One-way airstrips with slope of 8% or more, extracted from the PNG AIP. The slope, or strip gradient, is an average gradient only, unless otherwise indicated, based on a comparison of the elevation at each threshold, factored by the length of the runway (err... strip!). In most cases, the published slope gives little indication of the actual slope in any one section of the strip. There are many places where an individual segment of the strip has a slope of 15% or more and, in every case, the approach to land is "interesting".
The take-off can also be somewhat challenging.
AIRPORT/ELEVATION/LENGTH/SLOPE
ANGAI/731 M/430 M/10.00%
ARAGIP/505 M/585 M/8.00%
ARKOSAME/166 M/368 M/10.00%
BAMBU/2069 M/410 M/9.25%
BAWAN/1416 M/500 M/8.00%
BIANGABIP/294 M/420 M/10.00%
BIMIN/1755 M/585 M/10.00%
BODINUMU/1136 M/485 M/12.00%
BOIKOA/1468 M/600 M/10.00%
BUSILMIN/1593 M/500 M/12.00%
BU'U/1136 M/500 M/10.00%
DININGAT/1579 M/405 M/11.00%
DUSIN/1894 M/460 M/10.00%
EFOGI/1174 M/487 M/9.50%
ELIPTAMIN/1470 M/530 M/8.40%
ENGATI/1104 M/440 M/9.00%
ERUME/1990 M/480 M/9.80%
FANE/1344 M/451 M/12.00%
GUWASA/1505 M/600 M/10.00%
HABINA/1826 M/600 M/8.00%
HAUWABAGA/1353 M/414 M/12.00%
IMANI/1140 M/500 M/8.00%
IROPENA/1545 M/460 M/11.00%
ISAN/2127 M/410 M/8.00%
KABWUM/1323 M/610 M/10.30%
KAGI/1255 M/447 M/12.50%
KAINTIBA/613 M/450 M/13.30% (17.00% MAXIMUM)
KAMINA/646 M/350 M/9.00%
KAMULAI/1712 M/481 M/11.00%
KANAINJ/1218 M/388 M/13.00%
KASANOMBE/1732 M/457 M/11.30%
LANGIMAR/1525 M/504 M/9.00%
LEBAM/732 M/480 M/10.00%
LENGBATI/1727 M/468 M/10.00%
MAIMAFU/1568 M/442 M/14.20%
MASA/1755 M/385 M/10.00%
MATAK/1254 M/420 M/10.00%
MENGINA/1218 M/600 M/8.00%
MILEI/635 M/500 M/9.00%
NANKINA/1746 M/443 M/10.00%
NEGABO/1366 M/470 M/9.00%
OWENA/1640 M/400 M/10.00%
SAPMANGA/881 M/465 M/8.50%
SELBANG/1540 M/360 M/10.50%
SELTAMIN/1219 M/500 M/11.00%
SILA/762 M/455 M/9.30%
SIM/1652 M/425 M/10.00%
SIMBARI/1048 M/420 M/10.00%
SIMOGU/1444 M/520 M/10.00%
SISAMIN/533 M/436 M/8.6%
SOPU/1985 M/532 M/12.00%
SUMWARI/138 M/547 M/10.00%
TEKIN/1758 M/494 M/10.50%
TEP TEP/2124 M/640 M/10.00%
TOB/1428 M/460 M/9.00%
TUMOLBIL/1026 M/496 M/12.00%
UMBA/1767 M/487 M/12.00%
USARUMPIA/1730 M/457 M/9.50%
WANIKIPA/698 M/605 M/8.00%
WAU/1060 M/815 M/8.00%
WONENARA/1529 M/425 M/10.00%
YENKISA/1128 M/465 M/10.00%
YONGAI/1955 M/396 M/9.6%
ZENANG/964 M/487 M/9.00%
ZUEBAK/1020 M/420 M/10.90%
The above list represents 65 airstrips, out of a total of 504 airports of all types in the country. To save you the maths on that, 12.9% of all currently licensed airports in PNG have a published (average) slope of 8% or more. I didn't check to find out how many of these have had their licence pulled in the last 12 months or so, but you could safely say that at least 80% of the above list, probably as high as 90%, still have a current licence to operate.
On a day-to-day basis, the number of these that are actually in service is a somewhat more variable value. All the above airports - and 419 others - have natural surface runways, which suffer from heavy rain and, sometimes (?), maintenance neglect. But, if even only half of these airports are open on any given day, you'll find at least one service (of one sort or another) at each of them. Indeed, most of the 504 airports in PNG will see at least 3 flights each day, as a rough average.
We have quite a few level, or approximately level, surfaces and many of these will be found at places with very short strip lengths. These exist at all elevations from sea level to around 2100 metres elevation and higher, and these all have their own operational problems, which will include difficulty for approach as well as take-off.
A point that isn't quite so obvious, from any of the above data, is that some of the strips have a kink in them. For example, at Fane, the kink is at the top end, to avoid the missionary's residence. At Efogi (elev 1174 M, length 487 M, slope 5%), the kink is about half way along, to follow the ground contour. At Kanabea (elev 1307 M, length 540 M, slope 2.8%), the kink is also about half way along the strip, to avoid a rather large rock.
Most of our 484 so-called "minor ports" do not comply with ICAO, a point that should probably already be obvious anyway. All these airports are certified under a domestic classification that allows significant reduction in approach/take-off and fly-over area protection. The standard also allows for steeper climb-out gradients than those permitted in any of the ICAO classifications. In most places, the only gradient surveyed for take-off is 5% and, even then, only for a very short distance from the departure end of the runway.
We're mostly a bit too busy to take photos of these places during approach or take-off, but here's a few that might convey an idea of what these places look like from the air.
1. Ononge Airstrip, Goilala District, Central Province, PNG.
Average elevation : 5700 FT, length 500 metres, published slope 7.0%.
Land RWY 34, Take-off RWY 16.
It's actually straighter than it looks!
2. Tapini Airstrip, Goilala District, Central Province, PNG.
Average elevation : 3000 FT, length 915 metres, published slope 4.5%.
Land RWY 34, Take-off RWY 16.
3. Fane Airstrip, Goilala District, Central Province, PNG.
Average elevation : 4300 FT, length 451 metres, published slope 12.0%.
Land RWY 34, Take-off RWY 16.
4. Extract from "One-way strips of Papua New Guinea" ... diagram of approach to, and departure from, Tapini Airstrip, Goilala District, Central Province, PNG. 1st Edition, copyright 1993, author : Yours truly!
