Radar Separation for the A388
 

The FAA has recently told US ATCO's that approved radar separation for two A388 is three miles. My employer (The FAA) believes that an A388 following an A388 on a localizer should be spaced 3 miles apart but if the A388 is following a B757 it should be 4 miles in trail :ugh:. We are being told this separation minima is the ICAO standard. What does the rest of the world use? Thanks

HM79,

Are you talking about radar separation, in which case it does not matter what type of aircraft it is, or wake turbulence separation?

In the UK, A380 followed by;
i) A380 is 4nm,
ii) Heavy (747, 777, 340, 330) is 6nm,
iii) Medium (757, 737, A320 family) and is 7nm.
and so on.

The rest of the world are shaking their heads about the obvious absence of common sense in your management....but then, why should yours be any better than ours.

SKYbrary - Airbus A380 Wake Vortex Guidance

Interesting to see that the 757 is still considered MEDIUM in England, in Germany it´s HEAVY.

In the UK, the 757 is Upper Medium, so some separation standards do differ, but in the case of it following a Heavy/Super it receives the same separation as other Mediums, hence why I lumped them all together in the earlier post.

ICAO PANS-ATM does not require wake separation where the following aircraft is an A388, regardless of what's ahead of it.

Today I was told the UK will adopt ICAO wake turbulence separations for the A380 ie A380 or 747 following A380 = 3nm etc.

When did the ICAO wake separation between a Heavy following an A380 come down from 6nm to 3nm ?

In Spain, B757 is HEAVY, and until very recently, B737-800 was as well considered HEAVY.

Not sure about 388 though, i´ll look it up.

Chevvron, current ICAO or what is called RECAT?

Look on the bright side, no need for TEAM 0600-0700, now you're going to be able to get twice as many heavies down on a single runway, allegedly. :O

Australia has 6/7/8 for H/M/L behind Super. Super has no wake turbulence standard applicable as the following aircraft. B757 is medium but treated as H if lead aircraft.

Currently applying wake turbulence separation behind super on parallel runway at YSSY when following aircraft is <25,000kg mtow as a result of this...
Fright in wake: Airbus in scare with turbo-prop at Sydney | Crikey

Just for completeness since nobody has mentioned it yet but a Heavy followed by a Super (in the UK) requires 4nm too.

Yes, though we're told in post #6 that the other way round - a Super followed by a Heavy - is going to require only 3nm.

I'm still trying to understand how that will work.

I'm sorry to say it must be an error on Chevvron's part.

I think I'm right in saying that ICAO gives no minimum wake separation for an A388 following any other traffic, be it another A388 or a Heavy. Chevvron may have heard that the UK plans to drop the current UK requirement for wake separation when the A380 is the following aircraft but it would be news to me.

Frankly, it wouldn't be particularly helpful since current A380 runway occupancy would dictate that an A380 3nm behind another would 90% of the time (opinion!) result in a go around. An A380 following a Heavy at 3nm wouldn't be foolproof either...

Hangten - Agree 3nm separation between A388's or any two heavies increases risk of go-around due increased runway occupancy times

"A388 land after the vacating 747" should work on most days...

Here is the SAFO from the FAA. http://www.faa.gov/other_visit/aviat.../SAFO12007.pdf

Current Wake Sep at Threshold. Super to Super is 2.5nm

Under RECAT Super to Super is MRS (which for most airports in the US is 3nm)

Perhaps ICAO is following the FAA RECAT in which case, Chevron would be correct if the MRS is 3nm.

EDIT: Looking at the proposed tables, it is strange that the FAA used the opposite CAT designation for wake than for other aircraft CAT designations. ie A380 is CAT A for wake, while a Dash8 is CAT E.