B09_SA_140D0424R0028_0002_-_Attachment_I_0002.pdf

Revision B – 30-Apr-2023 Prepared for – The Nature Conservatory – Co No.: N/A

Palmyra Runway Inspection

30-Apr-2023 The Nature Conservatory

Prepared for The Nature Conservatory Co No.: N/A

Palmyra Runway Inspection

Revision B – 30-Apr-2023 Prepared for – The Nature Conservatory – Co No.: N/A

AECOM

Palmyra Runway Inspection

Client: The Nature Conservatory Co No.: N/A

Prepared by AECOM New Zealand Limited 8 Mahuhu Crescent, Tāmaki Makaurau|Auckland 1010, PO Box 4241, Tāmaki Makaurau|Auckland 1140, New Zealand T +64 9 967 9200 F +64 9 967 9201 www.aecom.com

30-Apr-2023

Job No.: 60589928

AECOM in Australia and New Zealand is certified to ISO9001, ISO14001 and ISO45001.

© AECOM New Zealand Limited (AECOM). All rights reserved.

AECOM has prepared this document for the sole use of the Client and for a specific purpose, each as expressly stated in the document. No other party should rely on this document without the prior written consent of AECOM. AECOM undertakes no duty, nor accepts any responsibility, to any third party who may rely upon or use this document. This document has been prepared based on the Client’s description of its requirements and AECOM’s experience, having regard to assumptions that AECOM can reasonably be expected to make in accordance with sound professional principles. AECOM may also have relied upon information provided by the Client and other third parties to prepare this document, some of which may not have been verified. Subject to the above conditions, this document may be transmitted, reproduced or disseminated only in its entirety.

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Quality Information Document Palmyra Runway Inspection

Ref 60589928 l:\legacy\projects\605x\60589928\500_deliv\501_reports\post construction inspection report\final\palmyra runway condition inspection report 2022 final.docx

Date 30-Apr-2023

Originator Craig Ridgley

Verifier/s Pieter Van Vreden

Revision History

Rev Revision Date Details Approved

Name/Position Signature

B 30 April 2023 Final Report Craig Ridgley Technical Director - Aviation

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Table of Contents Executive Summary i

1.0 Runway Formation Overview 1

1.1 Runway Walk Over Inspection 1

1.2 Georeferenced Site Photographs 2

1.3 Runway Pavement Condition 2

1.3.1 06 Runway end 0 to 977 ft 2

1.3.2 Main Runway Reconstruction Zone 977 ft to 4,198 ft 3

1.3.3 Original Runway formation 4,198 ft to 5,680 ft 4

1.3.4 Runway strip end area 5,680 ft to 5,800 ft 4

1.4 Runway Flank Areas 4

1.4.1 Grass Strip Flanks 4

2.0 Quarry Site Stockpiles 4

3.0 Runway flank drainage 5

3.1 Western Runway Flank 5

3.1.1 Recommended Maintenance Works 6

3.2 Eastern Runway Flank 6

There are 14 soakage pits and 3 lateral drains along the southern swale, all in good condition. The swale drain is becoming infilled with sand and silt from around 1,715 ft onwards. Tree vegetation has completely grown over the lateral drains. 6

3.2.1 Recommended Maintenance works 6

4.0 Runway Strip Vegetation Clearance 6

5.0 General Equipment Overview 8

5.1 Bobcat 3700 8

5.2 Tractors JD 5310 and 5410 8

5.2.1 Tractor Implements. 8

5.3 Compaction Rollers: PTR and Twin Drum 9

5.3.1 Dynapac C251 Tire – Drum Roller 9

5.4 Cat Backhoe 9

5.5 Recommended New Equipment 10

5.5.1 FOD Boss 10

5.5.2 HD agricultural tractor mower 10

5.5.3 Bobcat 3700 Attachments 10

5.6 Suitable Second-Hand Equipment 10

5.6.1 8t Rubber tracked excavator unit 10

5.6.2 4-wheel Bobcat Skid steer 10

6.0 Next Steps 10

6.1 General Maintenance activities 10

6.1.1 Runway 24 end area vegetation clearance works 11

6.1.2 Tree Clearance Works. 11

6.1.3 Culvert Protection Rocks Southern Runway End 11

6.1.4 Central Runway Localised Tuffs of Grass 11

6.1.5 Black Algae 11

6.1.6 Green Algae 11

6.2 Aircraft Operations Focused Wildlife and Vegetation Management Plan 11

6.3 Runway - Revised Rolling Procedure 11

6.3.1 Outer Flanks (edge of the central 75ft runway to the edge of the swale drain) 11

6.3.2 Sandy interface newly compacted coral to old formation at 75ft line 12

6.3.3 Central 75ft wide section, distance 0ft to 975ft 12

6.3.4 Central 75ft wide section, distance 975ft to 5160ft 12

6.3.5 Central 75ft wide section, distance 0ft to 5160ft 12

6.4 Day Before Planned Aircraft Arrival. 12

6.4.1 Day of Aircraft Arrival 12

6.5 Grass Flanks 12

6.6 Swale Drains 13

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6.7 Drainage laterals 13

6.8 Recommended Additional Plant Items 13

6.8.1 FOD-Boss 13

6.8.2 HD Agricultural Tractor Mower Attachment 13

6.8.3 Bobcat 3700 Skid Steer Attachments 13

6.8.4 Additional 4-wheel Bobcat Skid Steer 13

6.8.5 Small Hydraulic Excavator Unit 13

6.9 Repairs to Existing Plant Items 13

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Executive Summary This inspection report provides a summary commentary of the main observations from the site inspection of the Palmyra runway facility undertaken early October 2022. The central section of the runway was reconstructed in 2019 with the reconstruction works being practically complete by the end of November 2019. Due to Covid 19 restrictions the planned post completion 12-month maintenance inspection was not able to be completed as scheduled. The works contract Maintenance Certification was instead based on comprehensive site photographs as an interim means of approval.

AECOM’s Craig Ridgley mobilised to site Thursday 29 September 2022 through to Monday 3 October 2022 to carry out a walk over site inspections focusing on the following:

1. Runway surfacing condition

2. Runway flank drainage

3. Runway strip vegetation clearance

4. Maintenance equipment review

AECOM issued a site inspection close out report on 3 October 2022 immediately following completion of the site inspection. Overall, the runway and adjacent grass strip areas were found to be in sound condition, surface compaction trials where undertaken and additional stormwater sumps where bored to assist with drainage of standing surface water adjacent to the runway strip in low lying areas. Routine maintenance items were discussed on the completion of the site inspection and are revisited in more detail in this report. This final inspection report further develops several of the initial action items identified in the interim report, and includes the Google Earth based KML file as a technical appendix which presents all the site inspection photographs in a georeferenced format which can be loaded into and accessed on Google Earth freeware.

Overall Condition The runway surfacing is in sound condition for the currently operational aircraft certified for unsealed runway operations, these currently being the Falcon 50 and C130 Hercules regularly using the facility. Some minor loose stone and sandy material was observed along the runway outer flanks. Whilst on site the runway was rolled using both the PTR and steel drum rollers to imbed localised loose materials along the longitudinal construction joint line formed between the new to existing runway surfacing formations. In addition to rolling the surface prior to scheduled flight operations, consideration should also be given to using a specialist “FOD Boss” type runway broom unit to uplift any remaining loose materials. The FOD Boss units are specifically designed to uplift stones and small FOD items from the surfacing. The FOD boss can be towed behind one of the sites UTV’s for example and is a quick way of picking up any loose stones off the surfacing. The

FOD boss usage should be limited to the central 75 ft width of the central runway. Refer to figures 3 and 4 in the main report showing details of FOD boss broom units.

Reconstruction Interface to Flank Edge Zones: Along the edge flanks of the 75 ft reconstruction zones, there are localised areas of sandier material generated from the grading operations during the reconstruction works. These areas need a revised rolling procedure to lock the surface in, requirements are described in section 1.3.2 of the main report.

Runway End Areas: the existing runway end areas (distances 0 to 977 ft and 4,198 to 5,680 ft) either side of the reconstruction zone are prone to black and green algae build ups which sets up in the surface. The green algae swell significantly under rainfall, we recommend the acquisition of a sweeper bucket for the Bobcat skid steer unit, this could well be a very effective means of uplifting the swelled green algae from the runway surface, refer section 5.1 of the main report for details . The recommend FOD Boss unit might also prove effective in uplifting this material in a swelled state and is recommended to be trialled but noting the FOD Boss is not designed to manage large quantities for material.

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The black algae should be treated with specialised chemicals specifically targeting algal type growths, further details are presented in section 1.3.1.1 of the main report.

Culvert Protection Rocks Southern Runway End: these are a major runway strip obstruction and need to be removed to outside the grassed strip flank area. Reflective plastic road cones should be used to mark the culvert end points. Gently sloping concrete ramps are recommended at each end of the culvert, these are to minimise damage to an aircraft should it run off the runway into the flank area in this location.

Grassed flank Areas: These are regularly mown and are in sound condition. Naupaka ground cover is creeping in along the flanks and should be aggressively cut back to the 500ft strip offsets. A heavier duty agricultural mower is recommended to be acquired, these are more suitable for this type of work, refer section 5.2.1 of the main report for details of a recommended unit.

A flank levelling “beam” was observed during the inspection on the eastern flank at distance 4,272 ft.

The site team needs to move this clear of the runway strip area as this is a major obstruction should a plane runoff the runway into the flank area. The tractor box blade unit should be repaired by the site team and returned to service for future levelling works

Swale Drains: Previously the tractor broom unit had been used by the site team to clean out the drain.

This overloaded the broom causing the bristles units to break off, which in turn caused a major FOD issue with multiple large chunks of busted broom head removed from the swales during the inspection.

The bobcat bucket unit and or the tractor grader blade should be the preferred methods for swale drain clearance.

Strip Perimeter Tree Clearance: Ongoing tree clearance is needed from mid-runway length going north east, with intensive clearance of the runway end area required for safe operations in a rejected landing situation. This requires extensive tree clearance along the runway flanks and across the northern runway end area, refer section 4.0 of the main report for added details.

Habitat alteration: The general removal of the palm trees around the runway is making the remaining area more attractive to the larger birds on island. A wildlife and vegetation management plan should be researched by TNC in consultation with Fish and Wildlife and implemented so that Boobies and other larger birds are not attracted to this section of the island once the coconut palms are removed. Please refer to the following FAA documentation for general guidance.

https://www.faa.gov/newsroom/federal-aviation-administrations-faa-wildlife-hazard-mitigation-program

It may be beneficial to focus on complete tree removal from around the runway strip area to reduce the potential for aircraft bird strikes.

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1.0 Runway Formation Overview

The WWII runway formation was constructed from compacted marine reclamation coral within a nominal 500 ft strip width; the central 150ft width is the primary runway surface. The runway orientation is 06-24 and the formed runway is approximately 5,680 ft long.

The 06-runway end has a nominal 215 ft runway end area. There is a formed run-off area beyond the 24-strip end which continues for an additional 650 ft through to the northeast beach foreshore.

A small parking pad is located the southern flank at around 590 ft from the 06-runway end area, this area is generally not used with aircraft parking on the 06-runway end area. Running distances along the runway begin at 0 ft at the very end of the 06-runway strip and increase in the north-easterly direction.

Figure 1 provides an overview of the runway strip lateral extents (red dashed lines) and the 2019 reconstruction work extents (yellow highlighted area). The central placed 5160ft long runway is outlined in light blue, the north-eastern end of the runway also incorporates a 650ft grassed runway safety area

(RSA).

Figure 1 Palmyra Runway Strip General Configuration

The 2019 runway reconstruction replaced the central 75 ft wide section of the runway from distance 977 ft through to 4,198 ft (based on the current distance measuring wheel on site and visible transverse joint lines), the reconstruction section is highlighted in yellow in Figure 1 above. The reconstruction works lifted the runway crown to improve water run-off, the outer runway shoulders where regraded to improve crossfall into shallow swales from distance 0 ft through 6100 ft with both soakage pits and shallow lateral swale drains to divert rainwater off the central runway area. These drainage improvements have been quite effective compared to the extensive surface flooding and standing water that occurred during storm events prior to the 2019 works.

1.1 Runway Walk Over Inspection

This is the first inspection by AECOM since the runway reconstruction works practical completion inspection in November 2019. The initial walk over inspection was undertaken Friday 30 September 2022 commenced from the 06-runway end heading northeast to the 24-runway end with condition notes and photographs taken at 100 ft intervals.

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1.2 Georeferenced Site Photographs

A comprehensive set of site photographs has been taken as part of the inspection process, these have been sorted and formatted into a KML file format. The KML file can be imported into Google Earth freeware and the site photographs are georeferenced along the runway and related areas allowing items as observed during the inspection to be viewed by TNC staff.

The site inspection KML file is large file and comprises some 243 site photographs and will be made available as a downloadable data file which TNC can than store into their online archive Dropbox facility for future reference. The georeferenced site photographs are an important digital reference as it can then allow comparisons of future relative conditions to be undertaken and comparisons made. Three site photographs taken from a camera drone from the original construction phase works have also been included into the KML file, these provide a clear overview of the aggregate quarry sites and a general overview along the runway looking to the northern runway end area.

An overview of the KML view port is as follows:

Figure 2 Palmyra Runway KML viewport in Google Earth

When imported and opened in Google Earth, each site photograph thumbnail view can be clicked and opened into a full screen view.

The site inspection focusing initially on the runway surfacing, then flank features and finally vegetation clearance around the strip perimeter, an overview of site conditions as encountered is summarised as follows.

1.3 Runway Pavement Condition

The 150 ft runway formation has been subdivided into a central 75 ft runway and outer 37.5 ft shoulders. The central 75ft runway is further divided into 4 major zones as follows.

1.3.1 06 Runway end 0 to 977 ft From the southern 06 strip end, the first 977 ft compromises of a cement stabilised formation to nearly the full 150 ft width. This is in sound condition overall with minimal defects and no extra over maintenance requirements. There is observable grass invasion along the 75ft construction joints in the outer flanks, these are currently sprayed, consideration should be given to mechanically chipping the

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grass head off. Some minor loose small stones were observed and has possibly been transported by vehicle tires from flanking areas. Removal of this loose material could be undertaken with a heavy-duty leaf blower though this will be a slow process. Removal is best achieved with a towed FOD Boss sweeper unit. AECOM recommends acquisition of an 8 ft FOD Boss which can be towed behind the electric GEM or one of the stations UTV’s. The FOD Boss units are used by airports worldwide and are both durable and easy to maintain. The units roll into a compact rectangular box when not in use.

AECOM recommends getting a full complement of wear spares including the plastic sweeper bars, wears strips and rear roller wheels at the time of purchase. The manufacturers website address is as follows:

https://www.aerosweep.com/fodboss-ultimate-single-sweeper

An example of a FOD Boss unit and the patented sweeper units are shown below in Figure 3 and Figure 4.

Figure 3 FOD Boss towed units Figure 4 Patented sweeper units

The FOD boss may also prove to be effective in uplifting the swelling green algae that sets up post rainfall events.

1.3.1.1 Runway End Area Black Algae

Black Algae: This section of the runway does experience black algae growth which can become slippery when wet. Previous trials with a number of generally available chemical such as bleach and swimming pool chlorine have not been overly effective. AECOM recommends trialling a speciality product under the trade name Wet”n”Forget. This product has been formulated to specifically attack moss, moulds, algae’s and fungus / lichens and has a 6 to 12 month residual post application. This product is EPA approved and biodegradable.

The Wet’n”Forget manufacturers website address is as follows:

https://www.wetandforget.com/wet-and-forget-concentrate.html

1.3.2 Main Runway Reconstruction Zone 977 ft to 4,198 ft

In general, the 75 ft wide reconstruction zone is in sound condition. There are isolated sections on the outer edges where the material is sandier in makeup, these can be observed by the change in colouration from the grey-white hard compacted coral formation to a more off white to yellow colour where the higher sand content is occurring. A revised rolling procedure is proposed for these areas (this was trialled on site Friday afternoon). For the wider sandy edges (roller width or wider) this will involve using both the steel drum roller (no vibration, static only) initially for 3 passes to bed in loose material then followed by the PTR roller for another 3 passes. Longer term these sandy sections may need to be replaced with fresh graded coral from the quarry site maintenance stockpiles.

There were observable loose small stones across the area. This does not seem to be coming out of the surfacing and is likely to have been transported on from the flank areas by vehicles. Rolling with the

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steel drum roller can crush and embed this material as a short-term option, removal of this loose material is best achieved with a towed FOD Boss sweeper unit as described above or with a bobcat sweeper – bucket combo unit (refer Section 4 for further details).

Yellow tap and nails to define algae chemical trials - northern runway flank. Nails with washers have been driven into the runway to secure the tape defining the trial areas. The nails are currently well embedded, none the less the nails (and tape) need to be confirmed as being removed as they present a tire damage risk if a plane veers to the side of the runway for whatever reason. In general nails should not be used by site staff for any form of survey temporary marking within the runway formation – please use heavy applications of aerosol paint to mark out trial areas and renew as needed.

1.3.3 Original Runway formation 4,198 ft to 5,680 ft

This area has a number of sandy spots, from 4,197 ft through to around 4,600 ft. These sandy sections support grass growth and will progressively loosen the surrounding compacted materials. Whilst the grass tuffs are regularly sprayed, they would benefit from manually chipping off of the grass tuffs to reduce regrowth and hopefully elimination.

Longer term localised removal of the sandy soft spots and infilling and compacting with graded coral from the quarry site stockpile No 2 site, should be planned for.

Algae: This area does experience both black and green algae growth which can become slippery when wet. Previous trials with a number of generally available chemicals such as bleach and swimming pool chlorine have not been overly effective. A Wet’n’Forget trail is also proposed for this area.

1.3.4 Runway strip end area 5,680 ft to 5,800 ft

The grassed end area is well maintained. There is some invasive growth occurring around the perimeter and initial sprouts in the central area that need to be removed, ideally these are pulled out to remove the roots to limited regrowth.

1.4 Runway Flank Areas

Overall, these are in good condition. Whilst the site is currently relatively dry it would be beneficial to heavily roll the outer flanks of the runway from the edge of the 75 ft central zone to close to the swale drain invert with both the double drum roller (3 passes) and the PRT roller (3 passes) to tighten these areas. Both rollers need to remain at least 2 ft offset from the base of the swale, bogging down the rollers in the swale would then result in surfacing damage to pull them back out. Accordingly, a general caution on rolling the outermost run close to the swale is required. Having a spotter on the ground is beneficial in keeping the drum roller aligned and monitoring the ground conditions.

1.4.1 Grass Strip Flanks

These appear to be in an overall good condition and are regularly mowed. Keeping a slightly taller grass cover is beneficial in keeping the birds off these areas and the mowing frequency is to be fine-tuned with this requirement in mind.

A heavier duty agricultural grass mower should be considered, the current light duty mower struggles with the longer grass and rough ground conditions.

Recommend removal of the heavy levelling bar currently positioned on the southern flank at distance 4,272 ft.

2.0 Quarry Site Stockpiles

There are four material stockpiles at the old quarry site.

Stockpile 1: The stockpile closet to the main camp access road is general excavated feed rock and ranges from coarse oversize to sand. This is suitable for general backfilling but is not a graded product and is not suitable for runway repairs. Please use this material in preference to the other specialty graded material stockpiles 2, 3 and 4 which should be reserved for runway usage.

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To the north are three stockpiles in a row, from west to east these are described as follows:

Stockpile 2: This comprises of graded runway structural fill material, this is to be conserved and used for runway repairs only.

Stockpile 3: This comprises of coarse soakage pit cobbles with no fine materials. This is to be used for future stormwater soakage pits and galleries as needed.

Stockpile 4: This comprises fine graded sand. This can be used to infill coarse - bony areas on the runway (none observed to date) and can also be used as a surface filler during repairs if the finish comes up bony (lack fines to lock the aggregate together).

The various stockpiles are viewable in the project KML file.

Figure 5 Overview of the various aggregate stockpile locations (note aerial photograph is pre the 2019 site works)

3.0 Runway flank drainage

Overall the runway flank swales, lateral drains and soak pits are performing well and have made a significant improvement to the runway drainage overall. Some routine maintenance is required and would be ideally implemented in drier period where access along the grass strip is easier in the vicinity of the lateral drains (typically ground conditions are very soft at these locations).

3.1 Western Runway Flank

There are 5 lateral drains off the main swale. These are located at the following approximate distances from the runway strip 06 end point:

Lateral #1 1,663 ft – ground soakage only: test bores with Bobcat auger trials - ground water to near ground level 24 hours after boring.

Lateral #2 2,727 ft – coastal outfall, blocked at the beach line. Clearance required

Lateral #3 3,502 ft first arm of the small “Y” drain – coastal outfall clear right up until beach line.

Additional Clearance required

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Lateral #4 3,756 ft second arm of the small “Y” drain – same outfall as above. Water is ponding in the Y drain catchment due to the beach outfall build up.

Lateral #5 4,280 ft third arm forming the large “Y” drain - same outfall as above. This needs to be lowered by around 1 ft to improve drainage, there is a large open inland area with standing water – consider adding soakage bore holes (Bobcat auger and rock fill).

Distance 5,680 ft – end of runway formation, signs of ponding water and silt build up. 45 degree drain to the coast totally blocked with standing water occurring. Investigate Bobcat auger holes to see if this assists with soakage.

The swale drain is getting infilled with accumulated sand and silt and needs to be mucked out for most of the runway length. This is best achieved with the Bobcat unit. Clearance using the rotary broom unit is not recommended, this unit is not designed for this type of usage.

3.1.1 Recommended Maintenance Works

The base of the swale drain needs to be mucked out, the tracked bobcat with the hydraulic tilt bucket is the ideal plant item for this job.

All lateral drains have a build-up of silt and are now supporting rush growth, these are shallow rooted and needed to be cleaned out to allow water to run off the runway swale (use John Deere tractor and hydraulic grader blade to muck the laterals out, noting this work is ideally implemented with a hydraulic excavator).

Investigate boring bobcat auger holes in areas of standing water at the end of each lateral drain and infilling with coarse drainage cobbles from stockpile number 3 to see if these aid in getting the standing water to soak away. Initial trials on site indicated some ability to drain standing water into the underlying aquifer, additional soakaway bores with coral cobble infill should be implemented in areas with standing water to try and improve soakage into the underlying sandy strata.

3.2 Eastern Runway Flank

There are 14 soakage pits and 3 lateral drains along the southern swale, all in good condition. The swale drain is becoming infilled with sand and silt from around 1,715 ft onwards. Tree vegetation has completely grown over the lateral drains.

3.2.1 Recommended Maintenance works

The base of the swale drain needs to be mucked out, the tracked bobcat with the hydraulic tilt bucket is the ideal plant item for this job, combined with the tractor mounted grader blade for spreading of the removed material when deposited outside the strip edge.

Levelling of the surface layer of the soakage pit cobbles are needed at several locations, these have been dislodged by swale clearance activities.

Investigate adding new soakage pits at approximate positions 3,715 and 5,265 ft using the Bobcat auger. Monitor in the next wet weather event to gage the ideal low point positions for these new soak pits.

All lateral drains have a build-up of silt and are now supporting rush growth, these are shallow rooted and needed to be cleaned out to allow water to run off the runway swale (use the John Deere tractor and hydraulic grader blade to muck the laterals out, noting this work is ideally implemented with a hydraulic excavator). These will be quicker to clear than the western side. Clear back tree vegetation so the drains get sunlight over the alignment to help dry these out.

4.0 Runway Strip Vegetation Clearance

A plan needs to be developed by TNC in consultation with Fish and Wildlife for the staged clearance of the runway strip to the full 500 ft strip width.

There are five immediate action priorities for tree and vegetation clearance, these are:

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a) The 24-runway end area is overgrown along the beach line, this needs to be cut down to ground level to at least 150 ft width and ideally progressed to the full 500 ft strip width, this requires major coconut clearance on both flanks and active removal of the grown cover shrubbery that is actively encroaching back into the runway strip end area.

b) Significant groups of coconut palms are present along both runway flanks from midway length heading towards the 24-runway end area, these needed to be removed and given urgent priority for poisoning and or direct felling. If poisoned, the remaining trunks need to be cut down as well.

The required 24 runway end clearance envelope is shown superimposed on a runway end site photograph. The aim is to have the full runway width cleared and opened out across the beach area to facilitate a low-level emergency landing overrun to take off manoeuvre. This would also provide a clear unobstructed landing approach direct in from the north should this be required. Encroaching naupaka need to be grubbed out by the site team (refer blue circled areas).

Figure 6 Northern Runway End Area Tree Clearance

c) There is a noticeable narrowing on both runway flanks from 3,500 ft onwards to around 5,000 ft when moving towards the 24-runway end with tall trees on both sides, these need to be cleared back (tallest trees closet to the runway felled first). Overall a site strategy for the vegetation removal around the runway strip needs to be coordinated by TNC with Fish and Wildlife

d) 06 runway end; low level trees and coconut palms in the swales need to be removed.

e) The coconuts around the southern 06 runway end windsock need to be removed; the windsock needs to be visible to the plane’s crew on approach, currently it is obscured.

Thereafter a general vegetation clearance and tree encroachment cutting back program is to be coordinated by TNC and agreed with all parties.

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5.0 General Equipment Overview

Several of the stations plant units were used during the inspection works, summary notes, observations and recommendations are as follows.

5.1 Bobcat 3700

Overall an excellent machine, versatile and robust and well suited to conditions on Palmyra.

a) Recommend buying a second bobcat 4 wheeled unit for working on the runway.

b) Recommend buying a sweeper broom – bucket unit rather than repairing the tractor broom unit (this has not proven to be overly durable). Bobcat sweepers are used extensively by runway and road maintenance contractors world wide. The sweeper discharges into the bucket behind for immediate clean up rather than trying to windrow material clear of the work area. These units can also handle general surface clean up post runway repairs and are able to pick up larger volumes of materials than what the FOD Boss can handle.

https://www.bobcat.com/na/en/attachments/sweeper

Figure 6 4-wheel bobcat and bucket broom unit

5.2 Tractors JD 5310 and 5410

Both are in excellent working order and are surviving the rugged conditions at Palmyra.

5.2.1 Tractor Implements.

General repairs and maintenance are needed on the following tractor mounted implements:

Grader blade unit: Return this unit to full serviceability (repairs need to the control ram). This unit is needed to allow cleaning out of the soil build up out of the base of the lateral drains and for general grading of the longitudinal swale.

Box blade unit: Consider refitting the level wheels, this should be the preferential unit for levelling the grass berm areas rather than the towed steel beam

Tractor mounted mower unit: the existing mower is struggling with the workload and is designed for smooth surface utility mowing. A heavier duty agricultural mower should be investigated by TNC. We recommend the New Zealand manufactured Fieldmaster type units. https://fieldmaster.co.nz/hd-series-tractor-mower

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Figure 7 Fieldmaster HD70 agriculture mower

The Fieldmaster would also be very effective on the taller invasive naupaka shrubbery growth that is encroaching along the strip flanks.

5.3 Compaction Rollers: PTR and Twin Drum

Both units are serviceable and were used by TNC staff for rolling trials held on the Friday afternoon during the site inspection.

PTR: there is a major air leak on the tire inflation system in one of the rear wheels. It takes a good 10 to 15 minutes for all tires to fully inflate, the onboard compressor can keep up but a replacement angle

– swivel fitting should be procured by TNC to avoid inadvertently running the tires at low or zero pressure.

Twin Drum: Developed an oil leak on the power steering ram (Dave investigating). Otherwise working okay.

5.3.1 Dynapac C251 Tire – Drum Roller

No longer serviceable with engine – electronics issues. No need to replace this unit.

5.4 Cat Backhoe

This is no longer serviceable with engine – electronics issues. In the past the unit also had numerous problems with tire punctures, recommend considering procurement of an 8-ton rubber track excavator as a replacement and or a backhoe attachment to the Bobcat 3700 unit

Figure 8 Rubber tracked light weight excavator

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Figure 9 Bobcat excavator attachment

5.5 Recommended New Equipment

The following equipment items are recommended to be procured.

5.5.1 FOD Boss

Recommend buying a single 8 ft unit for cleaning the runway of loose stones and will likely be effective at scooping up the large green algae when it is in a sweeled up condition (after rainfall). Refer section

1.3.1 above for manufacturer details. Approximate budget cost is $18K.

5.5.2 HD agricultural tractor mower

Recommend acquisition of a heavy-duty agricultural tractor mower which will be better suited to the grass flank maintenance than current light duty units.

5.5.3 Bobcat 3700 Attachments

Recommend buying a combo sweeper bucket unit for the Bobcat 3700 unit.

Also Recommend consideration of a hydraulic backhoe attachment as an alternative possibility to a small hydraulic excavator.

5.6 Suitable Second-Hand Equipment

Consideration of acquiring low hour second hand units for the following.

5.6.1 8t Rubber tracked excavator unit Needed for lateral drain cleaning works. Rubber tracked units are more suitable for tracking along the runway formation than steel track units. This will also be suitable for a variety of camp related maintenance activities.

5.6.2 4-wheel Bobcat Skid steer The rubber-tired versions are more suitable for general runway repairs and sweeper duties than the current tracked unit. If a unit is acquired, make sure all buckets and related are cross compatible between the two units (generally they are but a cross check should be made).

6.0 Next Steps

Priority work items are summarised as follows:

6.1 General Maintenance activities

Overall, the airfield is well maintained, future forward focus on the following work items is recommended.

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6.1.1 Runway 24 end area vegetation clearance works

Vegetation clearance should focus on the Runway 24 end area followed by flank vegetation clearance from the 5000ft distance toward the 24-runway end, this should be actioned as soon as possible.

6.1.2 Tree Clearance Works.

Removal and or topping of the taller trees along the runway strip flank from distance 5000ft to the 24-runway end needs to be undertaken by TNC in coordination with Fish and Wildlife. The runway strip overall needs to be cleared out to the 500ft width wherever practical to do so.

6.1.3 Culvert Protection Rocks Southern Runway End

These are a major runway strip obstruction and need to be removed to outside the grassed strip flank area. Reflective plastic road cones can be used to mark the culvert end points. Gently sloping concrete ramps are recommended at each end of the culvert, these are to minimise damage to a plane should it veer off the runway into the flank area in this location.

6.1.4 Central Runway Localised Tuffs of Grass

On the 4,198 ft to 5,680 ft section of the runway there are localised grass tuffs that are well rooted into the surface. These should be sprayed with Roundup or similar and once dead, these need to be manually chipped out using a sharp spade. Chipping out should be implemented several days ahead of the planned maintenance rolling of the runway surface. Small divots deeper than 2” removed from the surface during the grass tuff chipping process should have make up coral from stockpile 2 added and be compacted into the surface using the steel drum roller in general accordance with the surface maintenance manual procedures.

6.1.5 Black Algae

Recommend trials with wet n forget or related products specifically designed to address algal growth, refer section 1.3.1.1 of the report for additional details.

6.1.6 Green Algae

Recommend removal using the recommended to be acquired sweeper bucket unit on the skid steer when the algae are fully swelled after rainfall as a mass removal. There after possible treatments with wet n forget or similar products could then be trialled to try and eradicate the algae longer term.

6.2 Aircraft Operations Focused Wildlife and Vegetation Management Plan AECOM recommends that a wildlife management plan focusing on safe aircraft runway operations should be implemented with reference to the following FAA documentation:

https://www.faa.gov/newsroom/federal-aviation-administrations-faa-wildlife-hazard-mitigation-program A wildlife and vegetation management plan focusing on making the runway strip and adjacent areas unattractive to bird roosting is recommended. Removal of the coconuts is in turn making the remaining vegetation habitat more attractive to the local bird life which is contrary to good practise for safe airfield

– aircraft operations. We recommend removal of trees that promote bird roosting and introduction of low-level ground cover along the runway strip flanks; TNC needs to establish a joint approach to this specific management requirement in coordination with Fish and Wildlife.

It may be beneficial to focus on complete tree removal from around the runway strip area to reduce the potential for bird strikes.

6.3 Runway - Revised Rolling Procedure

Further to our inspection and rolling trials on site the following rolling procedures are recommended

6.3.1 Outer Flanks (edge of the central 75ft runway to the edge of the swale drain) Roll the outer runway flanks with the drum roller in static mode (no vibration). Primary purpose is to use the steel drum to embed any loose material and to tighten the surface, 2 passes every 2nd month. Care is needed when getting close to the swale drain invert, the roller can get bogged if the swale invert has

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a build-up of material and the invert is saturated, this work should be done in fine weather periods when surface conditions are dry.

6.3.2 Sandy interface newly compacted coral to old formation at 75ft line There are localised longitudinal narrow bands of sandy material at the interface between the newly placed compacted coral and the original formation. These need to be checked and be rolled with the steel drum roller centred over the interface line to keep this material tight, for narrow area (lass than the width of the steel roller drum 2 passes of the steel drum roller should be adequate. For the wider sandy edges (roller width or wider) this will involve using both the steel drum roller (no vibration, static only) initially for 3 passes laterally offsetting by 50% of the roller drum width to bed in loose material then followed by the PTR roller for another 3 passes. Longer term these sandy sections may need to be replaced with fresh graded coral from the quarry site maintenance stockpiles if the surface does not remain compacted firmly.

6.3.3 Central 75ft wide section, distance 0ft to 975ft

Generally, the cemented runway end section from 0ft to 975ft should not need maintenance rolling. The surface is generally bound tight from the cement treatment. Any loose material present is likely to have been trafficked on from adjacent areas. Loose material in this zone should be uplifted with the FOD Boss unit.

6.3.4 Central 75ft wide section, distance 975ft to 5160ft

This should be rolled using the PTR unit with a minimum of 4 passes every 2nd month. Purpose of this work is to keep the compacted coral surface tightly knitted together which is best achieved with the multi wheel rubber tire roller which simulates the plane wheel loading.

6.3.5 Central 75ft wide section, distance 0ft to 5160ft

Any areas that are exhibiting breakdown of the surfacing layer and generation of loose material are of immediate concern, and if not able to be stabilized by rolling should be repaired via a dig out patch repair in accordance with the maintenance manual procedures.

6.4 Day Before Planned Aircraft Arrival.

TNC should plan to carry out a walk over inspection for the full length of the runway to check that the surface of the central 75ft width is “tight” and check for excessive green algae.

Swollen green algae, if present, should be uplifted with the Bobcat skid steer unit with the recommended sweeper bucket.

TNC should deploy the FOD Boss unit to uplift any loose stones from the 75ft central runway area over the full length of the runway. Photograph and weight the amount of material collected and log details into the runway maintenance records sheet. The unit should not be “full” from this sweep activity. If the FOD Boss is full after the sweep this indicates excess loose material is present, consider applying 4 passes of the rubber-tired PTR roller to the central 75ft section from 975ft to the 5160ft runway pavement end as a precaution.

6.4.1 Day of Aircraft Arrival

Conduct a drive over visual inspection of the runway surface on the morning of arrival to check there is no loose material – stones or other FOD items on the runway and inspect again after the aircraft landing looking for any surface defects such as dislodged material at the touch down zone and at the mid runway area under braking and at the turn around.

Deploy bird scaring measures as needed if birds are active in the vicinity.

6.5 Grass Flanks

These should be mown on a regular basis to keep the grass height down and manageable, recommend this is implemented at least bi-monthly. If regrowth is excessive, then the frequency of mowing needs to be revised by the site team to suit. Regular mowing should also help minimise lateral creeping in of the naupaka ground cover (which is occurring towards the 24-runway end area and along the western flank line)

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6.6 Swale Drains

These need to be mucked out on a 6 monthly cycle depending on build-up. The tracked Bobcat skid steer unit with the bucket attachment is the ideal unit for this work. The tractor mounting grader blade is another choice for clearance works. The site team needs to schedule this work to be undertaken in “dry” conditions to minimise equipment tracking damage to the adjacent areas.

6.7 Drainage laterals

Cleaning out of the lateral drains are best addressed with a small track mounted excavator unit.

Areas of open standing water are not ideal as they can be a major attraction for birds, additional soak holes are to be trialled in areas of ponded water clear of the runway strip to try and drain these areas into the underlying aquifer. Soak hole construction is best implemented with the bobcat auger unit as trialled on site during the inspection.

6.8 Recommended Additional Plant Items

AECOM recommends consideration of buying the following plant items for maintaining the runway longer term.

6.8.1 FOD-Boss

These are used world-wide at airports as speedy minimal maintenance surface cleaners; this will be an ideal unit for removing any small stones and related FOD prior to aircraft operations. The units fold down into a compact unit and are air transportable.

6.8.2 HD Agricultural Tractor Mower Attachment

A heavy-duty agricultural mower is recommended (refer section 4 of this report). Current mower units used on site are lighter duty parks and groomed grass units and are not suited to the current conditions, this results in added maintenance and higher wear and tear issues.

6.8.3 Bobcat 3700 Skid Steer Attachments

We recommend additional attachments for the bobcat skid steer unit be acquired, specifically a multi-use sweeper - bucket combo unit.

The sweeper bucket might also prove quite effective for removing the green algal growth that swells during rainfall and makes the runway quite slippery in locations.

We also recommend consideration of an excavator backhoe attachment; this should be priced compared to a small 8t hydraulic excavator unit as an alternative option.

6.8.4 Additional 4-wheel Bobcat Skid Steer

We recommend consideration of buying a second Bobcat 4-wheel skid steer unit, this will be more suitable for working on the runway than the tracked unit.

6.8.5 Small Hydraulic Excavator Unit

The current CAT tractor backhoe unit is no longer serviceable, recommend consideration of a small rubber track hydraulic excavator which will have allot of utility capability around the camp and for clearing out the longer lateral drainage paths to the coastline areas.

6.9 Repairs to Existing Plant Items

Recommend that the tractor grader blade and box blade units are repaired by the site team mechanical staff and be bought back into a serviceable condition. The grader blade is needed for regular mucking out of the swale drains. The box blade is needed for the levelling of the grass flank areas.

All ancillary mounted plant items should be consolidated around usage on the two serviceable John Deere tractors and the Bobcat 3700 unit as applicable.