• If In Doubt: The Art of the Baulked Landing


    skelsey

    By Simon Kelsey
    Contributing Editor

     

    How long is eight seconds?

     

    Count it out and it doesn’t seem long at all. A Microsoft study recently suggested that the average attention span of a modern human is eight seconds; down from twelve seventeen years ago. It’s probably taken you about eight seconds to read these two paragraphs.

     

    Eight seconds is also roughly the amount of time it takes a high-bypass jet engine to spool up from idle to full thrust.2017-8-24_14-56-31-714.thumb.png.4de6d100f88de7adba3c8025fe0c849a.png
    Mount Etna is the largest active volcano in
    Europe with a summit elevation over 10,000ft

     

    One of the hazards of having a fianceé who works in a school is that those long summer holidays have a severely detrimental effect on the amount of simming time available. So when Mrs announced that she was going in to work for a couple of days to help with a summer school class, it seemed like a good opportunity to give the FSLabs A320 a run out.

    I’d selected a nice trip of about three hours from London Gatwick down to Catania on the island of Sicily. Sitting in the shadow of Mount Etna, the airport has a 2,400 metre runway and fairly good facilities, though only runway 08 is equipped with an ILS. This isn’t too much of an issue, however, given that in common with many coastal locations an easterly sea breeze prevails during the day. There’s also some excellent freeware scenery by Antonio Baeli in the Avsim library, which I’d downloaded and installed.

    20170825_183706.thumb.jpg.b28a85d72bcd0ef13e089d26c11794e9.jpg
    Etna can cause some 'interesting' wind effects!
    Although Catania is surrounded by high ground on three sides, it is Mount Etna that dominates the landscape. The largest active volcano in Europe, Etna rises to over 10,000 feet just fifteen miles or so north of the airfield. As one might imagine, it has a significant effect on operations at Catania: apart from the turbulence and windshear that can be generated by a northerly wind ‘splitting’ around the peak, there are also contingency procedures in place should an eruption leave volcanic ash hanging in the atmosphere.

    At around 500 feet on the approach I became aware that something didn’t feel quite right. I’d drifted about half a dot low on the ILS glideslope; instinctively I squeezed on a little back stick to raise the nose slightly, placing the pitch symbol on the ADI just slightly above the 2.5 degree line.

    Glancing outside, I felt confused: the runway looked to be in about the right place, but the PAPI lights were indicating three white - slightly high - whilst the ILS glideslope was still showing fractionally low. Something wasn’t quite right: but what was it? Still, I was visual in severe CAVOK with the wind straight down the runway. Drifting slightly right of centreline: a little nudge of the sidestick brought things back nicely. Still a bit high: nudge forward, lower the nose just below the 2.5 degree line.

    Still a slight nagging doubt. A glance inside: now the glideslope shows close to three quarters of a dot low. But the runway’s just there, and the PAPIs are still showing high…

    FIFTY!Arrival briefing notes in to Catania
    Approach briefing notes for Catania

     

    The radio altimeter callout startled me. I was barely over the runway, the displaced threshold markings still visible over the glareshield, and now the jet was shouting THIRTY at me.

    I knew that somehow I’d got really low, but in the moment I couldn’t quite work out how. Suddenly aware that the ground was rushing up at me very quickly indeed, I eased back on the stick, conscious not to over-rotate and start floating down the shorter-than-average runway--

    TWENTY-TEN-BOOM! A great, juddering explosion of noise seemed to fill the room. The sixty-tonne jet literally leapt back in to the air, the main gear oleos flexing and extending like the legs of an Olympic vaulter.

    I knew I had to keep the pitch under control to avoid a tailstrike. Do not allow the pitch attitude to increase, particularly following a firm touchdown with a high pitch rate, is what the manual says. The jet, so eager to meet the surface just a few moments ago, had suddenly developed ground-shyness: hanging in the air at what felt like a few tantalising inches above the tarmac whilst the centreline stripes disappeared below the nose in a blur. Almost subconsciously I dipped the left wing slightly, stretching desperately for the runway.

    As the touchdown zone markings disappeared out of sight, I did what I should have done far earlier: throw it away.

    I slammed the thrust levers all the way forward. And waited. Everything seemed very quiet.

    59a613c253ce5_2017-8-24_11-49-55-852(2).thumb.png.93b4a0a37a6adc4015a5e175b4d0e7cc.png
    It takes longer than you might think for an
    IAE V2500 engine to spool up from idle!
    I was conscious of the airspeed hovering a few uncomfortable knots above the amber band. And still the thrust instruments remained rooted to the idle position.

    How long is eight seconds? When you’re gobbling up 72 metres of runway every second, it feels like a very long time indeed.

    Eventually the EPR dials started to flicker in to life. Slowly at first, then with gathering pace, the noise building from soft, almost eerie whine to trademark IAE buzz as the aeroplane finally started to claw itself back in to the hot, thin Sicilian air.

    With hindsight, I should have gone around from the first approach much earlier. It’s often said that every approach is to a go-around -- if you can land instead, then great. Or to put it another way - ‘if there’s doubt, there’s no doubt’.

    I knew something wasn’t quite right, but initially I couldn’t quite put my finger on it. Generally speaking our instincts are good: if we’re not comfortable, it’s always easier and safer to throw it away, get up to a safe height and work out what the problem is there rather than try and do so in the late stages of an approach!

    20170825_183742.thumb.jpg.69c149701b3c3d84d06e129faa2b6e23.jpg
    Items for consideration during an approach
    briefing
    Another point which was thrown in to focus was the importance of building a mental model of the approach in advance. This is why airline pilots brief before every takeoff and landing: to ensure that each crew member knows what the plan is and what to expect. I knew what I expected the relationship between the PAPIs and the ILS glideslope to be on a normal landing: I hadn’t prepared for the difference on this landing. It also drove home how quickly one can lose situational awareness -- ‘the big picture’ -- when distracted. Instead of focusing on what was most important during the landing -- the runway and the touchdown zone -- I was instead focusing on the discrepancy between the PAPIs and the electronic glideslope.

    The normal go-around actions are well-rehearsed: I will call ‘go around’, push the thrust levers to TOGA. Check that thrust increases and is sufficient for the go-around. Retract one stage of flap, rotate towards fifteen degrees nose up, follow the SRS. Positive climb, gear up. Above 100 feet select a roll mode, and verify the missed approach route is being tracked.

    Except that this sequence will not quite work for a so-called ‘baulked landing’, especially the ‘rotate to towards fifteen degrees and follow the SRS’ bit, which at best risks scraping the tail and at worst could lead to the speed getting dangerously low whilst waiting for those engines to spool up.

    Instead, a go-around after touchdown requires the pitch attitude to be held steady and the gear and flaps left alone until well established in the go-around. The manuals also caution that you will get a takeoff configuration warning if you select TOGA whilst on the ground with full flap -- a noisy distraction right at the moment you least need it! I was surprised how powerful the urge to rotate up in to the flight directors was, especially with the runway rapidly disappearing, despite the initial lack of thrust and airspeed. At least the Airbus allows quick, instinctive and unconditional selection of go-around thrust and modes: just slam the thrust levers full forward, unlike the Boeing design whereby the TO/GA switches are, for good reason, inhibited on the ground after landing (and at very low heights, as at least one real-world airline crew (and many PMDG 747v3 owners) have discovered to to their cost).

    Needless to say, baulked landing procedures will be high up on my list of things to practice in future! With a go-around generally remaining an option on jet aircraft all the way up to thrust reverser deployment, it is worth trying out in your aircraft of choice, thinking about how you will get around the various problems thrown up by a go-around at very low altitude or after touchdown. Spoilers, autobrakes and takeoff configuration warnings may all in some combination have to be overcome: do you know what you would do?

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