8490 South Power Road, Suite 105-181  Gilbert, AZ 85297  Office (480) 987-7823  Fax (480) 987-7824

Aeronautical Impacts of the North Shore Marine Transfer Station 

Executive Summary

Williams Aviation Consultants was retained by New York Metro Peterbilt to review the 

proposed North Shore Marine Transfer Station (NSMTS) located 1,850 ft southeast of 

LaGuardia airport (LGA). The purpose of the review was to determine: (a) if construction of the 

building and associated gantry cranes would prevent future safety enhancements to the airport’s 

instrument approach procedures, (b) to determine if the structures associated with the NSMTS 

would be a hazard to aircraft approaching LGA and (c) to determine the safety issues related to 

the NSMTS attracting large birds that can be ingested into jet engines of aircraft approaching and 

departing LGA.

The landing phase of flight puts a significant amount of stress on pilots. During an approach and 

landing the pilot is controlling the aircraft, referencing several instruments, talking to air traffic 

control and looking for other aircraft. Due to the great amount of multi-tasking and the need for 

concentration, the landing phase of flight is the most critical and most dangerous. Therefore, it 

should be the prerogative of both the airport owner and the authority that controls land use 

around an airport to provide pilots with accurate navigational equipment and to prevent 

unnecessary obstructions from interfering with an approach to the airport.

LaGuardia Airport (LGA) is one of the busiest airports in the United States. The airport has, on 

average, 1,038 operations per day and had over 370,000 operations in 2008. In 2009, 26 

scheduled airlines were operating from the airport. The airport has two intersecting runways 

which are perpendicular to each other. Aircraft that approach the airport from the southeast 

utilize Runway 31. Runway 31 is the only runway at LGA that lacks a precision instrument 

approach such as an Instrument Landing System (ILS).

Williams Aviation Consultants concluded that the proposed NSMTS would pose a significant 

safety hazard to aircraft approaching LGA. The comprehensive review found in Appendix I

concluded the NSMTS would be a significant safety hazard to aircraft for the following reasons:

1. The construction of the NSMTS buildings will severely restrict the potential Decision 

Altitude and visibility requirements of the proposed ILS approach procedure to 

Runway 31.
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2. The construction of the NSMTS will attract a significant amount of large birds that 

can be ingested into the jet engines of arriving and departing aircraft thereby causing 

a catastrophic failure of the engine.

3. The approval of the NSMTS is in direct violation of Federal Aviation 

Administration’s (FAA) Terminal Instrument Procedure Guidelines and should be 

determined to be a hazard to navigation by the FAA.

4. The proposed transfer station would be in the Runway Protection Zone (RPZ) of 

Runway 31. FAA airport design guidelines discourage any projects that could attract 

birds within the RPZ.

5. The NSMTS will be a significant obstacle and distraction located very close to the 

end of Runway 31 which pilots will need to avoid during the critical landing phase of 

flight.

Background

The North Shore Marine Transfer Station is currently under construction on Flushing Bay in 

College Point, NY. The new transfer station will receive in excess of 2000 tons of loose garbage 

daily. Garbage trucks will dump their loads inside the transfer station. Workers will then load the 

garbage into containers, and lid the containers. The containers will be placed on barges and 

transported, by barge, through waterways that cross beneath the flight paths of LaGuardia 

Runways 31 and 22. The barges will pass within 500 feet of the end of Runway 31 and through 

the flight path of Runway 22. 

Instrument Approach Procedures

During periods of low visibility and bad weather a pilot will navigate primarily by reference to 

instruments rather than by outside visual references. Instrument Meteorological Conditions 

(IMC) is a term used to describe the weather conditions that require the pilot to navigate using 

the aircraft’s instruments. When an aircraft is approaching an airport the pilot utilizes an 

Instrument Approach Procedure (IAP). Instrument approach procedures are classified as either 

“non-precision” or “precision”. 

A pilot who uses a non-precision instrument approach procedure is navigating with instruments 

that provide lateral guidance only. An example of this type of instrument approach is called a 

“localizer approach” in which a ground based antenna array called a “localizer” transmits a 

signal which is received by instruments in the aircraft. Using this type of approach means that 

the pilot only knows if the aircraft is in line with the runway but does not know if the aircraft is 

too high or low to complete a safe landing. Runway 31 at LGA is equipped with a localizer.

A pilot who uses a precision instrument approach procedure is navigating with instruments that 

provide both lateral and vertical guidance so the pilot knows if the aircraft is in line with the 

runway and that the aircraft is not too high or low to complete a safe landing. An example of this 

type of approach is called an Instrument Landing System (ILS) which consists of two ground 
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based antenna arrays. A localizer antenna provides the lateral information and a glide slope 

antenna provides the vertical guidance. Runway 31 is not currently equipped with an ILS, 

although an ILS for Runway 31 is in the planning stages at the Federal Aviation Administration 

(FAA).

Each instrument approach procedure is designed to ensure aircraft will remain a safe distance 

from structures and terrain. The elevation to which a pilot can safely descend is called the 

Decision Attitude (DA). The IAP also contains a minimum visibility requirement, which is the 

lateral distance an observer on the ground can see into the horizon. Visibility is reported in 

statute miles or fractions of miles. Visibility can also be expressed as Runway Visual Range 

(RVR) which is reported in hundreds of feet. 

If the pilot cannot see the runway environment upon descending to the DA, a missed approach 

procedure is executed. The missed approach procedure contains the instructions that the pilot 

follows to ensure that the aircraft will remain a safe distance from structures and terrain as the 

pilot navigates away from the airport and the aircraft increases in altitude. 

In order to maximize the number of possible operations and provide pilots with a safe option to 

approach an airport during periods of inclement weather and low visibility, it is desirous to 

design instrument approach procedures that allow pilots to descend to the lowest possible 

elevation, before the pilot must decide whether it is safe to land on the runway. Structures 

located near the airport often prevent the decision altitude from being set at its lowest possible 

elevation. In this situation a pilot may not be able to descend below the lowest cloud layer and 

therefore cannot land at the airport.

Issues

Impact to Runway 31 Instrument Approach Procedure

LGA has two Runways; 4/22 and 13/31. It is safer for aircraft to land into the wind. Therefore, 

in the event of a crosswind on Runway 4/22 it is preferable for aircraft to land on Runway 31. 

Since Runway 31 does not have a precision instrument approach, when visibility is below 1 mile, 

arriving flights cannot use Runway 31 and are forced to fight the crosswind on Runway 4 to land

or they must divert to another airport. Strong winds crossing Runway 4/22 substantially limit the 

use of that runway. The FAA, Air Traffic Control System Command Center reports: “If the wind 

[across the runways at LaGuardia] is strong enough to force the use of only one runway for 

purposes of avoiding a significant cross wind component on the other runway, the airport Arrival 

Rate [can be substantially reduced] which would cause demand to exceed capacity for a period

of several hours.”
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An ILS installation on Runway 31, with visibility requirements as low as 1⁄2 mile, would 

eliminate the need for pilots to land in a cross wind and allow the use of Runway 31 in nearly all 

inclement weather conditions, thereby making LGA a safer and more efficient airport. 

There are, at present, three obstructions in the flight path for Runway 31 that prevent the full use

of an ILS system for Runway 31. Two of these obstructions are silos employed for the storage of 

asphalt and cement located directly across Flushing Bay from the runway. Both of these 

obstructions could be removed or lowered, at minimal cost. The other obstruction is the existing 

transfer station, currently scheduled for demolition, which penetrates a surface used in designing 

the instrument approach by only 3 ft. It also is believed that this penetration is an obstruction 

light on the transfer station which could also be lowered at minimal cost. 

The construction of the NSMTS will eliminate the possibility of implementing an instrument 

approach procedure to Runway 31 with visibility requirements as low as 1⁄2 mile and a Decision 

Altitude as low as 219 ft AMSL. The NSMTS will instead require that the visibility requirement 

be set at 1 mile and the Decision Altitude be set at 311 ft AMSL.

According to the United States Standard for Terminal Instrument Procedures 8260.3B, the 

proposed transfer station should not be approved because it will penetrate the obstacle clearance 

surfaces (OCS) for an ILS procedure. According to these guidelines, proposed obstructions shall 

not penetrate the OCS.

Bird Attractant and Runway Protection Zone

Not only will the NSMTS impact the proposed ILS, but the transfer station will also attract large 

birds and, therefore, there will be a risk of wildlife ingestion and catastrophic failure of the 

aircraft’s jet engines. In the past nine months there have been three reported bird strikes at LGA, 

including the bird strike that brought down US AIR Flight 1451. The garbage processed at the 

NSMTS will leave that facility by barge, also a bird attractant that will pass within 500 feet of 

Runway 31, and Runway 22 at LaGuardia Airport.

The NSMTS would also be located in the runway protection zone (RPZ) for Runway 31 which 

extends 2,500 ft from the end of the runway. According to FAA guidelines bird attractants, such 

as waste management facilities should not be constructed within the RPZ. 

The NSMTS would be outside the RPZ if the FAA was not planning to install an ILS for 

Runway 31 with visibility minimums lower than 3⁄4 of a mile. But FAA guidelines state clearly 

that the calculation of the RPZ is determined not only by existing navigation aids, but by any 

plans to install a modern ILS navigation aid on that Runway.

Proximity of Approaching Aircraft

The NSMTS will rise 100.06 feet Above Mean Sea Level (AMSL) and above the level of 

Flushing Bay. In normal operations, the approach path for an aircraft landing on Runway 31 will 
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pass less than 70 feet vertically and less than 350 feet horizontally from the NSMTS structure.

As stated previously, the landing phase of flight places a tremendous amount of stress on the 

pilot. As a pilot approaches Runway 31, the NSMTS structures and birds flying around the 

facility will undoubtedly be a distraction to pilots approaching Runway 31. The transfer station’s 

proximity to approaching aircraft could place the aircraft, its passengers, crew and people on the 

ground in jeopardy.
8490 South Power Road, Suite 105-181  Gilbert, AZ 85297  Office (480) 987-7823  Fax (480) 987-7824

Appendix I

Aeronautical Impacts of the North Shore Marine Transfer Station 

Issue:

Williams Aviation Consultants was retained by New York Peterbilt to review the proposed North 

Shore Marine Transfer Station (NSMTS) located 1,850 ft southeast of LaGuardia airport (LGA). 

The purpose of the review was to determine: (a) if construction of the building and associated 

gantry cranes would prevent future safety enhancements to the airport’s instrument approach 

procedures, (b) to determine if the structures associated with the NSMTS would be a hazard to 

aircraft approaching LGA and (c) to determine the safety issues related to the NSMTS attracting 

large birds that can be ingested into jet engines of aircraft approaching and departing LGA.

This analysis included our review of a proposed Instrument Landing System (ILS) approach

designed by the Federal Aviation Administration (FAA) for Runway 31, as well as a review of 

an independent study by QED Consultants which suggested alternative ILS designs and 

examined the possible impacts of the proposed transfer station. Williams Aviation Consultants 

also reviewed additional ILS alternatives to determine if it is possible to reduce the Decision 

Altitude (DA)/Decision Height (DH)

1

and visibility requirements. Figure 1 displays the location 

and elevation of the proposed Marine Transfer Station as well as the location and elevation of 

other structures in the vicinity of the transfer station.

 

1 All terms used in this report are further defined in the Glossary found in Appendix II
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Figure 1

Instrument Approach Procedure Analysis

Background

During periods of inclement weather and low visibility a pilot approaching the airport will utilize 

an instrument approach procedure. The instrument approach procedure is designed to allow the 

pilot to descend to the lowest possible altitude while maintaining a safe distance between the 

aircraft and all obstacles. It is desirous to have the instrument approach procedure designed to 

allow pilots to descend to the lowest possible altitude and with the lowest possible visibility in 

order to maximize safe airport operations throughout the year.

If the pilot cannot see the runway environment upon descending to the Decision Altitude, a 

missed approach procedure is executed. The missed approach procedure contains the instructions 

that the pilot follows to ensure the aircraft will remain a safe distance from structures and terrain 

as the pilot navigates away from the airport and increases in altitude.

There are several types of instrument approach procedures that provide navigational guidance to 

pilots during periods of low visibility. For the purposes of this discussion, the ILS instrument 

approach procedure will be analyzed because it provides the pilot with the lowest possible DA 
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and most commercial aircraft are equipped with the necessary instruments to fly this type of 

instrument approach.

The guidelines for designing an ILS approach are contained in the United States Standard for 

Terminal Instrument Procedures (TERPS) FAA Order 8260.3B. The TERPS guidelines use a 

combination of imaginary sloping surfaces called Obstacle Clearance Surfaces (OCS), Glide 

Qualification Surface (GQS), obstacle identification surfaces (OIS) and Missed Approach 

Surfaces to determine the DA and visibility requirements for an instrument approach.

Obstacle Clearance Surfaces (OCS)

The OCS is made up of three separate surfaces called the W, X and Y surfaces. The W surface 

rises at a slope dependent on the Glide Path Angle (GPA) of the aircraft. The GPA is the angle 

at which the aircraft descends down to the DA. The X surface rises at a slope of 4:1 from the side 

of the W surface. The Y surface rises at a slope of 7:1 from the side of the X surface. Figure 2

displays how these surfaces relate to each other as they extend from the runway end.

Figure 2

If an obstacle penetrates the above surfaces, the glide path is first increased to eliminate the 

penetration. The DA is then increased if the penetration cannot be eliminated by increasing the 

glide path. As shown in Figure 3, Chapter 3, paragraph 3.8 of the United States Standard for 

Terminal Instrument Procedures Order 8260.3B only allows existing obstructions to penetrate 

the OCS. Proposed obstructions are not to penetrate the OCS.
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Figure 3

Glide Qualification Surface (GQS)

The GQS extends from the runway threshold along the runway centerline and extends to the DA 

point (Figure 4). It limits the height of obstructions between the DA and runway threshold. The 

GQS, must be free from penetration. If the GQS is penetrated, an instrument approach procedure 

with positive vertical guidance is not authorized.

Figure 4 – Runway 31 Glide Qualification Surface –

The proposed transfer station is less than 140 ft outside the surface that determines if a 

precision instrument approach procedure can be authorized to Runway 31.
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Obstacle Identification Surfaces (OIS)

There are two different obstacle identification surfaces (OIS) which extend from the runway 

threshold and increase in height at a slope of 20:1 and 34:1. These surfaces are used to determine 

the visibility requirements for the instrument approach procedure. If the 34:1 surface is 

penetrated the visibility for the approach cannot be lower than 3⁄4 of a mile/Runway Visual Range 

(RVR) of 4,000 ft. If the 20:1 surface is penetrated the visibility for the approach cannot be 

lower than 1 mile/ 5000 RVR.

Missed Approach Procedure Surfaces

A missed approach area is evaluated to ensure that an aircraft will remain a safe distance from 

obstacles in the event that a pilot cannot see the runway during an instrument approach and must 

therefore execute a missed approach. The area considered for obstacles has an initial width equal 

to the OCS and expands uniformly as it extends from the decision altitude point (Figure 5). If 

obstacles penetrate the missed approach procedure surface, the DA must be increased to prevent 

penetration. Section 1a takes into account that an aircraft will continue to descend slightly after 

reaching the DA. Section 1b increases at a slope of 28.5:1 and assumes the aircraft has begun to 

increase in altitude. Section 1C is a sloped surface which increases at a slope of 7:1 from the 

sides of Section 1b and 1a.

Figure 5 – Missed Approach Surfaces
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Analysis:

Five ILS alternatives were analyzed to determine how the proposed transfer station would impact 

potential DA and visibility requirements for an ILS approach to Runway 31 at LGA. The results 

were then compared with the QED and FAA analysis for consistency. The five ILS alternatives 

included:

1. An offset ILS approach to the north

2. An offset ILS approach to the south

3. Straight in ILS approach

4. Straight in ILS with key obstacles lowered

5. Straight in ILS with 3 degree glide slope and all off-airport obstacles lowered (test for 

Cat II ILS feasibility) 

Existing obstacle data for the analysis was derived from FAA documents. Figure 6 and Figure 7

display the height and location of key obstacles that would impact the proposed ILS approach:

Figure 6
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Figure 7
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The proposed Transfer Station location and elevation data was derived from the FAA documents 

and is displayed in Figure 8.

Figure 8

Analysis of ILS Approach to the North:

Presently, Runway 31 is equipped with a localizer instrument approach. This type of instrument 

approach procedure consists of a ground based antenna array called a “localizer” which transmits 

a signal that is received by instruments in the aircraft. A localizer only provides the pilot with 

lateral information, therefore, the pilot only knows if the aircraft is lined up with the runway but 

does not know if the aircraft is too high or low to land safely. 

The current localizer approach is offset slightly to the south. The QED report and FAA analysis 

reviewed alternatives which included further offsets to the south and a “straight in” ILS 

approach. An offset to the north was not studied in the QED report or FAA analysis.

In order for an offset ILS approach to the north to meet TERPS requirements, the localizer 

antenna would need to be located on the south side of the Runway 13/31. This would allow 

aircraft to cross the extended runway centerline at a safe distance from the runway. Figure 9

displays where the localizer antenna would need to be located (shown in yellow) in order for an 

ILS approach that is offset to the north, to be feasible.
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Figure 9

Conclusion: An ILS approach that is offset to the north would not be feasible because the 

localizer antenna would need to be located on the south side of Runway 13/31. There is not 

sufficient land on the south side of the runway for a localizer antenna. Aircraft using the 

taxiways would also pass in front of the localizer which would reflect the localizer signal and 

make the localizer unusable. An ILS approach that is offset to the north is not feasible.

Analysis of ILS Approach Offset to the South:

Both the QED and FAA analysis studied an ILS approach that is offset to the south. A Freedom 

of Information Act (FOIA) request of the proposed ILS procedure package revealed that the 

FAA is planning on implementing this offset ILS approach.

The controlling obstacle for this approach is an existing 345 ft AMSL building as shown in 

Figure 10. This controlling obstacle requires that the Glide Path Angle is increased to 3.07 

degrees. The existing 108 ft AMSL “cement stack” penetrates the OCS and missed approach 

segments of the instrument approach. Unless these “cement stack” penetrations are lowered or 

removed, the DA must be increased to 311 ft AMSL.
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Figure 10

When the proposed transfer station was included in the obstructions it was revealed that the 

proposed structure would penetrate the OCS. However the effect on the DA would not be greater 

than the existing 108 ft AMSL cement stack (Figure 11).Therefore, provided that the other 

obstacles are not lowered or removed, the proposed transfer station would not necessitate an 

increase to the DA of the offset ILS approach.
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Figure 11

The TERPS guidelines state that proposed obstructions shall not penetrate the OCS (Figure 12).

The proposed transfer station will penetrate the offset OCS by 21.2 ft. According the TERPS 

guidelines, the proposed transfer station should not be approved by the FAA.

Figure 12

An analysis of the 34:1 OIS, for the proposed off-set ILS approach to Runway 31, revealed that 

several existing structures penetrate this surface (Figure 13 and Figure 14). The structures that 

penetrate the 34:1 OIS include the: cement stack, localizer antenna, fence, the existing transfer 

station and existing 97 ft building. The proposed transfer station would also penetrate the 34:1 

OIS. Due to these existing and proposed penetrations, the visibility requirements of this approach 

could not be less that 3⁄4 mile or 4,000 ft RVR.
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Figure 13 – Top view of the 34:1 OIS

Figure 14 – Side view of 34:1 OIS – Proposed transfer station penetrates by more than 37 ft

An analysis of the 20:1 OIS revealed that only two existing structures penetrate this surface 

(Figure 15 and 16). The structures that penetrate the 20:1 OIS include the: localizer antenna and 

on-airport fence. The proposed transfer station would also penetrate the 20:1 OIS. Due to these 

existing and proposed penetrations, the visibility requirements of this approach could not be less 

that 1 mile or 5,000 ft RVR. It is worth noting that the two existing penetrations could be 

eliminated if the localizer antenna were moved further away from the runway and the fence 
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lowered. Eliminating these two existing penetrations would be reasonable in order to reduce the 

visibility requirements of this approach. If the proposed transfer station were constructed, this 

option would not be feasible.

Figure 15 – Top view of 20:1 OIS
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Figure 16 - Side view of 20:1 OIS – Proposed transfer station penetrates by 3 ft

Conclusion: The proposed transfer station will penetrate the OCS but would have no effect on 

the DA of an offset ILS approach because the existing 108 ft AMSL cement stack has a 

greater impact on the OCS then the proposed transfer station. The TERPS guidelines, 

however, state that proposed obstructions “shall not penetrate the OCS”. According the FAA’s 

TERPS guidelines the proposed transfer station should not be approved because it is a 

proposed obstruction.

The proposed transfer station will also penetrate the 20:1 OIS. Two existing structures already 

penetrate the 20:1 OIS. However it may be possible to eliminate these penetrations by moving 

the localizer antenna and reducing the fence height. If the 20:1 OIS were free from 

penetration the visibility requirements for this approach could be reduced from 1 mile/5,000' 

RVR to 3⁄4 mile/4,000' RVR. Constructing the proposed transfer station would make this option 

of reducing the visibility requirements to the offset ILS no longer feasible.

Analysis of “straight-in” ILS Approach:

Both the QED and FAA analysis studied a “straight-in” ILS approach. The controlling obstacle 

for this approach is an existing 345 ft AMSL building as shown in Figure 17. This controlling 

obstacle requires the Glide Path angle be increased to 3.08 degrees. The existing 108 ft AMSL 
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“cement stack” penetrates the OCS and missed approach segments of the instrument approach. 

Unless these “cement stack” penetrations can be lowered or removed, the DA must be increased 

to 312 ft AMSL.

Figure 17
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When the proposed transfer station was included in the obstructions analysis, it was revealed that 

the proposed structure would penetrate the OCS. However, provided that the other obstacles are 

not lowered or removed, the effect on the DA would not be greater than the existing 108 ft 

AMSL cement stack (Figure 18).Therefore, the proposed transfer station would not necessitate 

an increase to the DA of the straight-in ILS approach.

Figure 18

The TERPS guidelines state that proposed obstructions shall not penetrate the OCS (Figure 19). 

The proposed transfer station will penetrate the straight in OCS by 8.4 ft. According the TERPS 

guidelines, the proposed transfer station should not be approved by the FAA.

Figure 19
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An analysis of the 34:1 OIS revealed that several existing structures penetrate this surface 

(Figure 20 and 21). The structures that penetrate the 34:1 OIS include the: cement stack, 

localizer antenna, fence, existing transfer station and existing 97 ft building. The proposed 

transfer station would also penetrate the 34:1 OIS. Due to these existing and proposed 

penetrations, the visibility requirements of this approach could not be less that 3⁄4 mile or 4,000 ft 

RVR.

Figure 20 – Top view of 34:1 OIS

Figure 21 - Side view of 34:1 OIS – Proposed transfer station penetrates by more than 37 ft
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An analysis of the 20:1 OIS revealed that only two existing structures penetrate this surface 

(Figure 22 and 23). The structures that penetrate the 20:1 OIS include the: localizer antenna and 

on-airport fence. The proposed transfer station would also penetrate the 20:1 OIS. Due to these 

existing and proposed penetrations, the visibility requirements of this approach could not be less 

that 1 mile/5,000 ft RVR. It is worth noting the two existing penetrations could be eliminated if 

the localizer antenna were moved further away from the runway and the fence lowered. 

Eliminating these two existing penetrations would be reasonable in order to reduce the visibility 

requirements of this approach. If the proposed transfer station were constructed, this option 

would not be feasible.

Figure 22 – Top view of 20:1 OIS
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Figure 23 - Side view of 20:1 OIS – Proposed transfer station penetrates by 3 ft

Conclusion: The proposed transfer station will penetrate the OCS but would have no effect on 

the DA of straight-in ILS approach unless the existing 108 ft AMSL cement stack cannot be 

lowered or removed, in which case the proposed transfer station becomes the controlling 

obstacle. The TERPS guidelines state that proposed obstructions “shall not penetrate the 

OCS”. According the FAA’s TERPS guidelines the proposed transfer station should not be 

approved because it is a proposed obstruction and it penetrates the OCS.

The proposed transfer station will also penetrate the 20:1 OIS. Two existing structures already 

penetrate the 20:1 OIS however it may be possible to eliminate these penetrations by moving 

the localizer antenna and reducing the fence height. If the 20:1 OIS were free from 

penetration the visibility requirements for this approach could be reduced from 1 mile (5,000' 

RVR) to 3⁄4 mile (4,000' RVR). Constructing the proposed transfer station would make this 

option of reducing the visibility requirements to the straight-in ILS no longer feasible.
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Straight in ILS with 3 degree glide slope and all off-airport obstacles lowered 

(Test for Cat II ILS feasibility)

ILS approaches can be divided into three categories. An ILS is considered to be Category I if the 

instrument approach has a Decision Height (DH) not lower than 200 feet above the touchdown 

zone. A Category 2 instrument approach has a DH not lower than 100 feet above the touchdown 

zone. A Category III approach can have a DH as low as 0 feet.

An analysis was completed to determine how the proposed transfer station would impact the 

feasibility of a Cat II ILS approach. This analysis assumed that all the off-airport obstacles were 

lowered so as to not penetrate the 34:1visibility surface and an OCS associated with a 3 degree 

glide slope. Therefore this analysis assumed the following reductions:

1. The 108 ft AMSL cement stack was lowered 25 ft to a height of 83 ft AMSL

2. The existing 97 ft AMSL building was lowered 2 ft to a height of 95 ft AMSL

3. The existing 69 ft AMSL transfer station was lowered 3 ft to a height of 66 ft ASML 

4. The existing 345 ft AMSL building was lowered 8 ft to a height 337 ft AMSL (Note: 

It is believed this reduction is applicable only to an antenna on the Skyline Towers 6)

The analysis also assumed that the on-airport obstacles including the fence and localizer antenna 

were either moved or approved as exceptions by the FAA. It was also assumed that all on-airport 

requirements were fulfilled including the introduction of an airport lighting system, dual glide 

slope antennae, aircraft clearance areas and relocation of ILS antenna.

The analysis revealed that the new air traffic control tower (ATCT) penetrated the missed 

approach obstacle clearance surfaces associated with a straight-in instrument approach as shown 

in Figure 24.
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Figure 24

Figure 25 displays that the new air traffic control tower penetrated the missed approach segment 

by 15 ft. 

Figure 25

Assuming the existing structures were reduced, the new Air Traffic Control tower would then 

penetrate the missed approach segment of the obstacle clearance surfaces. A DA of 219 AMSL 

would be required to mitigate the penetration of the new Air Traffic Control Tower. The 

visibility requirements for this approach could also be reduced to 1⁄2 mile/RVR of 2,400 ft.

Conclusion: The TERPS design guidelines for a CAT II ILS approach include a requirement 

for the CAT I ILS to achieve a DH of 200 ft and visibility of 1⁄2 mile. The penetration of the 

new Air Traffic Control tower to the missed approach segment of the CAT I ILS surfaces

makes a CAT II ILS not feasible. Therefore the impact of the proposed transfer station on the 

feasibility of a CAT II ILS approach is not applicable.
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Straight in ILS with key obstacles lowered

An analysis was completed to determine how the proposed transfer station would impact a 

straight in ILS approach assuming key obstacle were lowered so as to not penetrate the 

34:1visibility surface and on airport obstacles including the fence and localizer antenna were 

either moved or approved as exceptions by the FAA. This analysis also assumed all on-airport 

requirements were fulfilled including the introduction of an airport lighting system. Therefore 

this analysis assumed the following reductions:

1. The 108 ft AMSL cement stack was lowered 25 ft to a height of 83 ft AMSL

2. The existing 97 ft AMSL building was lowered 2 ft to a height of 95 ft AMSL

3. The existing 69 ft AMSL transfer station was lowered 3 ft to a height of 66 ft ASML 

The controlling obstacle for this approach is an existing 345 ft AMSL building as shown in 

Figure 26. This controlling obstacle requires the Glide Path angle be increased to 3.08 degrees.

Figure 26

Assuming the existing structures are reduced, the new Air Traffic Control tower would then

penetrate the missed approach segment of the obstacle clearance surfaces as shown Figure 27. A 

DA of 219 AMSL would be required to mitigate the penetration of the new Air Traffic Control 

Tower. The visibility requirements for this approach could also be reduced to 1⁄2 mile/RVR of 

2,400 ft.
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Figure 27

The introduction of the proposed transfer station into this analysis revealed that the DA would 

need to be increased to 248 AMSL. The 20:1 OIS would also be penetrated; therefore the 

visibility requirements would be increased to 1 mile/5,000 ft RVR.

Conclusion: Assuming that key obstacles could be reduced in height so as to not penetrate the 

34:1 OIS, the DA could be reduced to 219 AMSL and visibility requirements reduced to 1⁄2

mile/RVR of 2,400 ft. The proposed transfer station would substantially impact this scenario in 

that the DA would be increased to at least 248 AMSL and the visibility requirements increased

to 1 mile/5,000 ft RVR.

Bird Attractant and Runway Protection Zone

The NSMTS will receive in excess of 2000 tons of loose garbage daily. Garbage trucks will 

dump their loads inside the transfer station. Workers will then load the garbage into containers, 

and lid the containers. The containers will be placed on barges and transported, by barge, through 

waterways that cross beneath the flight paths of LaGuardia Runways 31 and 22. The barges will 

pass within 500 feet of the end of Runway 31 and through the flight path of Runway 22. 

The North Shore Marine Transfer Station expansion, despite its planned facility enclosure, barge 

trash containers, and other potential mitigating efforts, will attract large numbers of medium to 

large sized birds; in particular, high concentrations of Crows and Gulls. 
Appendix I 

Williams Aviation Consultants, Inc. A1- 24 

Exposed trash from inadequately-sealed containers, peripheral trash spill over onto barge 

surfaces and continuous odors emanating from barges and the facility, will serve as powerful 

bird attractants as these vessels transit runway centerline. The presence of these birds pose high 

risks to aircraft.

In the past nine months there have been three reported bird strikes at LGA, including the bird 

strike that brought down US AIR Flight 1451. The garbage processed at the NSMTS will leave 

that facility by barge, also a bird attractant that will pass within 500 feet of Runway 31, and 

Runway 22 at LaGuardia Airport.

The NSMTS would also be located in the runway protection zone (RPZ) for Runway 31 which 

extends 2,500 ft from the end of the runway (Figure 28). According to FAA guidelines 

(Advisory Circular 150-520-33) bird attractants, such as waste management facilities should not 

be constructed within the RPZ. 

Figure 28

Were there no plans to install an ILS for Runway 31, the RPZ for that runway would extend only 

1,700 feet, and the NSMTS would be outside the RPZ. But FAA airport design guidelines 

(Adivsory Circular 150-5300-13) state clearly that the calculation of the RPZ is determined not 

only by existing navigation aids, but by any plans to install a modern ILS navigation aid on that 

Runway.
Appendix I 

Williams Aviation Consultants, Inc. A1- 25 

Proximity of Approaching Aircraft

The NSMTS will rise 100 feet above the level of Flushing Bay. In normal operations, the 

approach path for an aircraft landing on Runway 31 will pass less than 70 feet vertically and less 

than 350 feet horizontally from the NSMTS structure. As stated previously, the landing phase of 

flight places a tremendous amount of stress on the pilot. As a pilot approaches Runway 31, the 

NSMTS structures and birds flying around the facility will undoubtedly be a distraction to pilots 

approaching Runway 31. The transfer station’s proximity to approaching aircraft could place the 

aircraft, its passengers, crew and people on the ground in jeopardy.

Consultants Conclusions: 

An ILS approach that is offset to the north would not be feasible because the localizer antenna 

would need to be located on the south side of Runway 13/31. There is not sufficient land on 

the south side of the runway for a localizer antenna. Aircraft using the taxiways would also 

pass in front of the localizer which would reflect the localizer signal and make the localizer

unusable. An ILS approach that is offset to the north is not feasible.

The proposed transfer station will penetrate the OCS for both a “Straight-in” and offset ILS 

approach. These penetrations will result in the NSMTS being the controlling obstacle, unless

the existing 108 ft AMSL cement stack cannot be lowered or removed. The TERPS guidelines, 

however, state that proposed obstructions “shall not penetrate the OCS”. According the FAA’s 

TERPS guidelines the proposed transfer station should not be approved because it is a 

proposed obstruction.

The proposed transfer station will also penetrate the 20:1 OIS for both the “straight-in” and 

offset ILS approaches. Two existing structures already penetrate the 20:1 OIS, however it may 

be possible to eliminate these penetrations by moving the localizer antenna and reducing the 

fence height. If the 20:1 OIS were free from penetration the visibility requirements for this 

approach could be reduced from 1 mile (5,000' RVR) to 3⁄4 mile (4,000' RVR). Constructing 

the proposed transfer station would make this option of reducing the visibility requirements to 

the offset ILS no longer feasible.

The TERPS design guidelines for a CAT II ILS approach include a requirement for the CAT I 

ILS to achieve a DH of 200 ft and visibility of 1⁄2 mile. The penetration of the new Air Traffic 

Control tower to the missed approach segment of the CAT I ILS surfaces makes a CAT II ILS 

not feasible. Therefore the impact of the proposed transfer station on the feasibility of a CAT 

II ILS approach is not applicable.

Assuming that off airport obstacles could be reduced in height so as to not penetrate the 34:1 

OIS, the DA could be reduced to 219 AMSL and visibility requirements reduced to 1⁄2 

mile/RVR of 2,400 ft. The proposed transfer station would impact this scenario in that the DA 

would be increased to 248 ft AMSL and the visibility requirements increased to 1 mile/5,000 ft 

RVR.
Appendix I 

Williams Aviation Consultants, Inc. A1- 26 

According to the United States Standard for Terminal Instrument Procedures 8260.3B, the 

proposed transfer station should not be approved because it will penetrate the OCS for the 

offset ILS as designed by the FAA. According to these guidelines, proposed obstructions shall 

not penetrate the OCS. Constructing the proposed transfer station will prevent the DA from 

being reduced to as low as 219 ft AMSL should key obstacles be reduced in height in the 

future. The proposed transfer station would also eliminate the possibility of reducing the 

visibility requirements of this approach from 1 mile (5,000' RVR) to 1/2 mile (2,400' RVR) 

because the structure will penetrate the 20:1 OIS.

Exposed trash from inadequately-sealed containers, peripheral trash spill over onto barge 

surfaces, and continuous odors emanating from barges and the facility, will serve as powerful 

bird attractants as these vessels transit runway centerline. The presence of these birds pose 

high risks to aircraft.

The NSMTS would also be located in the runway protection zone (RPZ) for Runway 31 which 

extends 2,500 ft from the end of the runway. According to FAA guidelines (Advisory Circular 

150-520-33) bird attractants, such as waste management facilities should not be constructed 

within the RPZ. 

It is Williams Aviation Consultant’s professional opinion that the NSMTS should not be 

permitted to be constructed. As outlined in this report the proposed NSMTS would pose a 

significant safety hazard to aircraft approaching LGA and prevent an Instrument Landing 

System approach from achieving the lowest possible DA and Visibility minimums. This

comprehensive review concluded the NSMTS would be a significant safety hazard to aircraft 

for the following reasons:

1. The construction of the NSMTS buildings will severely restrict the potential 

Decision Altitude and visibility requirements of the proposed ILS approach 

procedure to Runway 31.

2. The construction of the NSMTS will attract a significant amount of large birds that 

can be ingested into the jet engines of arriving and departing aircraft thereby 

causing a catastrophic failure of the engine.

3. The approval of the NSMTS is in direct violation of Federal Aviation 

Administration’s (FAA) Terminal Instrument Procedure Guidelines and should be 

determined to be a hazard to navigation by the FAA.

4. The proposed transfer station would be in the Runway Protection Zone (RPZ) of 

Runway 31. FAA airport design guidelines discourage any projects that could 

attract birds within the RPZ.

5. The NSMTS will be a significant obstacle and distraction located very close to the 

end of Runway 31 which pilots will need to avoid during the critical landing phase 

of flight.
Appendix II – Acronyms and Definitions

A2 - 1

ASBL – Approach Surface Base Line - A horizontal line tangent to the surface of the earth at 

the runway threshold (RWT) point, aligned with the final approach course.

Category I (CAT I) Approach - A precision instrument approach and landing with a decision 

height not lower than 60m (200 ft) and with either a visibility not less than 800m (2400 ft), or a 

runway visual range not less than 550m (1800 ft). 

Category II (CAT II) Approach - A precision instrument approach and landing with a decision 

height lower than 60m (200 ft) but not lower than 30m (100 ft) and a runway visual range not 

less than 350m (1200 ft).

DA – Decision Altitude - A specified altitude in reference to mean sea level in an approach with 

vertical guidance at which a missed approach must be initiated if the required visual references 

to continue the approach have not been established.

DH – Decision Height - The height, specified in mean sea level (MSL), above the highest 

runway elevation in the touchdown zone at which a missed approach must be initiated if the 

required visual reference has not been established.

DME - Distance Measuring Equipment - On many instrument landing system procedures, a 

DME transmitter is placed at or near the localizer or glide slope transmitter to provide runway 

distance information for the pilot. The pilot has a DME receiver on board the aircraft which 

displays the distance from the DME transmitter.

FTP – Fictitious Threshold Point - The equivalent of the landing threshold point (LTP) when 

the final approach course is offset from runway centerline. It is the intersection of the final 

course and a line perpendicular to the final course that passes through the LTP.

GPA – Glide Path Angle - The angular displacement of the glidepath from a horizontal plane 

that passes through the LTP/FTP. This angle is published on approach charts.

GPI – Ground Point of Intercept - A point in the vertical plane containing the glidepath where 

the vertical path intercepts the ASBL. GPI is expressed as a distance from RWT.

GQS – Glide Qualification Surface - The GQS extends from the runway threshold along the 

runway centerline extended to the DA point. It limits the height of obstructions between DA and 

RWT. When obstructions exceed the height of the GQS, an approach procedure with positive 

vertical guidance (ILS, MLS, TLS, GLS, VNAV, etc.) is not authorized.

IFR - Instrument Flight Rules - When you are operating under instrument flight rules, you can 

fly in the clouds with no reference to the ground or horizon. Instrument flight rules govern flight 

operations in weather conditions below VFR minimums.
Appendix II – Acronyms and Definitions

A2 - 2

ILS - Instrument Landing System – A precision instrument approach system that normally 

consists of a localizer and glide slope electronics and visual aids, namely an outer marker, 

middle marker and approach lights.

LTP – Landing Threshold Point - The LTP is a 3D point at the intersection of the runway 

centerline and the runway threshold.

OCA – Obstacle Clearance Area - The area, defined by criteria, that is evaluated for obstacles.

OCS – Obstacle Clearance Surface - An inclined obstacle evaluation surface associated with a 

glidepath. The separation between this surface and the glidepath angle at any given distance from 

GPI defines the MINIMUM required obstruction clearance at that point.

OEA – Obstacle Evaluation Area - The area, defined by criteria, that is evaluated for obstacles.

OIS – Obstacle Identification Surface – A 20:1 and 34:1 surface which is used to determine 

the visibility requirements of an IAP.

RVR – Runway Visual Range - RVR is a system of measuring the visibility along the runway. 

An instrumentally derived value, it represents the horizontal distance a pilot will see down the 

runway from the approach end. RVR is based on the sighting of either high intensity runway 

lights or the visual contrast of other targets, whichever yields the greater visual range.

RWT – Runway Threshold - The RWT marks the beginning of that part of the runway usable 

for landing. It extends the full width of the runway. The RWT geographic coordinates identify 

the point the runway centerline crosses the RWT.