip. If the first officer is the PF, the SOPusually dictates that the captain raise the gear and flaps/slats after takeoff. To do this, the captain mustlean to the right of the throttle quadrant to grasp the gear or flap/slat lever(s). In several aircraft cockpits,specially widebodies, the captain cannot see the flap/slat detents very well and he or she can alsoaccidentally push the throttles rearward. The same error may occur when the first officer, as the PF,wants to use the speed-brakes located to the left of the throttle quadrant. Note that this incompatibility isdue to the operational philosophy of most U.S. airlines that encourages rotation of pilot flying duties. Incontrast, in some foreign airlines PF duties are not rotated every leg. For those airlines, thisincompatibility does not exist.There are two approaches for solving this incompatibility: (1) procedural, and (2) hardware.1. Some have argued that since the cockpit layout cannot be changed (within reasonable boundariesof cost efficiency), the procedure should be changed so that when the first officer is the PF, he orshe will retract/extend the gear.2. In contrast with the Douglas DC-10, the designers of the MD-11 located the landing gear lever inthe middle of the forward panel. It is within equal reach-distance for both the captain and the firstofficer. Likewise, the designers of the Airbus A-320 eliminated a portion of this incompatibilityby placing the speed brakes and flap levers on the pedestal between the two pilots.Note that both the MD-11 and A-320 aircraft were designed during a different social era than theirpredecessors. Social culture has affected the airlines’ philosophies of operation (a flatter cross-cockpitauthority and role gradient), the airlines’ policies (rotation of PF duties) and has thereby affectedassociated procedures (gear extension by PNF). To accommodate these philosophy, policy, andprocedural changes, the cockpits were designed differently. Not surprisingly, there is greaterinvolvement of airlines nowadays in the design phase of new aircraft (Aviation Week and SpaceTechnology, 1992b).Guideline #10: Airframe manufacturers and component suppliers (such as avionics firms)must be attuned to general airline procedures. Knowledge of such procedures may influenceergonomic considerations.6.1.6 Paperwork and ProceduresDocuments, manuals, checklists, and many other paper forms are used in the cockpit. The compatibilitybetween the procedures and their associated devices (manuals, checklist cards, etc.) exerts an effect onprocedural execution. Ruffell Smith (1979) reported that excluding aircraft flight manuals, the amount ofpaperwork needed for a flight from Washington D.C. via New York to London, had a single side area of200 square feet. Interestingly, the 15 years since Ruffell Smith's study have not yielded any reduction incockpit paperwork. On the contrary, the problem has only intensified (as evident from recent ASRSreports).33
Page 2 and 3: TABLE OF CONTENTSSUMMARY ..........
Page 4 and 5: 1. INTRODUCTIONWhen we try to pick
Page 6 and 7: Hendrick (1987) states that human f
Page 8 and 9: influenced by the individual philos
Page 10 and 11: 3. THE FOURTH P: PRACTICES3.1. AN E
Page 12 and 13: To summarize, the ultimate factor t
Page 14 and 15: Humor. Humor is closely related to
Page 16 and 17: technical deficiencies, induce work
Page 18 and 19: operations and the philosophy of th
Page 20 and 21: 5.3 MERGERS AND ACQUISITIONSMergers
Page 22 and 23: Figure 7. A Boeing B-757 checklist
Page 24 and 25: e made. Consider, also, the followi
Page 26 and 27: flight operations, the philosophy m
Page 28 and 29: 5.7.3 Technique and PoliciesAny giv
Page 30 and 31: For example, one company constantly
Page 32 and 33: 6. ISSUES IN PROCEDURE DESIGN6.1 CO
Page 36 and 37: On August 19, 1980, a Saudi Arabian
Page 38 and 39: 3. The procedures allow the other a
Page 40 and 41: coordination of tasks between agent
Page 42 and 43: Similarly, it has been a common pra
Page 44 and 45: 7.1.3 Structure of ProceduresAs men
Page 46 and 47: mission simulation (see Wiener et a
Page 48 and 49: felt that this is an efficient tech
Page 50 and 51: esponse. The PF, therefore, can con
Page 52 and 53: 7.5.1 Cross-fleet StandardizationCr
Page 54 and 55: 1. Training department (for both pi
Page 56 and 57: REFERENCESAviation Week and Space T
Page 58 and 59: Perrow, C. (1986). Complex organiza
Page 60 and 61: APPENDICESAppendix 1 - Guidelines f
Page 62 and 63: 14. In managing automated cockpits,
Page 64 and 65: APPENDIX 3 - QUESTIONS ASKED OF FLI
Page 66 and 67: APPENDIX 5 - QUESTIONS ASKED DURING
Page 68 and 69: 8. Change in operational environmen

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