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-   -   Transition from A320 to A321 (https://www.pprune.org/tech-log/269447-transition-a320-a321.html)

flyboy320 25th Mar 2007 05:23

Transition from A320 to A321
 
What is important to know when moving from the 320 to the 321. Anybody has some hints and tricks for the transition?
I heard the A321 is more stable compared to the smaller ones.
What about landing and flare?
Thanks everybody!

Wingswinger 25th Mar 2007 07:16

Feels better, flies better, lands better.

Longer by 6.9m so you need to steer more to the outside of turns to keep mainwheels near the centreline of taxiways.

Keep take-off rotation rate steady 3 degrees/sec - don't snatch it off and avoid sudden increases off pitch rate at 8 degress - you'll bang the tail.

Don't get slow on approach or any where near 9.5 degrees nose-up in the flare - you'll bang the tail again.

If heavyweight on take-off you need to be careful around F+1 limit as S speed can be above 210kts - best to have the A/P engaged, it's tuned for a two-stage acceleration to hold the aircraft at 215kts until the flaps are in.

F2 limits same as F1+F, 215kts; F3 195kts; F Full 190kts.

Some technical differences eg jet pumps for the centre tanks.

That's about it.

Dream Land 25th Mar 2007 08:12

You will enjoy the 321, all that was posted is true but I think the only thing you really should know is the difference in energy management, if you are landing at 70 tonnes and higher, you will definitely notice a difference in handling, mainly that if you are a little high, doing the normal A320 maneuver could get you in trouble, yes it will go down when the speed is dialed up, however it is another story getting it to slow down :eek: , in locations where I dive the A320, I will instead, slow down and configure when in the A321. Enjoy the smooth landings.:ok:

airseb 25th Mar 2007 13:05

i'd say that another big difference is the x-wind landing. because of the longer fuselage and the differences in flap design, the ailerons perform a little differently. mainly our sops recommend flap 3 with high x-wind and very turbulent landings.

nice transition

seb

flyboy320 25th Mar 2007 20:48

.....thanks guys, these all are really useful infos :ok:
.....and yes, i want smooth landings again
Happy Landing:E

DesiPilot 26th Mar 2007 14:17

I agree with all, I find 319 a bit squirrely compared to 321. While taxiing 321 needs more initial thrust compared to 319/320. Also be careful when doing a managed descent if you are high, the speed tends to get very close to Mmo at high altitudes.
Oh and enjoy the quiet flight deck.

Dan Winterland 26th Mar 2007 16:01

The wings are the same as the 318/19/20 and therefore not big enough for the job - it struggles at height. And you can take full airbrake with the AP engaged, but it's only as effective as half airbrake in the 320.

Tip: Manually input VAPP as computed plus a few as you will often find the FMC computed VAPP as being too close for comfort to the FAC computed VLS. And the AT is too slow to react on gusty approaches, so consider manual thrust to save that embarrasing conundrum below 100' as your speed reaches VLS.

It's a classic case of an aircraft being developed just past it's max potential.




And you get bad botty smells on the flight deck from the fwd toilet! :yuk:

fantom 26th Mar 2007 16:09

I was tempted to say exactly that; Dan has got it right. The wing is too small for the job.

Two hours at FL290 before you can climb.

Great.

Dan Winterland 27th Mar 2007 02:26

Much has been said about tailstrike. The statisitics (UK AAIB) show that the most likely scenario for a tailstrike in a 321 is a slow approach followed by a float, or a boucne after touchdown. The pilot thinks he is descending too fast and tries to arrest the rate of descent increasing the pitch angle.

BEagle 27th Mar 2007 06:20

I'm intrigued to know why the FMC computed Vapp is evidently too low?

FlapsOne 27th Mar 2007 07:34

It sometimes is.

The FMGC is based on a prediction/calculation that takes into account the crew inputs.

The FAC works 'backwards' using aerodynamic data to produce it's figures.

There's no real conundrum below 100'.
VLS isn't the end of the world, and indeed is a long way above it.
If you move the Thr lvrs out of the detent below 100', the A/THR disconnects - no big deal really, as long as you know it's gonna happen.

Right Way Up 27th Mar 2007 08:07


VLS isn't the end of the world, and indeed is a long way above it
Flaps, from what I remember in the A321 it was. :ouch:
It is quite different to the A319. When you get to fly the A321 I would fully recommend never getting into that scenario.

DME MILOS 27th Mar 2007 17:32

What is important to know when moving from the 320 to the 321.
 
The walk round takes longer :)

tuan74 27th Mar 2007 20:08

Harder to climb:\

Much harder to descend and decelerate..:*

Tree 28th Mar 2007 02:49

Dan is correct. The 321 is very undersized in wing area and the performance is anemic.

Capt Chambo 28th Mar 2007 04:26

In addition to what everyone else has posted may I add...
Simpler fuel system.
Simpler electrical system particularly when into non-normal phases.
Config 2 is much better. No "ballooning" on selection and much "draggier", which helps get the speed off.
Simpler to load and keep within the envelope, when full.
It's been some time since I flew them but that's what I remember.

Bearcat 28th Mar 2007 14:35

careful using speeds brake twds green dot when heavy....vls will charge thru your speed....stow speed brakes , select flap one and then use speed brakes again....vls is covered. This is what I do esp in th London TMA if I'm back at 220 and I need to get down.

TE RANGI 28th Mar 2007 22:25

Two different aircraft with the same cockpit and SOPs.

On the 321 I always crosscheck the FAC GW against the loadsheet. With a full payload with JAR weights you may find you're actually 1 or 2 ton heavier than the loadsheet. Keep that in mind for the approach speed.

As a matter of fact many guys edit Vapp by adding 2-3 Kts. I strongly recommend that. Otherwise you may find your Vapp very, very close to Vls, and the autothrust may be kinda slow in short final. It will do nothing to your ldg dist and you'll greatly reduce the risk of a tail strike upon ldg.

If you want a greaser just relieve a modicum of back pressure on the sidestick as the mains touchdown. The trick works much better than on the 320.:ok:

And thank god we don't get any lav stink in the cockpit on ours.

Dan Winterland 29th Mar 2007 13:39

Quote BEagle: "I'm intrigued to know why the FMC computed Vapp is evidently too low?"

The FMC takes it's speeds from the information input in the Init 2 page from the loadsheet, or from the fuel prediction page if the engines are running. Loadsheets are based on notional weights, and even in Asia where I fly, those are a bit behind the times. The FMC computes the Gross Weight from the fuel quantity and your V App is calcualted from the FMC figures. However, Green Dot, VLS, V Alpha Max and V Alpha Prot are calculated from the FAC which calcualtes the Gross Weight from angle of attack and IRS data. The FAC always thinks you are heavier in the A320 series and this is particularly pronounced in the 321. Today I flew one where the FAC weight was 3.6 tonnes more than the FMC weight, and this value is not unusual.

I always increase the V app manully by 1 knot per tonne with a minimum of 3 knots. I find this works well.

And the 'below 100' conundrum'. Easily manageable in a 320, not so in a 321. The 321's throttle response (V2500) is sadly lacking. The best policy is to set manual thrust before you get to 100' in gusty conditions IMHO.

TE RANGI 29th Mar 2007 14:35

Ditto, Dan. 100% agreed.

The worst scenatio on short final is being a little high on the last couple hundred feet. As you dive to regain the GSlope the Autothrust reduces thrust to keep the speed, and so you arrive very near terra firma with a bit of a high sink and the autothrust IS slow in adding power just when you reach the flare. But by all means, avoid the temptation to pull the nose to arrest the sink. Better to arrive like a load of bricks than scrape the tail.


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