Aviation Topic of the Week
By Michael Oxner, August 22, 2004


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This week's topic:
VFR Flight Example, Part 7: Arriving at Halifax International

Our pilot is nearing the end of his journey. Having departed Moncton, overflown Amherst, and bounced through Debert, he is talking to Halifax Terminal on the VFR frequency, and is now getting close to Halifax International Airport, his final destination.

Frequency Change to Tower
Calling Tower
Joining the Circuit
Landing and Clearing the Runway

Frequency Change to Tower

As our pilot gets closer, he knows he has to contact the tower eventually. Typically, it would be up to the pilot, and ultimately it is. The difference in this case, is that the pilot is currently working ATC, and normally you don't leave an ATC frequency for another one without being told, or at least telling the controller what you're up to. There are few things that bother a controller more than a pilot who leaves the frequency without telling him, especially when control action needs to be taken for separation and safety purposes. Imagine your license is on the line, you notice that you need to do something, and you can't get a hold of the aircraft involved. If you decide you have to leave ATC's frequency, for whatever reason, simply ask for a frequency change, or advise that you need to leave the frequency. ATC can then tell you if it's OK, or tell you that he can't release you because of traffic. ATC is aware of what you need to do with respect to frequencies and talking to other units, and they will understand your needs and try to accommodate you as needed.

Where Halifax Terminal feeds the Halifax Tower with traffic routinely, and our pilot is inbound to CYHZ, this change is normally anticipated to come from ATC, and the pilot should stick with the Terminal controller until told otherwise.

CYHZ_TCU: "Oscar Oscar Foxtrot, contact Halifax Tower now, one one eight four."
CGOOF: "Oscar Oscar Foxtrot."

It's just that simple. Remember, please, to acknowledge a frequency change. Have I said that enough?

Calling Tower

The normal stuff here. Dialing up the frequency, a respectable pause to ensure the initial call up doesn't step on someone else's transmission or into the middle of an exchange, and then:

CGOOF: "Halifax Tower, Skyhawk Golf Oscar Oscar Foxtrot, fifteen miles north over the one-oh-two, descending through three thousand five hundred."
CYHZ_TWR: "Skyhawk Golf Oscar Oscar Foxtrot, Halifax Tower, runway three three, winds three two zero at five, altimeter three zero zero one. Follow the highway to join right downwind for runway three three."
CGOOF: "Oscar Oscar Foxtrot."

Some would criticize me for the above exchange. First, some wouldn't like that I didn't say, "Request landing instructions" in GOOF's first call. Need I say that? The tower would have been told by Flight Services that the aircraft is coming, and would be given an estimated time of arrival based on the filed flight plan. Terminal just handed the aircraft off. They know what he wants to do: Land. To this end, they'll give instructions for joining the circuit. Secondly, what about a readback of the instructions? *Buzzzzzz* Not required. As long as the pilot gets the message, an actual readback is not necessary. It saves airtime to simply acknowledge with the aircraft's callsign, thereby letting the tower know that the instructions were received and will be complied with. If the instructions are not something that can be complied with, remember to tell ATC as soon as possible so he can make alternate plans as early as possible.

Joining the Circuit

Airport elevation is a concern, since our pilot has to know what circuit altitude is. This is typically 1,000 feet AAE (Above Aerodrome Elevation) unless otherwise specified. The Canada Flight Supplement had no "otherwise specified", so we use the general rule. Our pilot noted during preflight that the airport elevation is 478 feet ASL, and therefore circuit height would be 1,500 feet. That's his target altitude, and he descends to level off at that point.

Halifax is known for use of multiple runways, including use of the opposite end of the active as traffic permits. Our pilot is approaching the airport while following the highway, and when about 3 NM north, the radio crackles to life aimed at our pilot this time, amid the many transmissions to other aircraft.

CYHZ_TWR: "Oscar Oscar Foxtrot, traffic is a Navajo on four mile final for runway two four. Join right downwind behind this aircraft."
CGOOF: "Oscar Oscar Foxtrot, wilco. Traffic in sight."
CYHZ_TWR: "Oscar Oscar Foxtrot, roger. Are you able to land on runway three three and hold short of runway two four?"

The first part of this is fairly simple. He is being asked to fly behind a PA31 instead of in front of this aircraft as he flies in on approach for 24. The second part seems to some very stupid. Remembering the ATIS had the landing distances available (3,700 feet to land on 33 and hold short of 06/24), ATC doesn't have to provide the distance again to the pilot. Do you think ATC is unsure of whether a C172 can land and come to a stop in 3,700 feet of runway? Of course it can, and ATC knows darned well that he can. The issue is more one of will he accept such an operation. Some pilots refuse this for a variety of reasons. Some companies don't allow their pilots to do it, and some individuals don't like the operation. Our pilot is OK with the operation, and responds quickly with:

CGOOF: "Oscar Oscar Foxtrot, Affirmative."
CYHZ_TWR: "Roger, expect that. A seven thirty seven will be landing on two four as you land on three three. You're number two for three three, behind a Dash Eight on five mile final. Caution, possible wake turbulence."
CGOOF: "Oscar Oscar Foxtrot, looking for the traffic."

While joining the right hand downwind, the pilot flies behind the PA31 on 24, and finally spots the Dash 8 on short final.

CGOOF: "Oscar Oscar Foxtrot has the Dash in sight."
CYHZ_TWR: "Oscar Oscar Foxtrot, roger."

It's always good to let tower know you see the traffic. That way, he knows you'll stay out of the other guy's way. Incidentally, if you tell ATC, whether enroute or airport control, that you see your traffic, ATC will expect you to keep clear of the other fellow on your own without further instruction from ATC. Our pilot now has an additional point to deal with, and that's the possibility of wake turbulence behind the Dash 8. Anyone who believes wake turbulence isn't an issue really needs a slap about the head. Our pilot notices the Dash 8's descent path, and watches to see where he touches down. Knowing that he will be landing into the light winds, the wingtip vortices will likely roll to the side of the runway, and flow with the wind behind the Dash. This means that riding the approach higher than the Dash 8 did, and touching down slightly longer (further down the runway) than the Dash 8 did should provide adequate clearance from any invisible wake that would be there. He plans his circuit appropriately, and also considers the fact that he may be expected to hold short of 24 on landing. Given where the Dash touched down, and the runway available, our pilot considers this an easy task and sets up for the approach after completing his downwind checklist.

Landing and Clearing the Runway

The radio has been busy, and CGOOF watches the Dash 8 taxi ahead and clear the runway. He knows he is now #1 for 33, and that somewhere out there is a B737 on final for 24 by now. He turns final, and makes the appropriate radio call.

CGOOF: "Oscar Oscar Foxtrot final runway three three."
CYHZ_TWR: "Oscar Oscar Foxtrot, cleared to land runway three three, hold short of runway two four. Seven thirty seven two miles final runway two four."
CGOOF: "Oscar Oscar Foxtrot."

Anything missing from this exchange? I hope you caught the omission. I've been saying all along that readbacks of clearances and instructions are not terribly important in the VFR world. There is one notable exception, and some folks may have missed it here, simply because they often believe it doesn't apply in the air.

Taxiing aircraft, IFR and VFR alike, are required to readback "hold short" instructions. This also applies to aircraft in the air accepting a landing clearance with a hold short instruction. Don't think so? If you don't do it, the tower will bug you for a readback of the instruction, and they'll likely sound a little impatient for it, too.

CYHZ_TWR: "Oscar Oscar Foxtrot, I need a readback of the hold short."
CGOOF: "Oscar Oscar Foxtrot will hold short of runway two four."
CYHZ_TWR: "Oscar Oscar Foxtrot, roger."

So CGOOF lands on runway 33 and watches the B737 on short final. Now that he has landed and held short of 24 (this means at least 200 feet away from the edge of runway 24, by the way), when is he allowed to cross? The answer is, "not until ATC says so." ATC may have further traffic on final and may not be able to get you across right away. The 737 crosses the runway intersection...

CYHZ_TWR: "Oscar Oscar Foxtrot, no delay, taxi across runway two four and exit left in Foxtrot. Traffic on final for three three behind you. Contact Ground on one two one nine when off the runway."
CGOOF: "Oscar Oscar Foxtrot."

No hold short? No readback required. Simple. Running the throttle up a little the pilot does a fast taxi to get across 24 and exit 33 as fast as is reasonably practical. Exiting left on Foxtrot, the pilot must contact Halifax Ground on 121.9, as instructed by tower...




But that's for next week, the final topic in the VFR Flight Example series. Any comments or questions on this week's topic, or any other topic, can be directed to me through e-mail at moxner@nbnet.nb.ca. As always, thanks for taking the time to read!