You recently received your Commercial Pilot Certificate for Rotorcraft-Helicopter and have arrived via taxicab at Thief River Falls Regional Airport (KTVF). It’s 1300Z and you’re going to pickup and ferry a helicopter to another airport about 300nm away. Looking at the Sectional Chart, you see that the airport is not towered.
You preflight the aircraft and check all the paperwork—all is well. The current weather is reported as 2sm visibility and 2,000’ broken ceilings. Can you legally fly under Visual Flight Rules?
Back when I was a Check Instructor in a Part 141 helicopter pilot training program, I evaluated many students that gave an incorrect answer to a similar scenario. The question at hand involves an understanding of four things:
- Towered vs Non-towered Airports
- Controlled vs Uncontrolled Airspace
- Visual Flight Rules (VFR)
- Special Visual Flight Rules (SVFR)
Towered vs Non-Towered Airports
On Sectional and Terminal Area Charts, airports with an operating control tower are shown in blue, while all others are shown in magenta. Sometimes the tower may only be operational during certain hours, specified in the appropriate Chart Supplement and/or per issued Notices to Airmen (NOTAMs). In this scenario, we see that KTVF is a non-towered airport per the magenta used on the chart and checking the Chart Supplement.
Controlled vs Uncontrolled Airspace
In the United States of America, Controlled Airspace includes Class A, Class B, Class C, Class D, and Class E. Uncontrolled Airspace is Class G. But guess what: you can have a towered airport in any of these airspaces! For example, until not too long ago, Huston Executive (KTME) was a towered airport in Class G airspace, requiring pilots to check the Chart Supplement and NOTAMs for status updates. I even Tweeted about it.
We also know that Class E is the only controlled airspace where VFR flights are not required to communicate by radio. In this scenario, looking at chart we see that the airspace is Class E to the surface (indicated by the dashed magenta lines) with a note specifying there are effective hours. Looking at the Chart Supplement for the airport, while Class G would be in effect otherwise, Class E to the surface airspace is currently in effect in this planned flight’s timeframe. For a normal VFR flight, we don’t need to talk to anyone on the radio.
So far we have determined that we are at a non-towered airport inside controlled airspace.
Visual Flight Rules
This flight is being conducted under Part 91 (14 CFR 91) under Visual Flight Rules (VFR). 14 CFR 91.155(a) specifies that flight in Class E airspace below 10,000’ MSL requires at least 3sm of visibility and flight 500’ below, 1,000’ above, and 2,000’ horizontal (“3-152”) from clouds. There is no VFR exception for helicopters like found in Class G airspace.
Additionally, 14 CFR 91.155(c)&(d) require that flight in any controlled airspace designated to the surface of an airport have a minimum ceiling of 1,000’ and 3sm of visibility.
So far we have determined that we are at a non-towered airport, inside controlled airspace, with minimums of 3-152 required. The scenario involves 2sm of visibility at the airport, so we can’t fly…or can we?
Special Visual Flight Rules
The next regulation gives us a solution.
14 CFR 91.157–Special VFR weather minimums.
(a) Except as provided in appendix D, section 3, of this part, special VFR operations may be conducted under the weather minimums and requirements of this section, instead of those contained in §91.155, below 10,000 feet MSL within the airspace contained by the upward extension of the lateral boundaries of the controlled airspace designated to the surface for an airport.
(b) Special VFR operations may only be conducted—
(1) With an ATC clearance;
(2) Clear of clouds;
(3) Except for helicopters, when flight visibility is at least 1 statute mile; and
(4) Except for helicopters, between sunrise and sunset (or in Alaska, when the sun is 6 degrees or more below the horizon) unless—
(i) The person being granted the ATC clearance meets the applicable requirements for instrument flight under part 61 of this chapter; and
(ii) The aircraft is equipped as required in §91.205(d).
(c) No person may take off or land an aircraft (other than a helicopter) under special VFR—
(1) Unless ground visibility is at least 1 statute mile; or
(2) If ground visibility is not reported, unless flight visibility is at least 1 statute mile. For the purposes of this paragraph, the term flight visibility includes the visibility from the cockpit of an aircraft in takeoff position if:
(i) The flight is conducted under this part 91; and
(ii) The airport at which the aircraft is located is a satellite airport that does not have weather reporting capabilities.
(d) The determination of visibility by a pilot in accordance with paragraph (c)(2) of this section is not an official weather report or an official ground visibility report.
We see from this regulation that we can takeoff from this airport since it lifts the 3sm visibility limitation that is holding us back. However, it requires an ATC clearance. You can’t just takeoff on your own and depart. To get this clearance, you can either contact the center responsible directly over the radio (check the Chart Supplement for a frequency) or get a clearance relayed through a Flight Service Station (which I have had both positive and negative results with personally).
Why Is This Misunderstood?
When I present this scenario, many helicopter student pilots assume that because the airport is non-towered, the airspace is treated as Class G and thus allows for 1/2sm visibility as a minimum. Many responded that they would just takeoff and go on the flight without contacting anyone. Controlled airspace is what determines the minimums for VFR flight, not the tower status of the airport.
We must always make sure that we check the appropriate aeronautical chart(s), Chart Supplement(s), and Notices to Airmen (NOTAMs) to determine the status of an airport and its airspace during flight planning to make sure we are legal for our planned operation.
Landing own risk,