Tolerating an un-airworthy aircraft. Wing drops at stall
... shows how largely ignorant of the certification standards for Normal category General Aviation (part 23) aircraft most Pruners are.
... and generally in the Industry..
... and generally in the Industry..
Googling FAR 23 (never mind the applicable amendment), or referring to a random issue of AC23-8 merely shows the ability to use a keyboard, not to certify, or to comprehend the sum of all the individual conditions that apply to each individual point of compliance in order to certify an airplane. never mind that, even a knowledge that there is an overarhing regulatory requirement that is intended to make aircraft safer is a very good thing.
the original intent of the thread (as i understand it) was to draw attention to the fact that ANY aircraft presented for flight or hire from a reputable organization, MAY NOT be correctly maintained, even exhibiting a KNOWN deficiency or idiosyncrasy that is non-compliant is a real issue.
as an instructor pilot at a Flying School in a galaxy far away i was doing some TDY when an other instructor and student came into the crew room to ask if i could explain why their aircraft demonstrated different handling characteristics when turning one way to the other. they said they had checked the controls and everything looked normal, but it was not a good aerobatic aircraft normally, but seemed even worse on this day.
When we went to inspect the low wing aerobatic 4 place aircraft/ trainer ( normally highly maneuverable, as demonstrated by Roy Goon) the ailerons seemed to demonstrate full deflection up and down, and comparative side to side. when I held the Right aileron neutral and the student easily operated the yoke L and R, only one aileron moved, the other one not even a little bit. There was clearly an issue for safety of flight in this case, although a superficial inspection would not reveal it. this illustrated three things (at least)
1. there was concealed damage to the lateral control system
2. It was known the aircrfat was a bit sluggish in roll by reputation, i.e. it was an accepted issue that had become normalized
3. the damage was likely due to something that had occurred that SOMEONE KNEW ABOUT but did not report
3. this issue could have killed someone and three pax
Always whenever flying a new aircraft, a new type or from a new provider, i give the ailerons a bit of a doublet of travel by hand to check for slack or backlash. can also be done through the stick/yoke. i never knew why i did that, but i guess there was always a thought that things like the damaged pully bracket or a loose or jumped cable could hurt me. i do also check travel direction is correct, as reversed ailerons can kill you even quicker than reversed elevators. i also stand directly in front and often behind as well and visually do a one eye closed TLAR (That Looks About Right) of the washout, comparative incidence and tailplane angles. i have detected poorly set rigging this way even before turning a prop. Also it will usually show if the tryes are evenly and correctly inflated. some aircrfat do have eccentricities built into them, but if i see something I ask sosmeone who should be able to give me the right answer. once i was going spraying in an aircraft that had a new wing and strut on one side (Ag Plane ....NEW wing..hahahaha - not new, just new to IT) due to having hit a tree the previous day. Standing in front immediately showed that one wing had a dramatically different washout angle to the other, so before we flew it we did adjust the new strut end fitting. it flew fine, but it would have dropped a wing at stall for sure. ( NOT FAR 23 airplane, restricted CAR 3).
crikey, is that the time...
HD2
Moderator
... which is why we try to keep these sorts of concerns and thoughts in front of the PPRuNe folks - some of it, surely, will rub off along the way ?
Not for me to identify specific folks but, rest assured, PPRuNe has quite a few Industry-acknowledged experts in their fields - the two posters cited are but two of that number ....
Not for me to identify specific folks but, rest assured, PPRuNe has quite a few Industry-acknowledged experts in their fields - the two posters cited are but two of that number ....
In the 70s when I did a Twin Comanche rating, the instructor was reluctant to allow me to stall the aircraft because it he said that it would allegedly flip on its back. I never ever stalled the Twin Comanche to find out if it was an urban myth or not.
This tale scared the beejesus out of me, I seem to recall that 1.5Vs was as slow as I dared go to avoid meeting those “dragons“.
Out of curiosity has anyone here stalled a Twin Comanche with full flap?
This tale scared the beejesus out of me, I seem to recall that 1.5Vs was as slow as I dared go to avoid meeting those “dragons“.
Out of curiosity has anyone here stalled a Twin Comanche with full flap?
11:30 is where you want to be, PPrune changes the URL so I can't link directly to that time...
In the 70s when I did a Twin Comanche rating, the instructor was reluctant to allow me to stall the aircraft because it he said that it would allegedly flip on its back. I never ever stalled the Twin Comanche to find out if it was an urban myth or not.
This tale scared the beejesus out of me, I seem to recall that 1.5Vs was as slow as I dared go to avoid meeting those “dragons“.
Out of curiosity has anyone here stalled a Twin Comanche with full flap?
This tale scared the beejesus out of me, I seem to recall that 1.5Vs was as slow as I dared go to avoid meeting those “dragons“.
Out of curiosity has anyone here stalled a Twin Comanche with full flap?
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I did my FW training at a big Victorian aero club that had lots of PA-28s during a golden era and think I came out the other side all the better for it. Yes it was a bit of meat factory, but on the flip side there was a hell of a lot of variety in the experience stakes which coupled with a sense of self preservation was where the true value-add came from. The PA-28s were absolute shocker student hacks before their 100 hourly came up, and I really felt for the chief engineer charged with keeping these sh!t boxes airworthy. I came across many with flat spotted tyres, chipped props and some would backfire in the circuit, others would be leaking fuel on the ground, even found one with a huge ding in the leading edge (how on Earth!!). Flying them was just as variable, from fouling spark plugs to carby heat that was stuck either on or off, often discovered practicing an engine failure. I even had a character building engine fire on take off necessitating a forced landing. As for stalling them, it's quite a lame manoeuvre in a PA-28, I remember telling my instructor that if ever I was going to stall this thing it would be with full power, so we tried it, yes the wing dropped with a lot of effort but recovered just as quick, we gave up after breaching the CTA limit at 6500ft. I even got castigated for parking one one of these things just inches between a another parked aircraft and the club house due to lack of parking spots, not because of the feat but rightly because of human safety, and I can recall with a grand total of 20 hours of total aeronautical experience flying solo with a full tank of gas I took a PA-28 down to 500ft to avoid primary radar and headed across Western Port Bay into Bass Straight for a Captain Cook of King Island. A few minutes into this crossing the reality of the type of hack I was flying set in with single-engine-sound-over-water paranoia setting in, so I turned back and landed keeping my disappointment to myself. Yes, I had my favourite PA-28s in that fleet and others not so, but they were all much of a muchness, even when flying them backwards.
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A general comment about stalls in small aircraft. Many pilots will enter a stall without properly centering the ball. That will almost always result in wing drop, assuming the aircraft is properly rigged.
In my experience as flight instructor, it is the rare pilot who enters the stall with the ball centered.
Pity there was no YouTube 50 years ago. Likewise there was no internet to trawl through. All of us In GA operated in a bubble defined pretty much by hand-me-down wisdoms. It’s too easy to be critical when looking through the prism of today’s feast of information.
How the Myth of the stalling behaviour of the Twin Comanche morphed into becoming a “fact” that was best left untested was probably compounded by its unforgiving landing characteristics. Either way, at the time I felt lucky that I only did my IR training and maybe only a couple of charters in one and had dodged a bullet.
How the Myth of the stalling behaviour of the Twin Comanche morphed into becoming a “fact” that was best left untested was probably compounded by its unforgiving landing characteristics. Either way, at the time I felt lucky that I only did my IR training and maybe only a couple of charters in one and had dodged a bullet.
The problem with stall training is also how it is approached by some instructors - first stall for a student, and they reef the control column back and the aircraft pitches up into an accelerated stall, with acompaning sudden departure and eye-opening nose drop. Another student enters the "stalls are dangerous" category.
I always started with a slow deceleration, until the point of stall and then held the (piper) aircraft in the stall while I pointed out that the nose was gently bobbing, and we weren't dying. The student would be "Is that it??", and I would point out that we were descending at near 1000 fpm. Still holding the aircraft in stall, I would point out that the stick was fully back, but the nose wasn't pitching up - and THAT should be their recognition of the stall. If the aircraft is acting opposite to the control input - you have a stall (of some type). Input left aileron, and the aircraft rolls right? - STALL. Pull back and the nose pitches down? - STALL.
At this point (having been in the stall for a minute or so) I would draw their attention to the control column (still held fully back) and show that there is a simple fix - stick forward, stall stops.
One student who isn't afraid of stalls, isn't focused on IAS, and knows the magic solution. ... and then you go on to get them to recover quickly, and learn about accelerated stalls etc.
I always started with a slow deceleration, until the point of stall and then held the (piper) aircraft in the stall while I pointed out that the nose was gently bobbing, and we weren't dying. The student would be "Is that it??", and I would point out that we were descending at near 1000 fpm. Still holding the aircraft in stall, I would point out that the stick was fully back, but the nose wasn't pitching up - and THAT should be their recognition of the stall. If the aircraft is acting opposite to the control input - you have a stall (of some type). Input left aileron, and the aircraft rolls right? - STALL. Pull back and the nose pitches down? - STALL.
At this point (having been in the stall for a minute or so) I would draw their attention to the control column (still held fully back) and show that there is a simple fix - stick forward, stall stops.
One student who isn't afraid of stalls, isn't focused on IAS, and knows the magic solution. ... and then you go on to get them to recover quickly, and learn about accelerated stalls etc.
Still holding the aircraft in stall, I would point out that the stick was fully back, but the nose wasn't pitching up - and THAT should be their recognition of the stall.
From Pilots Notes for Mustang.RAAF Publication No. 780 date September 1950.
With fuselage tank full or half full, there is no buffeting to give warning of the approaching stall, but a series of stick reversals occurs just above the stalling speed; at the stall the right wing drops sharply, and unless immediate recovery action is taken, a spin may develop. If the control column is held back at the stall, a wing will drop very rapidly and the aircraft will become inverted.
Of course that is an extreme example as the student will never fly a Mustang, but it serves it's purpose to illustrate not all aircraft are as docile as a well maintained Warrior
