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Taking It Around…

May 28th, 2006 · 15 Comments

Every now and again, a pilot is forced to make a decision to abort an approach or landing and go around to try it all again. A go-around can occur for a number of reasons: not seeing the runway at the decision altitude or missed approach point of an instrument approach, another aircraft (or other vehicle/object/livestock) is on the runway, a windshear event is encountered, or the aircraft is not in the proper approach configuration or stabilized at the right speeds and descent rates.

In VMC, a go-around is typically a non-event to a seasoned pilot. The aircraft is merely re-accelerated and re-configured for climbing flight by advancing the throttles and retracting the flaps and landing gear. Typically, the pilot is given instructions by air traffic control to re-enter the traffic pattern.

In IMC, however, the maneuver can be made “interesting” by complex missed-approach procedures. These are instructions that pilots must follow exactly to ensure seperation of their aircraft with terrain and obstructions in the airport area. These procedures will include an instruction to climb to a specific altitude, as well as instructions for turning the aircraft to specific headings and intercepting specific navigational courses. Often, at the end of the missed approach procedure, the pilot is instructed to enter a hold so that it may be re-sequenced into the stream of arriving aircraft to re-attempt the approach.

From a pilot’s early days of learning the craft of aviation, he is instructed in go-around or balked-landing procedures. Handling an aircraft in a go-around takes practice. Prior to initiating the go-around, the aircraft is typically configured for landing with the flaps and landing gear extended, trimmed for the descent, and with its engines at a low power setting. Getting from that low-power descent-to-landing mode to high-power climbing-away-from-the-ground mode is a trick that involves a good understanding of your aircraft.

For instance, the way an aircraft behaves when you increase engine power depends upon a lot of things. First, it depends upon the type of engine. A jet engine takes longer to “spool-up” and create power after the throttles are advanced than a reciprocating engine does. Second, the behavior of the aircraft in a go-around also depends upon where the engines are mounted on the airframe. With turbojet aircraft, tail mounted engines (as on the Canadair Regional Jet) will cause an initial nose-down pitching moment. Under-wing mounted engines (like those found on the Boeing 757) will create an initial nose-up pitching moment. Low-to-the-ground go-arounds can get interesting with tail mounted engines, as the initial tendency of the aircraft after power is added is to dive towards the runway. Slow-speed go-arounds are tricky in wing-mounted engines because the aircraft wants to pitch nose up, which initially causes airspeed to decay if left uncorrected. Finally, every aircraft model reacts differently as its wing is being configured. Some experience very little changes in pitch as the flaps move from the high-drag landing configuration towards the low-drag go-around configuration. Others will have very noticable pitching tendencies. Combine the three of these, and you can see how the aircraft could become a handful to fly while you’re attempting to navigate on the initial portion of a missed-approach procedure. Of course, All pilots are familiar with the tendencies of the aircraft they operate.

Until a week and a half ago, I’d never performed a real go-around in the aircraft I’m qualified and current on, the Boeing 737. As I flew from LAS to SLC, the Captain I was flying with was telling us about how he “went-around” at one of the airports he’d visited the week before. After listening to his story, I commented that I hadn’t had to go-around in a 737 yet…at least not in anything but a simulator.

I should’ve simply kept my mouth shut.

As we approached SLC, we descended normally and I configured the aircraft for the descent to the runway. Through about 1,000 feet above the ground, I was flying at our target airspeed of approximately 135 knots with the landing gear down and the flaps extended to our landing setting of 30. Another aircraft was cleared for takeoff on the runway in front of us. Normally that wouldn’t be an issue, as at 1,000 feet, we’re still typically three miles or so from the runway…plenty of space for him to accelerate and takeoff. But this one started rolling rather slowly, and by the time we’d reached the 500 foot point was still not past the first thousand-foot marker on runway 34R. In anticipation of the go-around event, I rehearsed the procedure in my head and said to my Captain, “Well this could get interesting.”

Sure enough, we received the instruction to “Go around!” from air-traffic control.

I smoothly pushed the thrust-levers towards a climb setting and called for the captain to give me “Go-Around Thrust.” As the engines spooled up, I allowed the increasing thrust to help me pitch the aircraft’s nose up to a climb attitude of about 18 degrees nose-up. While holding forward-pressure on the control yoke to keep the aircraft from pitching beyond the desired attitude, I called for “Flaps 15″ (in real-time, the two callouts sound more like one: “Go-Around thrust Flaps 15″), while trimming the elevator to reduce the control pressure and ease my workload. As the aircraft’s flight path gradually changed from a descent to a positive rate of climb, I called for “Landing gear UP,” then I concentrated on adjusting the pitch to allow the aircraft to accelerate and maintain a speed of about 155 knots (twenty knots above our Vref speed). Passing through 400′ above-ground, I started the left turn that had been given to us by the control tower. As we climb through 1,000 feet above-ground I called for “Flaps 5…Climb thrust” as I lowered the nose to allow the aircraft to accelerate towards our normal climb speed of 210 knots. Around the airport we went, readying the aircraft for another (and this time successful) arrival attempt.

In the world of airline flying, the execution of the actual go-around maneuver is merely the beginning of the list of things to be done. After attaining a safe altitude and reducing the cockpit workload to a safe level, there are passengers to reassure, flight attendants to brief, company ground-ops to call, and new landing performance data to be figured. All this is done by the non-flying pilot (who in my case was the Captain). After all that extra work is completed, both pilots can concentrate again on the task of “Dangling the Dunlops…” or getting the aircraft ready to land again.

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15 responses so far ↓

  • 1 Flygirl // May 31, 2006 at 11:26 pm

    Doh!! I hate it when that happens!

  • 2 GC // Jun 1, 2006 at 3:22 pm

    Sam,

    I edited your comment simply to remove your references to my employer.

    —-
    Sam wrote:

    Since working for my current company, I’ve had about three missed approaches, but only one go-around. In my case it was because a Cessna taxied onto our runway without clearance, while we were at about 150′ AGL. The fact that it was entirely unexpected made the go-around a lot harder than a simple missed approach – I stumbled over the callouts a bit.

    It’s funny, you rarely see airliners go around, but I’ve seen three in the last month. In two cases they were… 737s… who said they received onboard windshear alerts, even though it was in clear, calm VFR. Do you guys have a mandatory windshear alert = go around policy? Or did these guys just not want to say they had an unstabilized approach?

  • 3 GC // Jun 1, 2006 at 3:39 pm

    And to respond to Sam:

    Yes. We guys have a mandatory windshear go-around policy. We have predictive windshear alert systems that give us three levels of alerts. With an advisory, an icon pops up on the radar display indicating a possible area of windshear. With a windshear caution, we get an aural alert “MONITOR RADAR DISPLAY” with the on-screen icon. With a windshear warning, we get an aural alert “GO AROUND! WINDSHEAR AHEAD!” Crew response with cautions and warning includes a go-around.

    The longer you fly with the predictive windshear systems installed, the more you’ll find that windshear “events” can occur in any kind of weather condition…meaning that the system isn’t infallible.

    As far as what was happening in the cockpits of the 737s you saw…who knows? I certainly can’t speak for those pilots, and I’d figure you for a less suspicious-without-evidence guy. ;)

  • 4 Gina // Jun 2, 2006 at 2:58 am

    Hi GC-
    Just another day at the “office” for you. Speaking of go-arounds, I work a half mile from LAX and saw my first go-around yesterday while at lunch; a Qantas 747…what a strange site. While I enjoyed watching the maneuver, my ears are still recovering (convertible with the top down + 747 above my head = OUCH!)

  • 5 GC // Jun 2, 2006 at 4:06 am

    If you were that close, you were probably sitting next to the In-N-Out off of Sepulveda, I’d imagine.

  • 6 Anonymous // Jun 3, 2006 at 12:10 am

    hi Glenn:

    Did you have have to do holding pattern
    over some holding point after the go
    around, or was it immediate 180 return
    for another try? how high AGL was the
    go around? what did atc tell
    you during the entire go around?
    did you need to recalculate the
    landing performance figures due to
    new landing weight?.

    love to hear more details…

    Great blog btw!

    a KSJC local

  • 7 Gina // Jun 3, 2006 at 12:35 am

    I wasn’t at the In-N-Out that day (although I’ve logged numerous lunch hours at that little park across the way…what a great spot). We had gone to the Proud Bird on Aviation so I was right at the threshold of the 25′s when our Aussie friends went around.

  • 8 GC // Jun 3, 2006 at 2:16 am

    Anonymous,

    The initial go-around call came at about 250′ AGL. After the initial left turn was given to us by the tower controllers, we were handed off to approach control so they could resequence us via vectors. It was pretty much an immediate left turn to the left downwind. It was VMC at the time and traffic was relatively light so we never had to hold. Our inital approach was to 34R in SLC, but they shifted us over to 34L because that’s where we fit best with the existing traffic. As I mentioned in the original post, we refigured landing data for the new runway and new weight. That’s a very quick thing for us, as we use a device called an Onboard Performance Computer to figure all of our performance data.

    Thanks for your compliment!

    Gina,

    How’s the food at the Proud Bird these days? It’s been a bit since I’ve eaten there.

  • 9 Gina // Jun 4, 2006 at 4:51 pm

    GC- I was at a retirement ceremony so we had a buffet to chose from and the food was great; I recommend the salmon!

  • 10 GC // Jun 4, 2006 at 9:14 pm

    Salmon? I love fish, but isn’t that what got the crew sick in the movie “Airplane!”?

  • 11 Gina // Jun 5, 2006 at 1:15 am

    Ah, Airplane! Quite simply the best movie ever.

    I think it was just “fish” that made the crew sick, but I may have to put the DVD in now just for the halibut.

  • 12 GC // Jun 5, 2006 at 4:17 am

    That joke was CARP!

  • 13 Gina // Jun 5, 2006 at 3:53 pm

    I know my joke was carp…I did it on porpoise!

    Must.Stop.Now. for fear of being voted off Rant Air island.

  • 14 GliderGuy // Jun 16, 2006 at 11:13 pm

    Go-arounds seem interesting. Never had one myself. Are they more or less common than rejected take-offs?

    Flying something much smaller, I recently had something equivalent: a rejected glider winch launch, which I’ve just written up on the blog – an interesting experience!

  • 15 Edge // Jun 29, 2006 at 8:36 pm

    Fascinating!

    ~Jef

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