Control column flailing during the flare - a dangerous practice by some pilots.
 

Frantic "see-sawing" of the control column, otherwise technically known as gross over-controlling, is a common characteristic seen both during simulator and line operations. Often the habit is ingrained from ab-initio days. Although it may or not result in a smooth touchdown, this rather distasteful technique invariably uses up extra runway which in turn is usually countered by heavy manual braking and passenger discomfort.

It appears not to be a deliberate landing technique, but rather an unconscious "twitch" factor habit where the pilot is feeling for the runway in the hope of making a smooth touch down. Interestingly, it often does seem to work on most occasions; thereby reinforcing the pilots belief that it is the best way to achieve a smooth landing. The usual ensuing float before final touchdown may also be a factor in over-runs, although this is never mentioned as a contributory cause in accident reports.

For any PM, it is a wise precaution to keep valuable bits of his/her anatomy well clear of the control column full aft movement when their compatriot is feeling for the deck in such a manner, as well as knees well spread to avoid being speared by the excessive lateral lashing of the control wheel. That danger to boobs, balls or knees fortunately does not exist with a side stick controller which may be a factor in the good safety record of the Airbus series of airliners.
Have any other Pprune readers witnessed at first this hand appalling landing technique by some pilots, which is quite distressing to those of us who consider a beautifully executed smooth and gentle flare and touch down on the right spot on the runway, an event of consummate skill?

In French we call that technique "faire de la mayonnaise", as it reminds the way to make a mayonnaise with a fork.
I think that a good remedy is to send the pilot to a glider club. Have him look at the instructor's technique while spiraling in a thermal, hand him over the controls, and he'll see by himself that the mayonnaise technique won't make the glider climb. Hand flying is all about angle of attack perception, it's an extremely difficult skill to acquire, as it can't really be taught on the ground. Gliding is a very cheap way indeed to improve one's visual perception. Once your perception is accurate enough so that you can perceive not only a variation of AOA, but also the rate of variation, then you can anticipate accurately enough not to over control.
Light helicopter flying (R22 for instance) is also a good school for visual perception, but by far more expensive.

We used to have an ex Navy Helicopter pilot do this a lot. Never made the blindest bit of difference to the flightpath though....it was an ATP after all. :ugh:

Answer: Yes, but that was many years ago although I still see it often in the 737 simulator. I first saw this habit or addiction, as a 17 year old standing behind the crew in the cockpit of a DC3 cargo plane as the aircraft landed. The captain was a former RAAF Mosquito pilot who had been awarded the Distinguished Flying Cross during WW2. Being an impressionable lad, I thought at the time if a DFC winner landed a DC3 like that it must be the right technique i.e. thrashing the control column in all directions and constantly greasing the landing.

When I later joined the RAAF and began flying training on Tiger Moths I must have been close to knee-capping my instructor in the front seat with the wooden joy stick which I was waving around in the back seat. His profanity instantly cured me of that technique..

Splendid!

This thread gave me a much needed laugh on this gray sunday morning :D

"For any PM, it is a wise precaution to keep valuable bits of his/her anatomy well clear of the control column full aft movement when their compatriot is feeling for the deck in such a manner, as well as knees well spread to avoid being speared by the excessive lateral lashing of the control wheel."

"In French we call that technique "faire de la mayonnaise""

"When I later joined the RAAF and began flying training on Tiger Moths I must have been close to knee-capping my instructor in the front seat with the wooden joy stick which I was waving around in the back seat. His profanity instantly cured me of that technique.."

Hilarious comments indeed!

I have seen this technique as well among the more nervous flyers.

I’ll admit it’s something I used to do when I first started flying. And that was on the 737. No idea why. I’ve moved on to larger aircraft and I don’t do it anymore. Whilst I fly significantly less sectors per year than I used to, perversely I hand fly more per sector than I used to when I was on shorthaul.

Maybe it’s because on a larger aircraft “stirring the pot” visually does absolutely nothing. Whereas on a 737 the responsiveness of the flight controls is much higher (though it has been nearly a decade since I last flew one).

Just my musings on the subject rather than being any kind of fact.

You move a flight control to change or maintain a bank or pitch. If flight controls are randomly moved you are inducing bank or pitch and cancelling it before it takes place and feeling good about it. In conventional aircraft one can literally feel the resistance of flight controls against the airflow and you can judge when intervention is required. In B707 during base flying it was very evident who is giving unnecessary input because it used to react late with lateral rocking while it was possible to fly it rock steady with proper handling.

Watched this video a while ago and thought to myself that this guy is over controlling his aircraft. Though its not only during the flare phase, it seams quite unnecessary to me, to make such violent control inputs in both pitch and roll during approach, even in gusty conditions.

What do you think?

https://www.mirror.co.uk/news/world-...g-737-10050106

Totally agree. In my 10 years on the 737, with it's highly responsive controls, I've never needed to make such enormous inputs so close to the ground (except when checking full and free). If he stays on twins he'll probably get away with it but any attempt to apply that technique on a 4 engined aircraft will probably end in tears and a nacelle strike. I do find it odd that some pilots feel the need to make constant control inputs in calm conditions. Maybe it's just nervous energy?

Yeah, the "yoke pumpers". I don't do this, but I know some who do. It seems strange to me, but I have flown with some "yoke pumpers" who fly the airplane quite well, and couldn't in any way be considered "nervous". It's their technique, and it they're producing a good outcome with that technique, the fact that it's different than my technique isn't going to cause me to miss a lot of sleep.

I’m on the 777 at the moment, which is a pretty stable aeroplane (especially the -300). Most people I fly with are smooth in pitch and roll but the odd few just can’t stop giving little sharp inputs all the time, which on a 200ft+ wingspan machine generates ripples that wang up and down the wing bouncing us all around but with little to no effect on the flightpath. Same for the elevator. I spend most of the time after takeoff thinking “please put the AP in, please...” as any turbulence is almost entirely self-generated.

I haven’t been able to find a common factor yet, although many have come off the FBW Airbus...

Quote:
"What do you think?"

https://www.mirror.co.uk/news/world-...g-737-10050106

The best part of that whole sequence was the orgasm at the end.
.

Spoiled when he didn't light up a cigarette.

Having said that, if ever a picture is worth a thousand words, then jack11111 provided it. A brilliant demonstration. The equivalent of Children of the Magenta Line except it was a lesson on how not to fly manually. Should be mandatory viewing during type rating training, under the title of threat and error management on the flight deck. The threat being the flailing control column. That should keep the aficionados of TEM happy too.

One way to convince a perspiring pilot the utter uselessness of this addiction to over-controlling, is to use CWS steering mode mode which makes it more resistant to large inputs. Better still, direct him to keep his hand on the control wheel during a coupled approach and autoland and tell him to emulate that in future.
If all else fails it should be back to simulator training until the perpetrator sees the folly of his ways.

I've seen quite a few CFIs that start that nonsense immediately on finals, that's one possible source ..I NEVER flew like that

And that is the common denominator on practically every occasion.

The poor technique is apparent in all types; there is not one individual type that creates the issue. It comes from poor instruction and a lack of understanding of the control system and how best to use it. On Airbus FBW types, I often see the stick stirring commencing as soon as the AP is disconnected regardless of what the air around the aircraft is doing. If you ask the guys what they are trying to achieve, the say they are "controlling the aircraft" when in reality the aircraft needs little controlling. The artificial stability of FBW systems largely means that if the aircraft is on the LOC and GS at the right speed when the AP is taken out, it should fly itself to the touchdown point itself with minimal correction. Any unnecessary control movements will only exacerbate the deviations and make the landing problematic in gusty conditions. I have often heard pilots complain about the Airbus control system with comments like "I was moving the stick right against the stops and it still wasn't enough". In this case, they were making demands against the stability system and not giving the aircraft a chance to respond. Probably a good thing as if it had, the aircraft would be deviating drastically. in reality, the A330 is the easiest aircraft to land in a crosswind In my experience. Components of 40 knots present no problems - providing it is flown properly.

A lot of this stems from poor training. I frequently hear pilots talk in terms of using the controls to move the nose up or down, or to roll - whereas what they should be doing is using the controls to select an attitude. It's basic stuff, but with current training systems such as the MPL where pilots can be at the controls of a large jet with less than 100 hours flying experience, the basics are either quickly forgotten as a result having not enough time to consolidate skills, or just not being taught correctly in the first place. We are creating aircraft drivers, not pilots.

Pilots in type rating on to Airbus initially do that trying to get a feel but that is not going to happen. On Air bus sidestick out of nuetral is a demand to the computer to bank or pitch. Do it only when you want the aircraft to do that. Otherwise you are destabilzing the flight path and then correcting it.This needs to be taught in simulator by frequent intervention to tell them to let go of the sidestick otherwise it gets carried in the aircraft.

It's poor under confident handling. This is similar to what a person does when thrown in water the first time.

I've seen this done by pilots that were certainly not nervous. I wondered why they did it, and figured it came about from poor technique learned early in their flying career. They made an easy landing look very hard.

Yes, if it's making the passengers feel sick! Still see it occasionally on the 787. I'm most impressed when I see little control wheel movement in gusty conditions, and invariably it results in a good landing.

I had a PhD student a few years ago looking at piloting technique in the simulator - he noticed that when flying a precision tracking task, if he plotted stick position against time - the pilots with the largest range and rapidity of movement both usually had the last hours, and the lowest ability to handle handling related emergencies (we were throwing loads through the sim at the time as part of a research project).

That said, I used to fly with an F/A-18 pilot from the USN who did this all the bloody time in a Hawk - and with the throttle as well. It seemed to make him happy, but the aeroplane responses were far slower than his inputs, so it made no difference whatsoever. He thought it was something to do with habits picked up on carrier landings!

Testing and teaching on light aeroplanes on the other hand - it can be positively problematic in ground effect as it makes it far too easy to enter a PIO.

G

There is an interesting comment on the subject of high gain and low gain pilots by John Farley in his book "A View From the Hover."

"Over-control is a common problem with learning to fly, almost regardless of the task but with experience we get better at relaxing, better at trimming, better at letting it fly itself for a bit and then coaxing it back to the desired state. In fact better at becoming a low gain (relaxed) pilot rather than being a high gain (overactive) one. Airplanes take time to respond and it is a waste of time to oscillate controls.”

I am not going to argue with such an eminent personage and it's the way I have always tried to do it.

Very close formation flying aside, we should try and do as the auto pilot does. To me the autopilot is the smoothest guy/gal in town. Now they're real smooth. In case you haven't noticed, on a non FBW aircraft, the control column will hardly move most of the time, when the A/P is strutting it's stuff. I have seen pilots manipulate the controls almost as smooth as the A/P but not quite.Some people will never be smooth. some people are "natural" pilots some aren't. However in airline operations, piloting skills/smoothness appear to be well down the list priorities. Apart from extra fuel burn, passenger discomfort. lack of finesse and wearing yourself out, not many people seem to care. The smoothest I've witnessed in my long career was an Ex WW2 mosquito pathfinder pilot. You either have it or you haven't. Period. Would loved to have flown with Bob Hoover for eg. he was of course good to see outside the cockpit but my money is on he would have been equally impressive inside the cockpit also.<br /><br />IMHO, of course.

I have noticed this tendency for some pilots to be very active on the controls - particularly during final approach and through flare. I am very curious what others who have noted this would have to say regarding the frequency range for such inputs. Particularly at low speeds (such as approach), transport category aircraft have response bandwidths that are half a Hz or less. Inputs at frequencies higher than this (less than two seconds per cycle) will have little impact on the airplane's attitudes (pitch or roll) and even less impact on flight path. One theory I have for this is that some pilots feel that they want greater bandwidth out of the airplane response and thus tend to drive the controls aggressively at higher frequencies thinking it will help.

A few entries back a question was posed as to whether or not this stirring the mayo actually causes the surfaces to move. The answer is yes. Transport category airplane control systems that I am familiar with have surface rate capabilities on the order of 50 degrees or more per second. For a control surface that has a stop to stop travel range on the order of 50 degrees, sawing the pilot controls back and forth half travel at 1 Hz will drive the corresponding surface(s) at their rate limits through a range of 25 or more degrees.

Abrupt inputs at higher frequencies will tend to stir up flexible structural modes. For larger transports the associated modal natural frequencies can be as slow as 2 Hz or less. Feeding energy into body flex modes does nothing toward controlling airplane attitude or path, but sure degrades the ride quality. One name for this is pilot induced turbulence as mentioned earlier in this thread! I wonder if pilots with experience on larger airplanes that tend to exhibit more flex effects have learned to resist being aggressive on the controls because of the negative impact of driving the flex modes while pilots on smaller airplanes don't get as much feedback from the seat of the pants that high frequency inputs are not a good idea.

FBW airplanes with stability augmentation control systems use both pilot controller inputs and stability enhancing feedback signals to command the control surfaces. If the pilot is really stirring the pot with large, higher frequency inputs the result can be that the surfaces spend most of their time sawing back and forth at their rate limits. When the surfaces are rate limited due to pilot input they are not able to simultaneously respond to stability augmentation feedback commands. The augmentation is essentially lost - not a good situation for a relaxed stability configuration.

For great examples, you have to look no further than youtube... Good milk churning going on there.

ancient memory
 

Vilas said I remember one particular day in late 1964 watching aircraft landing on a very gusty day at Heathrow, and noticing that the 707s were rocking quite a bit but the VC10s not at all. Anybody remember the VC10 being easier to control, or was I imagining it?

The VC 10 was probably on automatic pilot coupled to the ILS. That is always smooth unless severe turbulence. Otherwise 90% of the time it is the pilot that is overcontrolling while flying manually. That is the theme of the thread. It usually is simply poor technique.

That is interesting, because on the bus the less you move the stick the better, it will pretty much stay on path with ap off in gusty conditions.

To me, that kind of control flogging screams, "I'm so afraid the aircraft is going to get away from me, I have to stay on top of it". It's fear.
I'd doubt the airmen can ever admit that to themselves.