NOTAM Question

[Two_dogs]

G'day,

Came across these NOTAMS for YLHR. What is the part in blue all about?
I cant remember seeing this anywhere before and too lazy to find out for myself.


LOCKHART RIVER (YLHR) C5/06

RWY 12/30 DECLARED DIST AND GRADIENT CHANGES
RWY TODA
12 1560(2.08)
30 1560(2.29)

SUPPLEMENTARY TKOF DIST:
RWY 12 1282(1.6) 1490(1.9)
RWY 30 830(1.9) 1410(2.2)

RWY 30 EXTENT OF TKOF SFC 7500M
FROM 05 010323 TO PERM
C11/06 REVIEW C10/06

NDB 'LHR' PILOT MON
FROM 05 150549 TO 05 290600 EST

Regards,
Two Dogs

[RENURPP]

Its all blue!

Maybe the surveyed distance has changed? I don't know what was there before. That is the obstacle free gradient.

[Fragnasty]

7500M?!?!?!

That's a 'ken long runway in my book! New divert option for the A380??

[Richo]

Too Dogs, the AD operator is advising that the Obstacle free gradient has been surveyed out to 7500m only.

When you consider it may take up to 15km to achieve the LSALT/MSA for some 20.7.1b aircraft, 7500m is only a very small area to be surveyed. The high terrain in and arround LHR is what makes this important. At aerodromes where the LSALT or MSA are relitively close to the AD height (ie flat or costal terrain) this is rarely a problem and 7500m, which is the standard, is quite suffient for surveys and operating data.

What it really says, is that if you fly 20.7.1b aircraft into LHR, you need to assure your own terrain clearnce when outside the surveyed area (7500m). This can be done by doing your own legwork from Topo maps etc, having a survey done yourself and/or incorporating a procedure in your Opsmanual to meet the terrain clearance requirments.

Richo

[pakeha-boy]

RICHO....interesting mate!!!,does that explain why its in "blue",or is it a typo...and is this a common notam?? I dont seem to recall seeing this info as "normal" info in notam releases....PB