Big birds and the BRS debate.

[facthunter]

You are fairly likely to have serious injuries in a circuit collision situation and the plane won't be behaving normally most likely and you won't be that high  Nev.

[BrendAn]

i watched a yt today on a run of quad city challenger accidents . there were some that lost a wing midair due to a fatigued strut bracket. there were fatalities but the one pilot that survived had a brs and he walked away without a scratch, so they are great for structural failures. 

[facthunter]

Just don't get a quad city challenger. Put the weight of the chute into the structure.   Nev

[BrendAn]

14 minutes ago, facthunter said:

Just don't get a quad city challenger. Put the weight of the chute into the structure.   Nev

i just thought it was an interesting example of the one time brs could be worth it. ie: midair collision or in flight breakup.  

[facthunter]

I Know. But I've always gone for a strong airframe. The chute wouldn't be much if you're only 100 feet up. I'm also a non fan of the Quad City Challenger and the chute is extra load. .Nev

[Garfly]

Looking for more detail, I searched for the video BrendAn referred to. 

 

I think it's this one:

 

 

 

... which led me to the TSB Canada reports etc, that it was based on.

 

My takeaways from all that: first, just how seriously federal agencies in Canada take ultralight aviation and its safety. (Imagine so comprehensive a report being done by the ATSB on an ultralight crash, and RAAus, of course, doesn't have anything like the resources needed.)

And, second, that flying any fairly basic homebuilt ultralight might, itself, weigh-in on the pro side of a BRS installation, where practical.

After all, it's not like either this particular pilot/operator or the kit manufacturer were heedless or clueless regarding the importance of the wing bracket that failed. In fact, the manufacturer required that the part be replaced before 500 hours - as, indeed, it had been.

Anyway, I'm more convinced than ever just how crucial it is for all ultralight owners to keep a sharp pre-flight eye on lift-strut attachments (and to keep up a strict inspection schedule).  Hidden metal fatigue is still a killer, especially in aeroplanes built for lightness. 

 

 

 

Annual Report to Parliament 2019-20 - Publications - Transportation Safety Board

WWW.BST-TSB.GC.CA

---

Annual Report to Parliament 2019-20

 

 

EXERPT:

Risks associated with ultralight wing brackets

On 30 July 2018, a privately operated Quad City Challenger II advanced ultralight aircraft crashed into trees en route from North Bay to Rockcliffe, Ontario, after the right wing separated from the aircraft. The single occupant was fatally injured.

As part of its investigation (A18O0106), the TSBissued Aviation Safety Advisory A18O0106-D1-A1, “Quad City Challenger II Advanced Ultralight – Bracket Failure,” to alert Transport Canada to the possible risks associated with the failure of the attachment brackets that secure the wing lift struts on the aircraft.

Quad City, the Canadian distributor of the Challenger II, is conducting a stress analysis on the addition of a fixture to reduce flexing and spread loads around the bolthole, where fatigue cracks appear to start.

In response to the safety advisory, Transport Canada issued Civil Aviation Safety Alert 2019-02 to inform owners of the possible failure of the brackets and the need for disassembly, inspection and part replacement.

 

 

 

 Air Transportation Safety Investigation Report A18O0106 

IN-FLIGHT SEPARATION OF RIGHT WING 

Quad City Challenger II (advanced ultralight), C-IGKT   30 July 2018 

 

a18o0106.pdf

 

EXERPT:

 

Safety message

The lift strut brackets used on the Quad City Challenger II have been in service for 35 years and are installed on more than 4400 aircraft worldwide, of which 608 are in Canada. In this accident, a fatigue crack on the right front lift strut bracket went undetected during the routine inspection cycle undertaken by the pilot, and the bracket failed in flight before the 500-hour stipulated life span. The failure led to the right wing separating from the aircraft, resulting in an unrecoverable loss of control and collision with terrain.

Examination of additional brackets obtained from other aircraft, with various amounts of time-in-service, found that fatigue and delamination cracks are not isolated to the occurrence bracket.  As this occurrence demonstrates, it is possible for fatigue and delamination crack failures to occur on these brackets within recommended time-in-service limits and to remain undetected during basic manufacturer-recommended inspection practices. Cracks that develop on an airframe component need to be identified before the component fails completely. This is especially true when the component’s failure can result in an irrecoverable loss of control in flight.

 

 

Page images from the Report (click to enlarge):

 

 

 

 

 

 

Edited June 9, 2023 by Garfly

[Garfly]

 

On the subject of fatigued metal bits giving up the ghost:

 

 

 

NTSB report:

 

Report_ERA21LA183_102905_6_10_2023 6_57_08 AM.pdf

 

 

 

 

 

 

 

[facthunter]

You should be able to fly a single engined plane without rudder. Certainly can't without pitch control.  Nev

[Garfly]

Yes, perhaps one of the few times it's crucial is in take-off/go-around mode, catching you unawares, as in that case.

[sfGnome]

How can a broken rudder cause the aircraft to bank left? The only thing I can think of (which seems unlikely) is that there was a rudder trim spring/bungee that, in the absence of rudder control, pulled it hard left. Even in a go-around situation, it still doesn’t make sense. 
 

Another alternative was that in the process of the go-around, the aircraft stalled, and the attempt to recover with the rudder failed either because the rudder was already broken, or it broke at that point. If that’s the case, then it wasn’t the broken rudder that caused the accident…

[facthunter]

Go around is  often a critical  control manoeuvre especially with any x wind effect and near the ground and IF you have a high torque engine or a tailwheel configuration and still touching the ground.   Nev

[onetrack]

The 8 kt crosswind and a 17 yr old pilot with only 138 hrs in his logbook must have been the main contributing factors. The weather was good, 10 miles visibility, 16° ambient temp., no precipitation.

 

"Upon turning onto the final leg of the traffic pattern, he opted to land with only two notches of flaps because of an 8-knot crosswind.
He reported that, around 100 ft above the runway at an airspeed about 90 mph, he decided to go around, since the airplane was fast and it felt like the approach was unstable.

He smoothly applied full power, but the airplane did not gain any altitude, and started banking hard to the left.

By this time, the airplane was about 50 ft above ground level, left of the runway, and the pilot was applying right aileron and right rudder in an attempt to level the wings.

He had no further memory of the accident sequence."

 

"Review of the flight characteristics of the PA-28-140 indicated that, even without rudder, the vertical tail would provide enough directional control to counter the “left-turning tendencies” during take-off or go-around, though the rolling moment due to the sideslip would have tried to roll the airplane left without any right rudder input. Roll could be compensated by adding right aileron inputs."

[facthunter]

You could absolutely Guarantee (almost) He's NEVER been trained to fly like that although Controls effect and FURTHER effect would appear in the log book as signed off early in the Piece. Box ticking is alive and well.  Nev

[Garfly]

Excerpts from the Youtube comments.

(I'm with Fred Flintstone on this one ;- )

 

Thomas Altruda

1 day ago

Loss of the rudder still won’t cause the crash.. this doesn’t make any sense. The plane should still have climbed away from the ground and cleared the trees.. the pilot still had the ability to add full power, control of the ailerons, elevator, flaps… I don’t see this as the cause of the crash. Definitely cup and cone though! Lol

 

Fred Flintstone

1 day ago

@Thomas Altruda Without the rudder to counteract the immediate left yaw from applying full power I am guessing this happened very fast. He did not know he lost the rudder but taking out the power and letting the plane go straight would have probably kept him on the airport but maybe not the runway.

[kgwilson]

He had 2 notches of flap (25 degrees) so this would have affected the performance of the 140. They are underpowered anyway (even the 160 HP Warrior is marginal IMO) so he needed to dump the flap which in a PA 28 with the manual flap takes all of 1 second. You don't need much rudder in a PA28 at any time so I don't think it is much of a factor. He reported being at 100 feet at 90mph (78 knots) so had plenty of speed at that point. Maximum recommended speed with 25 deg of flap in a 140 is 80mph or 69.5 knots so he had too much speed at that point for the flap deployed.

 

There is no logic to the left bank other than the pilot going full power with 25 deg of flap & pulling the yoke back to gain height which wasn't going to happen with all that flap drag, getting close to stall and losing control. Sounds like some serious training inadequacies to me. Note that normal takeoff flap for a 140 is 0 degrees & 2 notches for short/soft field (which he'd most likely never encountered.

 

That accident would never have happened if there was a properly trained normal pilot at the controls.

Edited June 11, 2023 by kgwilson

[Garfly]

We don't actually have much detail to go on regarding what happened in those few seconds between his 100' decision to go around and his ending in the shrubs.

Certainly not enough, IMHO, to confidently condemn the young pilot. 

His decision to go missed in the first place, due an "unstable" approach, may well be counted a 'good' one; reflecting 'good' training and good learning.

And then, if the rudder did 'break' right at the point he went max power (with armfulls of forward stick and bootfuls of right rudder - as per propertraining) then who's to say that that wouldn't have caught out a 15,000 hr pilot as much as a 150 hr one? 

After all, aren't we supposed to add at least 3 seconds for the WTF!  factor while practising 'realistic' emergencies. 

Why not cut this guy at least that much slack?

 

[onetrack]

You can't put 20 years of flying experiences and skills into a 17 yr olds head. 17 yr olds brains are still developing, their response to stressful conditions and emergencies is slower as they try to work out what is happening from a small pool of life experiences.

Older people may have slightly slower reflexes, but older peoples responses to emergencies are faster when they understand what is happening, from prior experiences.

[Garfly]

Anyway, Instructor Google has some interesting insights into the four left-leaning amigos:

 

(Torque, spiraling slipstream, P-factor, and gyroscopic precession)

 

 

Technique - Left Turning Tendencies

WWW.AOPA.ORG

 

 

 

 

 

Edited June 11, 2023 by Garfly

[kgwilson]

At 70-80 knots its aileron that is going to counter the left turn even with the 25 deg of flap. The rudder will just keep it balanced. If there is no rudder then there will be obvious yaw but speed must then deteriorate rapidly for that to turn in to a major control loss and that may have been due to the climb angle of attack and 25 deg of flap drag.

 

Inexperience and the WTF factor will very easily get in the way of the basic function of dumping flap. I am sure this could happen to anyone no matter how experienced they are as well.

 

As an example a few weeks ago when a Mooney pilot lost his engine on climb out at less than 1000 feet, a successfull wheels up landing was made. He said to me that in thousands of landings his final mneumonic was "green fine flap" for 3 greens wheels down, full fine pitch, and flap to landing configuration, but he didn't do that, nor did he switch the electric fuel pump on. He could not explain why. All he wanted to do was miss the houses and trees which he did successfully & that occupied his brain to the exclusion of everything else.

 

I can't understand why those ingrained things failed him but they did and I am sure it could happen to any of us. I guess we only find out how we react when it happens to us for real.

[facthunter]

Blaming the training is not blaming the pilot. !00 Plus hours is a lot more than many pilots who were in the skies fighting the enemy had.  Nev

[Garfly]

1 hour ago, facthunter said:

Blaming the training is not blaming the pilot. !00 Plus hours is a lot more than many pilots who were in the skies fighting the enemy had.  Nev

 

True, but I don't see here (albeit without much to go on) a case for blaming the training, either.

 

 

I do remember in my own PA28 140 ab initio work in Moresby, yonks ago, dumping flap in a go-around was absolute anathema.

(The littlest Cherokee never seemed to have trouble climbing away, 2-up, full flap, despite the heat and the humidity.)

To dump flap is to dump lift, was the mantra. The lever had to be left where it was until a positive rate - on runway heading - was established and then, ever so gently, progressively eased off.

So if this young chap's training was anything like mine, flap dumping would've been the last thing to have 'kicked in', as they say.

Actually, I remember doing just that once, on a go around with an instructor who, as our climb-slope sagged alarmingly, went apoplectic, saying I'd get us killed doing that.

On reflection, I realised I'd done it reflexively; the imprint of all that touch-and-go practice, where you usually do need to dump landing-flap quick-smart before powering up again.

 

 

Edited June 11, 2023 by Garfly

[Carbon Canary]

I can't understand why those ingrained things failed him but they did and I am sure it could happen to any of us. I guess we only find out how we react when it happens to us for real.

 

UPRT explains clearly why this can happen to anyone, regardless of hours.

[RFguy]

PA180-180A -  If I dump from 40 deg flap in the Archer in the go around (say from baulked landing) , then I only go to 25 deg of flap in the go around-   until I am well and truly estabilished on climb, and my brain has caught up with the airplane ..... situation understood, and  flying in balance....... IE full power, trim, reduce from 40 to 25 flap when stabilized over run way, then climb, retrim to reduce stick pressure, stabilize, then reduce flap as required .... She climbs very well at 25  (which is the book  specificed short field TO flap), no need to dump the whole lot (which reduces all sorts of margins) .

This minimises  the trim changes, gets altitude, and minimises airspeed requirements, since there is a hefty change in minimum flying speed going from 25 to 10.  WOnt climb much faster than half way between Vx and Vy with 25 flap. You cant get much speed with 25 flap.    From a baulked landing where you might be getting very slow in ground effect  (so likely below book full flap stall) , there is no room for error at that juncture ! But that proceedure ----- NOT for HOT, WINDY, HEAVY. see below.

Edited June 12, 2023 by RFguy

[facthunter]

There's a heavy drag penalty for the extra lift simple flaps  provide. IF you CAN get the speed, clean is the way to go in the big picture especially IF you are relying on the fins input for directional effect. Nev.

[RFguy]

Hi Nev.. yeah, I would agree with that . Maybe I am over emphasising the change from full flap . 

If there is plenty of runway,  I might slowly remove all the flap while flying S&L above the runway gaining airspeed, then progressively reduce flap until I am back to the T.O.S.S for nil flap.

That's how I was taught, BTW . The other aspect is, that's when I have plenty of power in hand (only 1900 lbs out of the 2450 MTOW).  May be better to inject airspeed when heavy, I will have to do some bulked landings at MTOW. 
My book doesnt have a proceedure for a baulked landing I'll look at a few other PA28 books. 

Important to accept what the book recommends and only modify a proceedure if its wrong/not fully relevant.. 

Edited June 12, 2023 by RFguy