Cruise Mgmt

10  Download (0)

Full text




Introduction... 3

Climb Before Cruise Segment ... 3

Initial Altitude ... 3 PA Announcements ... 3 Roster... 4 ATC/Traffic Situation... 4 Some guidelines: ... 5 Flight Progress ... 6 Weather... 7

Enroute Climb Planning ... 8


Off Track Diversions ... 10


Revision Record

Version Date Source Change Reason Page/s

1 11/01/07 FOT S. Howard P. Donazzan • Subject matter updated. • Explanation of Cost Index added. • Aerodynamic section moved to it’s own “Aircraft Performance and Aerodynamics” General Briefing

Replace former Flying Manual Chapter with General Briefing. FOT Library Introduction.



This briefing remains the property of QANTAS. Copying for other than student’s own use is illegal. The subject content of this brief is correct at the time of publishing. In any case, the Flight Crew Operations Manuals are the

authoritative documents. It is the responsibility of users to ensure that they are aware of changes or corrections to subject matter circulated by QANTAS.



Efficient cruise management has many elements. The main aim is to achieve full situational awareness (S/A) and stay well ahead of the aircraft.


Analysis during the climb may assist in planning the early part of the cruise. A prime example is wind component on the climb. It is important to check wind direction/speed and component starting at FL260-280, depending on the initial cruise altitude. This can then be compared with the flight plan wind at TOC and the enroute spot wind [temp] data to determine if it might be more fuel-efficient to cruise at a lower altitude.

Tactics are also a consideration. On a busy long sector (say, from SE Asia to

Europe) it may be better to stay at the initial altitude rather than choose to start lower, since increased traffic congestion later in the flight may mean that a step climb is no longer available. On a trans-Tasman service, a careful look at the winds during the whole flight may enable selection of a better cruise level for the return trip (assuming a same-day return flight). Be very familiar with the break-even wind tables and the use of FMC calculations.


Having arrived at cruising level, it is prudent to do a full panel scan to ensure that all systems and switches are in the correct status/position for cruise flight. Check that the aircraft is performing correctly for the desired cruise regime, and then commence your management routine as outlined below.


Awareness of the situation in the cabin is a precursor to making non-intrusive, routine PA announcements. Operational PAs (e.g. after illumination of the Fasten Seat Belt Sign) can be made at any time. In liaising with the CSM prior to departure, the Captain should have details of the anticipated cabin service for the sector.

Announcements on the ground are well covered in the FAM; as is content of in-flight PAs.

Generally, the pilot flying should make no announcements below 20,000’. For daylight departures, the best time is in cruise following top of climb. At this stage, a meal/bar service would be underway in the cabin, the ‘welcome aboard’ video finished and passengers awake. On some types the use of the PA does not freeze the inflight entertainment but on all types the flight deck PA will override all

communications in the cabin.

Night departures require additional thought. On some sectors most passengers stay awake for a meal etc. However, on others (e.g. BKK-LHR), some may well be asleep


by 10,000'. In the latter case a brief introduction followed by very basic flight details and a caution on seat belt fastening while seated should suffice. Thus a brief PA above 20,000' is less likely to distract the operating pilot from the task and minimises annoyance for those pax who are already asleep.


Flight Crew must be aware that Flight Time Limitations are laid down by the CAOs. The FAM requires us to manage the flight deck duty time for inflight relief. In the past, more information was provided on rostering requirements, but as crew sizes and sector lengths increased, formal advice on calculation of flight deck duty ceased. Rostering of four pilot crews on the long-range aircraft is easy, with the use of the 2-person team - one team working, one resting. Similarly, a 3 pilot crew on advanced flight decks means simply dividing the cruise time by 3 and then splitting the answer into sensible breaks. The convention for teams is 2 hours on/2 hours off and for 3 crew an initial break of up to an hour, then one-hour off for the second break. It is wise to use the previously laid down procedure of calling off-duty crew 5 minutes prior to their scheduled return so that they can prepare themselves, especially if they've been asleep. . Modern research has shown that it can take some time to become fully functional after waking from a deep sleep, especially in the early hours of the morning. A returning crewmember usually comes on watch (in a non-team situation) with at least one other crewmember who is au fait with the operation and awake. However, the person returning from the last break prior to TOD may need a little extra time (e.g. fully occupied toilets on the 747-3 or 767), so don't cram the roster too close to TOD.

The use of a Flight Engineer on the B747 means that a Second Officer has to provide panel coverage. Thus, the cruise time is divided by 4 and breaks allocated, with the E/O traditionally having his time off last. At the E/O's request, it may be

advantageous to give him his long break first, since any reduction in cruise time will cut into his break.

On rare occasions, there may be situations where the Captain, as commander of the aircraft and with the overall responsibility for the operation, may need to take more time off. This can occur, for example, after a delayed departure where the crew have extended their duty time facing a demanding arrival at destination with a potential diversion. It is imperative that the Captain be functioning 100% in this type of situation and extra time off may be warranted.

It has also become practice to note the Volmet frequencies, times and weathers required on the roster sheet. This is a handy place to put them as we all look at the roster from time to time, thus we can be reminded of the weathers needed by the PF. Finally, there are times when specific crewmembers should be on duty. Such as, the Captain being on duty approaching DPA with a deteriorating destination weather. At these times, the crewmember preparing the roster must ensure that the required crew are on duty.


At locations where delay or congestion is known to occur, Qantas staff at the briefing counter may provide a summary of same direction flights with departure times. This can be very useful, both in predicting chances of an altitude blockage and enabling


monitoring of the clearance delivery frequency to check on clearances issued to those flights.

Monitoring of the clearance delivery frequency may assist us to be aware of our competitor's clearances and thus the likelihood of achieving initial cruise level. However, don't monitor the radio at this stage to the exclusion of other pre-departure preparation; it's only a ‘nice to know.’

When airborne, start to pick up an idea of traffic from those aircraft on frequency that appear to be going in the same direction.

Once established in the cruise, ascertain traffic ahead and behind at the same level. Look at how separation is achieved; radar distance, IRS distance, time [ ETA’s 10/15/20 minutes], time & Mach number [MNo], or distance & MNo.

It is important to develop an appreciation of where separation standards change. Firstly, identify the type, destination and cruising MNo of same-direction aircraft in the vicinity. Accurate time recording, and monitoring the ETAs of adjacent aircraft, can help to maintain 10/15min separation and often fill a slot , which may otherwise be lost.

Secondly, developing a similar picture for traffic above and below in the same direction, combined with an appreciation of the required separation, will assist in planning the next step climb. Anticipate aircraft that may be descending through the same level to their destination, with the potential for a breakdown in separation within a busy stream of traffic.

Thirdly and very importantly, listen for opposite direction traffic climbing/descending through the same level or requesting climb/descent. Routine reports of traffic maintaining correct standard levels are not a problem, but, should one of these aircraft request climb or descent, it is wise to have some idea of who and where it is on busy airways (e.g. Calcutta – Delhi). Just as a complete picture of same direction traffic to assess tactical information with some collision avoidance implications is essential, monitoring of opposite direction traffic is mainly for collision avoidance of those changing level.

Note that the Route Manual Supplement (RMS) lays down procedures in busy areas for crossing airways, traffic awareness, and track paralleling procedures for collision avoidance in FMC aircraft.

If there is information required from another aircraft, it may be useful to speak directly with it (as distinct from using ATC as an intermediary). Most professional operators have their crews monitor the ATC frequency and 121.5mHz as a minimum, with the third set on ACARS if so equipped. Speak directly to the aircraft. Calling on 121.5 and nominating contact on an ‘interpilot’ frequency may be one way to do it without disrupting ATC. However, this is not advisable in the USA or Europe where many ground stations monitor 121.5.


Call on a nominated interpilot frequency (e.g. 123.45mHz for the Pacific Basin) If no contact and/or the aircraft is known to be equipped with ACARS (e.g. B747, 767, MD11, A330/340, etc.) and outside continental USA/Europe/Asia, call on 121.5, nominating a reply on either; (a) interpilot frequency, or (b) the nearest company ground station frequency (the FIR manager won't be using it as an ATC frequency.)


If still unsuccessful, call on the ATC frequency, nominating a suitable interpilot frequency as in 2 above.

The subject of VHF comm set usage in cruise raises the subject of monitoring a second ATC frequency. In decades past, it was the norm on congested airways with rapid transit of FIR boundaries to monitor the next ATC frequency and assess the opposite direction traffic for conflict. However, with better ATC unit to unit

communications and inter-agency agreements on traffic flow on this type of airway, the need to monitor a second frequency for collision avoidance has all but

disappeared. Do not confuse monitoring with the requirement at some FIR

boundaries for prior contact with the next ATC unit giving an ETA and level. There are several drawbacks to monitoring 2 frequencies. Firstly, effective monitoring of 2 ATC frequencies means one pilot on each frequency. Thus, if the PNF is the primary communicator, he/she should stay on the current ATC frequency, with the PF on the 2nd. If the PF, as ‘pilot on watch’, is to retain full situational awareness, including ATC requirements, this is perhaps undesirable. Alternatively, the PF monitors the current ATC frequency and becomes, basically, a one-man band, with the PNF on the other frequency. The later is arguably the better method, but only where mandatory monitoring of a second ATC frequency is required.


There is no intention here to cover a complete analysis of the subject; that's better left to the excellent Fuel Courses run by Flight Training. However, there are some trends in flight progress which are worth noting.

One of the first things to consider is the management priority of maintaining schedule v fuel usage. QF aircraft are operated to a Minimum Cost Cruise [MCC] by setting a Cost Index in the FMC of those types so equipped and setting a variable Mach No. on the B747-300. The FAM gives Captains the flexibility to operate at a different schedule, but we should always remember that fuel has become the number one cost that we can control.

The monitoring of fuel usage verses time is carried out in Qantas by tabulating actual fuel remaining at a position, then comparing this with the planned fuel remaining, and similarly comparing ATA v ETA at that position. Thus, down the right hand side of the nav log, there evolves a running summary of fuel trend.

A ‘normal’ ahead/behind datum is approx. 200kgs(B744/747) , 100kgs (A330/B767) or 60kg (737) for each minute of time. This can be fine-tuned for actual fuel flow if required. Apparent discrepancies can be caused by under/overfuelling, long/short taxi, longer than normal ground running of the APU, extended flight departure (with or without set heading allowance), extensive use of bleed air for anti-icing, or not

climbing in the leg where the fuel was allowed in the plan. What is important here is that an increasing discrepancy must be accounted for otherwise the possibility of a fuel leak must be considered.

Assuming cruise has been as planned, a slow loss of fuel may indicate poor trim, anti-ice unwittingly left on (e.g. There is NO indication of wing anti-ice in use on the 747-300), mis-rigged controls, or loose/missing panels. A trim check and full panel scan may help solve the problem.

There are some traps associated with flight progress which do not normally cause any concern, but may be a big problem when fuel over destination is marginal. The worst case is being ahead on time and behind on fuel. Be aware that

DPA/DPD/DP1/DPE are all geographical positions, not simply times! Thus, when we are ahead on time, but behind on fuel, we arrive at the DP position earlier than


planned, but with less fuel. This may require some recalculation, but even worse is to wait until the time and then check the DP fuel, finding that we have to divert, but have inadequate fuel!

The flight planning system and fuel policy was specifically tailored to make DPA a position fix/waypoint on the plan, as distinct from PNR, which usually fell between waypoints. However, the other DP points are normally between waypoints and this should be considered in considering our fuel situation. If required, these DP point/s may be entered in the FMC and so provide a pictorial reminder of their location. It is worth noting that DP positions can be adjusted inflight. In the case of DPA the dispatcher has to choose from a menu provided for the particular route sector in the Phoenix system. The Nav Analyst who determines the ports available for DPA on a particular route is constrained by the CAA Ops Spec wherein our term DPA is really a PNR. Thus, the DPA ports available to the dispatcher will never normally be beyond the destination. However, the definition in the FAM talks about ‘the position on the fuel flight plan furthest removed from the departure airport to divert to a suitable airport with all engines operating.’ Inflight, we can always use any suitable airport for DPA calculation with the caution that for a port beyond destination, fuel to DP port will be greater than that to destination, unless the destination has an operational requirement (e.g. w/x hold, ATC hold, alternate, etc.)

A similar caution should be issued anytime the fuel to DPA port is greater than that to destination. In 99% of cases, with the weather at destination fine, we have the

required fuel to proceed to destination from well before the flight plan DPA. However, if the destination weather is poor and we are down on fuel, there is a danger that we may end up in ‘no man's land’ for a portion of the flight, not complying with the inflight fuel policy requirement to always be able to ‘proceed to a suitable airport’.

Continuing on the subject of DPA fuel requirements, it is considered good practice to check the DPA fuel calculation. Naturally, you could use the computer figures from the flight plan, but this would only really be checking that the computer can add correctly! Use of the Inflight Diversion Fuel Requirements graph, which includes FFR & VFR, will enable an independent check and is a handy page to use if recalculating another DPA.

On FMC equipped aircraft, the flight plan winds are inserted against waypoints in the RTE DATA page, with capacity on some later FMCs to enter multiple cruise altitude winds (refer type FCOM). These entries are blended by the FMC with current

measured wind to enhance performance predictions for target speeds, fuel burn and ETAs. Firstly, in the multiple case, there's no use in putting in every altitude W/V shown on the flight plan Enroute Spot Wind Data if you are incapable of reaching those altitudes (e.g. entering the 200mb/FL387 data for a B744 SIN-LHR prior to, say, Calcutta. Secondly, interpilot communication may enable you to get actual winds further ahead and/or at higher altitude to update those entered from the flight plan. This will enhance the FMC cruise calculations to give you the best information.


At flight planning, we would have received forecasts valid for the time of anticipated use at our destination, DP ports, and alternate/s (if required.) From a strictly legal point of view (with the exception of an Isolated Airport which needs an alternate), we need obtain no other weathers than these to complete the flight. However, we should all agree that it would be poor airmanship indeed not to update that information inflight where the facilities are available.


Some of us can remember flying to Europe from, say, Bahrain, when the Captain requested arrival weather from the HF volmet as soon as the gear was in the wheel wells! Others said, ‘We are going there anyway’ and did not bother. How do we find a philosophy which is both practical and embodies good airmanship?

Since all sectors over 1000nm have a DPA shown on the flight plan, the first principle we could suggest is that an updated actual weather at the destination be obtained prior to DPA. This may be enough to confirm the forecast, and, if fine, no more need be done. However, if an alternate is required, it is also advisable to obtain actual weather for the alternate. In this case, the fuel remaining at destination may permit diversion to more ports than the nominated alternate, so these could be obtained too, in order to keep our options open.

Of course, with most international 24/18hr forecasts being issued 6 hourly and some regions issuing 9hr forecasts 2 hourly, it is often prudent on longer flights to monitor any change in the updated forecast which could affect your arrival. If these show a deteriorating trend, the actual weathers can then be monitored more closely to give an expectation of the arrival conditions. This will help with Approach/Diversion planning discussed later.

Thus, the degree of emphasis we give to obtaining both actual weathers and revised forecasts enroute will depend upon the urgency of the situation on the day. Confirm that all is well without fuss on a fine day (avoiding complacency - not bothering at all!) and monitor trends on a questionable day. This trend monitoring need not commence until within reasonable range of the destination and before DPA. Simply treat the task as one of ‘Gathering’ in the G.R.A.D.E. process.

Another principle concerns the possible enroute diversion ports. Forecasts for these ports may not be provided in the preflight Qantas documentation. Some authorities require that a separate local preflight Met Briefing be given to crews and the TAFs for enroute ports may be contained therein. However, while passing these locations, a local weather observation, ATIS, or even a forecast can be obtained to have some idea of conditions should you suddenly have to divert unplanned or in an emergency. Often another flight will be heard on VHF requesting a weather you may want. You can then quickly copy it down because of your situational awareness and save bothering someone later.

To summarise, the preflight forecast covers the legal requirement for weather information. Good airmanship dictates that at least an actual weather at destination be obtained prior to DPA, with trend monitoring of actual and revised forecasts for relevant ports being obtained if the weather is questionable. Similarly, obtain weather for possible enroute diversion ports, when passing, to check their suitability in an emergency.


We are all familiar with the Performance Manual requirements for cruise flight, whether we use books and FFRATS/manual thrust on the B747-300 or an FMC on the electronic types. Thus, in the ideal world we would wait until the weight reduced to that for the next 2,000’ or 4,000' step( as required for airspace type), then climb and continue the process until descent.

It may prove to our long-term advantage to climb heavier than the optimum start weight, but normally only on the SE Asia-Europe sectors where once at an altitude, you may be able to stay there for a long time on a first come, first served basis. Only route experience gives you a feel for when to take this option. The factors mentioned earlier in CLIMB relating to temperature deviation from ISA and the Thrust Limited


Start Weight are again relevant here. Be cautious too, of the reduced buffet margins available with turbulence, and temperature inversions in the vicinity of Cb activity! Generally, however, it is far better to accept being held down and simply reduce the Mach No. in accordance with the MCC schedule for the type. The fuel loss will be small for a few hours and buffet margins are preserved. On B744 aircraft, using the PERF INIT page to change the STEP SIZE from ICAO to 0 will optimise performance at the current altitude and the FMC calculations of destination fuel/ETA will be more accurate.

Returning to our monitoring of other traffic to achieve a tactical advantage, when we know we are approaching a climb point, we may be able to manoeuvre ourselves to fit a slot at the higher level while maintaining the relevant separation standard. This may involve achieving an ETA at a certain point and/or cruising at the current or higher altitude at a Mach No. above or below MCC. The keynotes here are knowing your aircraft, the ATC system and being flexible in your thinking; the permutations and combinations are many.

As mentioned above, obtaining actual winds from other aircraft further ahead and/or at other altitudes will also assist in making a climb decision. These winds may be inserted into the FMC to provide a real time picture.

Optimum Altitude for some given weight refers to optimising NAM/Kg. Where windshear with altitude is present, better ground mileage may be had at some other flight level.


(Crossing ETA restriction on next WPT) List of options:

• Speed reduction

• Orbit or racetrack

• A zigzag track at 60 degrees to the flight plan course (ATC clearance) which doubles the track miles and elapsed time.

Carefully consider the option or combination of options which is/are safest and best suited to the particular circumstances and negotiate approval with ATC if required. When choosing the speed reduction method it is inadvisable to reduce below your optimum holding speed/ minimum drag speed (Vimd).

Note: If the speed is reduced below Vimd and turbulence is encountered, high thrust may be required to prevent excessive speed loss. Further should an actual engine failure occur, an immediate descent may be required to prevent a stall.


A quick review of cost index.

COST INDEX. The Flight Management Computer (FMC)/ Flight Management Guidance and Envelope Computer (FMGEC), as fitted, uses Cost Index (CI) to optimise performance calculations. The cost index is defined as:

Cost Index (CI) = Cost Of Time in dollars/hour Cost Of Fuel cents/pound


Cost index is used by the FMC to calculate economy climb, cruise and descent speeds and optimum altitude, for minimum trip cost. Use of cost index allows Qantas to determine the most economical speeds of operation. In addition, cost index can be adjusted to account for cost differences between routes or changes in cost structure over time.

A cost index of zero means that the cost of time equals zero. The economy speeds for CI = 0 result in minimum trip fuel; the aircraft will climb at close to the best rate of climb speed, cruise at Maximum Range Cruise Speed, and descend near minimum drag speed. High cost index values mean that the cost of time is considered to be high relative to the cost of fuel, and the economy speeds at very high CI values will therefore result in minimum trip time but an increased fuel cost.

The determination of cost index values for use in the FMC presents a challenging problem for Qantas. While the cost of fuel is a known value, the cost of time is much more difficult to determine. The cost of time includes those costs, which vary as a function of flight time, which are primarily the airframe and engine maintenance costs.

Additionally, time costs can include any components of direct operating costs accounted for on the basis of cost per hour of aircraft operation. These may include crew pay, insurance and depreciation.


An off track diversion without an ATC clearance in RVSM - RNP airspace require the use of specific procedures involving altitude deviations and prescribed track

displacement, as well as radio calls on interpilot and guard frequencies. These procedures are laid down in the onboard Jeppesen WorldWide Text / Text (as applicable) or AIP.


Good cruise management requires strong situational awareness. The professional flight crew, working as a team, will take up any opportunity to improve the overall efficiency of the aircraft operation, whilst being mindful of the primary concerns of safety and passenger comfort.




Related subjects :