Wake turbulence category!?

[DutchDutch]

Dear fellow pilots,

recently I came across something that bothered me and hopefully somebody is able to give me a good explanation.

As most of you know wake turbulence is divided into several categories,
the most used are light (L), medium (M) and heavy (H). They all have their specific weight, see the website below for more info.

Wake turbulence - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Wake_turbulence)

According to the website above the Hawker 800 (MTOW: 28000 LBS) is in wake turbulence category type 'M'. However if you check:

Doc 8643 (http://www.icao.int/publications/DOC8643/Pages/Doc8643.aspx)

On this ICAO website it states that the Hawker 800 is considered 'L'.
My question is why!? What causes this exception?

Thank you! :ok:

[COBO27]

Whenever an aircraft is certified, the manufacturer has to proof the kind and extension of the wake turbulences; and the result of these test also are part of the given category.

Another example can be the Boeing 757. If preceeding other traffic, this aircraft is considered to be "heavy", when following another aircraft, the 757 is "only" medium and the ATC controller has to maintain a lower separation.

In your list, "J" for "super" is missing, a category, actually only given to the A380.

[westhawk]

Sometimes the wiki info doesn't agree with official sources. The FAA 7110.65U (most current FAA air traffic controllers handbook) classifies the H25B in the (L) wake turbulence category. However stand by for a change! According to a SAFO issued last October, the FAA will be transitioning to a new 6 category wake turbulence classification system in the near future. The SAFO doesn't address the issue of how this will work in terms of international flight plans or how ICAO compatible this will be in the future.

[DutchDutch]

Ok thanks guys for the info! Can´t wait until they will divide it into 6 categories:}

[Aviast]

This is a data-entry error which will be corrected in the next revsion of ICAO Doc 8643.