Cessna 421 Cockpit Modernisation - Essay Example

? Cessna 421 cockpit modernization Introduction The Cessna 421 commonly referred to as the Golden Eagle was developed from the Cessna 411 which was a light, twin engine personal transport aircraft. The old aircraft is unpressurized and uses mechanical gyroscopic instruments in its cockpit. The major difference with the earlier design is that the 421 is pressurized. It uses geared Continental GTSIO-520-D engines. The gearing is such that the drive shaft drives through a set of reducing gears instead of being directly connected to the propeller. The 421 series was first produced in May 1967 followed by the 421A in 1968 which was redesigned in 1970 and sold as the 421B. The 421C came into service in 1975 replacing the earlier versions 421A and the 421B. The aircraft had wet wings, the absence of wing tip fuel tanks and landing gear which was changed from straight leg to a trailing-link design which was produced from 1981 onwards. Its production came to halt in 1985 after 1901 aircrafts had been delivered. The 421C is a light passenger transport aircraft which was approved on October 28, 1975. The aircraft is powered by two Continental GTSIO-520-Ls or Continental GTSIO-520-Ns which are turbocharged, fuel injected and geared six-cylinder horizontally opposed air-cooled piston engine that produce 375hp each. Some general characteristics of this aircraft include a crew of one or two, a capacity of six passengers, and length of 11.09, wingspan of 12.53m, wing area of 19.97m2, empty weight of 4501 lb, height of 3.49m and a maximum takeoff weight of 3379kg. It has a maximum speed of 256 knots with a cruise speed of 240 knots and a range of 2755km. the service ceiling is 9,205 m and a rate of climb of 1940 ft/min. (Cessna 421 Golden Eagle: Cessna model 421C information manual. 1979) Aim The main objective here is to upgrade the existing avionics panel of the Cessna 421C to the Garmin G600 display in order to reap the benefits of this modern design. Some of these include improved situational awareness, pilot safety and workload reduction. The other objective is to introduce modern avionics to the display panel for the venerable Eagle to make it more modern and efficient. To achieve this, we will employ the G600 together with some other retrofits to come up with a cockpit that is not only modern but also perfect in operation. Additionally, further improvement of the passenger In Flight Entertainment System is also conducted to bring it to modern levels of service. The upgraded panel offers much more capability and comfort to the pilot. With the space so created from the reduced clutter, the interior design is refurbished. It is fitted with new light gray lather seats, writing tables, refreshment center and a belted potty. Discussion Cessna 421C Cockpit Diagrams are shown here bellow. Before retrofitting Fig 1: Cessna 421 Cockpit before upgrade Source: http://sarasotaavionics.com/panel-gallery/cessna-421/ After retrofitting Source: http://sarasotaavionics.com/panel-gallery/cessna-421/ The cockpit of the Cessna 421 in figure 1 above has several instruments cluttered across the main display panel making it rather tedious to the pilot to work. Most instruments here are mechanical and thus time consuming to read and interpret. Some of these instruments include: a Comm. Dual King KTR 905, Nav Dual King KNR 630, MFD Avidyne EX500, King KLN- 90B Approach GPS, ADF Dual King KDM-805, and Transponder Dual King KXP-755. It also includes autopilot King KFC 250 with Flight Director and yaw. Other important features are the dampener, the HIS Dual Cessna 1000 and a fuel management system. For instance, the altimeter which measures the aircrafts barometric settings, the attitude indicator, the horizontal situation indicator, the gyroscopes, all engine and emergency equipment are all mounted in the basic T fashion. It is therefore my desire to retrofit this window to a modern digital panel by using the Garmin G600 display. With this upgrade, we expect a safer, easy to operate and much more efficient panel. This display combines a primary flight display (PFD) and multi-function display (MFD) in a 10-inch wide glass window thus dramatically making the cockpit much simpler. In the older aircraft, the instruments have been displayed in the basic T format. These instruments include: airspeed indicator, attitude indicator, horizontal situation indicator, altimeter etc. they are mainly operated mechanically by being fed directly by pitot-static ports located strategically on the fuselage. Sensors such as the EGT and other pressure sensors and fire alert sensors are all connected to the display panel (Cessna Model 421 Golden Eagle and executive commuter owner’s manual 1975). The G600 chosen for this purpose combines critical flight data and presents it on two 6.5 inch flat- panel LCDs which are mounted side by side into the instrument panel. These displays are brilliantly colored with great backlighting and provide sharp images even in direct sunlight. The PFD is located on the left-hand side and it smoothly integrates all information about the position, attitude, speed, vertical rate, altitude and the flight progress. It intergrates all the primary flight instrument information and seamlessly displays it on the 6.5’’ diagonal G600 screen. The MFD provides a detailed moving-map graphics of the aircrafts current position with respect to terrain and ground features, chart data, navigational aids, and flight plans etc. In the G600, the mechanical gyroscopic flight instruments are replaced with the more reliable GRS77 Attitude and Heading Reference System. This provides accurate digital output and reference of the position, rate, and vector and acceleration data of the aircraft. More importantly, it can restart and properly reference itself in flight. The MFD of the G600 seamlessly combines built in terrain and navigation databases which provide clear picture of your location and heading. They use color coding to alert the pilot when approaching terrain and can further be enhanced with full Class B TAWS which improve safety margin. Movement on ground is assisted with Safe Taxi database which provide current position on taxiways. Other important information such as the weather including NEXRAD, METARs,TAFs,Lightning etc. are also displayed directly over Jeppesen and topographic map databases. The beauty is that it can still further be enhanced by adding a Garmin Mode S transponder and display Traffic Information Services used to identify the surrounding traffic hence further improving safety. The new a.c wiring is redesigned and placed in the main nose bulkhead of the plane instead of being wired around the C.O.G as is the case with the older design. This is expected to shift the C.O.G forward by a few inches. To avoid clutter of electrical system, the switches are replaced with Eaton switches with built in lighted labels marked ON and OFF. There are sensor transducers that interface left and right engine and fuel tanks. These sense engine and exhaust gas temperatures, oil temperatures, fuel level and flow, fire alerts etc. the wiring for these sensors are mounted right behind the engine to make installation easy. The sensors are connected such that there is only a single serial cable routed from each remote sensor box to the display panel thereby reducing clutter. A 28V battery can be added to serve as additional power outlet to the added equipment and other uses (Cessna pressurized 421 Golden Eagle 197) The installation of the G600 should be done after thorough preliminary design to avert malfunctions in the upgraded panel. The power of the aircraft is maintained at 35000 horse power with the same range and ceiling. Much more sensitive pitot –static gauges are installed to enhance the performance capability of the aircrafts instruments. The upgrade creates a lot of space in the cockpit allowing more room for the pilot. The displays also enable the pilot to work without much movement hence alleviating fatigue. The instruments that were initially hidden are now more visible. Further, the additional battery can be used to provide power for operating other standby avionic equipment and for passenger use e.g. charging their laptops. This overhaul of the cockpit makes the Eagle to be truly beautiful and much more dependable. The comfort and coziness of the aircraft cockpit and cabin makes it quite pleasurable to fly in. the instrument capability is quite enhanced and flying is possible even in poor weather conditions. Garmin International has successfully presented Flight-Desk Avionics over the years with excellence. In 2009, Garmin created the Silver Award to recognize Exemplary Performance among its top producers and represents a first-class level of sales performance, technical expertise and good customer service (Model 421 Golden Eagle and executive commuter owner’s manual 1975). This Glass Cockpit retrofits for the twin-engine 421C. The installed avionics suite includes Garmin G600 with primary flight display (PFD) and multifunction fight display (MFD), GMA340 Audio Panel, GTX 330 Dual GNS530W and GNS430W, WAAS/GPS/NAVCOMs, GDL69 XM Weather Receiver, and a 406MHz ELT from Artex. Further safety improvements can also be installed in the form of Airbag systems. Moreover, the analog engine instrumentation is replaced by J.P Instrument’s EDM-930 Engine Data Management Unit. The instrument panel is completely redesigned, fabricated, and custom coated. Summary Installation of the G600 certainly makes the 421C more comfortable, more efficient and safer. The capability of the aircraft is therefore much more improved raising the avionics capability to come at par with that of the plane. The aircraft feels much newer and more efficient. The installation of additional devices such as the battery and cables are expected to slightly shift the C.O.G of the aircraft. This can however be corrected by proper loading of the aircraft before flight after measuring and determining the new C.O.G. the Garmain G600 is preferred because of the much larger (6.5’’) LCD square display which provide high quality display. The aim to improve ergonomics in the 421C is thus achieved with the G600. The new plane is therefore more comfortable at its cabin is quite spacious which allows more room for installation of additional In Flight Entertainment equipment and safety equipment. The improvement of the weather radar allows this plane to fly even in bad weather and the inclusion of terrain warning systems ensures safety is maximized making the newly upgraded plane to be in a class of its own in terms of customer service. Safety of the aircraft should always be observed in order to avoid the occurrence of accidents (Cessna 421 G-AYMM: report on the accident near Stansted Airport, Essex, on 4th September 1978) Reference Cessna 421 G-AYMM: report on the accident near Stansted Airport, Essex, on 4th September 1978. 1979. London: H.M.S.O. Cessna 421 Golden Eagle: Cessna model 421C information manual. 1979. Wichita, Kan.: The Company. Cessna Model 421 Golden Eagle and executive commuter owner’s manual. 1975. Wichita, Kan.: Cessna Aircraft Co. Cessna pressurized 421 Golden Eagle. 197. Wichita, Kan.: Cessna Aircraft Co. Endres, G. G., & Gething, M. J. 2005. Aircraft recognition guide, 4th ed. New York: HarperCollins. Sarasota Avionics Aircraft Panel Gallery. n.d. SarasotaAvionics.com - Aircraft Avionics Sales, Avionics Service, Installation and Repair, Garmin Platinum Dealer. Retrieved April 28, 2013, from http://sarasotaavionics.com/panel-gallery/cessna-421/ Read More