SkyDemon Forums

Depiction of Parachute Jump Exercise (PJE) / Drop Zones

http://forums.skydemon.aero/Topic31152.aspx

By hairy_kiwi - 5/13/2020 4:33:50 PM

Please (re)consider depicting NOTAM’d PJE / Drop Zone diameters as a function of altitude, where the associated NOTAM specifically describes the exercise/zone as being contained within a cone.

The following NOTAM clearly describes a conical drop zone in field E:
Q) EGTT/QWPLW/IV/M/W/000/120/5204N00244W012
B) FROM: 20/05/13 15:00C) TO: 20/05/13 21:00
E) PJE WI 12NM RADIUS 520407N 0024333W (HEREFORD, HEREFORDSHIRE).
DROP CONTAINED WI FLW CONE (ALL HGT AMSL): SFC-3000FT 3NM RADIUS,
3001-6000FT 6NM RADIUS, 6001-9000FT 9NM RADIUS, 9001-12000FT 12NM
RADIUS. DROP HGT SUBECT TO ATC CLEARANCE. FOR INFO 07791 573562.
2020-05-0219/AS4
LOWER: SFC
UPPER: 12000FT AMSL

The 24 NM diameter (!) of each of the SIX Overlapping PJE’s in the screenshot below gives the initial impression the entire area should perhaps be avoided, however the associated NOTAM for each clearly stated the drop zones are conical.



Avoiding the promulgated cones of such drop zone conglomerations would be far easier — and relatively safer — if the cones lateral extents were accurately depicted on the SD chart.

Any argument that such areas are simply best avoided does nothing for those pilots who have aircraft permanently based within the lateral extents of massive volumes of such NOTAM’d airspace, when compared to, for example, the efficiency by which SD facilitates the navigation of a complex controlled airspace corridor.

That articles or personnel *may* fall outside the drop zone cone, as I vaguely recall a recent argument went in favour of the current cylindrical depiction on SD’s Facebook discussion — fails to recognise that ultimate responsibility for navigation rests with the PIC, and in this respect SD is merely a tool for facilitating such decisions by the PIC.

In the same vein that flying right up to the lateral limit of controlled airspace might be considered poor airmanship, flying in close proximity to the lateral extent of a NOTAM’d drop zone might also be considered bad airmanship. In the case of former, the margin by which a pilot does so is clearly evident to a pilot utilising SD, whereas in the latter, a pilot using SD may only ‘eyeball it’.
By hairy_kiwi - 5/19/2020 3:39:01 PM

 
Tim Dawson - 5/18/2020 8:56:15 AM
Do you have any evidence that these cones are actually created to a strong specification? If they were, we could conceivably implement a parser...

I'll make some enquiries. Smile