Thx... How does it affect brake temps and ability to vacate A, or B on the 320? I've always thought distance to vacate is a bit short-ish for F3... |
''Brake Fans usually end up on for the 320s anyway as we have a SOP that they must be on whenever there is an arc on the temps.''
Well, the cost of doing that will absorb the 5kg of fuel savings immediately! Or is it necessary to achieve fast turnarounds? |
Actually the SOP EcamSurprise is mentioning is an SOP for TAXING OUT to prevent hot brakes in the air. It is crew discretion taxiing in:
When turnaround times are short, or brake temperatures are likely to exceed 300 C, use brake fans, disregarding possible oxidation phenomenon. |
Dan winterland, EZY don't pay for individual brakes. As such we don't care about brake wear. Until the maintenance contract gets reviewed that is. So althoigh there is a cost, easyJet don't pay for it. At least it doesn't show in the spreadsheets:ok:
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Stuck in ATR has made a reference to Airbus presentation on overall cost savings if Flaps 3/Rev Idle is used. The jist of the presentation is - use Flaps 3 and Rev Idle ONLY if you are able to vacate at the suitable or designated exit (with shortest taxi to your bay) with the use of AUTOBRAKES LOW. If you have to use Med or harsher manual braking the break wear offsets the fuel savings of 7 kgs(for 320). All the saving figures quoted earlier are all paper calculations, assuming that they save 6 to 8 kgs per landing with Flaps 3. What they have not calculated is the additional payment the airline has to make for brake wear. In last one year of operations with Flaps 3 in our airline, the management guys in Flt Ops have showed a saving of 2 million US$ due to use of Flaps 3 and in the same period the Engg Dept has shown an additional payment of 6 million US$ due to excessive brake wear. Moreover, the guys calculating the fuel saving do not cater for additional taxi time due to "next exit" vacation. At 11kgs/min any additional taxi would result in net loss to the company.
Lastly the FDM data for 320 fleet has indicated that the number of hard/firm landings have increased with use of Flaps 3 and the number of cases of high pitch at touchdown (>9deg) have also shot up. Vilas you may be a gifted pilot but for an average line pilot the landing 'g' has shown an increasing trend with Flaps 3. |
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You guys should pick up the FCOM rather than giving distorted opinions.
The brake fans are NOT to be used whenever the arc comes... Where do you guys come up with this rubbish?! :hmm: |
Originally Posted by Vilas
The aircraft is already almost in landing attitude a minimal of flare and you get a greaser.
I liked the crack by Airbus at pilot costs for extra taxi time. On my jalopy, one minute extra taxi uses far more fuel, cost-wise, than the drivers get paid! |
It's nothing to do with the FCOM, but a reaction by the company to some issues of hot brakes warnings in flight which required re-lowering of landing gear. Hence, the company standard SOP is a more restrictive 'Use on taxi-out when an arc appears'.
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Cap'n blogs..
The flap 3 approach is at a higher speed, so the elevator is more effective-hence we feel like we flare less in order to achieve the landing attitude. In addition to this, as the power is chopped prior to flare you loose less speed during the flare hence the wing works a little better... Fans... Our FCOM PRO after landing procedure states that fans aren't to be used unless temp is going north of 500C or turnaround is short.. Taxy out is as above whenever the arcs are shown. |
"Vinayak" "You guys should pick up the FCOM rather than giving distorted opinions.
The brake fans are NOT to be used whenever the arc comes... Where do you guys come up with this rubbish?! http://images.ibsrv.net/ibsrv/res/sr...lies/yeees.gif" You mean we should read our manuals which state the following: During taxi out, if an arc indication appears above the brake temperature on the ECAM WHEEL page set the brake fans on. The maximum certified brake temperature prior totake-off is 300°C. In circumstances when brake temperatures approach this limitation, the recommended procedure is to use brake fans to reduce the temperature to 150°C. |
Airbus driver ... I think he is coming from the angle of during taxy in...
Hence you don't put them on whenever you see the arc! |
I wasn't sure if he was talking about on the way in or out!
Here is the SOP for the way in: Check brake temperature on the ECAM WHEEL page for discrepancies and high temperature. Brake fans should be used to manage brake temperatures, ideally brake fan selection should be delayed for around 5 minutes (to allow thermal stablisation) or done just before stopping on the gate (to prevent blowing carbon brake dust on ground personnel), whichever occurs first. When turnaround times are short, or brake temperatures are likely to exceed 300°C, use the brake fans, disregarding possible oxidation phenomenon. Refer to FCOM PRO-SUP-32 for the brake temperature limitations requiring maintenance actions. |
Does the break even point include the taxi routing or just the additional required runway when landing flaps 3?
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easyJet have conducted studies at certain airports (LGW) to calculate the specific breakeven point for F3 v FF and the associated taxi routing to stand.
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Capn bloggs and Casper 63
What I suggested is valid for all aircrafts. I have landed A300,310, 320 and 747 with the same technique and with the same results.Flap full has all drag hardly any lift so if you flare same amount with flap3 you tend balloon, actually that is the only way to mess it up, the other problem is with those who habitually flare high then the attitude will become higher at touch down.otherwise it easier, gives better control and has better go around performance. It is for these reasons reccommended in gusty wind conditions. I am really surprised at the apprehension that is being expressed. |
Vilas, fair enough, but unless one is regularly doing a good mix of both full flap and partial flap landings, one will probably end up with the results that Casper has pointed out unless of course they have stick and rudder skills like you and I. :}
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Vilas, I fully agree with you that after logging more than 20,000 hours on 300, 310, 747 and 320, landing 320 with Flaps 3 is a piece of cake. However, nowadays pilots get to land an Airbus 320 with a total time of 300 hrs with 200 hrs on Cessna 152. That is the reason why even Airbus document also state in RED INK that to maximize safety margin Full flaps landing is preferred.
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casper63
With all the automation, doing consistantly smooth landings within correct distance is the only seat of the pants skill left. However executing safe landings should not be a problem. If a pilot cannot do acceptable landing in flap3 he will not be doing good landings in flap full either. I suggested before pilots can be explained the technique and introduced to flap3 in the SIM. Pilot who is apprehensive of normal flap3 landing what will be his mental state landing in direct law with failures and conf3? to get acceptable landing all you have to do is flare and close the thrust. From ROD of 750ft/mt to appx.350ft a mt. which is even acceptable overweight landing. Full is preferred only from landing distance point. |
I got you to open your FCOMs, didn't I? :}
http://pilotpitstop.com/docs/Externa...akes%20Use.ppt Here's another useful something... |
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