Airbus - same version - different tailwind limitations

[C.M]

Why is it that different MSNs have different tailwind limitations even though they are the same models exactly ?
And speaking on the subject wind limitations is not the only difference one might find . There are Different weight limitations for example . Once when asking about weight limitations I was told that if you pay airbus accordingly they certify you for a higher weight limitation . But what is it they actually do when coming up with these different limitations?

[Denti]

It all depends what the ordering airline paid for, or any other airline that used that MSN if they wanted to recertify it. On some aircraft you actually have a sticker on the main landing gear for which MTOM version that particular gear was build, so that might have to be switched out if you want to use a higher weight.

[tdracer]

Often times, a higher tailwind/crosswind limitation, or higher MTOW is an extra cost option even though all that changes is the paperwork.
Engine companies doe the same thing with thrust ratings - a higher thrust rating will change nothing but the name plate on the engine and the rating plug on the FADEC, but it costs more money. You get more value, you pay more money.
It's called capitalism :)

[Down Three Greens]

Airbus divide the extra certification / flight demonstration costs between the ‘expected/forecast’ number of operators wanting the modification. Viola...roughly the cost for the modification.

[The Banjo]

You forgot to multiple the above result by your grandmother's age before sending the bill.

That is capitalism :eek:

[C.M]

For me it comes down to be able to use a higher level of limitation in a difficult situation - almost reaching emergency situation ( i am choosing using my words carefully because an actual emergency with not much , if any option you may override issues like these) , if i know it is well within the capabilities of the aircraft . If these limitations were somehow equipment related that we did not have then i could be adding more trouble in such a decision .

[C.M]

Airbus divide the extra certification / flight demonstration costs between the ‘expected/forecast’ number of operators wanting the modification. Viola...roughly the cost for the modification.

considering how many operators indeed fly airbus , but how reluctant they are because of the additional cost , i think its much more than a case of dividing this cost among the expected number of operators that want the extra modification . (how expensive a single demo for a particular higher certification be ? )

[krismiler]

On some types, the brakes affect the tailwind limits and one manufacturer may have a higher limit than another. Aircraft which appear identical can have numerous differences under the skin as I’ve found out when engineers tell me the flight control computers are incompatible and we can’t simply swap from one aircraft to another.

I’ve seen A320s with tailwind limits as follows for take off and landing: 10/10, 15/15, 15/10 and 10/15 depending on the S/N.

[bucks_raj]

I reckon its a EADS thiny...

On the ATR , we had 15kts approved with the AFM mentioning the same , how ever at Toulouse the ATR trainers refused to believe it saying 10 is the max ,

it was further clarified.. you get what you pay for

[tdracer]

There are many things that go into something like this. 10 knot tailwind is pretty standard and is usually part of the basic cert package. If operator X comes in and says, 'you know, 10 knot tailwind is really limiting us at xxx airport, could we get 15 knots?', Airbus (or Boeing) does a quick study to see if:
A) it's doable, and if the answer is yes
B) how much will it cost to certify.
They go back to the operator and say, 'yes, we can do that, but it'll cost you $$$'. Operator says, 'OK, let's do it' , contracts are signed, money changes hands, and before long the operator has a 15 knot tailwind capability.
Later, another operator hears that 15 knot tailwind is available and asks about it. Now Airbus isn't likely to give away to the second operator what they charged the first operator $$$ for, so they also charge the second operator $$$ as well.
Now, perhaps Airbus figures that once they have the option available other operators will purchase it, so they'll discount the price to the original operator, but that has obvious risks if no one else buys it.
Multiply that by hundreds of potential changes/options, and that's what the manufacturers regularly deal with...


(how expensive a single demo for a particular higher certification be ? ) You'd be amazed. I've been on fight tests where we had to fly 4,000 miles to do a remote test just to get to where we could obtain the needed conditions (and then the weather had changed and we had to hang around a few days to get the needed conditions - about 50 people total since we needed ground crew, flight crew, test crew, and cert people). And of course, if you need to add instrumentation for the testing, that adds up really fast.

[galaxy flyer]

And, then, take all the test data back, verify it, turn it into to usable charts, amend the AFM, get that approved by the regulator or engineering designee, have tech pubs produce and send it to the operator with any required placards, MEL changes, AMM changes, if required, like an new inspections. An OEM has lots of overhead to allocate to these offices, too.

The AFM supplement to REDUCE to TOGW on a Global, used for operations at maybe 4 airports, cost about $18,000. Steep approach (LCY) add-on, which required some repinning of the FMS and an EEC software change was on the order of $50,000. But, lots of engineering there.

[krismiler]

Airbus offer a “crippled” version of the A330 for short range use. It’s exactly the same as other A330s but for the lower price and different performance manuals. It will do exactly what any other A330 will do but isn’t legal at the normal weights because of the paperwork.

It can be upgraded at any time simply by paying for new manuals. This way Airbus can offer a lower price for specific needs without discounting normal aircraft.

[john_tullamarine]

.. more likely the demand is for lower MTOW to get a lower airways and facilities charge. Been the case in Australia for donkey's years.

[Sidestick_n_Rudder]

galaxy flyer

That actually sounds quite cheap to me, compared to the price of the plane, or eg. the cost of a type-rating...