Oct 18, 2007

A Day in the Life (28) Set…

A description of a typical day's flight from Montreal to Vancouver and return - as a backdrop for a detailed, non-technical description of what an airline pilot does. (check left hand column for series index).

Log Entry 2003 - A320 Capt - TOD (Top of Descent)
Time: CYVR Arrival minus 0H30M

“GooseAir one eleven requesting descent.”

Vancouver center responds with a clearance to flight level 200 along the expected CANUCK STAR. F/O Paula dials in the altitude which confirms she also got the message.

The green hockey stick slides into the center of the nav screen track as she pushes the ALT knob on the autoflight panel. “Flight Level 390 for 200. Descent managed…” The Nav screen mode annunciator changes to signal the trolls have received the message, and we hear the sounds of engine power reducing while the banks of engine indicators shift accordingly. It used to spook me that with all this going on the thrust levers never moved, but I’m used to it now. I draw my cues from secondary indicators of engine thrust such as the background noise and the sounds of cabin air conditioning.

The nose smoothly pitches down, but not quite fast enough to prevent a small loss of airspeed. Sometimes pilots will ‘fiddle’ by using vertical speed mode to begin the descent while staying on the speed profile. Today FO Paula doesn't bother because she knows something the computer doesn't. She can see the clouds below and is already planning to use engine anti-ice during part of the descent. The speed and flight profile will be affected by the extra thrust produced in keeping the engine cowls warm.

“GooseAir one eleven leaving three nine zero for two zero zero,” I announce into the mike. Vancouver center responds with a curt “Roger,” between other transmissions.

After the buildup of activity, there’s now a lull and I use it to speak to the passengers. I make a few quick notes regarding our arrival time, and the latest weather, then I pause for a breath and to assume my “captainly P.A. voice” before beginning. And just before keying the P.A. mike, I double-check that the proper button is pushed on the audio control panel. Many a pilot has given his best announcement over the VHF channel and payed the price of having to listen to the caustic remarks of colleagues. “Nice announcement, now you’d better push the p.a. button and tell the passengers!”

A cloud layer hides the mountains below, and turrets of cumulus jutting above the general stratus deck tells us the ride will get rough again. I include an appropriate comment and flip on the seat-belt sign. Just as I finish the announcement and hang up the P.A. mike, I see the datalink printing out a long list of connection gate information. Ringing for Connie I make sure she knows about the chop during descent and pass the connection message to her so she can include this in her announcements. And then I tap in a few more codes to pull up the latest weather reports for Montreal.

As suspected, the visibility is now dropping rapidly and the newest forecast (still amended) is calling for one eighth of a mile visibility in blowing snow for the time of our arrival later tonight. I underline a few key phrases in the report and offer it to FO Paula. “Should be fun going home.”

My next chore is to send a message to Flight Dispatch telling them we will be looking for as much fuel as possible for the return flight. I know we will be close to gross takeoff weight, so there won’t be room to carry much extra. But every bit counts tonight and might make the difference between landing at Montreal, or diverting to the alternate. And while I'd like to use Ottawa, the closest airport, their forecast doesn't look very good. Keeping enough fuel for Toronto will shorten our available holding time over Montreal. Compromises, compromises.

We’re nearing our target altitude. Time to check with ATC for further descent so I key the mike again.

Time: CYVR Arrival minus 0H15

6 comments:

Anonymous said...

Great to see you are back with the "All in a days life of an Airline Pilot". Please do not make us wait so long for the next installments.

dan said...

Welcome back Captain! Looking forward to the final instalments.

Is the Montreal - Vancouver route your standard flight, or are you typically flying all over Canada and US?

Aluwings said...

Hey Dan - basically a pilot's routes will depend on the aircraft he or she is assigned to. The A319/320/321 does a lot of transcons as well as flights to the Caribbean and all over the US and Canada. The longer flights tend to be favored by the senior pilots as we get more hours of actual flying (i.e. Pay time) for each day we're at work.

Soaring Student said...

Great to see this story picking up again. Thank you.

A question regarding the thrust levers: I had a 320 jumpseat ride from PHX to YYZ pre-9/11, and saw there was basically two rotary knobs that were the primary inputs to the autopilot during cruise, one for each of altitude and direction. What happens if you crank the altitude setting knob to descend, Otto sets the engine power at a much lower setting than the physical position of the levers, and then you dis-engage Otto? How do the levers and the actual thrust setting get resynchronized?

Aluwings said...

RE: How do the levers and the actual thrust setting get resynchronized?

That has been known to cause some of those "training moments" in the flight deck when the automation suddenly starts doing something we didn't expect.

If the auto-thrust is disconnected with a large discrepancy, a thrust surge will occur (ask me how I know!) ...

Usually, we move the thrust levers to align them with the actual thrust before we hit the "instinctive" red button. Small donuts on the power gauge help us do this.

In case of an auto-thrust failure/disconnect for other reasons, a condition called "Thrust Lock" kicks in and freezes the current thrust setting until the pilot has a chance to re-sync the levers, then clear the "Thrust lock" condition.

And when the thrust levers are pulled all the way back to idle setting, auto-thrust disengages and the engine power reduces to match the commended setting.

As with a lot of the magic on the bus, it can cause some 'oops' moments while learning, but in actual practice it works well.

Aluwings said...

... a green hockey stick...

I should probably explain that this is the nickname given to the "top of descent" symbol on our track line. It is obviously meant to picture the transition point from cruise to descent, but what else would Canadians call a symbol comprised of a short line with an angled end on it?