• 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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    User Feedback


    Simon, I like the technical and procedural details as much as the narration and the atmosphere you're creating. Almost like Ernest K. Gann going fly-by-wire ...   ;-)

    Thanks a lot for your efforts, pls. keep them coming and may your future wife have many more summer school classes ...   ;-)

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    In a Boeing you have to stand the levers up too which is instinctive is it not? (Possibly not if you fly B777 for EK....)

    My worst bouncer happened recently and the thrust reversers were actually deployed by the time it got airborne again. Not nice but got her down smoothly and stopped in good time on that one. Very breezy day at LBA as usual...

    It's always good advice to have the go-around in mind but in practice not that easy as the startle factor is high... even in LBA!

    Look on the bright side... you have a pause button... I've got a big drop off at one end and another quite steep bank the other end and 189 folk down the back expecting a featherbed arrival... (and 4 who know it probably won't be whilst smiling at the rest) plus enough fuel for maybe one go-around and approach if I'm lucky...

     

     

     

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    Thank you for all the kind comments! Glad you are enjoying the articles and I look forward to writing more.

    9 hours ago, Gone said:

    Almost like Ernest K. Gann going fly-by-wire

    :laugh: I'm certainly not worthy of mention in the same sentence as the great man, but thank you!

    6 hours ago, MarkJHarris said:

    In a Boeing you have to stand the levers up too which is instinctive is it not? (Possibly not if you fly B777 for EK....)

    One would hope so, though one of the things highlighted by EK is that a GA at very low altitude/after touchdown is essentially the one and only occasion where pressing the TOGA switches will not send you skywards. One would hope that wouldn't be a problem and that nobody would attempt to go around without applying (by whatever means) sufficient thrust, but then again...

    The advantage of the Airbus system in this case is that there's no ambiguity about whether the GA switches will operate, whether the FD guidance will transition to GA, etc: just shove the thrust levers fully forward and everything else follows, whether you're at 500R, 2R or after touchdown. Of course the downside is that a GA from very near the missed approach altitude requires either briefly firewalling the T/Ls (to get out of GS | LOC) or, effectively, switching everything off and back on again whereas a tap of the TOGA switches in a Boeing will give you a nice gentle 2,000 (or less) fpm climb and level off. Neither system is perfect, that's for sure!

    6 hours ago, MarkJHarris said:

    Look on the bright side... you have a pause button... I've got a big drop off at one end and another quite steep bank the other end and 189 folk down the back expecting a featherbed arrival... (and 4 who know it probably won't be whilst smiling at the rest) plus enough fuel for maybe one go-around and approach if I'm lucky...

    Absolutely Mark - very much puts things in to perspective. No pause or reset button in real life...

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    It is a shame that neither is foolproof, but you can also see from the fundamental logic where each has evolved. Zeigler makes you leave the thrust levers in position till the very end, they are in effect thrust limit selectors, not thrust levers. The aircraft can always give you less than the lever position, but never more.

    Treat them like that and it makes sense. The detents are in place and handily in the case of a baulked landing, it works perfectly. 1:0 to Airbus.

    With a Boeing, some cretins like to stow the speed brake lever by momentarily shoving the thrust levers forwards. I've seen it and the nasty looks rarely stop these people as they are  not that kind of person. Not many left out there BTW...

    Certainly in the 737, flying the last part of the approach manually with SPEED OFF selected is common, but I don't do it. When I say I have control,. I really do. Its natural to push them forward and in really any situation, 400ft is the standard point to even start to think about FMA selections and guidance. Before that, stand the thrust levers up (this should give 85-88% ) and SMOOTHLY rotate to 15 degrees. Then look out the bloody window to keep it going where you want it. PM calls positive rate and thrust up and away you go.

    I guess the different thrust capabilities of the types make a difference here too. A pair of GE90s or Trents on the B777 at full chat makes for a proper homesick angel event, but an A321 on full chat wouldn't pull the skin from a rice pudding so not a problem. A332 though.....

    I'm still quite old school. Only been on a Boeing for a few years and previous 27 years of flying were on non auto throttle aircraft.

    Still not comfortable with Autobrakes yet either! 

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    Invaluable, and as others have observed, you have a very engaging writing style. After reading this yesterday, I took the extra time to think through what I would do in the event of a landing becoming problematic before ticking the checklist item for Approach Briefing on the 777 when landing UAE 772 at FACT this morning.

    Your efforts are really a great contribution, I'm sure I speak for many on here when I say I hope you keep 'em coming.

    Edited by ClearedtoLand
    Poor syntax
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    The biggest issue with the Boeing system is the weight on wheels scenario.

    In every normal scenario you will be initiating the go around by pushing the TOGA button a single time to initiate the soft go around. Then all of a sudden after years of training in soft go arounds "if" the wheels have touched it will not engage.

    Firstly on a widebody it is very possible particularly in turbulence to have wheel contact without the crew knowing it. So having already decided on a go around a click of the TOGA button to initiate the soft go around and "if" the wheels have touched nothing will happen.

    It is a MASSIVE flaw in an otherwide excellent go around system.

    If you have ever flown an aeroplane for 12 hours on a back of the clock you will know how dependent you are on automation for the clear purpose of safety.

    Your brain operates FAR more slowly and your reactions and startle factor are multiplied significantly. You make errors and a system which 99.9% of the time works perfectly in the single time you need it the most ie fatigued, early morning arrival, poor weather will let you down because of the weight on wheels disabling of go around. Almost all go arounds after long flights will be soft ones because the last thing you need after a 14 hour duty is 4000'/minute into a 2000' level off. To top it off there is no warning it is disabled!!!!!

    The soft go around has just been incorperated by Airbus into its FMGC suite as its a great feature but to have it disabled with no warning and relying upon the crew after huge duties to "sense" if a large aircraft has touched which can easily be missed or not sensed is and was a disaster waiting to happen.

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    Possibly but I still disagree fundamentally on your logic. As a Boeing Pilot, I fly it like I fly any simple aeroplane. I don't trust the automatics fully, and on a go-around, or baulked landing (both of which has happened to me before including taking over from a First Officer's overload situation) I push the levers forward. Full stop. Push them forward, worry about the button later. 

    On my landings the autopilot and auto-throttle are off. Or it's an auto-land and they are both on. In the later case, certainly at my home field, a go around is perfectly possible if it floats, but in that situation, it is also likely to happen at or after touchdown due to it being a claggy night and visibility very poor.  The auto-throttle dropping out is a loud click as the relay lets go of the MCP switch.  You get a red alert light but you really are not looking for that! Trust me.

    Push the damn levers forwards works in any aircraft- if the auto-throttle was still engaged in RETARD mode, pushing them would to as in Amsterdam- fight the desire for more power. So cutting the auto-throttle and TOGA mode is Boeing's way of making sure you do react by pushing the levers forward. Like on any aeroplane-Airbus included.

    The disaster waiting to happen, is a company that insists crews use maximum automatics at all times, punishes severely any display of airmanship or common sense and refuses to admit any blame for anything, anytime. EK are losing folk faster than they can hire right now..

     

     

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    I agree with all the kudos here, well-done Simon. I actually wasn't sure at first if this was a real-world experience or a sim flight! You took us with you on that approach and made us feel like we were riding right seat with you throughout the white-knuckled go-around.

     

    Superb,

     

    Alex Christoff

    Baltimore, MD

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