Interactive Challenge 3 Answered

The iPilot readers that took Challenge #3 did very well and bounced back from a poorer performance on the previous challenge!

The second challenge that I issued several weeks ago proved to be a real stumper with only 31% answering correctly. I was quite happy to see that the third challenge (click through and scroll down) was much better! Over 90% got the basic questions correct — but there were some ‘non-standard‘ procedures that readers could have used to be even more correct.

To understand the questions posed you must have a clear understanding of why there are two different colors used to depict the airspace around Owensboro. The blue dashed line around the Owensboro Airport is a Class D airspace that starts at the ground, which is 406 feel MSL, and extends up to 2,900 feet MSL (approximately 2,500 feet tall). But this airport has instrument approaches that line up with the runways and pilots on these approaches could use a ‘corridor‘ in which to descend toward Owensboro and remain in controlled airspace. This could be accomplished using blue dashed lines — but that would also extend the responsibility of the Class D into those extensions. So, a compromise is struck. Magenta dashed lines are used to illustrate that the controlled, Class E airspace comes down to the ground, without having it also be part of the control tower’s responsibility. The questions were asked to highlight these differences.

Question 1: Can Mr. Bigger fly his J-3 Cub, with no electrical system, over to visit his friend Mr. Goode on a day with great VFR weather of 10 miles visibility?

Answer: This J-3 Cub is perfectly suited for this flight, because the colors on the chart indicate that communications are not required. The Bigger Airport is located outside the magenta dashed line, while the Goode Airport lies just inside the line. This means that the Bigger Airport sits in uncontrolled, Class G airspace while the Goode Airport is in controlled, Class E airspace. Class E airspace requires 3 miles visibility, but in this question we have all of 10. So a flight from Bigger to Goode can be made without any problems — because the dashed line is magenta. Had the line been blue it would have been included its contents in the Class D airspace, and communications with the Owensboro control tower would have been necessary. Note that the cub is without an electrical system, which implies it has no radio.

Question 2: Can the same flight be made on a day when the visibility is only two miles? (Short question, long answer.)

Answer: Yes, but it will require some fancy coordination. Flying off the Bigger Airport with two miles in the daytime is already legal because it sits in Class G airspace. The Bigger Airport’s elevation is 406 and it not only lies outside the magenta dashed line, but also the near-by magenta shading. Therefore Mr. Bigger could fly his J-3 up to 1,606 feet MSL and remain in uncontrolled airspace where only one mile is the visibility requirement. But, remember that the Goode Airport is in controlled airspace where three miles is the visibility requirement.

To fly into Goode, the pilot would need a Special VFR Clearance. The regulation (91.157b) says that in order for Special VFR operations to take place the pilot must receive a clearance prior to entering controlled airspace — but it does not say that this clearance must be received over the radio. The AIM (paragraph 4-4-5) also says that when departing an airport that does not have a control tower, a pilot can obtain a Special VFR clearance by contacting the nearest tower, FSS, or center — but again it does not require that this request be made using an airplane’s radio. So what do you do? Call the tower or FSS on your cell phone of course!

Mr. Bigger, before departing the Bigger airport enroute to Goode, should call the Owensboro control tower from his house or on his cell phone. He should ask for a Special VFR clearance to fly to the Goode Airport, which the controller will know lies just inside controlled airspace. Now the controller will double check that no incoming IFR airplanes will be coming through at the same time Mr. Bigger wants to make this flight.

Remember: The reason there is controlled airspace at and around the Goode Airport in the first place is to protect descending airplanes preparing to fly an instrument approach from the south into the Owensboro Airport. The controller can assure separation between Mr. Bigger’s J-3 and other IFR airplanes as long as there is not an IFR airplane on the approach at the time of Mr. Bigger’s flight.

The tower controller can issue a Special VFR clearance over the phone. Mr. Bigger does not have to file a flight plan in order to get the clearance. The clearance will not have a specific altitude to fly, but probably will have a maximum altitude and a clearance ‘void time. The void time is the time limit that the clearance remains in effect. If Mr. Bigger taxis to the end of the runway, completes his pre-takeoff checklist, and then makes the call on his cell phone from the airplane it will cut down the time between receiving the clearance and takeoff. This will help insure that the time limit given is long enough to make it to the Goode Airport.

Question 3 (Part I): Can Mr. Bigger pick up Mr. Goode at the Goode Airport and then fly on to the Owensboro Airport in the non-radio equipped J-3 Cub with 10 miles visibility?

Answer: Ordinarily you must establish two-way radio communications with the control tower inside a Class D airport, but there is a non-radio procedure to fly into a Class D airport.

How: First, you could call the tower on the telephone and let them know you were seeking ‘non-radio authorization‘ to enter the Class D airspace. Once in the air — even if you did telephone ahead — the AIM (paragraph 4-2-13) says you are to remain clear until you determine the direction that traffic is flowing into the airport. You may then join the traffic pattern and look for light gun signals (which you, of course, know by heart). Acknowledge that you see and understand the signals by ‘rocking your wings.‘ So Mr. Bigger and Mr. Goode could take off in the J-3 for Owensboro, get the light gun, and land without a radio or any further problems.

Question 3 (Part II): The same flight to Owensboro with only 2 miles visibility…

Answer: This would require a combination of non-radio authorization and a Special VFR Clearance. The procedure would be a combination of question 2 and 3 above. This will take coordination, and some indulgence on the part of the control tower. The controller will not be able to grant these requests if there are numerous inbound or departing IFR flights. It may also be the end of a very long day and that might play a part in how successful your request may be.

Strategy: One iPilot reader who wrote in with the answers to these questions related a story of his friend who had to wait 6 hours and made many phone calls without getting a clearance. Eventually the friend flew in one minute after the control tower closed and the airspace became Class G at the surface!

Interactive Challenge #4

Look at the airspace in the diagram. An irregular boundary of thick dashed magenta lines surrounds an area of railroad tracks and towers. What kind of area is this, and what are the pilot responsibilities to fly in or over it?