How different does hand-flying an Airbus (with the side stick) feel, as opposed to a Boeing? Does one feel 'out of the loop'?
There's a fair amount of human factors research out there on this very subject, and as usual there seem to be furious differences of opinion?I like Chin Sau Yong's take on the subject -- flying is fun, and training can turn an analog pilot into a digital pilot or a Boeing pilot into an Airbus pilot, so just get used to the way your bird flies and fly it. That said, there are some instances where so-called "habit reversion" or "habit interference" can get in one's way when a recently learned response comes into conflict with an ingrained habit, or where a given flight control input is not accompanied by an expected sensation and thus leads to confusion or inattention.Let me first offer a link to a very straightforward discussion of how pilots (usually) learn to perceive the relationship between the application of a control input and the aircraft's response: Flight Control Forces. Next, take a look at an engaging essay by Patrick Smith (Boeing vs. Airbus: The pilot weighs in) that points out the fact that, yeah, different airplanes feel different, but the differences between Boeings can be just as dramatic as the differences between those built by two different airframers.Okay -- that's enough even-handed leveling. Now, let's dig a little deeper. A 1990 research paper (Analyzing manipulator and feel system effects in aircraft flight control) describes a model for assessing the results of flight tests which "hypothesizes proprioceptive information to be a fundamental feedback quantity in the pilot's ability to adopt the compensation characteristics required by the crossover model of the human pilot." In other words, this particular approach assumes as a starting point that pilots fly by feeling what's happening to the aircraft and adjust their inputs based on what they feel. That's essentially how Boeing (and others) build their aircraft. Airplane designs started out with the controls connected to wires and pipes, that's about as "direct" as you can get. As planes got bigger, the control surfaces and the forces needed to move them grew as well. At some point, hydraulics started being introduced to reduce the amount of work a pilot had to do to climb, turn, etc. As this evolution took place, designers realized that they still needed to prthe sensation of direct connection between the controls and the control surfaces, so the control systems incorporated features to emulate direct connection responses. "Fly by wire" systems -- where there no longer is a physical connection between the flight controls in the cockpit and the surfaces they move -- led many designers to come up with even more creative ways of making the controls feel like they would if they still were attached to the wing and tail-mounted control surfaces. (A great although somewhat technical discussion of how this was accomplished in the Concorde is available at CONCORDE SST : FLIGHT SYSTEMS.) However, other designers chose this evolutionary point in aircraft-building to try a different path.Airbus engineers started with essentially a clean piece of paper, intending to take advantage of automation that could work between the pilots and the flight control surfaces to allow the former to push the latter to -- but never beyond -- the capabilities of the aircraft itself. In an article explaining the design philosophy of Airbus A320, 330 and 340 aircraft, two Aerospatiale engineers highlight the primacy of this kind of "fault-tolerant" thinking as it shows up in aircraft design: "One of the contributions of the electrical flight controls to the safety of the aircraft is the protections which are an integral part of the flight control laws. The structure is therefore protected during normal flying (G - load factor, speed). A third protection, called high angle-of-attack, prevents the aircraft from stalling. These protections lighten the pilot’s workload, in particular, during avoidance maneuvers whether for an obstacle(near-miss) or windshear. These protections enhance safety." (See Page on psu.edu.)"Flight control laws" are the secret to how Airbuses are so easy to fly when everything is working nominally. I have a small amount of A320 simulator time, I found it quite intuitive just doing point-to-point and traffic pattern work. However, I didn't have to deal with any of the degraded modes of operation, which is when things reportedly can get a bit more interesting. There's a lot of book-learning that goes with understanding the different ways the aircraft will react (and feel) in different modes, a useful if somewhat insider-written explanation of these differences is available at Airbus Flight Control Laws. Probably the most contentious aspect of this debate relates back to the notion of feedback to the pilot mentioned above. One concept of flight control design sees a yoke or stick moved to start a climb or descent and remaining at least somewhat displaced in that direction until you level off. The other involves starting the maneuver with a control input, at which point the control moves back to the neutral position and stays there until an opposing input is applied to terminate the maneuver. Personally, I don't like the latter simply because it requires an analytical response to certain confusing, physiologically-based scenarios that have caused many accidents over time. In other words, you have to think your way out of a situation in which your body is telling you one thing while your brain tells you another. For example, the crew of Air France 447 couldn't figure out what was happening to them as they mushed down out of the sky in a full stall. Lacking a decent seat-of-the-pants sense of the aircraft's attitude, if they'd seen or felt a yoke yanked all the way back to the stops, maybe they would've been able to diagnose the problem. A neutral stick doesn't offer that kind of physical or visual cue.You don't have to look far into pilot forums to realize that there are Boeing supporters, Airbus supporters, and those who have gone A-to-B or B-to-A who either love their old ride and hate their new one, or vice versa. From the standpoint of how the aircraft flies, there's an awful lot of personal preference that comes into play. Design-wise, the two families of aircraft take a fundamentally different approach to how they're flown. But the bottom line is that each works well, and they have roughly comparable safety records.