Block Levels

[jumbojohn]

Okay, I've been flying for 10,000 hours now, much of it wordwide and I still do not understand what "block Flight Levels" (heard requested, mainly in USA and Australia) are all about?

I can understand if general handling is required but this does not appear to be appropriate in the requests that I have heard.

[Spodman]

3.4 Block Levels
3.4.1 On request from the pilot, a flight may be cleared to operate within controlled airspace within a Block Level provided that other aircraft are not denied the use of that airspace contained within that block.
3.4.2 IFR flights will not be allocated block levels in Class E airspace.
3.4.3 A glider or balloon cleared to operate in controlled airspace will be assigned block levels.
3.4.4 The pilot shall have complete freedom to change levels within the block, provided that the upper and lower limits are not exceeded. However, a clearance to operate within a Block Level shall be cancelled or amended if another aircraft requests the use of a level within the block.
3.4.5 When cancelling or amending a Block Level clearance, the aircraft operating in a Block Level shall be instructed to climb or descend to an appropriate level or block level in order to provide vertical separation from the other aircraft requesting one of the levels.
3.4.6 Aircraft at standard flight levels will be afforded priority over aircraft using non-standard flight levels.
3.4.7 Mach number technique separation will not be applied to aircraft using block level clearances.
Note: As most altitude alerting systems do not provide protection
for both upper and lower assigned levels, flight crews are reminded to be vigilant in monitoring the aircraft altitude when operating within a Block Level.

[C Yeager]

Interesting ...
Could you qoute the source of your references ......sounds like like some "local" ATC manual .......also if possible where "block levels are mentioned in ICAO Docs / Annexes ...TKS .....I could not find anyting .......

Ps. I am genuinely interested ...just in case you thought I was being facetious....

Ciao

[Scott Voigt]

Block altitudes in the US will be found in the Air Traffic Control Handbook known to us as the 7110.65. We use block altutudes for aircraft who can't get to say FL410 but can make it to FL400. So if there is no traffic we will issue FL390 Block FL410 and allow the aircraft the most efficient altitude.

The military also uses it for multiple aircraft flights of large aircraft of refueling.

The other place you will find it used is for rough air where lighter aircraft are having a hard time maintaining an altitude and we will give them a block to operate in...

regards

[willadvise]

Often requested when
-aircraft are having trouble finding a smooth level and hence minimise the number of level change requests.
-aircraft wishing to conduct a cruise climb
-by ba146 aircraft (Block F260-F310) who are trying to get over the top of bad weather but have to go back down to F260 if they can't.


C Yeager
Spodman is quoting from the Australian Manual of Airtraffic Services.

[Spodman]

Actually from AIP - Aeronautical Information Publication - Australian equivalent of AIM.

[jumbojohn]

Great, thanks for all that info. This is not really used in Eurpean airspace......never stop learning:)