717 Advanced Flight Deck


The 717-200 twinjet, the newest airplane in the Boeing fleet, is scheduled for first flight in 1998 and type certification and first delivery in 1999. The 717, which was based on the popular DC-9, offers an advanced flight deck modeled after the MD-11 and 777 airplanes. An airline advisory group of pilots and maintenance personnel from several airlines, all with many years of experience operating Douglas-designed twinjets, assisted in defining the flight deck design. The resulting benefits to operators range from the capability to present more information to the flight crew to improved dispatch reliability.

The new flight deck offered on the 717 is among the most advanced in the industry. It is capable of performing new functions in order to adapt to changing operational environments, and can present more information to the flight crew in ways that are easy to comprehend and require less interpretation. Dispatch reliability will be enhanced, both by a reduction in the number of line replaceable units (LRU) and through improved troubleshooting procedures that take advantage of sophisticated diagnostic and fault reporting. The new flight deck also offers several other changes to enhance flight operations. Flight crews familiar with the flight decks of Douglas-designed twinjets will notice that many improvements, both significant and subtle, have been incorporated into the Boeing 717. Flight crews familiar with Boeing-designed twinjets will also benefit from the improvements made in the following areas:

1. Flight deck amenities.

2. Liquid crystal displays.

3. Alerting system.

4. Flight guidance.

5. Overhead panel.

6. Pedestal.

7. Central maintenance.

Flight deck amenities
Flight deck amenities have been improved considerably to reduce flight crew workload or provide needed enhancements. These include:

The most obvious cosmetic change that flight crews familiar with Douglas-designed twinjets will notice is the new color scheme. This light- and dark-gray scheme is similar to that of the flight deck of the next-generation 737 models (737-600/-700/-800/-900) and the MD-11.

Liquid Crystal Displays
Six 8- by 8-in liquid crystal displays (LCD) on the instrument panel form the heart of the new advanced flight deck. They are driven by two versatile integrated avionics (VIA) computers installed in the avionics compartment. The three left-hand LCDs are normally driven by VIA No. 1, and the three right-hand LCDs are normally driven by VIA No. 2. However, either VIA can drive all six LCDs if required. The LCDs automatically reconfigure to display all data in the unlikely event that one or more of them fails.

PRIMARY FLIGHT DISPLAYS.
The No. 1 and No. 6 LCDs are the primary flight displays (PFD). Each of these LCDs combines all the primary flight information previously presented by the six "round dial" instruments used in traditional older electromechanical flight decks. Attitude, airspeed, altitude, and heading presentations retain the basic "T" arrangement of the traditional flight decks. Attitude data, which replace the traditional attitude display indicator, are presented in the center of the PFD as shown in figure 1. NAVIGATION DISPLAYS.
The No. 2 and No. 5 LCDs are the navigation displays (ND). The NDs present any of five different pages: VOR AND APPR.
A traditional horizontal situation indicator that consists of a compass rose and a course-deviation indicator.

TCAS.
The positions of other airplanes in the area.

PLAN.
Used mainly for flight planning prior to flight. It is oriented with north in the up position, and it can be centered about any point in the flight plan.

MAP.
The format most commonly used in flight. It is oriented with the airplane heading, or track, up, and it rotates as the airplane turns to keep the map in the same orientation as what the flight crew sees through the windshield. The airplane symbol remains constant, and is situated in the center of the display one third of the distance from the bottom of the LCD. The MAP page shows the current flight plan, ground speed, time, and the distance and time to the next way point. Map range can be selected to 10, 20, 40, 80, 160, 320, or 640 nmi. Navigation aids, nearby airports, and other navigation data can also be displayed. Weather radar, terrain information, and other airplane positions can be shown relative to the current position of the airplane.

ENGINE AND ALERT DISPLAY.
The No. 3 LCD is the engine and alert display (EAD) (figure 2). It shows primary engine instrumentation data and displays flight crew alert messages. The EAD has a column of engine instrumentation data for each engine (left and right). Parameters displayed are engine pressure ratio, which is the primary thrust setting parameter for the 717; engine turbine gas temperature; N1 and N2. A digital presentation of fuel flow is displayed below the N2 gauge. At the top of the EAD is the current thrust limit mode and thrust limit.

SYSTEM DISPLAY.
The remaining display, No. 4, is the system display (SD). It consists of 10 pages that can be selected by the flight crew using the pushbuttons on the systems control panel (SCP) (figure 3) on the pedestal. The SCP contains six ON/OFF knobs that also adjust BRIGHTNESS for all six LCDs. System synoptic information is displayed on 6 of the 10 SD pages. They use a pictorial representation of the airplane system, and include an area for alert messages. The synoptic pages are related to the following systems (figures 4 through 9):

AIR (environmental). Displays the status of the airplane engine bleed valves, air-conditioning packs, auxiliary power unit (APU) bleed air, and airfoil anti-ice. It also shows the selected and actual cabin and flight deck temperatures, along with the temperature of air entering those areas.

FUEL. Displays the status of the fuel-boost pumps and the quantity of fuel in each of the fuel tanks. Green lines indicate fuel flowing from the tanks to the engines. The number displayed in the engine symbol indicates the quantity of fuel burned.

HYDRAULICS. Displays the status of the hydraulic system. It shows the hydraulic fluid quantity in each of the reservoirs, as well as the engine-driven, auxiliary, and transfer pumps. Green lines indicate hydraulic pressure. System pressure is shown at the top of the display.

ENGINE. Usually selected for continuous display. It shows engine oil pressure, temperature, and quantity, as well as the level of engine vibration. If the APU is operating, the APU speed and temperature is displayed on the right-hand side. The engine page also shows aileron and rudder trim positions, airplane gross weight, total fuel quantity, and cabin altitude.

ELECTRICAL. Displays the status of the airplane electrical system. Engine and APU generator data are presented at the bottom of the display. Electrical busses illuminate green when powered, amber when failed, or white when unpowered. The main airplane power relay symbols indicate whether the relays are open or closed.

CONFIGURATION. Presents a view of the airplane looking forward from behind the airplane. All control surfaces -- ailerons, elevators, flaps, rudder, slats, and spoilers -- are shown pictorially. Landing gear indicators provide a backup display of landing gear position. They also provide the temperatures of individual brakes. Rudder trim and aileron trim positions are shown around the airplane symbol. Brake pressures are displayed at the bottom of the page.

Three other SD pages consist of only text:

The final page that may be selected on the SD is a display that serves as a backup for the ND. This page is available only in the event that one or more of the LCDs has failed or is switched off.

Alerting System
A highly integrated, advanced alerting system replaces most conventional indicator lights, warning lights, annunciator panels, and other dedicated indications. The alerting system consists of the EAD; system displays; the master warning, master caution lights; and the central aural warning system. When a condition requiring an alert is detected, the VIA displays the alert, illuminates the master warning or master caution light if required, and sounds an appropriate aural warning. The flight crew acknowledges the alert by pressing the lighted cue switch on the SCP, which displays the appropriate synoptic display. If a checklist procedure is required, the flight crew refers to the abnormal checklist to accomplish the required corrective action. Flight Guidance
The 717 autoflight system is adapted from the MD-11 system. It consists of two flight control computers (FCC) and a glareshield control panel (GCP). The FCCs provide autopilot, autothrottle, flight directors, stall warning, wind-shear detection and guidance, engine synchronization, and various other functions. The flight crew interfaces with the autoflight system by using easy-to-operate controls on the GCP.

The speed, heading, and altitude controls are similar in function. The flight crew can preselect a speed, heading, or altitude by rotating the knob assigned to that function. The window above each knob displays commands. Pulling the knob commands the airplane to the new speed, heading, or altitude. Pushing the knob commands the airplane to hold the current speed, heading or altitude. Vertical speed is selected by rotating the vertical speed wheel.

The flight crew uses the flight management system (FMS) by entering the desired flight plan into the multifunction control and display unit (MCDU) on the pedestal. Flight plan information is displayed on the MAP page. The FMS contains a database of airports, navigation aids, and airplane performance parameters. It also provides lateral and vertical guidance along the selected route, as well as performance predictions.

Overhead Panel
Most of the system control switches reside on the overhead panel. The panel is noticeably simpler than previous Douglas-designed twinjet panels because the LCD displays and integrated flight crew warning and alerting system permits removal of most of its gauges, dials, and indicator lights. The remaining control switches have been rearranged. The switches are grouped by function across the overhead, and they are aligned vertically by left system, center system, and right system. The exterior and flight deck lighting controls, passenger address, intercom, and attendant call controls are grouped along the forward edge of the overhead panel. Other controls, such as the APU, engine and airfoil anti-ice, and cabin pressurization are located along the sides of the overhead panel.

Pedestal
The center pedestal, located between the two flight deck seats, is a new design. Its one-piece casting allows modular units for the throttles, flap/slat handle, and speed brake handle to be replaced easily. The spoiler/ speedbrake system is a new, electrically controlled, hydraulically actuated system. The spoilers work in concert with the flight crew's control wheel inputs to provide roll augmentation. As the speedbrake handle is pulled aft, the spoilers deploy symmetrically as speed brakes to reduce speed or to increase rate of descent. The throttle levers provide control of the engines through an electronic engine control system. The auto-throttle system drives the throttles in response to flight crew and autopilot commands.

Central Maintenance
The new flight deck was designed with ease of maintenance in mind. A central fault display system (CFDS) provides single-point maintenance access to most onboard systems. Ground crews access the CFDS by using either MCDU on the flight deck. The CFDS displays current faults, up to 40 legs of fault history for each system, and allows return-to-service testing and detailed troubleshooting. This system, along with improved fault isolation procedures, will allow the 717 to meet its aggressive dispatch reliability goals.

Summary
The new flight deck on the Boeing 717 is among the most advanced in the industry. Besides offering the capability to perform new functions when required to adapt to changing operational environments, it provides flight crews with more information, and presents it to them in ways that are more easily comprehensible and accessible. Improved dispatch reliability is another operator benefit of the advanced flight deck, which also offers improved displays and functions for ease of operation and maintenance.

An overview of the Boeing 717 was published in Aero No. 1, January 1998. - Editor

Susan Koppel
Design Engineer
717 Design Office
Douglas Products Division

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