Just posted to the Cirrus Owner's site...

[FastEddieB]

...and worth a read:

 

 

CEN13LA212

**This report was modified on 9/20/2013. Please see the public docket for this accident to view the original report.**

 

On March 29, 2013, about 1045 central daylight time, a Cirrus SR22T airplane, N1967N, was substantially damaged after impact with terrain (frozen lake) near the Chandler Field Airport (AXN), Alexandria, Minnesota. The private pilot and one passenger sustained minor injuries, and two passengers were not injured. The airplane was registered to MWBS Holdings LLC and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 with no flight plan filed. Day visual meteorological conditions prevailed for the flight, which originated from the Marv Skie-Lincoln County Airport (Y14), Tea, South Dakota about 0904.

 

While on pattern downwind to AXN, the pilot reported a loud noise during flap extension. The pilot initiated a climb as he struggled to maintain roll control. He attempted to reduce the airplane’s rolling tendency by adjusting flap position. As his control of the airplane worsened, the pilot pulled the ballistic recovery system handle. The parachute deployed and the airplane descended onto a frozen lake.

 

The flight recording device was recovered from the accident airplane and forwarded to the National Transportation Safety Board’s Vehicle Recorder Laboratory for evaluation. While on pattern downwind, the recorder indicated that the flaps were adjusted from up to half and the airplane made several left bank turns, with a maximum of 30 degrees of left bank. About 18 seconds after initial flap movement, the flaps were briefly adjusted to up and returned to half.

 

About 36 seconds after initial flap movement, the flaps were adjusted from half to full and the airplane began a right roll to a steep right bank attitude. A stall indication was recorded 38 seconds after the flaps were adjusted to full. The Cirrus Airframe Parachute System (CAPS) was deployed two seconds after the stall indication. The CAPS handle pull occurred at a pitch of 22 degrees nose down, a roll attitude of 86 degrees right bank, and an altitude of about 519 feet above ground level.

 

The airplane was examined at the accident site by Federal Aviation Administration (FAA) inspectors and a representative of Cirrus Design Corporation. The right flap rod end was found disconnected from the right flap actuation fitting. The right flap rod end mounting bolt and washer were found lying on the snow under the airplane. No evidence of a safety wire was present on the mounting bolt or on the right flap actuation fitting.

 

An examination of the CAPS Rear Harness assembly revealed that both reefing line cutters had fired but the rear harness remained “snubbed.” The impact scars on the snow and Ice, and the damage to the aircraft indicated that touch-down occurred while the airplane was in a 40-50 degree nose-down attitude. This nose-down attitude is consistent with a touch-down prior to “tail drop.”

 

A review of maintenance records indicated that the right flap was reinstalled on August 3, 2011, at a Hobbs time of 66.4. According to maintenance manual procedures, the mounting bolt and washer hardware were to be torqued to a measured 50-70 inch pounds, then safety wired to the flap actuation fitting. An annual inspection was conducted on July 10, 2012 (163.9 Hobbs), a pre-buy inspection was conducted on November 5, 2012 (177.2 Hobbs) and the accident occurred with a Hobbs time of 278.0.

According to the Cirrus SR22T pilot operating handbook, the preflight checklist states to "inspect flap hinges, actuation arm, bolts, and cotter pins.....secure." 

 

 

[FastEddieB]

I was always taught to never change one's flap setting in a turn, and have taught that to my students.

 

Why? If a "split flap" condition were to present itself, you'd have more time to recognize it from level flight than from a banked turn, where you might be confused by why the bank was suddenly increasing or decreasing unexpectedly.

 

I was told that due to the design, this was not an issue in a Cirrus. This proves once again the power of Mr. Murphy and his Law.

[Ed Cesnalis]

Eddie,

 

I think that is good device, I have one departure where I am retracting as I turn crosswind, no reason I can' t wait 4 seconds and turn first.

[coppercity]

No substitute for a through preflight using your checklist.

[Roger Lee]

We can all learn from relevant and small aircraft incidents, but posting all of them or 747 incidents aren't very relevant to us. This one is relevant because it could happen to any of us.

[Jim Meade]

I don't agree that a split flap condition would be less recognizable in a turn. What evidence do we have for that statement? Are there some accident reports that state that? It would seem to me that if one is in a turn, deploys flaps and the airplane maneuvers in a non-typical manner our first inclination would be that it is the flaps.

One reason I had students activate flaps in the pattern in straight flight is that I wanted to minimize variables. I always wanted the student to see that some one thing was involved in whatever change the airplane manifested.

These were students. As they got experienced I no longer required them to isolate their inputs.

I'm not saying that isolating flap deployment is wrong, I just don't' think it's necessary for experienced pilots.

[FastEddieB]

Funny, I didn't think this could lead to an argument.

 

Over on COPA two pilots just thanked me for reminding them.

 

No statistics, just Fast Eddie Logic.

 

Let's say the split flap rolled you 45° in a heartbeat.

 

From wings level flight, you'd find yourself in a 45° bank from which to recover.

 

From a 30° banked turn, worst case scenario you would find yourself in a 75° bank.

 

I'd choose the former.

 

Anyone here can make their own choice and deploy flaps whenever they want.

[FastEddieB]

Pointed out on COPA:

 

After the safety wire was left off, the plane went through an annual and it wasn't caught.

 

Also not caught on numerous preflights.

 

Maybe a head's up for us all to be just a tad more detail oriented.

[Roger Lee]

 

Hi Eddie,

 

I didn't think Andy's spark plug question would either.

[Jim Meade]

What argument? You that you don't deploy flaps in a turn. I say I do. Who's arguing? I don't intend to persuade you that you should adopt my practice and of course you are not going to persuade me that I should adopt yours, subject to more factual information.

I think that if I followed some practice that you disagreed with that you would say it was not for you. That's all I'm saying here.

[Duane Jefts]

Several great lessons here:

 

1. During the movement of the flap handle and subsequent unusual roll movement, immediately return the flap actuator to the previous flap position.

 

2. Though he may not have been thinking "climb to safe chute deployment altitude" it sounds like he was trying to buy some time.

 

3. When climbing he may have overlooked his airspeed. Always fly the aircraft FIRST.

 

4. When it came time to let the chute do it's job, he pulled the handle. Good for him. Some would have fought the controls longer and may not have survived.

 

5. All survived the landing and that is the important part.

 

Thanks for sharing Eddie.

[Doug G.]

It made the local news here. Good to now have the details.

[Doug G.]

One other point... as a repairman, double-check everything you do.

[N89WD]

Suggestion, there should be a "like" button for posts. Thanks FE for the info. I frequent COPA site. Much depth there also.

[Doug G.]

I second the "like" button (or something similar). I would also like to see a way of making a particular post ( not the whole thread) for future reference.

[Ed Cesnalis]

http://www.invisionpower.com/apps/board/feature-list

 

This link lists the available features that this board has access to.

 

Custom features beyond those require programming and then running and maintaining a custom version. As new releases become available more programming would be required.

 

Unless I.P board implements the features that you are requesting they are probably not in the cards.

[FastEddieB]

A partial recreation of the plane's flight data recorder:

 

[Darrenr]

Thx for sharing. I also learned and do not deploy flaps in a turn. I was taught easier to recognize a failure and if you are in a banked turn and there is a failure of one flap you will have even less time to react before over banking situation. Just the way I do it.

[FastEddieB]

Thx for sharing.

 

You're welcome!

 

I also learned and do not deploy flaps in a turn. I was taught easier to recognize a failure and if you are in a banked turn and there is a failure of one flap you will have even less time to react before over banking situation. Just the way I do it.

 

Yes.

 

1) The argument was made that perhaps an experienced pilot* would have skills such that it would make no difference. I still hold that the procedures we teach, if they have sound bases and are explained properly, can make flying safer for all pilots. I still try to fly "in real life" using the same general procedures I teach to beginning pilots - what makes things easier and safer for them tends to make things easier and safer for me.

 

2) I might modify my stance if I heard a really good argument for why flaps had to be deployed while in a turn. My patterns tend to be (somewhat) rectangular, so there seems to be plenty of opportunity to deploy in unbanked flight. In my Sky Arrow I normally go 10° abeam the numbers and full (30°) on base. I just don't see the rush.

 

3) The odds that any of this will make a difference for any given pilot on any given approach are vanishingly small. I daresay that split flap scenarios are very, very rare and most pilots will never face one. Still, the pilot in this incident did, and we know that in rare cases it can and does happen. So why make things any trickier than necessary?

 

 

*Anyway, had to be reminded of this quote:

 

 

Truly superior pilots are those who use their superior judgment to avoid those situations where they might have to use their superior skills.

[Runtoeat]

This is very educational. On occasion, I apply 30 or 40 flaps during my turn to final. Due to my lack of experience, I'm not sure I could correctly recognize and react to a flap failure such as this. Will now make the turn to final further out to allow time to apply flaps after the turn is completed and I'm on a stabilized approach.

[FastEddieB]

I spent the vast majority of my flying career going to full flaps on final. "With the field made" comes to mind as the trigger for full flaps. In the C150 I learned in, that was a substantial 40° of flaps.

 

When I trained to be a Cirrus Instructor, they wanted the procedures standardized, and called for full flaps on base. So I started teaching that way, in spite of the fact it was new to me.

 

But guess what? It worked really well. So well that I do so now as a general rule.

 

The case for it is you then have no configuration changes on final, making it easier to achieve the desired "stabilized approach". Students (and pilots in general) sometimes struggle with the change in pitch needed on final when they deploy that last bit of flaps.

 

The case against is usually stated as a question: "But what happens if you lose power and you have full flaps?" My answer to that is, traffic permitting, to fly a close enough base that the field would be "made" even with full flaps.

 

But this is really just a matter of technique and timing. Where you go to final flap setting is not all that critical. Just pointing out that an old dog learning a new trick sometimes actually does happen!

[Jim Meade]

What kind of flap failures occur? Does anyone have any statistics or information?

Does one side stay in position and the other side extend? Does one side extend and one retract? Does one side cut loose and flop in the wind and the other go to maximum? Does one side jam and the other extend as programmed or commanded? Are we talking about mechanically controlled flaps (Johnson bar) or electric motor driven, or what?

 

Someone come up with some plausible scenarios, preferably backed by experience in the kind of airplanes we fly, and then let's talk about it.

 

Short of that, we are talking about what seems to me to be an extremely unlikely event. And, in the case of some scenarios, what Jett said - the airplane adage I was taught by a hoary old pilot - if you flip a switch in an airplane and don't like what it did, return it to it's original position.

 

So, let's discuss facts as we know them and see what we can come up with for actual, real flap issues, especially those that would be affected by deployment during a turn.

[FastEddieB]

What kind of flap failures occur?

 

Apparently all sorts.

 

Does anyone have any statistics or information?

 

Google "Split Flap Condition".

 

Here's one in a 737: http://www.37000feet...oach-Executed-a

 

<quote>Does one side stay in position and the other side extend? Does one side extend and one retract? Does one side cut loose and flop in the wind and the other go to maximum? Does one side jam and the other extend as programmed or commanded? Are we talking about mechanically controlled flaps (Johnson bar) or electric motor driven, or what?<quote>

 

Any and all of the above.

 

<quote>Someone come up with some plausible scenarios, preferably backed by experience in the kind of airplanes we fly, and then let's talk about it.</quote>

 

I think I just did. One started this thread, for instance. In any case, I don't know if a CT is totally immune from this sort of thing. If so - never mind.

 

<quote>Short of that, we are talking about what seems to me to be an extremely unlikely event.</quote>

 

Stipulated.

 

<quote>So, let's discuss facts as we know them and see what we can come up with for actual, real flap issues, especially those that would be affected by deployment during a turn.

</quote>

 

Google "Split Flap Condition".

 

BTW, do you have a strong reason to deploy flaps in a turn?

 

 

 

PS - why the low limit on quoted blocks? Other sites don't seem to restrict them as much.

[Jim Meade]

This site is goofy for it's restrictive formatting.

 

Next time anyone is in an airliner keep an eye on the maneuvers and the flap and spoiler positions. I bet you will find they are deployed in any normal flight attitude subject to airspeed limitations.

When I was flying little big planes there was never any issue with flap deployment save for speed and some parts of the profile, such as 400 feet before flaps up on the Citation.

 

Asking why I deploy flaps in a turn is kind of like asking when I quit beating my wife. It assumes something is bad or substandard in the first place. I think I can guess that you do not deploy flaps in a turn for reasons you stated above, reasons I find to be based on excess caution. One could say I deploy flaps in a turn because I've never found a good reason not to and I deploy flaps depending on the situation. Most commonly, we deploy flaps in the landing profile. I have deployed flaps for practice and familiarization during stall practice.

 

My reaction to admonitions like don't deploy flaps in a turn is that we are limiting our ability to fly the airplane to a safe and recognized portion of the flight envelope out of excess caution. I might ask why one would have full flaps deployed on base such that if one got caught with a little following wind and was not always keeping the wind in mind and judging the speed over the ground the turn to final might be a little steep. All of a sudden we are in a steep turn near the ground with full flaps and a sudden wind gust or microburst might cause some consternation - even a stall.

 

When we learn and teach, we often begin with very conservative profiles with limited options. That's fine for students and insurance companies. As we gain experience and expertise, we may want to fly the airplane in the safe but more permissive part of the envelope. I've heard so many mechanics and pilots admonitions that are not based on science or deep knowledge that I push back when I see them. I don't think it's unsafe to deploy flaps in a turn, so why should I not? What will I do straight and level that I will not do in a turn if I get a split flap condition? Will I not reverse the command? Will I not try to use rudder and power to effect attitude? Will I not recognize that split flaps and aileron deployment might create some interesting aerodynamics over the wing? Will I not pull the chute if indicated? (And, if we're in the landing pattern and have a split flap condition such that control is affected, we are admonished to pull the chute anyway - and don't delay.)

 

I'd be happy to conclude from my perspective that if Fast Eddie prefers to never deploy flaps except when straight and level and others are comfortable deploying flaps in a turn that both are fine, consonant with flight conditions, pilot competence and airframe limitations.

[Ed Cesnalis]

Jim,

 

You are making me think, and I am persuaded. At first Eddie's question about recovering from 90° as opposed to 45° persuaded me. After thinking about it the time I'm most likely to retract in a turn is when I turn crosswind departing 27 at Mammoth.

 

Strait out is an uphill departure and by the time I turn crosswind I really need to turn and head towards lower terrain. In that case, assuming I recognized split flaps, I wouldn't want to level my wings I would want to continue the right turn even if the attitude was unusual to deal with the flaps.