Odd A321 Take Off

[phllax]

My brother was on 29 today from PHL-SFO. PHL was using the 27's, with departures using 27L in the pouring rain.

My brother told me that the pilot came on and said that they would be using 27R due to its longer length than 27L and performance issues with the 321. My brother estimated that they used almost all of the runway, as they were still on the ground well past the end of the UPS facility.

Then after no more than 15 seconds in the air, they throttled back and had a slow 15 minute climb to 10,000.

We all know that the 321 climbs slowly, but with the weather being what it was, why did the pilot throttle back so quickly? I've been on my fair share of 321's and while they usually throttle back shortly after gear up, some have kept the power up longer due to wind and rain conditions.

 

[george]

Had to take SWA home tonight and they did the same thing. At first i thought something might be wrong, but it eventually went into a climb. It seemed like forever. Anyone know whats up?

 

[BoeingBoy]

My brother told me that the pilot came on and said that they would be using 27R due to its longer length than 27L and performance issues with the 321.

Somewhat odd since 27L is about 1000 ft longer than 27R. Maybe there was some temporary restriction limiting the usable length of 27L. Alternatively, there may be some obstruction in the departure plane of 27L that requires a higher climb rate that they couldn't meet - my manuals are at the airport so I can't check.

Then after no more than 15 seconds in the air, they throttled back and had a slow 15 minute climb to 10,000.

I've never timed it, but 15-20 seconds sounds about right for climbing to 1000 ft above the ground. That's where we normally set climb power (throttle back) and begin to retract the flaps.

Anecdotally, all the 320-series climb poorly. No matter which model we take off behind, we're always climbing above them by around 20,000 ft.

Jim

 

[US1YFARE]

The same thing happened this afternoon to SFO. The pilot said we were too heavy. I thought it was because of the senior FA's onboard.

 

[PHL]

27R is 9500', 27L is 10506'. The UPS facility is actually just beyond the end of 27R (across the field), so it seems that your brother probably was cruising down 27L, where the UPS facility is just about 1/2 way down the runway.

The A321 is definitely a slower climber than the 757, but according to ATC logs, the flight took only 6 minutes to reach 10,000 feet. Looking at this flight logs for the last week, it has consistantly taken 6 minutes to reach 10,000 feet.

http://flightaware.com/live/flight/USA29/h...L/KSFO/tracklog

This isn't meant to discredit your brother. But these are the facts. Sometimes people have perceptions of an event, even as its happening, that are not necessarily a true representation of what's really occuring.

 

[US1YFARE]

No, see my post above, other than the FA comment, our flight to SFO did the same thing. We actually had to wait for about 10 planes to land and then we could get onto the runway. The pilot said we had too much weight. the flights were PACKED today. Maybe that is why they started serving us salad?

 

[FLYAWAY]

The 320 series transitions to a climb speed of mach .78 which is faster than the cruise speed of the 737. The climb rate is insignificant...the time to destination is the issue.

Somewhat odd since 27L is about 1000 ft longer than 27R. Maybe there was some temporary restriction limiting the usable length of 27L. Alternatively, there may be some obstruction in the departure plane of 27L that requires a higher climb rate that they couldn't meet - my manuals are at the airport so I can't check.
I've never timed it, but 15-20 seconds sounds about right for climbing to 1000 ft above the ground. That's where we normally set climb power (throttle back) and begin to retract the flaps.

Anecdotally, all the 320-series climb poorly. No matter which model we take off behind, we're always climbing above them by around 20,000 ft.

Jim

 

[BoeingBoy]

Absolutely, the 320-series takes more time to accelerate to climb speed which means longer at a low climb rate while accelerating.

But silly me - I thought fuel burn might enter into the equation. Get to altitude quicker and burn less fuel. Especially when the speed difference is only worth 1-2 minutes per hour.

Jim

 

[flyin2low]

The 320 series transitions to a climb speed of mach .78 which is faster than the cruise speed of the 737. The climb rate is insignificant...the time to destination is the issue.

What's the hurry? You get paid for the sched or greater block.

 

[A320 Driver]

Absolutely, the 320-series takes more time to accelerate to climb speed which means longer at a low climb rate while accelerating.

But silly me - I thought fuel burn might enter into the equation. Get to altitude quicker and burn less fuel. Especially when the speed difference is only worth 1-2 minutes per hour.

Jim

The 737 does climb a little better than an A320. An A319 weighs about 20,000 more pounds empty than a B-737 but burns about the same fuel or less on a longer stage length due in part to it's having better altitude capability than our 737 300/400s. True it climbs slower but it always cruise climbs anyway. Also, that A320 your outclimbing might weigh as much as 169,000 lbs.

Happy flying Jim

A320 Driver B)

 

[BoeingBoy]

Happy flying Jim

A320 Driver B)

Same to you. I just like to rib the "Busdrivers" once in a while.....

Jim

 

[Seatacus]

I've never timed it, but 15-20 seconds sounds about right for climbing to 1000 ft above the ground. That's where we normally set climb power (throttle back) and begin to retract the flaps.

I wonder why you wouldn't throttle up and get to altitude as quick as you can. Isn't it safer to have more space between you and the ground just in case of anything going wrong (like losing an engine).

 

[BoeingBoy]

We're supposed to be able to handle loss of an engine - even if the engine quits an the runway at/after V1 (the speed at which we're to continue the takeoff because there's not enough runway left to stop). We get to do it once a year in the sim (and that's the only time if we're fortunate).

All these 2-engine planes will fly pretty well on one engine since they have to meet the same engine-out performance criteria as planes with more than 2 engines. You could honestly say they're somewhat over-powered by design.

It's partly driven by dollars and partly by noise.

If you think going to climb thrust at 1000 feet is bad you would love the old days in the 727 leaving DCA - pulling thrust back to well below climb power at 1000 feet plus making the turn to follow the river to the northwest.

Jim

 

[Art at ISP]

One thing I have noticed on the 320 and on the 319 sometimes is that there is little perceptible difference between takeoff and climb thrust (at least in sound). The 321 usually has a pronounced power reduction which is quite audible. On the 320 and 319, sometimes you don't even perceive a pitch change in the engine sounds when reducing to climb power. At gross weight is climb and TO close or the same?

Also, I thought the 319 climbs pretty quickly--on a 13 departure from LGA with a left turnout it is sometimes at 10,000 ft just past the GW bridge turning southwest bound.

Then again I am no expert.....

 

[supercruiser]

In an airline jet, you take off at "take off thrust" and usually at 1000' above the ground (sometimes higher at certain airports or in certain conditions) thrust is reduced to climb thrust, and that's where it stays until you level off. All airlines also use reduced thrust takeoffs when runway length and aircraft load permits, which saves engine wear and tear. Reduced thrust takeoffs are calculated using assumed higher temperatures than actually exist, so a lower takeoff thrust setting(sometimes climb too) is used. If an emergency occurs or weather conditions dictate, the thrust can always be instantly pushed up to the higher maximum setting.

As far as feeling an exaggerated "throttling back" to climb thrust in the A321, that model is super sensitive to thrust setting changes from the takeoff setting, compared to the A319 and A320. So it's much more noticeable when going from takeoff thrust to climb thrust, unless it's done very slowly, which most pilots try to do. A relatively low initial level off altitude on departure (2 or 3 thousand feet) would probably give you the same feeling.