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B757_Symposium_(2004)

<P>B757_Symposium_(2004)</P>
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2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 1 of 15<BR>757/767 Breakout Questions and Answers<BR>Center Tank Fuel Pump Status:<BR>1. How will the normal procedures be synchronized for the 757/767? Operators receive the revisions<BR>to the 757 and 767 6 months apart and thus have to wait to update their ops manual.<BR>&lt;Answer&gt;. Both sets of procedures will be published in both old and new versions, though the<BR>publication dates will be staggered. The versions will be effective for about a year during<BR>which time the airlines can synchronize on their own schedule.<BR>2. Are there any plans to incorporate the 767 shared flow operations manual bulletin into the fuel<BR>CONFIG operations manual procedure?<BR>&lt;Answer&gt;. Boeing does not plan to do this. Airlines can modify their own books or they can contact<BR>Boeing if they have a contract for plan 2 service. Please contact Boeing Flight Technical<BR>Integration &amp; Data to request that your operations manual bulletin be incorporated.<BR>3. How big of a job is it to retrofit a scavenge system on the 767? Is there a Boeing service bulletin to<BR>do this?<BR>&lt;Answer&gt;. One operator has purchased a Master Change from Boeing to install scavenge systems on<BR>their 767-200 airplanes. The service bulletin indicates approximately 40 hours of task<BR>time (2 people at 20 hours) are required to install the system on these airplanes.<BR>4. What is the projected cost of the Auto Shutoff SB? Will Boeing be providing the auto shutoff<BR>service bulletin at a reasonable price?<BR>&lt;Answer&gt;. Please be advised that the cost of retrofit for the auto shutoff system has not yet been<BR>determined.<BR>5. If auto shutoff will be considered an AMOC to the fuel pump AD which requires wet shutoff, why<BR>is Boeing still pursuing a design change to the 767 fuel pumps? In other words, if installation of<BR>the Auto Shutoff feature is terminating action to the AD and installation of the cast-in diffuser<BR>pumps is another, why should an operator install both features? Why install cast-in diffuser<BR>pumps? What is the cost of the Auto Shutoff?<BR>&lt;Answer&gt;. The Auto shut-off feature is intended to minimize dry running of pumps. The machined<BR>diffuser configuration of pumps has a failure mode within the pump which could cause an<BR>ignition source in the pump. Boeing intends to ask for an AMOC for the wet shutoff<BR>requirement, but the 1000 hour inspection will still be required. Current terminating<BR>action for the AD (which removes the 1000 hour inspection) is installation of the cast-in<BR>diffuser pump. The cast-in diffuser pump has performance issues, causing a premature<BR>main tank fuel consumption anomaly. Boeing is continuing to investigate a redesign of<BR>the pump in order to address the performance issues with the cast-in diffuser and relieve<BR>the operators of the 1000 hour inspection with the machined diffuser pump.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 2 of 15<BR>6. How big of a job will it be to incorporate the auto shutoff feature? Will it be true for both the 757<BR>and 767?<BR>&lt;Answer&gt;. Installation of the auto shutoff feature should only involve placing a couple of relays and<BR>some wires in the EE bay and could be accomplished overnight. This would apply to<BR>both the 757 and 767.<BR>7. Will the auto shutoff feature require installation of new EICAS computers or result in new EICAS<BR>messages? What will be done about the uncommanded ON pump?<BR>&lt;Answer&gt;. There are no plans to add any new EICAS messages as EICAS changes are costly and<BR>time consuming.<BR>We are in discussions with the FAA at this time regarding the uncommanded ON<BR>function and are currently unable to provide any details on this issue.<BR>8. Regarding AD 2002-19-52 for the 757 airplane, what is the inspection interval?<BR>&lt;Answer&gt;. There is no established inspection interval. When a pump is first inspected it is identified<BR>with a special suffix. Each time after that the pump is reworked it must be re-inspected<BR>with a boroscope.<BR>9. Will the auto shutoff feature prevent the metal to metal contact on the 767?<BR>&lt;Answer&gt;. Auto shutoff does not prevent the metal to metal contact within the pump. The auto<BR>shutoff feature will minimize the dry running of pumps to 14 seconds. The current AD<BR>mandates a 1000 hour inspection which will ensure that there are no liberated parts within<BR>the pump.<BR>10. Is this a change in philosophy? There seems to be a contradiction between the current procedure<BR>to turn the pumps off at 500kg and the Auto Shutoff that waits until a low pressure indication. If<BR>a wet shutoff is the right answer, why let the pump go a little dry?<BR>&lt;Answer&gt;. The FAA has directed that there will be no dry running of pumps at any time. By<BR>installing the auto shutoff procedure there is no concern that the pilots might forget or are<BR>distracted with other more pressing duties to turn the pumps off. Installation of auto<BR>shutoff may allow operators to get rid of the operational wet shutoff, but it is unlikely the<BR>pump inspections would be removed. Auto Shutoff turns off the pump 14 seconds<BR>following indication of low pressure. That timing was tested in the lab to preclude dry<BR>running and the generation of heat in the event the pump has failed.<BR>11. Don’t we risk inspecting the pump into a failure mode by re-inspecting them every 1000 hours?<BR>&lt;Answer&gt;. No, the inspection involves removing the pumps from the housing and does not take the<BR>pump apart. The inspection just looks at the screws, etc.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 3 of 15<BR>12. Is there a change of material (to composite) in store for future fuel pumps (7E7 for example)?<BR>&lt;Answer&gt;. We are unaware of any plans or any current research on that issue. The cast-in diffuser<BR>pump eliminated screws in the assembly that were a significant part of the problem.<BR>13. What is the status of nitrogen inerting?<BR>&lt;Answer&gt;. Boeing is studying nitrogen inerting for the center wing tank as a service bulletin retrofit.<BR>In addition, we note that the FAA is considering mandating such a system on airplanes.<BR>The 737 and 747 airplanes would most likely be the first models to incorporate such a<BR>system. At the present time there is no plan to mitigate SFAR 88 requirements by<BR>installation of the NGS.<BR>Contaminated and Slippery Runways:<BR>14. Does the definition of “wet runway” include grooved or non-grooved runways? What is the<BR>definition of a “damp” runway?<BR>&lt;Answer&gt;. Wet is considered to be “not dry” or “not contaminated” by some definitions. It is<BR>generally accepted that a surface that appears “reflective” is considered wet. A damp<BR>runway is not wet. However, airlines must decide how they will treat these different<BR>conditions.<BR>15. Is “good” characterized as “wet” in Boeing data? If a grooved runway is wet, can we assume it is<BR>“dry”? If a non-grooved runway is wet, can it be assumed to be dry?<BR>&lt;Answer&gt;. Boeing data is based on testing of the 707, 727, 737 and 747 in Roswell, NM (not a<BR>grooved runway). A wet, grooved runway cannot be considered dry. Boeing testing<BR>shows that braking capability on a wet, grooved runway is about 85-90% of that on a dry<BR>runway.<BR>16. What is “advisory” data?<BR>&lt;Answer&gt;. Advisory data is data that has been computed according to the same standards and with<BR>similar methods as certified data, but since the data is not required by certification or<BR>operational rules Boeing publishes the data as Advisory.<BR>17. Is there friction data published in Boeing documents?<BR>&lt;Answer&gt;. Boeing does not publish friction data from runway friction measuring carts.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 4 of 15<BR>18. The contaminated runway data takes credit for thrust reversers, but the published dry data does<BR>not. Is there thrust reverser inoperative data available for contaminated runways? And does the<BR>Boeing data for one thrust reverser operating normally consider that the pilot may be judicious in<BR>his application of reverse thrust because of the asymmetric condition?<BR>&lt;Answer&gt;. Boeing does have some data available for one or two inoperative thrust reversers on<BR>contaminated runways; the data consider a "judicious" application of thrust. New data is<BR>being added for no reversers.<BR>19. Does Boeing publish contaminated runway data for inoperative equipment such as hydraulics and<BR>anti-skid?<BR>&lt;Answer&gt;. Boeing provides landing information for some inoperative systems in the Operations<BR>Manual - PI section for landing with non-normal configurations.<BR>20. Are the published crosswind guidelines piloted simulations?<BR>&lt;Answer&gt;. The 737 classic, the 757, the 767 and the 777 takeoff crosswind guidelines are based on<BR>piloted cab simulations assuming an engine out refused takeoff maneuver at an adverse<BR>loading condition using normal piloting techniques. The published crosswinds were<BR>selected to provide adequate airplane control. The 737NG and 747 takeoff crosswind<BR>guidelines are based on engineering analysis and simulation studies assuming the same<BR>engine out refused takeoff maneuver.<BR>The 737 classic, 737NG, 747-400, 757, 767, and 777 landing crosswind guidelines are<BR>based on piloted cab simulations at an adverse loading condition using normal piloting<BR>techniques. Both all engines operating and engine out landings were considered. As<BR>above, the published crosswinds were selected to provide adequate airplane control.<BR>21. What is the difference between the crosswind guidelines and the demonstrated crosswind data in<BR>the airplane flight manual?<BR>&lt;Answer&gt;. The AFM "demonstrated" value is simply the highest crosswind conditions that were<BR>encountered during the airplane flight test program. The recommended crosswind limits<BR>were determined by analysis and piloted simulator evaluation, not by flight test.<BR>22. Were the evaluations based on both takeoff and landing?<BR>&lt;Answer&gt;. As described in the answer to Q20, piloted cab simulations were used in determining both<BR>the takeoff and landing crosswind guidelines. The crosswind guidelines are different<BR>because different maneuvers were considered for takeoff and landing.<BR>23. Are these "theoretical" numbers?<BR>&lt;Answer&gt;. The crosswind guidelines are not “theoretical” numbers. The crosswind guidelines are<BR>based on piloted cab simulations where the simulator aerodynamic, thrust, and ground<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 5 of 15<BR>models are based on flight test data. The crosswind guidelines represent a conservative<BR>assessment of the steady state crosswind.<BR>24. Are the crosswind guidelines based on engine out?<BR>&lt;Answer&gt;. The takeoff crosswind guidelines are based on an engine out refused takeoff maneuver<BR>with an engine failure just before V1. The landing crosswind guidelines considered<BR>engine out landings and recommend that the landing crosswind guidelines be reduced by<BR>5 knots on wet and contaminated runways when using asymmetric reverse thrust.<BR>25. MTH - What is the minimum recommended runway width for operations in crosswind?<BR>&lt;Answer&gt;. The minimum width is 45 meters. Boeing has provided narrow runway crosswind and<BR>takeoff speed and field length adjustment information to operators based on specific<BR>requests.<BR>Flight Crew Use of Circuit Breakers:<BR>26. How will Boeing send this revised circuit breaker cycling policy for a dual FMC lockup out to the<BR>fleets?<BR>&lt;Answer&gt;. If internally approved in Boeing Flight Operations, Boeing would issue an Operations<BR>Manual Bulletin to 757/767 operators advising of the revised policy for circuit breaker<BR>use.<BR>27. Operators need a list of circuit breakers (e.g., FMC, ACARS) that are acceptable to cycle.<BR>&lt;Answer&gt;. Boeing may allow circuit breaker cycling via an operations manual bulletin on a case-bycase<BR>basis to grant temporary relief from a known system anomaly. There will not be a<BR>blanket recommendation or the establishment of a general policy. Please note the<BR>distinction between cycling and resetting of circuit breakers. Recommendations<BR>concerning circuit breaker resetting are already provided in the manuals. That policy is<BR>not changing.<BR>28. Why is Boeing concerned about cycling of circuit breakers? What about circuit breaker cycling<BR>for the “Connexion by Boeing” system?<BR>&lt;Answer&gt;. Flight crews are not trained in circuit breaker location or use. In many cases, circuit<BR>breakers are installed in different locations on different airplanes within a model. Circuit<BR>breakers are not designed to be switches; this impacts life expectancy of the circuit<BR>breaker. The flight crew is not always in a position to easily reach circuit breakers. In<BR>addition, the circuit breakers themselves are not necessarily clearly and uniformly<BR>labeled. Boeing is also concerned that if the crew becomes habitualized to using circuit<BR>breakers they will eventually use them in a situation they should not use them.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 6 of 15<BR>29. We need this ops manual bulletin, with respect to recovering a locked out FMC, in every<BR>operator’s operations manual.<BR>&lt;Answer&gt;. Boeing Flight Operations will review the Boeing circuit breaker policy as it applies to the<BR>FMC lockup failure mode(s). Any approved change in policy will be disseminated, as<BR>appropriate, to affected operators.<BR>30. Will there be similar language regarding cycling circuit breakers in the QRH procedures?<BR>&lt;Answer&gt;. No, such information would only be issued as an Ops Manual bulletin as it would be only<BR>temporary in nature. Our intent, as with all system malfunctions, is to permanently<BR>correct the problem necessitating cycling of C/B’s.<BR>31. Will cycling circuit breakers shutdown other systems?<BR>&lt;Answer&gt;. Boeing will investigate this when establishing recommendations on a case-by-case basis.<BR>Yes, it is possible one system’s circuit breaker could disable all or part of another system.<BR>757 Pilot Induced Oscillations (PIO):<BR>32. Please confirm when the Wheel damper service bulletin will be available.<BR>&lt;Answer&gt;. The wheel damper Service Bulletin will be released sometime in mid to late August,<BR>2004.<BR>33. Will vortex generators be mandated?<BR>&lt;Answer&gt;. As of May, 2004, installation of flap vortilons are a 'planned AD' (reference: FAA<BR>worksheet # 02-AD-166). This means that there is a very good chance that installation of<BR>the vortilons will be mandated. Boeing recommends that all operators install the<BR>vortilons.<BR>34. If there are two (2) vortex generators missing will a flaps 25 landing be required? Why is this<BR>requirement necessary if the airplane has been flying around for years without vortex generators?<BR>&lt;Answer&gt;. Per the CDL, if more than one vortex generator is missing on either side, use of flaps 30<BR>is prohibited and Flaps 25 landings will be required..<BR>The vortilons, or vortex generators, are installed on the leading edge of the outboard flap<BR>to remove an aerodynamic anomaly that could be a potential trigger for a lateral PIO.<BR>They are designed to prevent a sudden air flow separation on the outboard flaps caused<BR>by the spoilers deflecting. Thus, these vortilons will make lateral roll control authority<BR>more linear and smooth and predictable with wheel position. This lateral aerodynamic<BR>anomaly does not occur at flap detent positions other than 30.<BR>The degree/level to which these vortilons prevent this premature separation is a function<BR>of how many vortilons are on the flap leading edge and their location. An aircraft with<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 7 of 15<BR>different missing vortilon patterns left compared to right will exhibit different roll<BR>characteristics left when compared to right. For this reason, the operator is prohibited<BR>from using flaps 30 when more than one vortilon is missing on either side.<BR>These vortilons are held in place by glue and rivets. It is unlikely they will depart the<BR>airplane by working themselves loose while under air load and vibration. Their departure<BR>most likely would be the result of something impacting the flap leading edge. In this<BR>case, it is likely that there would be other structural damage to the leading edge of the<BR>flap that would draw attention.<BR>35. When will all service bulletins (for Vortex Generators) be available?<BR>&lt;Answer&gt;. The vortilon Service Bulletin was originally released as a "SPECIAL ATTENTION"<BR>Bulletin on 3/9/00. On 1/10/02, it was re-released as an "ALERT" Service Bulletin.<BR>The wheel damper Service Bulletin will be released sometime in mid to late August,<BR>2004.<BR>36. Do the simulators reflect this PIO tendency?<BR>&lt;Answer&gt;. Boeing does not think crew training simulators accurately represent the PIO<BR>tendencies/proneness of our airplanes.<BR>37. At what line number will the control wheel damper be implemented?<BR>&lt;Answer&gt;. The first 757 to receive a wheel damper on the production line was line # 1039; a CAL<BR>757-300 (NL106).<BR>38. Have there been any reports of PIO’s on airplanes with the vortex generators installed?<BR>&lt;Answer&gt;. Yes.<BR>39. Which airplanes have vortillons installed?<BR>&lt;Answer&gt;. Vortilons were installed in the factory for all 757-200s delivered on or after 2/3/00. The<BR>vortilons are part of the 757-300 production configuration; so, all have them.<BR>40. How many incidents of this have there been industry wide?<BR>&lt;Answer&gt;. There have been thirteen (13) confirmed 757 lateral PIO events since early 1995.<BR>41. Is the “revised rigging” a separate service bulletin?<BR>&lt;Answer&gt;. No<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 8 of 15<BR>FMS Upgrade Summary Pegasus 2003:<BR>42. Will the 737NG have the same Pegasus update?<BR>&lt;Answer&gt;. The 737 has a different FMC altogether; the Smiths’ FMC (on 737NG) already had the<BR>holding pattern entry/exit displayed.<BR>43. The Ops Manual description of the FMC indicates that resets will only occur during single FMC<BR>operation. They actually occur in dual FMC operations also. Is the Ops Manual going to be<BR>updated to correct this?<BR>&lt;Answer&gt;. Boeing is making a change to the system description information in the operations<BR>manual to describe the fact that resets can occur during dual FMC operation.<BR>43A. Have the power transfer problems that caused resets in the FMC been corrected in Peg 03?<BR>&lt;Answer&gt;. Pegasus 2003 included changes intended to correct the problem with resets on power<BR>transfer however there have been some reports of resets with Peg03 installed. It appears<BR>that the problems are much less frequent with the new software installed.<BR>Single Engine Taxi - Brad Caban (DAL):<BR>44. Please provide a copy of Brad Caban’s pitch for the CD.<BR>&lt;Answer&gt;. A copy of the Delta Airline presentation by Mr. Caban is on the CD.<BR>45. Are there restrictions on which engine should be shutdown?<BR>&lt;Answer&gt;. The airplane configuration may dictate procedures. This procedure is not in the Boeing<BR>Operations Manual.<BR>46. What percentage of DAL’s operations are actually single engine taxi?<BR>&lt;Answer&gt;. DAL is unsure. A fleet audit is necessary to determine actually how much this option is<BR>utilized by the flight crews. DAL believes single engine taxi is used more than the<BR>numbers presented in the financial analysis.<BR>47. What are the costs associated with the increased number of crossbleed starts versus using APU?<BR>&lt;Answer&gt;. For the crossbleed starts, DAL shuts down the APU so there are comparable savings.<BR>DAL believes it costs about $3 per start to bump up the operating engine to perform the<BR>cross bleed.<BR>48. Is the DAL airplane taxiing (moving) when the second engine is started?<BR>&lt;Answer&gt;. Yes, the DAL airplane is taxiing while the second engine is starting.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 9 of 15<BR>49. Do you specify to the flight crews which engine should be shutdown during taxi?<BR>&lt;Answer&gt;. No, DAL does not specify which engine is shutdown.<BR>50. Does DAL provide maximum breakaway thrust guidelines for the flight crews?<BR>&lt;Answer&gt;. No<BR>51. Please provide Boeing’s recommendations regarding single engine taxi.<BR>&lt;Answer&gt;. Page 2.11 of the Boeing 757/767 Flight Crew Training Manual summarizes Boeing’s<BR>recommendations regarding single engine taxi. It states:<BR>“Because of additional operational procedural requirements and crew workload, taxiing<BR>out for flight with an engine shut down is not recommended. High bypass engines<BR>require warm up prior to applying takeoff thrust and cool down prior to shutting down. If<BR>the engine has been shut down for several hours, it is desirable to operate at as low a<BR>thrust setting as practical for several minutes prior to takeoff. If taxiing in after landing<BR>with an engine shut down, the crew must be aware of systems requirements, (hydraulics,<BR>brakes, electrical). If possible, make minimum radius turns in a direction that puts the<BR>operating engine on the outside of the turn. In operational environments such as uphill<BR>slope, soft asphalt, high gross weights, congested ramp areas, and wet/slippery ramps and<BR>taxiways, taxi with both engines operating.”<BR>In addition, a general article on single engine taxi operations from the Fuel Conservation<BR>and Operations Newsletter included in the January - March 1991 issue of the Boeing<BR>"Airliner" magazine.<BR>Autothrottle Use with Autopilot Off:<BR>52. Is this information in the Flight Crew Training Manual (FCTM)?<BR>&lt;Answer&gt;. The FCTM provides this recommendation.<BR>Revision to 767 Flap Checklists:<BR>53. Would it be possible to develop different non-normal checklists to address these separate failure<BR>conditions? In other words, could Boeing publish a separate checklist for mechanical failures and<BR>another checklist for sensor failures; each with a different condition statement?<BR>&lt;Answer&gt;. There are concerns that separate checklists in such a manner could possibility to<BR>determine the best course of action.<BR>54. An operator advised that passenger seat 29 was the cause of a flap disagree. Any comment?<BR>&lt;Answer&gt;. No.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 10 of 15<BR>Oxygen Requirements - Brad Caban (DAL)<BR>55. Can we get the presentation on the CD?<BR>&lt;Answer&gt;. The DAL Oxygen Requirements presentation is on the CD.<BR>RNAV/RNP Operations &amp; VNAV Approaches:<BR>56. Are there more plans by Boeing to incorporate or display RAIM?<BR>&lt;Answer&gt;. It is incorporated into the algorithm for calculating ANP. There are no plans to display<BR>RAIM.<BR>57. Is the flight crew required to accomplish a raw data check prior to approach on pre-Pegasus<BR>boxes?<BR>&lt;Answer&gt;. Yes, the flight crew must confirm they are using DME-DME updating.<BR>58. Can the “UNABLE RNP” message display on a non-Pegasus FMC?<BR>&lt;Answer&gt;. No.<BR>59. Will the Pegasus FMC display “flight technical error”?<BR>&lt;Answer&gt;. No, the FMC does not display flight technical error. We do not consider it necessary to<BR>monitor cross track error.<BR>60. Why does Boeing recommend MDA + 50 used as the DA?<BR>&lt;Answer&gt;. Boeing has determined that an additive of 50 feet above the published MDA(H) is<BR>adequate to comply with the MDA(H) when on a constant angle approach and a missed<BR>approach is initiated at MDA(H) + 50 feet<BR>61. When do you set MDA?<BR>&lt;Answer&gt;. Set MDA in the AFDS mode control panel just prior to selecting VNAV to commence<BR>the final approach. This is done by Boeing procedures when approximately 2 NM prior<BR>to the FAF or final approach segment.<BR>62. If, for example, we have a DA of 640 feet, what should we set the MCP altitude to?<BR>&lt;Answer&gt;. As in A60, set MCP to the next lower altitude number, in this case 600 feet. Once<BR>established on final approach in the descent, and at least 300 feet below the missed<BR>approach altitude, set the MCP to the missed approach altitude.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 11 of 15<BR>63. The 757 AFM has a requirement (limitation?) for 250 ft AGL or 5000 RVR…. What is the history<BR>behind the 5000 ft RVR requirement?<BR>&lt;Answer&gt;. We have not been able to locate the noted requirement (limitation) in the 757 AFM.<BR>64. Should the green arc be used to determine if the airplane is on the proper flight path to arrive at<BR>the runway?<BR>&lt;Answer&gt;. While the MCP is set at MDA(H) the green arc will indicate where the airplane will<BR>arrive at the MCP altitude, but this indication may be of questionable value in turbulence<BR>and will not be available once the MCP altitude is reset to the missed approach altitude.<BR>If flying final approach in VNAV PTH, this technique for monitoring path performance is<BR>not necessary.<BR>65. Some airlines were advocating setting the field elevation in the MCP during the approach and<BR>then using the green arc as a cross check to ensure they were on the proper path.<BR>&lt;Answer&gt; This isn’t recommended. If a windshear is encountered during the approach the autopilot<BR>could capture the field elevation if the airplane was 800 ft AGL at some point during the<BR>maneuver. This is also unnecessary once in VNAV PTH mode on final approach.<BR>66. Does the green arc show the next altitude or the runway end?<BR>&lt;Answer&gt; The green arc remains only where the MCP is set and provides a prediction of point of<BR>arrival at the MCP altitude. There is no need to keep the green arc once the airplane has<BR>captured the path.<BR>67. The RDMI pointer points to the next waypoint in MAP mode, so how does this relate to the AFM?<BR>We are not meeting the first AFM requirement to monitor raw data.<BR>&lt;Answer&gt;. Your unique airplane configuration is certified for this operation. There is no need to<BR>monitor raw data.<BR>68. If ILS or LOC+DME do you need DME update?<BR>&lt;Answer&gt; RNP operations do not require DME or timing, however we encourage monitoring raw<BR>data if it is available.<BR>69. Are the altitude and temperature corrections on the Legs page?<BR>&lt;Answer&gt; If cold temperature altitude corrections are made, normally the crew would at least add<BR>the correction to the FAF (and if needed the IAF or transition altitude) waypoint altitude<BR>constraints.<BR>70. Please explain the AFM limitation which does not allow use of LNAV or VNAV with QFE?<BR>&lt;Answer&gt; The FMC navigation database is coded by mean sea level (MSL), so there will be vertical<BR>error if VNAV is used during QFE operation. The use of LNAV is restricted during QFE<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 12 of 15<BR>operation because of the possibility of altitude-based constraints associated with<BR>conditional waypoints in a selected departure, arrival or missed approach procedure.<BR>71. Does changing the altitude on a waypoint affect the approach logic?<BR>&lt;Answer&gt;. No, it does not.<BR>72. Will temperature corrections to waypoint altitude adversely affect the approach?<BR>&lt;Answer&gt; No assuming the correction is appropriate for the temperature and height above the<BR>airport. A Statement from the floor said that Transport Canada mandates a temperature<BR>correction.<BR>73. Is there a limitation in QFE for LNAV below transition altitude?<BR>&lt;Answer&gt;. Yes. See A70 above.<BR>74. Is there a time limit on how soon before commencing the approach DME-DME updating must be<BR>checked?<BR>&lt;Answer&gt;. No, the AFM simply says "prior to approach."<BR>An Enhanced Boeing QRH:<BR>75. We like the sample checklist with conditional statements and the choices, but what about a<BR>scenario where there are not, at least, two choices?<BR>&lt;Answer&gt; We are looking for ways to address such a situation where there is a conditional<BR>statement with only one choice. We are considering using an IF statement for these cases<BR>and would reserve the term IF for only these single choice cases.<BR>76. Will Boeing provide a copy of the “raw” version of the QRH so operators may edit them by<BR>adding their logo and extra items?<BR>&lt;Answer&gt;. Operators may purchase digital data formats for their operations manual from Boeing or<BR>contract for plan 2 revision service. Interested operators should contact Boeing Flight<BR>Technical Integration &amp; Data at <A href="mailto:FTID@boeing.com">FTID@boeing.com</A>.<BR>77. With regards to the possible use of color pages; will Boeing consult with the FAA regarding the<BR>use of color on the final design?<BR>&lt;Answer&gt;. Yes.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 13 of 15<BR>78. In the sample, the Smoke/Fumes checklist title is in a larger font. Will that carry over to the final<BR>design?<BR>&lt;Answer&gt;. We are unsure at this time. The larger font is better for cases where masks/goggles or<BR>smoke hoods may be used and visibility may be impaired.<BR>79. How much larger will the new QRH be?<BR>&lt;Answer&gt; We do not anticipate the QRH will initially be any thinner in thickness than today's QRH<BR>because in the “near term”, duplicate checklists will not be removed. Boeing plans to<BR>publish the QRH in the current size (length and width).<BR>RTO Manual vs. Auto Speedbrake Deployment:<BR>80. Some operators are not using manual speedbrakes; how did that happen?<BR>&lt;Answer&gt; These operators have received approval from their authorities and implemented<BR>appropriate training programs which include monitoring the speed brake handle to assure<BR>deployment. In addition, Boeing has been asked, and provided, a statement of No<BR>Technical Objection when appropriate training and standard procedures are provided to<BR>the flight crews.. Boeing is currently reviewing the capability to make automatic<BR>deployment of speedbrakes during RTO a standard policy.<BR>81. Can we get relief on a long runway with a light airplane to disarm the auto brakes on an actual<BR>RTO?<BR>&lt;Answer&gt;. Autobrakes may be disarmed at the Captain’s option.<BR>Miscellaneous:<BR>82. The 767/CF6-80C2 ENGINE OIL PRESSURE non-normal checklist advises the flight crew to<BR>shut down the engine if the oil pressure is at or below the red line. Wouldn’t it be prudent to<BR>check both the low pressure indication and the digital pressure indication to verify that a low<BR>pressure condition actually exists?<BR>&lt;Answer&gt;. General Electric and Boeing consider the conservative approach to provide flight crew<BR>guidance in the QRH if either the low oil pressure sensor (which provides the EICAS<BR>alert message and amber ENG OIL PRESS light) or the pressure transmitter (which<BR>provides the oil pressure indication on secondary EICAS engine page) indicate red-line.<BR>As such, General Electric and Boeing provide QRH flight crew guidance if either sensor<BR>(low pressure switch or low pressure transmitter) detects low oil pressure.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 14 of 15<BR>83. Is Boeing aware of any fuel tank ruptures on the 757 or 767 airplanes?<BR>&lt;Answer&gt;. No, Boeing has not received any operator reports of tank ruptures on either the 757 or<BR>767.<BR>84. What is the intent of the engine fuel leak procedure? How should the flight crew address a tank<BR>fuel leak?<BR>&lt;Answer&gt;. The engine fuel leak procedure is primarily provided to address an engine fuel leak (a<BR>leak downstream of the engine fuel valve). The flight crew however may not be able to<BR>exactly determine the type of leak. When executing the ENGINE FUEL LEAK<BR>checklist, if the engine is shutdown and the leak continues, it is logical to assume a tank<BR>leak. As such, diverting and landing at the nearest suitable airport is the most prudent<BR>course of action.<BR>85. The flight control check is moving from its current position before engine start to after engine<BR>start. If the flaps are down and there is aileron droop will there be interference?<BR>&lt;Answer&gt;. No, there is no problem doing the flight control check with the flaps extended.<BR>We are moving the 757/767 flight control check to a position after engine start as a result<BR>of an accident investigation, and for standardization purposes. The flight data recorder<BR>does not record parameters prior to engine start so it is not possible to determine if the<BR>flight control check has been accomplished using this data. As most other Boeing models<BR>accomplish this check after engine start it was prudent to move the 757/767 flight<BR>controls check to be common with other models.<BR>86. Can we use the Assumed Temperature Method for reduced thrust with a tailwind on our 757 and<BR>767 airplanes? Our 757 airplanes may not use the ATM for reduced thrust when a tailwind is<BR>present, but the 767 may use ATM with up to a 10 kt tailwind.<BR>&lt;Answer&gt;. We are unaware of any tailwind restriction associated with use of the assumed<BR>temperature method for reduced thrust.<BR>87. We experienced a power loss on a 767 operating into Bogota. The event was caused by improper<BR>ground of a bracket for a TRU shelf. What is the latest status of the investigation?<BR>&lt;Answer&gt;. A 767 airplane, while enroute from Buenos Aires to Washington, experienced an<BR>electrical power system failure in flight forcing it to declare an emergency and divert to<BR>Bogota, Colombia. All electrical generators appeared to have been working properly, but<BR>the aircraft electrical system failed in such a way that Advisory and Status messages were<BR>displayed on the upper EICAS display with the illumination of main battery discharge,<BR>antiskid and auto speed brake indicator lights on the P5 overhead panel. The F/O<BR>displays (EADI/EHSI) also went blank, and the left VHF radio was intermittent through<BR>out the remainder of the flight. The crew suspected loss of both main AC buses and<BR>diverted. From the time of the initial indication to touchdown in Bogota, the aircraft flew<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:19 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 15 of 15<BR>for approximately 42 minutes, while battery bus and standby DC bus power was being<BR>supplied mainly by the Main Aircraft Battery.<BR>It was determined that the bracket that holds the grounding studs for the TRU-L, TRU-R<BR>and Battery Charger, had high bonding resistance; this resulted in the DC bus voltage<BR>falling below acceptable limits on these buses. The main battery was forced to carry the<BR>battery bus and standby DC bus loads. Boeing considers this single failure condition to<BR>account for the multiple Advisory and Status messages condition experienced in<BR>N644UA. The F/O display blanking is considered an isolated event and is still under<BR>investigation.<BR>88. We have experienced where bleed light illuminates inflight and on takeoff. The Boeing<BR>procedures say the OFF light should be illuminated, but this is not the case?<BR>&lt;Answer&gt;. Boeing Flight Operations Technical Bulletin 767-72 has been issued and addresses this<BR>phenomenon. This FOTB has been released in paper form but is also available via<BR>internet at MyBoeingFleet.com.<BR>89. Speedbrakes are armed, but the spoilers don’t deploy. Has this been reported to Boeing<BR>previously?<BR>&lt;Answer&gt;. The Airplane Maintenance Manual has a discussion regarding this issue. There is no<BR>flight deck feedback that the speedbrakes are armed. Please see FRM 27-62-00/101, Fig.<BR>104, Block 1 and AMM 27-62-01-00.<BR>90. Are there recommended flight tests out of C &amp; D checks to verify?<BR>&lt;Answer&gt;. Recommended tests are in the Airplane Maintenance Manual. Flight tests are not<BR>recommended unless specifically mentioned.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:20 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 1 of 6<BR>757/767 Caucus Report<BR>1. Operators would like to see the Battery Start procedure included in the ops manual Supplemental<BR>Procedures.<BR>&lt;Answer&gt;. Boeing will be reviewing our documentation and manuals to improve the visibility of the<BR>Battery Start procedure.<BR>2. The REVERSER ISOLATION VALVE non-normal procedure includes the following note:<BR>“Additional system failures may cause inflight deployment”. This caution note applies to both the<BR>757 and 767 and should be clarified or elaborated upon. Are there additional status or caution<BR>messages associated with this condition that the flight crews should be aware of?<BR>&lt;Answer&gt;. With the third locking system installed the L/R REV ISLN VAL advisory level alert<BR>message is inhibited above 80 knots on the takeoff roll; however the message can still<BR>display during taxi out. As such, there must be a checklist to address possible display of<BR>the message during taxi.<BR>With the addition of the third lock and associated changes, Boeing demonstrated that an<BR>in-flight T/R deployment is extremely improbable; less than e-9. Note that Boeing<BR>analyzes both powered and unpowered deployment. Further, if the sleeve actually<BR>moves, the Rev Amber or Rev Green will be displayed; these are not inhibited in flight.<BR>3. Most operators cycle circuit breakers. There is concern that the new Boeing policy which advises<BR>that it is acceptable to cycle breakers for certain systems may actually be more restrictive than<BR>operators’ current policies. As the new proposed policy may be more restrictive perhaps it should<BR>be worded more loosely?<BR>&lt;Answer&gt;. Wording for a new Boeing policy that would allow an aircrew to cycle specific circuit<BR>breakers has not been determined.<BR>4. Operators would like a list of circuit breakers that can be cycled; with and without maintenance<BR>direction.<BR>&lt;Answer&gt;. Providing such a list of circuit breakers that can be cycled is under review.<BR>5. Boeing needs to clarify what is acceptable for circuit breaker cycling. Airlines need something to<BR>take to their regulatory agencies. The Airbus Industries ops manual includes a list of circuit<BR>breakers that may be cycled.<BR>&lt;Answer&gt;. Providing such a list of circuit breakers that can be cycled is under<BR>review.<BR>6. Boeing must pursue MMEL relief for 757 fuel tank scavenge system.<BR>&lt;Answer&gt;. Boeing has discussed MMEL relief for the scavenge system with the FAA. If industry<BR>desires to propose the scavenge system as an MMEL item, it should submit a proposal<BR>that can be discussed at the next FAA/Industry MMEL meeting where input from all<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:20 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 2 of 6<BR>effected parties can be heard. Boeing and the FAA caution that the MMEL may not be<BR>the optimum way to approach malfunctions in this system because the maximum deferral<BR>permitted will not exceed 10 days, and repairs to the system may require significant time.<BR>7. Cockpit pre-flight flow versus the security door check. Is there any guidance on how often this<BR>should be accomplished?<BR>&lt;Answer&gt;. AFM limitation: “Verify that an operational check of the Flight Deck Access System has<BR>been accomplished according to approved procedures once each flight day.”<BR>8. One operator inquired if other operators have had a problem with new security door jamming?<BR>&lt;Answer&gt;. No notable cases of doors jamming, although there have been – and continue to be –<BR>concerns about the high forces required to open the secure flight deck door. Engineers<BR>are working on a 3rd generation design to lower the forces.<BR>9. Enhanced GPWS, same question on cockpit preparation guidance. When do operators accomplish<BR>an operational check of the EGPWS system?<BR>&lt;Answer&gt;. An operational check is typically done at a 1C interval (6000 flight hours). The<BR>maintenance check intervals for each specific model however can be found via the<BR>Airplane Maintenance Inspection Interval Documents or Maintenance Planning<BR>Documents available on line at <A href="http://myboeingfleet.cs.boeing.com/boldweb/index.bhtml">http://myboeingfleet.cs.boeing.com/boldweb/index.bhtml</A><BR>For the EGPWC however, the built in test is robust enough that the flight crew will get an<BR>INOP indication if the system is compromised and the audio amplification interface and<BR>speakers are checked every time the airplane lands.<BR>10. Do other operators lock the cockpit door while the airplane is on the ground? Does it matter if<BR>the crew is on or off the airplane; doing a walk around, for example? Do other operators disarm<BR>or manual lock the security door with a key during through flights if no pilots are on the airplane?<BR>&lt;Answer&gt;. We have left it to operators, and their regulatory authorities, to establish their own<BR>procedures for cockpit security on the ground. Operators have naturally been reluctant to<BR>disclose their policies and procedures on this topic. The FAA’s position is that the<BR>electronic entry code (emergency access code) is not the normal entry method.<BR>11. Power to locking mechanism may be an issue of cockpit security. If power is lost to the door<BR>locking mechanism shouldn’t there be a new procedure to use the deadbolt? There is no Boeing<BR>guidance….there is no indication of loss of power to the security door autolock. Boeing may need<BR>to address this, especially on the 767 (no EICAS indication on power loss).<BR>&lt;Answer&gt;. Losing power to the door lock system will cause the LOCK FAIL light to illuminate on<BR>the P5 overhead panel. The LOCK FAIL non-normal procedure has the following note:<BR>The door can be locked with the deadbolt.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:20 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 3 of 6<BR>12. Fuel migration on diffuserless and cast-in diffuser pumps; Boeing doesn’t want to update manuals<BR>if the fix is not immediate. There are some ops manual bulletins that are around for years.<BR>Operators do not like this; bulletins should be incorporated in the ops manuals in a timely fashion.<BR>&lt;Answer&gt;. As of this date, there are only 4 Bulletins in the 757 and 4 in the 767 that do not contain<BR>closing action. Any anomaly for which there is no planned fix is incorporated in the<BR>FCOM and the OMB cancelled at that time.<BR>13. Ops manual bulletins are in volume I of the ops manual, yet the procedures they affect are in the<BR>QRH. Pilots do not like having the bulletins in effect for so long and in the wrong place.<BR>&lt;Answer&gt;. Operations manual bulletins with QRH pages are listed as INC (Incorporated) on the<BR>Bulletin record pages. The bulletin is only retained for background information. All<BR>necessary crew actions are contained in the QRH. If the procedure is the only known fix<BR>for the problem, the background information is incorporated into the FCOM and the<BR>bulletin is cancelled.<BR>14. How does Boeing handle long term ops manual bulletins versus incorporation into applicable<BR>manuals?<BR>&lt;Answer&gt;. Please see response to questions 12 and 13.<BR>15. Will the flight crew be able to override the auto shutoff function on the fuel system? The service<BR>bulletin needs to be clear on this issue.<BR>&lt;Answer&gt;. The auto-shutoff function, when certified, will be capable of being overridden, however,<BR>the intentional design of the auto-shutoff function will be transparent to the flight crew<BR>both in normal operation and non-normal operation. As such, the QRH checklist for<BR>FUEL PUMP will instruct the flight crew to select the respective pump switch OFF, and<BR>keep it off. The remaining center tank pump will continue to operate to empty the center<BR>tank. Therefore, the QRH checklist will not provide for overriding the auto-shut off<BR>function, per design and certification. If auto-shutoff removes power to the pump, it will<BR>be considered a pump failure and the pump, per the FUEL PUMP checklist, should be<BR>secured.<BR>16. Do operators see differences between FMC calculated versus totalizer fuel quantities on the 757?<BR>Can Boeing explain this difference?<BR>&lt;Answer&gt;. The Fuel Quantity Indicating System (FQIS) processor receives data from the fuel tanks<BR>and calculates the weight of fuel in each tank, and the total weight of fuel. The FQIS<BR>Processor passes this information to the FMC for display on the P5 overhead panel.<BR>There is a Fuel Flow Transmitter (FFT) located on the main engines that provide EICAS<BR>information on fuel used. EICAS displays this information and provides it also to the<BR>FMC.<BR>The two different sources of fuel information do at times show a difference, primarily<BR>due to differences in tolerances in the detecting/transmitting devices. The fuel tanks use<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:20 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 4 of 6<BR>stationary fuel tubes that have an accuracy of +/-2.5% full volume of the tank, and the<BR>FFT tolerance varies with the fuel flow rate. At low flow rates, such as at idle, the<BR>inaccuracy can be fairly large. In addition, if the APU is running, the FQIS will record<BR>the lower fuel levels in the tanks, but the FFTs on the main engines will not record the<BR>fuel being used.<BR>17. Please ensure all the pitches are on the breakout CD. Particularly Bill McKenzie’s slides and<BR>Captain Morgan’s (Air New Zealand) slides.<BR>&lt;Answer&gt;. These will be included.<BR>18. There needs to be similar guidance between the ops manual and the maintenance manual. In<BR>some cases the ops manual advises a condition is not normal whereas the AMM says it is normal.<BR>&lt;Answer&gt;. The AMM is written for maintenance operations purposes. The AOM is written for flight<BR>crew operations purposes. What may be acceptable from a maintenance standpoint may<BR>not be acceptable from a flight operations standpoint. Conversely, the same is true. As<BR>such, what may seem like conflicts between the manuals may be written that way<BR>intentionally. If operators have specific issues they would like addressed, please contact<BR>Boeing through the operator’s Field Service representative to have the issue reviewed by<BR>the appropriate Boeing personnel.<BR>19. Does everybody mandate FRM code entries?<BR>&lt;Answer&gt;. Show of hands indicated a nineteen (19)% utilization of the FRM.<BR>20. Will there be an overweight landing checklist in the 757 and 767 (like the 777)?<BR>&lt;Answer&gt;. This issue is under review with Boeing Flight Operations and Flight Operations<BR>Engineering. At present, an OVERWEIGHT LANDING checklist has been issued for<BR>the 777 and the 757-300 due to specific certification issues, which did not pertain to other<BR>Boeing models.<BR>21. Would like to see common 757 and 767 ops manual volume II.<BR>&lt;Answer&gt;. There are no current plans underway to combine the 757 and 767 Volume 2 manuals. The<BR>current standardization effort will reduce the number of unnecessary differences.<BR>22. The smoke/fumes/electrical non-normal checklists should be integrated. In other words, combine<BR>the air conditioning smoke, electrical smoke checklist; all smoke troubleshooting” should be in one<BR>checklist.<BR>&lt;Answer&gt;. Boeing will take this under advisement.<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:20 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 5 of 6<BR>23. The AC BUS checklist contains lots of IF statements. Could this be broken into three (3) separate<BR>checklists instead of one?<BR>&lt;Answer&gt;. Boeing is reviewing this proposal. All proposed checklist modifications are subject to<BR>committee reviews and flight operations board approvals. If approved, such modification<BR>would appear in a future Operations Manual revision. Be advised, Boeing receives<BR>conflicting requests on this subject from operators worldwide. As such, while some<BR>operators believe they would prefer separate checklists, other operators prefer a single<BR>checklist. Some operators want more information, some operators want less information.<BR>There are varying opinions worldwide on this subject.<BR>24. Boeing should add more notes to checklists to help “understanding” or the rationale for the item<BR>with regards to system operation.<BR>&lt;Answer&gt;. We are reviewing the content of non-normal checklists to identify how additional<BR>information and guidance should be presented and what the information should convey as<BR>part of our long-term standardization effort. Some of this information may be presented<BR>as “notes” but some information may be presented in new ways, such as operational<BR>consequences and considerations.<BR>25. Inadvertent fuel shutoff; is there any good explanation on why there is no suction feed? May be<BR>PW4052 engine related only.<BR>&lt;Answer&gt;. All engine models (PW, GE, and RR) for all production airplanes (Seattle production<BR>models) now have information published in Volume II, chapter 12, on Suction Feed<BR>operation. In addition, the FUEL SYSTEM PRESSURE checklist has been revised to<BR>provide more explicit recommended guidance for suction feed operation.<BR>26. Boeing ops manual system description should cover more on suction feed design.<BR>&lt;Answer&gt;. In-service events, which received attention of the NTSB, were the driving force to<BR>include suction feed description in the Operations Manual. Boeing, the NTSB, the<BR>Seattle ACO, and airline personnel involved in the in-service incidents, authored the<BR>existing information contained in all Boeing-Seattle production model Operations<BR>Manuals. All parties concluded the existing coverage of suction feed operation is<BR>positive and satisfactory.<BR>27. When the cockpit door mechanism fails inflight you must use the deadbolt. Has Boeing done a<BR>risk assessment in case of a pilot incapacitation?<BR>&lt;Answer&gt;. First there has to be an in-flight failure of the access system. As a result of this failure the<BR>flight crew could engage the dead bolt. The LOCK FAIL procedure simply reminds the<BR>crew that there is a dead bolt. Boeing does not direct them to engage it. The reliability of<BR>the access system is 10 E-5 per flight hour.<BR>The estimated probability for incapacitation of the either member of the flight crew is<BR>estimated to be 10 E-7 per flight hour. Therefore, assuming the flight crew chooses to<BR>2004 Flight Operations Symposium Questions 8/23/2004 10:20 AM<BR>May 9 – 12, 2004, Bell Harbor Convention Center<BR>Page 6 of 6<BR>engage the dead bolt, the combined probability of crew incapacitation while the dead bolt<BR>is engaged is 10 E-12 per flight hour, or three orders of magnitude beyond the FAR 25-<BR>1309 criteria for extremely improbable.<BR>28. Does Boeing plan to do an inexpensive (cheap) service bulletin to eliminate the noise generating<BR>opening near the tail skid?<BR>&lt;Answer&gt;. Boeing considers installation of the tailskid negative pressure cover a satisfactory method<BR>to eliminate the noise generated from the air which exists through the tail skid assembly.<BR>29. Has Boeing done a sound level survey in the 767 cockpit and identified what effect use of Active<BR>Noise Cancellation headsets have on those levels? Do any other airlines use ANC headsets?<BR>&lt;Answer&gt;. Typical 757 and 767 flight deck (pilot's inboard ear) noise spectrums for cruise flight at<BR>35000 ft, mach 0.80 are as follows:<BR>PREFERRED OCTAVE BAND - HZ<BR>(-SOUND PRESSURE LEVEL DB REF 20 MICRO PA-)<BR>63 125 250 500 1000 2000 4000 8000 OA DBA SIL<BR>757-200 72 76 73 75 68 63 58 49 80 74 63<BR>767-300 70 67 66 68 68 66 59 60 76 72 64<BR>Boeing has never evaluated active noise cancellation headsets in the laboratory. We<BR>suggest operators obtain performance and limitations regarding ANC headsets from the<BR>particular headset manufacturer. We are aware that some operators do use, or have used,<BR>active noise cancellation headsets.

robbertmd 发表于 2010-6-1 18:07:35

是英文还是中文的丫

ak1557 发表于 2010-7-13 16:59:58

谢谢,那来看看。有翻译的吗?

谢谢,那来看看。有翻译的吗?

benny0426 发表于 2010-8-7 12:10:58

thank for your post
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