BRAD BACHTEL OPERATIONS LEAD AIRPORT TECHNOLOGY BOEING COMMERCIAL AIRPLANES

MONTE FRAZIER DIRECTOR OF LONG-RANGE OPERATIONS STRATEGY MARKETING BOEING COMMERCIAL AIRPLANES

OREN HADALLER PRINCIPAL ENGINEER PROPULSION TECHNOLOGY BOEING COMMERCIAL AIRPLANES

CAPT. CARL MINKNER MANAGER FLIGHT TECHNICAL SERVICES HONEYWELL COMMERCIAL ELECTRONICS SERVICES

MOHAN PANDEY SENIOR MANAGER OPERATIONAL REGULATORY AFFAIRS BOEING COMMERCIAL AIRPLANES

WILLIAM ROYCE 777 SENIOR TECHNICAL PILOT The official opening of cross-polar routes in FLIGHT OPERATIONS TECHNICAL SUPPORT February 2001 marked an important step in air travel BOEING COMMERCIAL AIRPLANES DONALD RUHMANN MANAGER between and . These new routes 777 ETOPS AND LONG-RANGE OPERATIONS offer time, fuel, and environmental advantages BOEING COMMERCIAL AIRPLANES FRANK SANTONI 777 CHIEF PILOT over conventional routes and allow nonstop service ENGINEERING FLIGHT TEST between new city pairs. Operations are similar BOEING COMMERCIAL AIRPLANES JAMES VASATKA PROGRAM MANAGER in many ways to conventional long-range routes. STRATEGY After two and one-half years and more than BOEING COMMERCIAL AIRPLANES ANTON ZHIGANOV SENIOR MANAGER OF COOPERATIVE PROGRAMS 650 demonstration flights, airlines have the experience /COMMONWEALTH OF INDEPENDENT STATES and planning tools to make polar operations routine. BOEING OPERATIONS INTERNATIONAL, INC.

FLIGHT OPERATIONS

AERO 11 1 REGULATORY GUIDANCE

The U.S. Federal Aviation Administration (FAA) requires An autothrottle system. U.S. operators to obtain specific approval to conduct Flight crew communication systems that satisfy the polar operations. The approval process validates airlines’ FAA requirement for effective communication capability. preparedness to conduct such operations. The FAA defines the North Polar area of operations as the area lying An expanded medical kit with automated external north of 78 deg north latitude (fig. 2, p. 14). The FAA defibrillators. information memorandumGuidance for Polar Operations (March 5, 2001) outlines 10 issues: Airline training. Operators must meet five requirements for their training Airport requirements for designation programs: as en route alternates. All operators must define a sufficient set of alternate air- Training for flight crews and dispatchers on queen's field elevation (QFE), queen's normal height (QNH)and, ommercial airlines were flying north of the ports, such that one or more can be reasonablyxpected e to C through reduced fuel consumption and asso- be available in varying weather conditions. The FAA will meter/feet altimetry as well as cold-temperature altitude Circle before the jet age. Today, commercial ciated emissions. (See “Polar Routes Offer New assess the operators’ ability to safely land and maneuver correction procedures. airplanes off the runways at selected alternate . traffic routinely flies in the region on routes between Special curriculum segments on cold fuel management Opportunities” on p. 22.) The selected alternates also must be able to provide for procedures for maintenance, dispatch, and flight crews. and the West Coast of North America. When preparing and conducting polar opera tions, crew and passenger needs. The new cross-polar routes connect eastern airlines should consider the following: Airline recovery plan for passengers Route-specific training on weather patterns. and interior regions of North America to Asian cities 1. Regulatory guidance. at diversion alternates. Instructing maintenance personnel to provide informa- via the North Polar region (fig. 1). These airways All operators must have an FAA-approved recovery plan 2. En route alternate airports. tion on airplane system capabilities to dispatch and provide an attractive shortcut to Asia, which can for unplanned diversions. The recovery plan should address flight crews, which will aid flight crews in diversion the care and safety of passengers and crew at the diversion decisionmaking. open new air travel markets. These shortcuts also 3. Cold fuel management. airport and provide a plan to transport passengers and crew make service to existing city pairs more efficient 4. Communication and navigation. from that airport. Operators should be able to demonstrate The use of cold-weather antiexposure suits. their ability to launch and conduct the recovery plan on their initial applications for polar route approval. Operators must Long-range crew requirements. 1 NEW CROSS-POLAR ROUTES VIA THE NORTH POLAR REGION maintain the accuracy and completeness of their recovery Consistent with all long-range operations, operators must plans as part of their annual audits. FIGURE have approved crew rest plans and a clear progression of pilot-in-command authority. Fuel freeze strategy and monitoring requirements. Operators can use a fuel temperature analysis and monitoring Dispatch and crew considerations during solar flare. program in lieu of the standard minimum fuel freeze Operators should be aware of the content of FAA temperatures. In such cases, the program must be accepted Advisory Circular (AC) 120-52,Radiation Exposure of by the FAA. Air Carrier Crewmembers,and provide crew training as stated in AC 120-61,Crewmember Training on In-Flight Communication capability. Radiation Exposure. Operators must have effective communication capability for all portions of the flight route. Operators accomplish this Special equipment. by using a combination of very-high-frequency (VHF) voice,The FAA requires a minimum of two cold-weather VHF data link, high-frequency (HF) voice, HF data link, antiexposure suits on board North Polar flights so satellite communication (SATCOM) voice, and SATCOM that outside coordination at a can be data link systems. accomplished safely. Minimum equipment list considerations. Validation requirements for area approval. For polar operations dispatch, operators’ minimum equipment Operators are required to conduct an FAA-observed lists (MEL) must include the following: validation flight and reaction-and-recovery plan for a simulated airplane diversion at one of the designated A fuel-quantity-indicating system that includes en route alternate airports. The flight and plan imple- temperature indication. mentation may be conducted together or separately. If For two-engine airplanes, an auxiliary power unit the reaction-and-recovery plan is completed before the (APU) that includes electrical and pneumatic supply to validation flight, the validation flight may be conducted its designed capability. as a revenue flight.

AERO AERO 12 13 2 AREA OF NORTH POLAR OPERATIONS of Ð50ûC. (Note: Because specifications potential exists for fuel temperatures may vary by country, operators should FIGURE to approach the freezing point. However, extended-range twin-engine opera- ensure that they are using the appro- current airplane systems and operating tions. The ASOAs also identified how priate fuel procurement specification the airport infrastructures comparedprocedures provide confidence that fuel for the fuel being dispensed.) with the international standards will continue to flow unobstructed to The maximum freezing point for of the International Civil Aviation the engines in all plausible cold-weather some jet fuels can vary by the geo- Organization (ICAO). conditions likely to be experienced on graphical region in which the fuel is polar routes. refined or uplifted. Test methods for Airlines preparing for polar opera-Properties of fuel at very low tions should review the ASOAs to determining the fuel freezing point also temperatures. determine which airports suit the needs introduce variability; reproducibility is of their particular operational philoso-The fuel freezing point is the tempera- approximately 2.5ûC. phies. Airlines also should contact theture at which wax crystals, which form Some operators in the airports to assess changes that may in the fuel as it cools, completely measure the actual freezing point have occurred since the assessmentsdisappear when the fuel is rewarmed. of delivered Jet A fuel at the time of were conducted. Copies of the ASOAs(This should not be confused with the dispatch. Data show that the freezing are available to Boeing operators fuel becoming cloudy upon cooling, point of delivered Jet A fuel is approxi- on line through MyBoeingFleet.comwhich results when water dissolved in mately 3ûC lower than the specification and on CD-ROM through their Boeingthe fuel freezes, forming a suspension of maximum of Ð 40ûC. Table 1 (p. 16) Field Service representative. (Note:very fine ice crystals. Airplane fuel and shows the results of a study completed Although the ASOAs are detailed engine systems are designed to handle at several airports in the United States assessments, they do not constitutewater ice crystals safely.) to verify the actual freezing point of certification of the individual airports.)The Jet A fuel specification limits the Jet A fuel as delivered to the airplane. 3 COLD FUEL MANAGEMENT freezing point to a maximum of Ð 40ûC; (An airline must verify the freezing the Jet A-1 limit is Ð 47ûC maximum. point of the loaded fuel at dispatch if Because of the extended flight dura- In Russia, the fuels are TS-1 and RT, the airline uses a value other than the tion and the prevalence of very cold which have a maximum freezing point maximum specification.) air masses on the polar routes, the

EN ROUTE ALTERNATE AIRPORTS 2 The FAA looks for the following capabi- lities at alternate airports: BOEING-CONDUCTED AIRPORT SAFETY AND OPERATIONAL ASSESSMENTS The availability of alternate airports A diverting airplane can land safely 3 along a route is an important part of at the airport given the existing run- FIGURE ensuring flight safety. Though much way length, width, and load-bearing attention is paid to the very rare case capacity. of an in-flight engine failure, the vast Airport Terminal majority of diversion causes are not The diverted airplane can be cleared engine related. It is very important, from the runway so that another air- plane can land with maintenance per- of 16 airports in Siberia and the therefore, for all airplanes, regardless sonnel or depart with the passengers. Russian from July 1998 to of the number of engines, to consider February 2001 with the Russian State the availability and suitability of Passengers and crew are able to Civil Aviation Authority, FAA, and emergency alternate airfields. Con- deplane in a safe manner. airlines. The assessments examined sidering this and the remote nature the conditions of each airport and its of cross-polar operations, the FAA Facilities at or near the airport can capability to support flight diversions. has developed specific requirements provide passengers with shelter In addition to onsite visits to regarding en route alternates on the and food while the airplane can be facilities in the Russian Federation, polar routes. repaired or until alternate transpor- tation can be provided. three facilities in were assessed in support of North Pacific and Russian Regulatory considerations for The recovery plan can be executed Far East tracks: Cold Bay, King Salmon, alternate airports. and completed within 12 to 48 hr and Shemya Island/Eareckson Air The FAA Guidance for Polar Operations after diversion. Station (fig. 3). from the Flight Standards Service (AFS-1) Although the capabilities of the requires airlines to define a sufficient Airport safety and operational airports varied, all were shown to be set of alternate airports, such that one or assessments. capable of supporting emergency di- more can be reasonably expected to be Boeing conducted airport safety and versions, and the majority were deemed available in varying weather conditions. operational assessments (ASOA) adequate for use as alternates in

AERO AERO 14 15 FREEZING POINT OF DELIVERED of Jet A and Jet A-1 fuel in service LOW FUEL TEMPERATURE INDICATION ON THE 777 1 JET A FUEL AT SELECTED AIRPORTS highest freezing points solidify first, letter 747-SL-28-68 (Nov. 4, 1991). 5 TABLE forming wax crystals. Further cooling If the freezing point of the fuel on FIGURE causes hydrocarbons with lower freez- board cannot be determined using the Airport location Average freezing point (˚C) Range of freezing points (˚C) ing points to solidify. Thus, as the fuel published procedure, Boeing suggests Atlanta – 43 – 41.6 to – 46.6 cools, it changes from a homogenous using the highest freezing point of the liquid to a liquid containing a few fuel used in the last three fuel uplifts. Chicago – 43 – 42.4 to – 44.7 hydrocarbon (wax) crystals, to a slush For example, if Jet A-1 fuel was used Dallas–Ft. Worth – 43 – 41.1 to – 45.9 of fuel and hydrocarbon crystals, and for two uplifts and Jet A fuel was – 50 – 46.8 to – 58.2 finally to a near-solid block of hydro- used for one uplift, then a Ð40ûC freezing carbon wax. Because the freezing point point would be used for the current Miami – 47 – 41.0 to – 53.1 is defined as the temperature at which refueling. If Jet A-1 fuel was used in three New York – 45 – 44.0 to – 46.4 the last wax crystal melts, the freezing consecutive refuelings, then a Ð 47ûC – 45 – 44.2 to – 56.1 point of is well above the freezing point may be used for the current temperature at which it completely refueling. In the 747- 400 and 777, if solidifies (fig. 4). the fuel freezing point is projected to However, the fuel freezing point is is approximately 6ûC lower than the Refueling airplanes at different be critical for the next flight segment, not what dictates fuel flow to the boost fuel freezing point. However, the exact stations creates a blend of fuels in the Boeing advises the transfer of wing tank pumps. The critical condition of cold relationship between freezing point and tanks, each with a unique freezing point. fuel to the center wing tank before fuel in an airplane fuel tank, in terms pour point depends on the source of the The resulting fuel freezing point in each refueling. This makes it possible to use of flight safety, is its propensity to flow crude oil and the refining processes. tank can vary widely. The flight crew the freezing point of the fuel being toward and into the boost pump inlets. Because jet fuel is a mixture of many must operate with caution and not uplifted for that flight segment. Pumpability, or flowability, depends different hydrocarbon molecules, each automatically assume that the freezing on the pour point of the fuel, defined as with its own freezing point, jet fuel point of the uplifted fuel is the actual the lowest temperature at which the does not become solid at one tempera- freezing point of the fuel on board. Fuel systems and temperature fuel still flows before setting up into a ture as water does. As fuel is cooled, Boeing published a procedure for measurement. semirigid state. Generally, the pour point the hydrocarbon components with the estimating the freezing points of blends On the 747-400, the engine indication and crew alerting system (EICAS) dis- plays the fuel temperature continuously on the upper CRT display except during RELEVANT TEMPERATURES RELATED TO FUEL FLOW PROPERTIES 4 jettison operations, when it is replaced FIGURE by the FUEL TO REMAIN indication. contained in the master minimum fuel. However, the EICAS message The temperature signal originates from equipment list.) can be set to other values. For example, a single resistance-type temperature Freezing point plus 3˚C Freezing point plus 3˚C Freezing point plus 3˚C The 777 has a fuel temperature if Jet A-1 fuel is used, the message probe located within the no. 1 main Freezing point Freezing point probe located between ribs 9 and 10 can be set to Ð 44ûC (fig. 6, p. 18). tank. The temperature probe is mounted of the left main tank. The probe is On the 777, the fuel temperature can Pour on the rear spar approximately 8.5 in approximately 12.6 in from the lower be entered in two ways: as the minimum point off the bottom of the tank and approxi- wing skin and is located one rib over, fuel temperature or fuel freezing point. mately 40 in outboard of the aft boost approximately 40 in outboard, from Both options provide an indication at pump inlet. the aft boost pump inlet. Because the 3ûC above the fuel freezing point. Fuel When the fuel temperature on the left wing tank contains a single heat temperature is not displayed during 747-400 reaches Ð37ûC, a FUEL TEMP exchanger, its fuel can be slightly fuel jettison. LOW message is activated, and the fuel colder than that in the right wing On the MD-11, a fuel temperature temperature displayed on the EICAS tank, which contains two hydraulic probe is located in the outboard com- changes color from white to amber. heat exchangers. partment of tank no. 3 and another is in The 747-400 system automatically Fuel temperature on the 777 is dis- the horizontal stabilizer tank. At 3ûC defaults to the limit associated with the played in white on the primary EICAS above the fuel freezing point, the probe highest freezing point of fuel approved in the lower right corner. If the fuel in the no. 3 tank signals a FUEL TEMP for use on the 747, which is Ð37ûC for temperature reaches the established LO message display in the flight deck. Jet A fuel. When the fuel-temperature- minimum, the indication turns amber To establish when the message should sensing system is inoperative, the in color and the FUEL TEMP LOW be displayed, the flight crew can enter FUEL TEMP SYS message is displayed. advisory message is displayed (fig. 5). the freezing point of the fuel being carried The flight crew then is instructed to The 777 system automatically defaults or select the type of fuel being carried. use total air temperature (TAT) as an to the limit associated with the highest When the crew does not enter a value Liquid fuel with no wax crystals Liquid fuel and wax crystals Mostly wax crystals and some liquid fuel indication of fuel temperature. freezing point of fuel approved for use or specify the type of fuel, the system (Instructions for this procedure are Fuel remains flowable above the pour point. on the 777, which is Ð37ûC for Jet A defaults to Jet A fuel, which has a

AERO AERO 16 17 6 MINIMUM FUEL TEMPERATURE ENTRY ON THE 777 speed; an increase of 0.01 Mach results FIGURE Whether a tank is full or partially in a TAT increase of 0.5û to 0.7ûC. indicated by the fuel tank temperature jargon may create confusion. SATCOM depleted of fuel alters the rate at which (It should be noted that any of these probe. Details on FTPPs are available should be considered as a backup, the fuel temperature changes. techniques increases fuel consumption, to airlines through Boeing Field although it is generally not available During long-range operations at possibly to the point at which refuelingService representatives. above 82 deg north latitude. high altitudes, fuel tank temperatures becomes necessary.) Measuring the actual freezing point A typical polar flight initiated in can approach the freezing point of fuel. It takes approximately 15 min to of the fuel being uplifted can be a valu- North America has routine VHF com- On long flights, the fuel temperature 1 hr for a change in TAT to affect the able step in the flight planning process munication with the various Canadian tends to adjust to the temperature of the fuel temperature. The rate of cooling for flights during which fuel freezing ATCs. As the airplane progresses aerodynamic boundary layer over the of the fuel is approximately 3ûC/h. A point is a concern. In general, actual north, the flight makes a transition to wing skin. This boundary layer tem- maximum of 12ûC/h is possible under fuel freezing points tend to be about the Edmonton control center and then perature is slightly lower than the TAT the most extreme cold conditions. 3¡C below the specification maximum to Arctic Radio, a general-purpose because theoretical TAT is not achieved. A minimum in-flight fuel tempera- requirement. Details on measuring the communication provider that handles Initially, TAT is much lower than the ture advisory message provides a freezing point when fuel is being up- the interface between the airplane fuel probe temperature because of margin of safety under all atmosphericlifted are available to airlines through and controllers at the Anchorage and the thermal lag of the fuel. Thermal and operational conditions to ensure Boeing Field Service representatives. Edmonton control centers. Arctic Radio, analysis of the 747-400, 777, and MD-11 that the fuel will continue to flow to which operates on HF frequencies and airplanes shows that the fuel tank the boost pump inlets. Besides the 3ûC Before an airplane has several VHF remote sites, covers temperature is driven more by TAT margin between the advisory message the northern flight information region Operationsthan airplane and procedures configuration. with temperature and fuel freezing point,enters the polar region, (FIR) to the Russian FIRs (i.e., from low fuel temperatures. there typically is a 6ûC difference the airline should Norway to Churchill, Canada, on its In flight, a temperature differential must between the freezing point and pour southern border and past the be maintained between the observed point of fuels, which provides an addi-provide the flight crew on the northern border). temperature indication and the freezing tional margin. A review of the service The flight crew’s first contact with history of transport airplane operations freezing point of Ð 40ûC; a message point of the fuel. For the 747-400, 777, with the latest Arctic Radio is made on VHF, and worldwide for the past 40 years does communication eventually switches to displays at Ð37ûC. fuel temperature is affected by wing skinand MD-11, the observed fuel tempera- not show a single reported incident information on HF. On initial contact, the flight crew The temperature probes in the temperatures. A tank with a high surface-ture must remain at least 3ûC above the of restricted fuel flow because of low should request a primary and secondary 747-400, 777, and MD-11 are located to-volume ratio transfers heat through specified freezing point. (The actual fuel weather and en route fuel tank temperatures. This service frequency along with a selective calling where the bulk of the fuel is coldest. the wing surfaces at a higher rate than freezing point may be used if known.) history affirms that the criteria used (SELCAL) check. (Airlines provide However, some fuel may be colder than a tank with a low surface-to-volume When fuel temperature decreases to alternate airports. to establish the advisory message are crews with alternate contacts such the fuel measured by the probes, such ratio. Thus, fuel temperature is affected3ûC above the freezing point, a message adequate and conservative. as Radio, Bodo Radio, and as the fuel that is in contact with the at different rates depending on the of FUEL TEMP LOW displays in the However, flight crews on polar Stockholm Radio to use in the event lower wing skin. This creates a temper- airplane model and tank design. For 747-400 and 777 flight decks; the mes- routes must be knowledgeable about COMMUNICATION AND that crews cannot contact Arctic ature gradient in the fuel tank from the example, because the 747-400 outboardsage FUEL TEMP LO is displayed in wing skin to the location of the probe. fuel freezing points. Flight crews also 4 Radio.) Arctic Radio passes messages main tanks are long and narrow and havethe MD-11 flight deck. If this condition NAVIGATION As fuel travels to the boost pump must be cognizant of the en route fuel between the airplane and the airline’s about half the total fuel volume of the is reached, the flight crew must take In addition to the general requirements inlets, the bottom, cold layer flows temperature and the possible need for dispatch department. (Arctic Radio 777 main tanks, the surface-to-volumeaction, as described below, to increase for long-range operations, communi- through small flapper valves located on corrective action to ensure continued currently does not have the capability ratio on the 747-400 main tanks is muchthe TAT to avoid further fuel cooling. cation and navigation considerations solid tank ribs next to the bottom wing safe, routine polar operations. to provide a telephone patch. If a higher. This means that heat transfer In consultation with airline dispatch unique to the polar region must be skin. These valves are used to control telephone patch is needed, airlines through the wing surfaces is greater onand air traffic control, the flight crew addressed in airlines’ polar operations fuel slosh. Thus, the cold fuel tends should consider Stockholm Radio, the 747-400, and the fuel temperature decides on a plan of action. If possible, Operational aids for flight planning. to ensure that flight crews have the to flow toward the boost pump inlets. Rainbow Radio, Houston Radio, or changes faster than it does on the 777.the action should include changing the Boeing has developed the Fuel information needed to conduct safe and Because the probes are located near San Francisco Radio.) On the MD-11, the outboard compart-flight plan to where warmer air can be Temperature Prediction Program (FTPP) efficient flights. the bottom of the tank, the temperature Communication with Russia begins ments of tank nos. 1 and 3 have the expected. Another action is to descend for the 777 and is developing FTPPs for reading is representative of the critical before the airplane enters Russian highest surface-to-volume ratio. The to a lower altitude. The required descent other airplane models. The FTPP Communication. fuel temperature in the tank. next highest ratio is that of the hori- airspace. Airlines should coordinate would be within 3,000 to 5,000 ft of assists operators in addressing fuel Communication in the polar region zontal stabilizer tank. These tanks are with air traffic management at the optimum altitude. In more severe cases, freezing point concerns during the should be handled according to the the most critical for fuel flowability at Russian State Civil Aviation Authority a descent to 25,000 ft might be required. flight planning process. The program is applicable procedures described on Factors affecting fuel temperature. low temperatures on the MD-11. regarding specific contact procedures Recent experience on polar routes intended to interface with or be incor- en route charts. Both VHF and HF Factors that affect fuel temperature are Fuel is managed differently on the and locations. has shown that the temperature may be porated into an airline’s flight planning equipment are needed to communicate the size and shape of the fuel tanks, fuel 747-400, 777, and MD-11, but in all Communication with Russian higher at higher altitudes, in which system. The FTPP for the 777 has been management, and long-range operations cases, the wing main fuel tanks are the with air traffic control (ATC). It is ATC is available on HF when operating case a climb may be warranted. The calibrated with flight-test data obtained at high altitudes. last to deplete. On some models, fuel in important to use only standard ICAO beyond the VHF range of the ATC flight crew also may increase airplane by Boeing and several airlines. The The size and shape of the tanks tanks with high surface-to-volume ratios terminology for effective communication facilities (fig. 7, p. 20). In Russia, a significantly affect how quickly the is held until near the end of a flight. data are based on fuel temperature with ATC; nonstandard terminology or call sign with the radio designator is

AERO AERO 18 19 7 EXAMPLE OF COMMUNICATION COVERAGE ON CROSS-POLAR ROUTES: NEW YORK TO HONG KONG VIA POLAR 3 FIGURE SUMMARY Flight crews should use caution when using automatic direction finders (ADF) The FAA requires operators to obtain specific or VHF omnirange navigation equipment approval to conduct polar operations. Current (VOR), or both, because the heading requirements for an airline to develop necessary reference in use will affect the display of data. With the heading reference plans in preparation for polar flights are con- in TRUE, ADF bearings are true and tained in the FAA information memorandum vice versa. VOR radials are displayed Guidance for Polar Operations (March 5, 2001). according to the orientation of the To determine which en route alternate airports VOR station, either true or magnetic. suit the needs of their particular polar operations, Crews should be prepared to operate in QFE and metric altitude airlines should review the airport safety and where required. Some airports will operational assessments available from Boeing. provide QNH upon request even if Airlines also should periodically contact their their standard is QFE. en route alternate airports to assess changes In the event of a diversion, the that may have occurred since the time of flight crew should leave the IRU and ADIRU on if SATCOM will be needed the assessments. for communication. During preflight As for fuel temperature during polar opera- planning, extremely cold air masses tions, implementing a cold fuel management should be noted and cold fuel temper- process allows airlines to address cold fuel atures considered. (See “Cold Fuel temperatures during dispatch. Safety is ensured Management” on p. 15.) because of the conservative design of the fuel- If an active route takes an airplane over a pole, the preferred mode is temperature-indicating system, the corrective not a general-purpose communications action available to the flight crew if required, service as it is with Arctic Radio. airports. This ensures that the flight But as the airplane nears the southern and the dispatch aids available to more clearly Instead, it indicates HF communications crew has the information needed to portion of the Canadian Northern Control identify the controlling variables. with an actual ATC center. Russian conduct safe, efficient operations. Area (NCA), it approaches the area of Much of the material needed for communica- ATC centers usually list at least two Airlines can update information using magnetic unreliability. HF frequencies; the higher frequency HF and SATCOM data links. In the polar region, magnetic heading tion and navigation on polar routes is contained is used during the day, and the lower Airlines also need to consider the is unreliable or totally useless for navi- in the operations and training manuals used frequency is used at night. effects of solar activity on HF commu- gation. Magnetic variations typically for existing long-range operations. Additional Flight crews should be familiar with nication: poorer quality, a shift to lower are extreme, often are not constant at the following points of HF communi- usable frequency bands, and more noise crew and dispatch procedures needed for polar the same point, and change rapidly cations in Russia: or fading. During extreme solar activity, operations include cold fuel management, HF communications may not be avail- as an airplane changes position. Flight QFE/metric altimetry, cold-weather altitude An unused HF frequency may not able in the polar region. (Information on crews must ensure that the computer correction, and FMC polar operations, limitations, flight plan shows true tracks and be monitored. solar activity is available at the follow- lateral navigation with the autopilot and specifications. ing web sites: www.sec.noaa.gov/SWN/ headings. It is important to note that engaged. The flight management Russian HF stations are not areas unmapped for enhanced ground Airlines should include the HF propagation and www.hard-core-dx.com/solar/ system (FMS) on the 747 and the equipped with SELCAL. proximity warnings systems (i.e., those forecasts as part of the dispatch process and solarindex.shtml.) 777 are operational in the polar areas areas beyond the limits of the terrain ensure that flight crews are familiar with appro- Listening watches are required for SATCOM and SATCOM data links with no restrictions. The 757 and 767 HF frequencies assigned by ATC. generally should be available south of database) are displayed as magenta flight management computer (FMC) priate communication and navigation require- 82 deg north latitude in the polar region. dots on the map display, regardless of ments in the polar region. Airlines also should Strong HF signals with distortion and the 757 and 767 Pegasus FMC For SATCOM to be available on the airplane altitude. are operational to 87 deg north latitude provide flight crews with the latest weather and may require selecting the AM mode The Canadian area of magnetic un- or requesting that the controller ground, the inertial reference units and 87 deg south latitude because en route alternate airport information before a reliability encompasses the NCA and the of airplane certification restrictions. broadcast on the upper side band. (IRU) or air data inertial reference flight enters the polar region. units (ADIRU) must be aligned. Arctic Control Area. The Russian area The MD-11 FMS is considered to be Before an airplane enters the polar of magnetic unreliability is not formally in the polar region when the airplane region, the airline should provide the Navigation. defined. Russian airways south of is above 85 deg north or south latitude. flight crew with the latest information The departure and initial cruise portions 74 deg north latitude are referenced (See “Polar Route Navigation by on weather and en route alternate of a polar flight are routine operations. to magnetic north. Airplane Model” on p. 24.)

AERO AERO 20 21