The most interesting thing I found about that article was the supposition that the G loading on the wing of the FW 190 changed it's twist, leading to an abrupt accelerated stall as opposed to the one G stall condition. Also some interesting items about boundary layers, cooling drag and whatnot.
Power-On vs Power-Off Stall Speed
- Thread starter Zipper730
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Great article! Thanks. You've got the gist of it. The critical point here is that there's no wash in the inboard 40% of the wings, so that entire portion of span quits flying all at once. There's no warning for the pilot, since there's no gradual stall progression from root outward, hence no disturbed airflow to cause elevator buffet, the normal cue pilots expect of an incipient stall. The loss of elevator authority when this occurs is sudden and complete and the airflow around the empannage is so disturbed that that the vertical stabilizer and rudder don't have enough control authority to counteract P-factor, torque, spiral propeller wash, and all the infamous bugaboos that go along with high AOA and high power. With all of the inboard portion of the wings stalled and the tips still flying but very close to stall, it doesn't take much powerplant induced yaw to drive the retreating wingtip firmly into stall, while giving the advancing wingtip an increased-airspeed boost in lift and a momentary reduction in AOA, thus temporary protection from stalling. This is exactly the phenomenon generated by a pilot deliberately entering a snap roll, and occasionally duplicated by a nervous ham-fisted student trying to demonstrate their prowess at power-on stalls to an instructor. I've ridden through a number of such whifferdills, though seldom with my own students; usually when I was phase-checking other instructor's protégés. Yaw awareness was a frequent weakness in flight instruction back in the day. Instructors who had learned in Cherokees and had never been past 60° bank and certainly never upside down in their lives tended to produce students of the same ilk. Flight schools at Piper dealerships usually instructed in Cherokees that were placarded against spins, so to meet the spin requirement for Commercial and CFI, they usually had an old tired Cessna or Beechcraft around that they would approach with trepidation as if it were an XF104 out at Edwards. I taught almost exclusively in Cessnas and Beeches, and make no excuses for being an aeronautical bigot.
Cheers,
Wes
GregP
Major
In most single engine general aviation aircraft, you can just add opposite rudder and release the wheel. If you do, you will recover promptly, but since you aren't holding the wheel, you will lose more altitude than absolutely necessary.
Standard stall recovery is:
1) Power to idle
2) Ailerons to neutral
3) Opposite rudder
4) Elevator forward (actually release back pressure). If you aggressively push forward and hold it, you CAN get into an inverted spin. Depends on how much down elevator your plane has.
There are a few aircraft that specifically ask you to do the steps in a different order in the POH. Can't recall one offhand, but have come across one or two. Never fly a plane without reading the POH for speeds and special stall recovery and loading / fueling techniques.
Want an example, go read fueling and CG procedures for a Mitsubishi MU-2. In a Bonanza, the CG moves aft as fuel burns off. So, you CAN be fine to take off but out of CG aft when landing. Frequent Bonanza pilots know that and plan accordingly. These aren't the only two, just examples of different from "standard." If you fly your airplane by the book, it's pretty hard to go wrong most of the time, assuming a competent pilot.
Standard stall recovery is:
1) Power to idle
2) Ailerons to neutral
3) Opposite rudder
4) Elevator forward (actually release back pressure). If you aggressively push forward and hold it, you CAN get into an inverted spin. Depends on how much down elevator your plane has.
There are a few aircraft that specifically ask you to do the steps in a different order in the POH. Can't recall one offhand, but have come across one or two. Never fly a plane without reading the POH for speeds and special stall recovery and loading / fueling techniques.
Want an example, go read fueling and CG procedures for a Mitsubishi MU-2. In a Bonanza, the CG moves aft as fuel burns off. So, you CAN be fine to take off but out of CG aft when landing. Frequent Bonanza pilots know that and plan accordingly. These aren't the only two, just examples of different from "standard." If you fly your airplane by the book, it's pretty hard to go wrong most of the time, assuming a competent pilot.
The forktailed doctor killer strikes again.
I've given BFR rides to doctors, lawyers, and other workaholic professionals in their Bonanzas, Barons, and Comanches, and been appalled sometimes at their rusty flying skills, limited knowledge, and cocky attitudes. In fact, I've gotten in trouble with my bosses for refusing to endorse these yahoos logbooks with a BFR sign off. If I didn't think they were safe, I wouldn't sign.
Cheers,
Wes
Well I am neither a pilot or an aerodynamicist so that's about as good as its ever going to get. I am interested in the aerodynamics "stuff" but as long as I remember the main issue, the design of the FW could cause a sudden stall spin tumble in high g turns that will do for me.
I was always taught to 'wait' after the opposite rudder. It gives you time to relax a bit and not rush the next step and not try to punch yourself out the roof (or test your harness in an open cockpit!)...
You have never hated life until you have to rig the flight controls on a V-Tailed Doctor Killa Bonanza.
Ain't the "mixing box" a bitch? And isn't there some sort of recurring AD on the stabilizer leading edge D tube where it attaches to the fuselage? Our local FBO won't do V-tail annuals any more.
Cheers,
Wes
I honestly don't remember any of it. I had never worked on one before, until a 1954 Bonanza V-Tail showed up for a Pre-Buy at our 145 Repair Station. We were a Beech certified station, but not a single person in the hangar had ever worked on a V-Tail before. We mostly worked on King Airs, but would occasionally get a Baron or regular tailed Bonanza. Man we were lost like chickens with our heads cut off when it came to rigging that thing. Not going to lie. No shame in admitting when you are having trouble with something. Every adjustment made to any flight control affected the "Rudervators" or whatever the hell they are called. We ended up having the aircraft in our hangar for ever (Literally months). There was so many things wrong with it. The guy ended up letting it sit for another half a year trying to sell it to the next schmuck after he saw the price of the pre-buy and annual. We were very, very thorough in our jobs, and made sure that aircraft would leave in a better condition than it came in as. I left the company before the job was completed, but they ended up bringing back an old retired mechanic who used to work at the company years before I got there. He had plenty of V-Tail experience. In the end she flew like never before, and everyone was happy.
It's funny, we could turn out complete phase 1-4's on King Airs in 2 weeks, a bonanza annual in a week or two, but not the V-Tail. That one took months...
That works great for a boxy, draggy, machine like a Moth or a Cub, but a clean all-metal monoplane will pick up speed mighty quick once the rotation stops, and if you dawdle you're looking at redline and a high G pull out. And you don't need forward stick to break the stall, as the nose will go down all by itself, and right quick, too.
Cheers,
Wes
It wasn't a big pause, about as long as it takes to say the word. I've been almost ejected from the cockpit during a recovery - not the nicest experience!
GregP
Major
Actually, everyone else above me posted correctly.
The only reason I chimed in was a fight school (east coast? ... can't quite recall) that used to teach "let go of the controls" as their ONLY means of spin recovery. In single-engine GA aircraft, it generally works.
But I doubt that in a former military trainer, such as a T-6 ... and it almost surely won't work in a former fighter warbird or an unlimited aerobatic bird. Might .... Most of us don't fly warbirds, anyway. I'd LOVE to, but just don't have the money.
If I did, I'd try very hard not to have a cocky attitude, just because I run across XBe02Drvr's cocky Bonanza pilots too often, sometimes not only in Bonanzas. They don't often make anyone's day and rarely leave you thinking how cool they are.
A really friendly warbird pilot, on the other hand, has quite the opposite effect most of the time.
The only reason I chimed in was a fight school (east coast? ... can't quite recall) that used to teach "let go of the controls" as their ONLY means of spin recovery. In single-engine GA aircraft, it generally works.
But I doubt that in a former military trainer, such as a T-6 ... and it almost surely won't work in a former fighter warbird or an unlimited aerobatic bird. Might .... Most of us don't fly warbirds, anyway. I'd LOVE to, but just don't have the money.
If I did, I'd try very hard not to have a cocky attitude, just because I run across XBe02Drvr's cocky Bonanza pilots too often, sometimes not only in Bonanzas. They don't often make anyone's day and rarely leave you thinking how cool they are.
A really friendly warbird pilot, on the other hand, has quite the opposite effect most of the time.
davparlr
Senior Master Sergeant
When I flew the T-38 (some 49 years ago), it did not have an AOA indicator and we flew emphasizing airspeed control. Of course, those were the days when the T-38 was the "white rocket" and did not have that horrible pseudo-camouflage paint they have now. It was also the time the AF had one syllabus for its pilots and all were expected to fly any aircraft in the AF inventory (sans helicopter) so all pilots trained in the T-38.
I agree it is a great aircraft and certainly fun to fly. My first impression-things happened really fast. You certainly had to keep airspeed discipline on approach and landing and do not get behind the power curve.
Those airframes that I flew almost 50 ago are the same ones flying now, it probably could have a record for length of time airframes have been active military aircraft.
If I remember correctly, stall in the T-38 was rather gentle with no wing break, typical of jets. The plane was supposed to be difficult to spin. If you did get into a spin, procedures, I think, raise seat handles, squeeze handles.
I was surprised to hear the F-15 could spin but then I remembered from my AMRAAM integration days that the F-15 was not a full fledged fly-by-wire system. Follow on aircraft, F-16 et.al., should not spin since I suspect the flight control system will not let them stall.
We never practiced spins in the C-141 or stalls for that matter.
I'm a bit confused. I was of the understanding that small commercial aircraft were required to recover from a spin without control inputs. It seems I was mistaken.
special ed
2nd Lieutenant
- 5,667
- May 13, 2018
A friend, now passed away, said as I remember, he was in the first T-38 class that began only in the T-38. He soloed but washed out because he cut someone off in the landing pattern. I'm not sure how or what exactly happened because he wouldn't discuss it.
You aren't wrong. I can vouch for the Cessna 150-52/172, Beech Sundowner/Sierra and Skipper, and Piper Traumahawk as meeting that requirement, although in some cases a "hands-off" recovery will result in nudging up against Vne and uncomfortably high G loads. A little back pressure once you've stopped rotating and are accelerating downhill will keep the speed from building quite so fast. The T34, OTOH, requires a little rudder encouragement from the pilot to stop the rotation, but then it's draggy airframe and high Vne eliminate any pullout worries.
Cheers,
Wes
Wow! Isn't that a bit of a handful for an ab initio student??
One of my instructors in mech school was a retired AF fighter pilot who went through Primary in '48-'49, starting off in T6s. He said of his class, 40% died in Primary, 30% washed out, and 30% graduated. He said he went to more funerals in Primary than he did in two tours in Korea. He didn't have a very favorable opinion of the T6 as an ab initio trainer.
Cheers,
Wes
special ed
2nd Lieutenant
- 5,667
- May 13, 2018
What Lee did tell me about wash outs sounds similar.
When I flew the T-38 (some 49 years ago), it did not have an AOA indicator and we flew emphasizing airspeed control. Of course, those were the days when the T-38 was the "white rocket" and did not have that horrible pseudo-camouflage paint they have now. It was also the time the AF had one syllabus for its pilots and all were expected to fly any aircraft in the AF inventory (sans helicopter) so all pilots trained in the T-38.
I agree it is a great aircraft and certainly fun to fly. My first impression-things happened really fast. You certainly had to keep airspeed discipline on approach and landing and do not get behind the power curve.
Those airframes that I flew almost 50 ago are the same ones flying now, it probably could have a record for length of time airframes have been active military aircraft.
If I remember correctly, stall in the T-38 was rather gentle with no wing break, typical of jets. The plane was supposed to be difficult to spin. If you did get into a spin, procedures, I think, raise seat handles, squeeze handles.
I was surprised to hear the F-15 could spin but then I remembered from my AMRAAM integration days that the F-15 was not a full fledged fly-by-wire system. Follow on aircraft, F-16 et.al., should not spin since I suspect the flight control system will not let them stall.
We never practiced spins in the C-141 or stalls for that matter.
I'm a bit confused. I was of the understanding that small commercial aircraft were required to recover from a spin without control inputs. It seems I was mistaken.
Davparlr,
I was in 89-12, 1988-1989 and experienced only the Tweet / Talon. The T-1 came well after my time as well as the other than white paint scheme on T-38A's. Currently the standard configuration is the T-38C, with full glass, GPS and HUD and is used in the Advanced pilot training as well as Introduction to Fighter Fundamentals (IFF).
They also got rid of the FAR / TTB rankings while I was there, but still tracked guys / gals under that philosophy.
The only A models left are hand me backs from Singapore that fly Red Air for the F-22 and F-35.
The USAF C models have had new wings installed at least twice, new seats with chute built in, and new intakes.
Cheers,
Biff
davparlr
Senior Master Sergeant
The AF never had a T-38 only training syllabus. For its day, and today, it is a hot plane. When introduced, it set the time to climb record to 40k in 90 seconds and it flies final at close to 180 mph, minimum. Not a plane for training new pilots. In 1969, when I started AF training we started off in the T-41 (C 172) to weed out early incompatible trainees, then went into the T-37, a rugged little twin engine jet, where we learned basic flying and aerobatics, and yes, spin recovery. Then for the last half of training we flew the T-38 where we learned instrument flying, navigation, and two and four ship formation flying. And, of course, handling a high wing-loading, fast, fighter type aircraft. During the year of training, I don't remember any fatal training accidents at any of the five or six or so training bases.
Pix show a no-flap touch and go. When flying a no-flap approach, final is flown at 190 mph! I could have flown that very aircraft 49 years ago!
Pix show a no-flap touch and go. When flying a no-flap approach, final is flown at 190 mph! I could have flown that very aircraft 49 years ago!
Attachments
My dad went through Navy flight training during WWII and they lost about 5% killed in primary. That was flying Stearmans.
Takeoff in a fully loaded 747, flaps up maneuvering speed was about 280 knots. Max landing at Mexico City, one came over the fence at 190 knots TAS. However you sat so high above the ground it seemed more like flying a light plane into a somewhat short and narrow runway. Not the sense of speed that one gets from flying the "skate boards".
At least in the various 747's we got a pretty good introduction to high AOA maneuvering and all sorts of wild stuff such as severe windshpear in the repetitive simulator events. The best lesson? Never give up! Seat of the pants feel still has it's place, try a two engine go around at 50' with all the crap hanging out...
High T/W fighter aircraft now have some truly phenomenal capabilities!
Takeoff in a fully loaded 747, flaps up maneuvering speed was about 280 knots. Max landing at Mexico City, one came over the fence at 190 knots TAS. However you sat so high above the ground it seemed more like flying a light plane into a somewhat short and narrow runway. Not the sense of speed that one gets from flying the "skate boards".
At least in the various 747's we got a pretty good introduction to high AOA maneuvering and all sorts of wild stuff such as severe windshpear in the repetitive simulator events. The best lesson? Never give up! Seat of the pants feel still has it's place, try a two engine go around at 50' with all the crap hanging out...
High T/W fighter aircraft now have some truly phenomenal capabilities!
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