Va Speed and GA Training Aircraft

[Ozgrade3]

The Risks of Maneuvering Speed Myths - AVweb Features Article (http://www.avweb.com/news/features/The-Risks-of-Maneuvering-Speed-Myths222680-1.html)

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSAIB.nsf/dc7bd4f27e5f107486257221005f069d/3c00e5aa64a2827e8625781c00744393/$FILE/CE-11-17.pdf

Just had a read of these two articles regarding the general misunderstanding of most pilots on the subject of Va speed. This was sparked by the report of the A300 crash in new York where the FO put rapid, opposite rudder inputs which subjected the tail to more than double its design loads, even though they were below Va for their weight.

In the training context, especially in sequences such as effects of controls, it's customary to demo control inputs to show their effects and allow the student to try the controls himself. Naturally their efforts are ham fisted and they over control, especially on the rudder, . Now you dampen their over enthusiastic efforts as much as you can but is the damage already done? Should we instructors be modifying our practices?

Why aren't the ailerons subject to the same restrictions, to stay wings level in turbulence you often go full left to right and back etc.

[Oktas8]

It's a good accident report to read, certainly.

For effects of controls, the student is usually quite gentle, from nervousness. If they aren't, it's a good time to teach the importance of being gentle! So, the aircraft should not be suffering from full or abrupt inputs. Half inputs, gently applied, are more than sufficient to achieve the aims of the lesson.

AFAIK the ailerons are subject to the same restriction. If full aileron inputs are required in rough air, the turbulence is probably "severe". I recommend flying an attitude rather than heading/altitude, and making cautious control inputs. That is, it is better to be briefly at 45* AoB with a steady half aileron applied (gently increasing to full perhaps), than to be continuously wings level while sawing away at the control column like a demented lumberjack.

In 15 years of GA & now airline flying, I've never needed full & abrupt control inputs due turbulence (although I have had my share of severe & wake turbulence) so it is possible!

Cheers,
O8

[Homesick-Angel]

What about the demonstration of stability in S+L? Is that still taught out there? The boat analogy- just ride it out.

There's no need to correct every disturbance. Little but firm applications of rudder can help along with ailerons on those days when control is more difficult and you are getting more violent wing drops, but I always taught students to ride it out rather than chase every rise, fall, pitch and roll.

[dubbleyew eight]

have you ever thought that the limiting of control inputs approach is total nonsense.
you have identified a deficiency in design standards that needs to be corrected.

....of course that would require the national airworthiness authority to actually understand the aeronautical engineering.
In CAsA I'll bet there is no understanding at all.

[Oktas8]

You could make the structure stronger and the control surfaces smaller, less powerful. Then a pilot could have carefree handling (full & abrupt, etc) at all speeds. The downside is that, at low speeds, the pilot would be unable to make the substantial corrective actions required to control the aircraft for take-off & landing.

Alternatively, you could make aircraft clever enough, with fly-by-wire, to limit control inputs only when necessary. Airbus use this philosophy, and Boeing too to a lesser extent. The downside is that your ACME Bugsmasher Mark II would cost $2,300,000. This may have a negative impact on the health of our industry!

[Grogmonster]

I have often thought about this subject during my aviation career. Many years ago when I was a teen living in PNG I actually witnessed a fatal accident in C182 dropping parachutists at a strip not far from Rabaul in New Britain. It was over 40 years ago so my recollection may be a bit vague. It appeared that after dropping two chutes he was returning to drop two more who were on the other side of a small Cu cloud which the pilot chose to fly through. Unfortunately they, the first two parachutists, had opened early and were caught in an updraft so that when he exited the cloud the chutes were directly in front of him. As a result he took violent evasive action with elevator which snapped the tail off the aircraft. It still hit the chute with a female attached. Both she and the drop pilot perished with the instructor exiting so late that I believe he was injured because his chute only just deployed. Very sad.

The point being I guess is that if you pull hard enough on any control you are at serious risk of breaking the aircraft. As a result I have always been very gentle with control inputs during my flying career. I always take another 10 or 20 knots of all limitations even flap and gear extension because I believe it will give you that extra margin.

Groggy

[Homesick-Angel]

The way aircraft are designed, there really doesn't need to be much of a margin.. The engineers know better than most of us pilots...

Thing is, I doubt they ever expected the same planes they designed 40 years ago to still be flying.. Eventually something's gotta give..