AFS-12-051-E 

June 22, 2012 

 Exemption No. 4760N 

 Regulatory Docket No. FAA-2001-9353 

Mr. Tony Dupea 

Chief Pilot 

PM Air, LLC d.b.a. Promech Air 

1515 Tongass Avenue 

Ketchikan, AK 99901 

Dear Mr. Dupea: 

This letter is to inform you that we have denied your petition to extend Exemption 

No. 4760, as amended. It explains the basis for our decision and describes its effect. 

The Basis for Our Decision 

By letter dated October 17, 2011, you petitioned the Federal Aviation Administration (FAA) 

on behalf of PM Air, LLC d.b.a. Promech Air (Promech), for an extension of Exemption 

No. 4760, as amended. That exemption from § 135.203(a)(1) of Title 14, Code of Federal 

Regulations (14 CFR) allowed Promech to operate under visual flight rules (VFR) outside 

controlled airspace over water at an altitude below 500 feet. 

Your original grant of exemption from the 500-foot altitude restriction in 14 CFR 

§ 135.203(a) stems from an exemption that was granted to the Alaska Air Carrier Association, 

Inc, (AACA) in March 1979. AACA petitioned on behalf of 10 air taxi operators who 

operated exclusively within a 150-mile radius of Ketchikan, Alaska, to fly below 500 feet 

within a certain corridor that was prone to congested traffic following completion of the 

newly constructed airport in Ketchikan on May 24, 1973. The FAA created this corridor to 

permit simultaneous instrument flight rules (IFR) and seaplane VFR operations. Because the 

ceiling of the corridor was limited to 400 feet, seaplane operators wishing to use this corridor 

for VFR operations had to seek an exemption from the altitude restrictions in 

14 CFR § 135.203(a). 
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As an additional basis for this original exemption request, AACA asserted that a weather 

phenomenon unique to the Alaskan coastal areas was also making it difficult to conduct 

commercial operations in the region. Given the frequency of snow, rain, drizzle, fog, and low 

ceilings due to the coastal weather, many of these operators could not conduct operations into 

remote villages, logging camps, and fishing and hunting areas. Further complicating these 

operations were the lack of navigational aids, IFR route and instrument approaches into these 

areas. Furthermore, given that waterways are acceptable landing fields for seaplanes, AACA 

asserted that seaplanes could be operated safely below the 500 foot limitation in 14 CFR § 

135.203 over the sheltered inland waterways of Southeast Alaska within the established 

corridor, without an adverse impact on safety. 

The FAA, in consideration of the public interest to provide service to these remote areas, 

granted the exemption but limited it to operations conducted in an area that encompassed the 

Tongass Narrows between Ward Cove and Ketchikan Harbor, along and within 500 feet of 

the Revillagigedo Island shoreline. The 10 operators authorized to use this exemption were 

also required to have a letter of agreement on file with the FAA Flight Standards District 

Office in Ketchikan, Alaska, which permitted them to use this corridor. 

Since its original limited grant in 1979, similar exemptions have been granted to 

approximately 38 other operators. These exemptions appear to have expanded the limitations 

of this exemption beyond the FAA’s original intent, which was to address a safety issue 

unique to a specific corridor following completion of the Ketchikan airport in 1973. 

In late 2009, the FAA began to assess these exemptions given the current operating 

environment, advances in technology and availability of weather sources since 1979, as well 

as new operating rules for air tour operators that were introduced in 2007. In the course of 

this evaluation, we have identified new facts and safety concerns that warrant no longer 

extending these exemptions as originally granted. 

First, the exemption appears to create circumstances that could result in controlled flight into 

terrain (CFIT). Since the original issuance of this exemption, the FAA has published 

guidance addressing the inherent risk of CFIT with suggested mitigation strategies. We have 

found that CFIT accidents are often the result of a pilot trying to fly or maneuver beneath a 

lowering ceiling and hit an obstacle or terrain or impact water. One situation permitted by the 

exemption, flight below 500 feet above the surface with only minimum visibility 

requirements, may tempt pilots to operate under ceilings considered instrument 

meteorological condition when reported in weather reports and forecasts. VFR pilots in 

reduced visual conditions may develop spatial orientation and lose control. Additionally, the 

risk of CFIT is compounded by overwater flight. 

Second, we now have new information about the unique weather phenomena the petitioners’ 

have asserted as one of the reasons for this exemption. The petitioners have stated that VFR 

conditions under low cloud layers frequently occur in Southeast Alaska. However, the 

National Weather Service has informed the FAA that it is also common for IFR ceilings and 
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visibilities to exist together, meaning as the ceiling gets lower, so does visibility. These 

conditions are the most likely to result in flat-light and glassy water conditions. Flat light can 

obscure terrain features, creating an inability to distinguish distance and closure rates. 

Additionally, the National Weather Service has informed the FAA that the variability of 

weather conditions across the inner channels of Southeast Alaska can be drastic and the 

amount of variability between two points is not easily predicted. 

Third, we are aware of at least 12 accidents since 1988 that occurred under conditions similar 

to those allowed by the exemption, including marginal VFR. A review of these accidents 

indicates pilots were likely unaware of an impending collision with water or other terrain. 

Contributing factors appear to be inadequate training, lack of planning, insufficient 

operational control and failures in management communication. 

Our Decision 

The FAA has determined that the justification for the issuance of Exemption No. 4760, as 

amended, is no longer valid as it does not provide an equivalent level of safety to that 

provided by § 135.203(a) and is not in the public interest. Therefore, under the authority 

provided by 49 U.S.C. 40113 and 44701, which the FAA Administrator has delegated to me, 

your petition to extend Exemption No. 4760, as amended, is denied. 

Any new request for exemption from the altitude restrictions in 14 CFR § 135.203(a), must be 

submitted in accordance with 14 CFR § 11.81 and will be considered on a case-by-case basis 

and evaluated carefully as to whether it would have an adverse impact on safety and whether 

it would serve the public interest. 

Sincerely, 

/s/ 

John S. Duncan 

Deputy Director, Flight Standards 

 Service