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-   -   Full/Idle reverse (https://www.pprune.org/questions/403819-full-idle-reverse.html)

TotalBeginner 29th Jan 2010 12:31

Full/Idle reverse
 
Can anyone tell me why easyJet always seem to use idle reverse and yet Ryanair normally use full reverse? Is it something specific to the A319/B738? Are the 738's brakes more prone to wear or more costly to replace when stacked up against overall engine wear and tear? Just curious...

BOAC 29th Jan 2010 13:18

Either some personal love or hate-fest from the Chief Pilot or a question of the maintence contract comparative rates for brake wear against engine costs and fuel.

Denti 29th Jan 2010 13:23

Most probably depends on the maintenance and lease contracts. For example we use an idle reverse SOP on 737s, main reason is the brake maintenance cost is included in the aircraft lease rates, engine maintenance costs extra.

cortilla 29th Jan 2010 14:13

I don't work for ryr so not au fait with their SOP's but I'd heard that their general policy is no brakes above 100 knots and full reverse due to brake cooling schedules and quick turnarounds. Maybe brake cooling isn't as much an issue in an A319?

Right Way Up 29th Jan 2010 16:51

TB,
Easy busses have carbon brakes where wear is proportional to the amount of applications. Thus using only reverse idle saves engine wear & costs less whilst not increasing brake wear. On most A319 routes brake temps will not be an issue. Plenty of time on turnrounds to get down to a reasonable temp.

TotalBeginner 29th Jan 2010 17:23

Are all of easyJet's A319 fleet equipped with brake fans?

Right Way Up 29th Jan 2010 17:46

Yes they are.

PA38-Pilot 30th Jan 2010 19:04


Maybe brake cooling isn't as much an issue in an A319?
It's actually the other way around. The A320 brakes can heat above t/o maximums just by taxing... I've seen them over 400 routinely on many landings.

Doors to Automatic 31st Jan 2010 19:56

Not sure how much truth there is in the rumour but I did her once that Ryanair use steel brakes on their 737s (as opposed to carbon fibre) as they are cheaper.

On-MarkBob 7th Feb 2010 19:13

Modern Carbon brakes are much more efficient than the old sintered metal brake units. They operate best when they are hot, but most importantly the brake ware is also reduced when the brakes are hot. The resins that bind the carbon is baked 'on the wheel' so that when the brakes are cold they ware much quicker. Easyjet are correct to use this method as it allows the brakes to heat quickly after touchdown. The price of a carbon brake pack is very cost effective for the time the unit is on the wheel and the applications used, if they are operated properly. I don't know what easyjet do but many operators now lease the brake units and pay a fix cost depending on the way they operate. Easyjet might pay a sum dependent on the use of Autobrake level 3, for example.
However, the biggest saving of all comes from FOD (Foreign Object Damage). The cost of engine damage is now far greater than using the brakes. Full reverse should never be used unless it is absolutely necessary as the chance of ingestion of foreign matter into the engines is hugely increased with reverse thrust.

CheekyVisual 7th Feb 2010 21:28

FR SOP is not full reverse but use of revese thrust appropriate for landing performance in order to keep the brakes cool for quick turnrounds. Idle reverse suggested on last flight of the day only.

Other operators have other SOPs. Baby I believe want idle reverse when appropriate and safe and I believe Easy is similar. There is less of a brake temp issue on the 73 classics as the 300 is smaller and lighter than the 800 with a slower landing speed. Not sure about the bus, because, I've fortunately never had the pleasure.

Capt Scribble 7th Feb 2010 21:59

Fuel cost and thermal shock on the engines are also given as factors in the decision whether or not to use TR.


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