Crew autonomy and cost index

[Will]

Assume you have a long haul flight that's set up by your dispatcher to use CI 120.

Next, assume you have a broken widget flange that needs fixing, and it takes the mechanics 30 minutes to swap out the broken part. You will depart 30 minutes late.

Now, you have the choice of making up the time by flying faster (CI 300, for example), or just sticking to the preflighted CI 120 and arriving late, all other things being equal.

Who makes the call about flying faster? Is it entirely up to the crew? Or would the crew need to get "permission" to fly faster if that's what they wanted to do? Or is this totally out of the crew's control, and instead dictated to them by the dispatch office? ("Hey guys, you need to stick to CI 120 on this trip and arrive late, happy landings.")

I remember reading a post from a 744 pilot on this forum a few years ago that the crew would move the CI around to try to arrive at the scheduled time, to make up for delays, and to make things easier for the arrival airport, etc. Is that common?

[Mariano]

Will,

Speaking only about our operation, here, as I am sure that this varies greatly with operators and individual crews.

Once we estimate or are told that we will be late, we send a departure delay message to Dispatch via ACARS, stating the estimated out and off times, fuel onboard and reason for the delay. Should they want us to alter speed from the OFP, they would make the call then, run a new plan and send it over (condensed format via ACARS if changes are not many, or a printed regular format one via the station representative if the changes are significant (i.e. new route because of new winds). The vast majority of times that we have departed late, we flew the original plan.

Most of the crews fly the planned cost index, but very few speed up once inflight if showing excess fuel on arrival, even if on time (mostly in order to arrive at the hotel before breakfast is over, or to catch a flight home if on their last day ;-). We are required to contact Dispatch for an inflight reanalysis if we fly at altitudes different from planned by more than 4,000 feet or if we deviate from course by more than 100 nm.

Because of the many operators and customers for whom we fly, contacting Dispatch for things that might alter planned or estimated (delayed) arrival time is the wisest course of action due to gate congestion, even if runway congestion is not an issue. Plus, if you fly the plan, you will be safe and have less questions to answer should something go wrong and they start looking for someone on whom to pin the blame.

On some occasions, as when flying to Sydney where arriving within a very specific window is critical, contacting Dispatch takes on a whole new level, even if showing a late arrival, as they might have gotten approval from Sydney for the new late arrival time and arriving early would end up causing problems (and a hold). (Flying to Sydney, by the way, is when the RTA function becomes quite useful).

Best regards,

Mariano

[emerydc8]

I don't know if the difference here is between a flag operation (Mariano's employer) versus supplemental (my employer), but to think our "dispatch" (actually flight following) would even know what cost index we were using at any particular time (or whether they could even check) is a major assumption. I rarely use the cost index given on the flight plan.

Lately, since the weights have been so high in the DHL system, they've been giving us flight plans with 130+ CI which increases the likelihood that we'll hit the overspeed sometime during the flight if we fail to intervene -- probably on climbout. For that reason, I normally insert 60 and then fly with the speed window open during cruise because we are usually late and I'm trying to make up time by pushing it as close to the BP as I can. Thankfully, our flight followers have never asked me to use a higher cost index when late, and since DHL is paying for the fuel, I've presumed that they want to get there as close to on-time as possible rather than conserve  fuel.

There is greater control of the speed with the speed window open rather than allowing VNAV to control it. This is especially true when the speed gets slow. VNAV will allow you to get unacceptably slow (in my opinion) before it tries to get back on speed; and probably for that reason, on oceanic flights, when assigned a mach number in a clearance, we usually don't use cost index to control the speed -- we insert the mach into the VNAV page or better yet just speed intervene. As for having to report a difference in altitude or deviation from course or ETA, for us it's only for B44 flight plans.

There are some pilots who constantly seem to be contacting fight following and bothering them with all kinds of minutiae that they don't really care about. My philosophy is not to get them involved with anything unless it's absolutely necessary. In my view, the more you ask them how to operate the airplane or lean on them for guidance (e.g., can we speed up?, is there any weather ahead?, something broke in flight, etc.), the more authority is taken from the PIC and given to people on the ground.

Just my 2 cents, FWIW.

Jon

[skelsey]

For one particular operator the guidance is that extra fuel should not be loaded purely for the purpose of flying faster, unless specifically requested by Flight Ops. However it is acceptable for contingency fuel to be burned for this purpose.

Early arrivals in some instances can be just as problematic (curfews, availability of stand/handling resources etc) and if a particularly short flight time is expected crews are encouraged to delay startup, taxi as slowly as possible and fly slowly in order to meet the target arrival window (typically around STA to STA-15).

[DougSnow]

As a major scheduled US cargo operator it depends. If its a weekend where making a service commitment is less critical, we'll eat it. If its a critical service commitment, we'll bump the CI up to make time if possible. I dispatched a 15 hr flight at max CI (CI-800) to save 25 minutes to at least plan for a near ontime arrival for an international ultra long haul leg (B777F). Burned a crap ton a gas to save those 25 minutes, but that's what ops control needed as the aircraft had a min turn at the destination.

[Will]

Doug, it sounds like this is dispatcher-dependent in your airline. What if the crew did this on their own? Say they saw they had enough fuel to fly faster and bumped up the CI on their own to make up for a delay. Would that be ho-hum, or would it get them sent to the chief pilot's office for a stern talking to?

[DougSnow]

Doug, it sounds like this is dispatcher-dependent in your airline. What if the crew did this on their own? Say they saw they had enough fuel to fly faster and bumped up the CI on their own to make up for a delay. Would that be ho-hum, or would it get them sent to the chief pilot's office for a stern talking to?

Nahh - our flight plans identify the add fuel burn for various CIs. But the goal is if the captain wants to something different than the plan, lets talk about it and I can cut a plan so we're both on the same page. Unlike Jon's airline, we're a domestic/flag air carrier, which means I share 50/50 operational control with that captain. At Jon's carrier, under supplemental rules, the dispatcher under regs has no real responsibility to an individual flight - the responsibility for operational control is shared between the Director Ops and the PIC.

Because I share 50/50, we are required to go Jumpseat in the cockpit annually, for example last year I went to Paris via Tokyo; this year due to the bug I'll probably do a sim.

Here is a sample of what that looks like - for a 777F.
                         OPERATIONAL IMPACTS
                         -------------------
FL CHANGE           UP 1 FL        BURN P0.2      DIFF    +02
---------           DN 1 FL        BURN P0.5      DIFF    -04
---------           DN 2 FL        BURN P1.7      DIFF    -07
WEIGHT CHANGE       UP 10000 LB    BURN P2.4      DIFF    -01
-------------       DN 10000 LB    BURN M2.6      DIFF    +01
SPD CHANGE          CI 0           BURN M1.5      DIFF    +13
----------          CI 150         BURN M0.7      DIFF    +03

[Jeroen Hoppenbrouwers]

Up 1 FL: -- is that 100 ft, 1000 ft?

[DougSnow]

1000 ft

[Will]

Okay, that makes sense. Thanks.