Stall warnings in high capacity aircraft

[Brian Abraham]

May be of interest to you plank drivers.

From Aviation International News

The Australian Transport Safety Bureau (ATSB) has released a research report examining every incident of stall warning activation between 2008 and 2012 in transport-category aircraft operating in Australian airspace. The incidents recorded in the October 31 report include both local aircraft as well as those of foreign registry. During this five-year period, 245 stall warning incidents were reported, most of which were categorized as low-risk, short-duration events in which the outcome was never in doubt. Thirty-three incidents, however, were classified as serious and occurred during the approach phase. Seventy percent of the warnings were deemed actual alerts rather than mechanical failures. Fifty-five percent of reported stall warnings occurred in VMC, while most of the IMC-related alerts took place during cruise, often when the aircraft was near the high end of its altitude-operating envelope. Findings showed common precursors to stall activations were rapid changes in pitch or airspeed. In one-fifth of IMC events, the stall warning activated when the autopilot tried to correct the aircraft’s speed or flight path in response to a disturbance such as turbulence. Scrutiny of the serious events revealed that the crews’ failure to recognize decreasing airspeed and increasing angle of attack before the stall warning increased the risk of a stall developing. The crew was often focused on correcting the approach path before the stabilized approach height when a go-around would have been the more prudent option.

ATSB report http://www.atsb.gov.au/media/4359010/ar-2012-172_final.pdf

Go arounds Safety Forum: Too Few Go-arounds Executed | Aviation International News (http://www.ainonline.com/aviation-news/aviation-international-news/2013-08-03/safety-forum-too-few-go-arounds-executed)

[Natstrackalpha]

You know, they want more Go-Arounds in training, more Go-Arounds in PPL/basic training, more Go-Arounds in Line training - in the sim,
more Go-Arounds in Base training,

Make Go-Arounds as nice an event as landing - why? Because sometimes it is the only option - and yet, in training, people who have lived with Go-Arounds for ages tend to think they are silly - yet to a trainee pilot they are interesting and absorbing and to do a good one takes skill and good CRM - As one is going to land for most of their flying lives - FIRST TIME, then Go-Around City once in awhile is not a bad plan.

Then, when it happens for real in an environment of traffic as thick as minestrone it will prove prove quintessentially apt. (pun for the level off)

Once - a million years ago, a fellow trainee instructor got awful mad at me as I went for my second go-around thinking my landing was not. . . the one to be . . he went ballistic and insisted I land, which, like a :mad: I did - quite successfully - on the walk back to the big C he explained that if it weren`t for the fact that we were on a course he would have punched me on the nose.

In retrospect - I regret not having done the same to him as a pre-emptive strike - course or no course. If you want to go around then go around. Thats what it is for.

The fact the above landing was successful - was a fluke.

[underfire]

I dont agree.

While a GA may be necessary as an emergent issue, for the most part, a GA is the result of a failure much further back.

Given the amount of redundency in an approach procedure, as the study illustrates, the need for a GA is mostly due to pilot error.

A GA really fuks up the DEP queue, crossing, LAHSO, and generally, the airspace. It is, and should be considered an emergency procedure.

I have seen much more abuse of GA due to pilot error (overspeed, underspeed, etc), much of which could have been prevented prior to needing GA, than actual necessity of use (such as runway occupied)

Conclusion: I feel that GA is overused as a result of pilot error, not emergent issues. Dont train the pilots to use more GA as a means to supplant better pilot training.

[Wizofoz]

I don't think I have ever read an opinion I agree with less than that, under fire.

Error happen. Environmental factors happen. Other traffic happens.

I have been sent around by ATC on more occasions than I have elected to initiated myself, but in both cases it meant a safe outcome while the alternative would have been disaster.

GA is a normal procedure that should be easily accomplished and readily used as required, and even suggesting pilots "avoid" GAs is a negative in terms of overall safety.

There are no end of accidents that would have been prevented by a GA that didn't happen. Can you one that happened because a Pilot went around when he didn't need to?

[Intruder]

underfire:

I hope I never inadvertently ride in your airplane, or fly mine near yours.

I've made a handful of go-arounds in my airline career, and virtually all of them were due to ATC miscalculations or ground-based problems. I've ridden as FO or relief pilot through a few others that were due to weather or unstable approach. I'd MUCH rather ride through a go-around than a vain attempt to salvage a bad approach.

You seem to forget that a huge part of our training is on the job, and daily we run into situations that are not quite like we've seen before. Maybe a significant number of go-arounds could be prevented with perfect foresight, but I believe the vast majority of them are warranted NORMAL operations -- NOT "emergencies". In fact, a timely go-around is more likely to PREVENT an emergency.

[Check Airman]

I dont agree.

While a GA may be necessary as an emergent issue, for the most part, a GA is the result of a failure much further back.

Given the amount of redundency in an approach procedure, as the study illustrates, the need for a GA is mostly due to pilot error.

A GA really fuks up the DEP queue, crossing, LAHSO, and generally, the airspace. It is, and should be considered an emergency procedure.

I have seen much more abuse of GA due to pilot error (overspeed, underspeed, etc), much of which could have been prevented prior to needing GA, than actual necessity of use (such as runway occupied)

Conclusion: I feel that GA is overused as a result of pilot error, not emergent issues. Dont train the pilots to use more GA as a means to supplant better pilot training. :ugh:

Are you from one of those cultures where saving face is more important than saving lives? I assume you aren't a pilot.

A GA is not an emergency. If your instructor is telling you that it is, I think you should change instructors.

[oceancrosser]

For years and years at my outfit, in the sim G/As were always accompained with an inevitable engine failure. And completed as such. No problems as such.

Then one day, I had a G/A initated by ATC when preceeding traffic stopped on the runway, instead of vacating. I kept waiting for the engine to fail. :ugh: Which it did´nt.

Getting home, I called a TRI/TRE friend and gave him a tongue lashing, how about training some normal G/As? Soon after the sim programs changed, and now include NORMAL G/As.

In 30 years of airline flying, I have only done a handful. But I want to be trained and ready, and my F/O better be as well.

Underfire... I really disagree :=

[Wally Mk2]

Indeed that is a most disappointing way of looking at GA's. As most know it's a normal flight maneuver & conducted for all sorts of reasons inc pilot error, I mean we are all human & makes mistakes.
'Intruder' you would do well to consider it a safety net, a get out of jail free card that A/C are designed to do.

[westhawk]

Go-arounds are normal maneuvers. Every pilot should consider that one may become necessary until it's no longer a viable option. It's certainly not reserved only for "emergency" use. In my experience, typical events prompting a go-around include preceding traffic unable to clear the runway in time for your arrival to meet ATC runway separation standards or just recognizing that insufficient in-trail spacing exists to reasonably expect sufficient runway spacing to exist. It happens every day at airports the world over, especially busy ones. Better to go around from 500' than in the flare. Pilots need to be proficient and comfortable with the maneuver and associated procedural actions. Thinking that a go-around is an admission of failure or is always the result of a lack of skill or judgment is a dangerous and counterproductive attitude that should be strongly discouraged.

Most pilots have done some approaches and landings that upon objective reflection, weren't their finest. Maybe even right there on the cusp of "should have been abandoned", but were salvaged anyway. Gusty crosswinds or NPAs to mins are both likely circumstances acting to set up a greater likelihood of a go-around becoming the better part of valor. Sometimes the approach just isn't going to terminate with a full stop landing and being unwilling to admit that is at the head of the causal chain in a great many runway overruns and excursions.

Funny story from my charter days:

I had this fat cat business mogul on board our Hawker one time going into Bozeman, Montana on a charter flight. Nice enough guy, but you could tell he was one of those tense types used having things his own way. We contact the tower on a 5 mile final and he clears us to land behind a C-170 on a short final. By the time we spot him, he's on the runway and we're 3 miles out. Cool, he should make the next turnoff we think. He doesn't. 2 miles out. Well, the next one then? Us to tower: If that Cessna makes the next turnoff, we won't have to go around. Cessna now taxiing down the runway at near walking speed, passing the next turnoff. Now we're at about a mile, I look at the other guy and shrug my shoulders as I add thrust and pitch the nose up. My pard tells the tower and we fly the pattern and land normally. Getting off the airplane the biz guy asks: Hey what was all that about? Do I have to pay for that? Me: No sir, it's included, no charge. Big smile. The chief pilot and I both had a good laugh when I shared the story!

[captjns]

Surely Underfire, you're not serious about your belief Go Arounds should be treated as emergency:}? And I won't call you Shiela either. LAHSO???? We never accept LAHSOs.

Go arounds are not always from poor planning... I think you need to check your facts.