Spin Recovery
Awesome but Affordable
Crazy Cesna,
Congratulations, your findings exactly tally with my own. It is, I would imagine, true of all Cessna 150/152 aircraft.
The reason the ailerons do work at low speed and even into the stall lies in the FAR 23 design requirements which require the ailerons to function normally, if sloppily, in that condition. The Cessna designer incorporated a significant degree of washout at the tips which reduces the angle of incidence compared with the rest of the wing. Thus the outer wing is at a lower angle of attack and stalls later than the rest. This means the ailerons remain effective in the normal sense into the stall and spin modes.
Enjoy your flying and remember, height is insurance..............!!!!!!!!!!!!!!
Cheers,
Trapper 69
Congratulations, your findings exactly tally with my own. It is, I would imagine, true of all Cessna 150/152 aircraft.
The reason the ailerons do work at low speed and even into the stall lies in the FAR 23 design requirements which require the ailerons to function normally, if sloppily, in that condition. The Cessna designer incorporated a significant degree of washout at the tips which reduces the angle of incidence compared with the rest of the wing. Thus the outer wing is at a lower angle of attack and stalls later than the rest. This means the ailerons remain effective in the normal sense into the stall and spin modes.
Enjoy your flying and remember, height is insurance..............!!!!!!!!!!!!!!
Cheers,
Trapper 69
Bristol Scout:
TBH I think this is a little harsh as some types (C152?) are said to have a delayed recovery with flaps down, so it's not unreasonable to check flaps up. If I'm honest, it's not part of my brief - mmm, perhaps it should be.
HFD
Incidentally, I was amazed at a recent Instructor Seminar where they were preaching a spin recovery technique where the first action was check flaps up. Fumble, fumble, high ROD, splat!
HFD
Join Date: Jul 2007
Location: West Britain
Age: 74
Posts: 209
Likes: 0
Received 0 Likes
on
0 Posts
HFD.
True enough, but my concern is that an unintentional departure towards a spin is usually going to happen relatively close to the ground in normal operations, since this is where the pilot will be at the slower end of the speed envelope. One less thing to do might just be the difference between recovery and a hole in the ground. In any event, we're all duty bound to state that the spin recovery in the aircraft flight manual is the one to use.
Confundemus
True enough, but my concern is that an unintentional departure towards a spin is usually going to happen relatively close to the ground in normal operations, since this is where the pilot will be at the slower end of the speed envelope. One less thing to do might just be the difference between recovery and a hole in the ground. In any event, we're all duty bound to state that the spin recovery in the aircraft flight manual is the one to use.
Confundemus
Join Date: Jun 2006
Location: anywhere
Posts: 121
Likes: 0
Received 0 Likes
on
0 Posts
this is an interesting thread.
i was looking back at the c150/c152 recovery techniques.
in a fully developed spin a c150 will not recover by itself. a fully developed spin in a c150 is a difficult thing to achieve. this is due to the genius design of the engineers at cessna.
for a spin to be fully developed it must continue to spin without any control input by the pilot. if control inputs are required the aircraft is not in a fully developed spin, only a DEVELOPING spin.
the c150 will not enter a fully developed spin unless it is induced by the pilot. because of the genius of its design(idiot proofing), the c150 will recover from a developing spin if the pilot releases the flight controls. regardless of the nunmber of rotations the aircraft has completed, if the pilot is required to hold control inputs to keep the aircraft turning, the aircraft is not in a fully developed spin, only a developing spin.
to induce a fully developed spin a c150, full aileron in the direction of the spin must be used. trickle of power, slow speed reduction, just prior to the point of stall, full back stick, full rudder in the desired spin direction, AND full aileron in the desired spin direction. AND then you must hold it. after a number of rolls, the aircraft will settle into a developing spin with an increasing rate of rotation. the control inputs are still being held at full deflection. the aircraft will then pitch nose up and the rate of rotation will reduce markedly. at this point, all the flight controls will will remain in the position where they were positioned by the pilot to induce the manuovere. even when they are released. ie: full back stick, full rudder, and full aileron. it can be very disconcerting to a pilot who has not experienced that before.
centralising all the controls will not cause the aircraft to recover. the g loads and low rotation rate are all very comfortable. this is the dangerous part. the aircrafts rate of descent is well and truly beyond the limit of most GA vsi's.
the only way to recover is with controls fully centred, apply full and brisk nose forward elevator. and hold it. if this does not work within 2 or 3 rotations, you can try applying power in conjunction with the nose down elevator. the problem is this, you risk flattenning the spin further. also it is not uncommon for the engine to stop in this manouvere. application of full opposite rudder will actually increase the rate of rotation. bizarre but true.
this manouvere takes thousands of feet to conduct. it should not be attempted by persons who have not been trained for it. this includes instructors who have not been trained to do it properly. as i read previously, yes the little baby can bite, but like a placid dog, it has to be severely provoked.
this is not how we taught students to spin the aircraft. it was taught in the same benign way as it is still being taught. most students find the developing spin scary enough without being shown that beasty is quite capable of injuring them. the advanced and fully developed manouvere was taught to instructors who would be teaching spinning and aerobatics.
bear in mind, this was 25 years ago, when the aircraft were new. i dont know if i would want to be doing these sort of things in aircraft that are now 25-30 years old, the entry to the manouvere can be quite stressful.
anyway, just musings from an old fart.
i was looking back at the c150/c152 recovery techniques.
in a fully developed spin a c150 will not recover by itself. a fully developed spin in a c150 is a difficult thing to achieve. this is due to the genius design of the engineers at cessna.
for a spin to be fully developed it must continue to spin without any control input by the pilot. if control inputs are required the aircraft is not in a fully developed spin, only a DEVELOPING spin.
the c150 will not enter a fully developed spin unless it is induced by the pilot. because of the genius of its design(idiot proofing), the c150 will recover from a developing spin if the pilot releases the flight controls. regardless of the nunmber of rotations the aircraft has completed, if the pilot is required to hold control inputs to keep the aircraft turning, the aircraft is not in a fully developed spin, only a developing spin.
to induce a fully developed spin a c150, full aileron in the direction of the spin must be used. trickle of power, slow speed reduction, just prior to the point of stall, full back stick, full rudder in the desired spin direction, AND full aileron in the desired spin direction. AND then you must hold it. after a number of rolls, the aircraft will settle into a developing spin with an increasing rate of rotation. the control inputs are still being held at full deflection. the aircraft will then pitch nose up and the rate of rotation will reduce markedly. at this point, all the flight controls will will remain in the position where they were positioned by the pilot to induce the manuovere. even when they are released. ie: full back stick, full rudder, and full aileron. it can be very disconcerting to a pilot who has not experienced that before.
centralising all the controls will not cause the aircraft to recover. the g loads and low rotation rate are all very comfortable. this is the dangerous part. the aircrafts rate of descent is well and truly beyond the limit of most GA vsi's.
the only way to recover is with controls fully centred, apply full and brisk nose forward elevator. and hold it. if this does not work within 2 or 3 rotations, you can try applying power in conjunction with the nose down elevator. the problem is this, you risk flattenning the spin further. also it is not uncommon for the engine to stop in this manouvere. application of full opposite rudder will actually increase the rate of rotation. bizarre but true.
this manouvere takes thousands of feet to conduct. it should not be attempted by persons who have not been trained for it. this includes instructors who have not been trained to do it properly. as i read previously, yes the little baby can bite, but like a placid dog, it has to be severely provoked.
this is not how we taught students to spin the aircraft. it was taught in the same benign way as it is still being taught. most students find the developing spin scary enough without being shown that beasty is quite capable of injuring them. the advanced and fully developed manouvere was taught to instructors who would be teaching spinning and aerobatics.
bear in mind, this was 25 years ago, when the aircraft were new. i dont know if i would want to be doing these sort of things in aircraft that are now 25-30 years old, the entry to the manouvere can be quite stressful.
anyway, just musings from an old fart.
Last edited by ithinkso; 21st Aug 2007 at 06:42.
Awesome but Affordable
ithinkso,
Thanks for another confirmation of this spin mode.
Some 25 years ago I asked Cessna for comments on what I had found to be the case and which was not mentioned in any way in the flight manual or pilots operating handbook. The silence was absolutely deafening. No doubt for reasons of product liability. Perhaps the corporate policy was wise - but one day...................???????????????????
Cheers,
Trapper 69
Thanks for another confirmation of this spin mode.
Some 25 years ago I asked Cessna for comments on what I had found to be the case and which was not mentioned in any way in the flight manual or pilots operating handbook. The silence was absolutely deafening. No doubt for reasons of product liability. Perhaps the corporate policy was wise - but one day...................???????????????????
Cheers,
Trapper 69
Join Date: Jun 2006
Location: anywhere
Posts: 121
Likes: 0
Received 0 Likes
on
0 Posts
yep trap i think youre right.
also, the recommended spin entry technique in their manuals does not allow the use of ailerons during the entry to the manouvere. ie: they will not teach you the wrong thing, only the right. that is a particular entry to the manouvere is recovered from by blah blah. in other words if you want to do something outside their described, amplified procedures they are not liable.
from memory, it was great fun, and it was always fun seeing the raised eyebrows of the guys who said they knew all about spinning--" I've been doing this for years, I know what I'm doing". in a previous post i read, someone mentioned instructors sh...ing themselves when the beasty wouldnt recover straight away. this was also my exact experience when training instructors.
cheers.
ps: height is insurance, airspeed is insurance for insurance!
also, the recommended spin entry technique in their manuals does not allow the use of ailerons during the entry to the manouvere. ie: they will not teach you the wrong thing, only the right. that is a particular entry to the manouvere is recovered from by blah blah. in other words if you want to do something outside their described, amplified procedures they are not liable.
from memory, it was great fun, and it was always fun seeing the raised eyebrows of the guys who said they knew all about spinning--" I've been doing this for years, I know what I'm doing". in a previous post i read, someone mentioned instructors sh...ing themselves when the beasty wouldnt recover straight away. this was also my exact experience when training instructors.
cheers.
ps: height is insurance, airspeed is insurance for insurance!
Last edited by ithinkso; 21st Aug 2007 at 11:39. Reason: spelling
Join Date: Aug 2007
Location: Austria
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Ithinkso,
Your post about c150/c152 spins was very interesting to me. I am not sure but I think there is another developed spin mode in C152s. As you can see in my post I tried to do 3 to 4 rotations with full power but ailerons centred. As expected the nose comes up and stays up. I have not checked if the controls remain in the same position when released but as far as I found the spin is stable in the sense that no pilot input is required to continue the spin.
This spin can be recovered by power idle, centre aileron, opposite rudder, full forward and wait. The problem is it takes 3 to 5 revolutions to stop. I found that my Cesna drops back to the steep mode when aileron in spin direction is used. This would be the standard recovery technique for a flat spin and it works.
It’s surprising that in your spin neither the aileron nor the rudder has any influence. I would think that your spin mode is quite flat and due to the relatively low rate of rotation there is absolutely no clean airflow over the ailerons. So forget the ailerons.
But there are two things I can’t explain:
1) Why does rudder against the spin increase the rate of rotation?
2) Why does the elevator still work?
Do you have any thoughts about that?
There must be some people (probably old ones) who did the original spin testing for the c152. It would be very interesting to hear their opinion on these issues. I know some test pilots form diamond aircraft and they can tell a lot about recovering “unrecoverable” spins in a DA40.
Crazy Cesna
Your post about c150/c152 spins was very interesting to me. I am not sure but I think there is another developed spin mode in C152s. As you can see in my post I tried to do 3 to 4 rotations with full power but ailerons centred. As expected the nose comes up and stays up. I have not checked if the controls remain in the same position when released but as far as I found the spin is stable in the sense that no pilot input is required to continue the spin.
This spin can be recovered by power idle, centre aileron, opposite rudder, full forward and wait. The problem is it takes 3 to 5 revolutions to stop. I found that my Cesna drops back to the steep mode when aileron in spin direction is used. This would be the standard recovery technique for a flat spin and it works.
It’s surprising that in your spin neither the aileron nor the rudder has any influence. I would think that your spin mode is quite flat and due to the relatively low rate of rotation there is absolutely no clean airflow over the ailerons. So forget the ailerons.
But there are two things I can’t explain:
1) Why does rudder against the spin increase the rate of rotation?
2) Why does the elevator still work?
Do you have any thoughts about that?
There must be some people (probably old ones) who did the original spin testing for the c152. It would be very interesting to hear their opinion on these issues. I know some test pilots form diamond aircraft and they can tell a lot about recovering “unrecoverable” spins in a DA40.
Crazy Cesna
Join Date: Apr 2009
Location: Perth
Age: 42
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
YouTube - MegaSpin II - 14 Rotations
Is a video of a mate and I performing this exact kind of spin in an Aerobat.
Spin is entered with idle power but full back-yoke and inspin aileron.
As the spin is established we feed in some power, and it goes flatter. It feels out of control - you're literaly pushed sideways. To recover we reduce power back to idle and hold proper spin recovery inputs, but it takes a few turns to break out of the spin. You'll notice in the video that during the attempted recovery the spin rate seems to increase.
I'm not entirely sure why, but I wonder what the angle of attack is during a flat(ter) spin compared to a steeper nose-down spin...
Is a video of a mate and I performing this exact kind of spin in an Aerobat.
Spin is entered with idle power but full back-yoke and inspin aileron.
As the spin is established we feed in some power, and it goes flatter. It feels out of control - you're literaly pushed sideways. To recover we reduce power back to idle and hold proper spin recovery inputs, but it takes a few turns to break out of the spin. You'll notice in the video that during the attempted recovery the spin rate seems to increase.
I'm not entirely sure why, but I wonder what the angle of attack is during a flat(ter) spin compared to a steeper nose-down spin...
Aero Adz
The spin is the least predictable manoever in any flight test program. This is not the place to experiment with non standard control/power actions. I would suggest that unless you have had comprehensive aerobatic training which should include how to recover from any attitude, and spin type, you should not be exceeding 6 turns flown in accordance with the POH spin entry and recovery procedures and with lots of extra altitude. In any case any indications that the spin is starting to flatten should cause an immediate application of spin recovery control inputs.
Sorry to be rude but if I was the chief flying instructor at the school you worked at, we would have a one way conversation that would indicate any further attempts at playing test pilot would result in your immediate termination.
The spin is the least predictable manoever in any flight test program. This is not the place to experiment with non standard control/power actions. I would suggest that unless you have had comprehensive aerobatic training which should include how to recover from any attitude, and spin type, you should not be exceeding 6 turns flown in accordance with the POH spin entry and recovery procedures and with lots of extra altitude. In any case any indications that the spin is starting to flatten should cause an immediate application of spin recovery control inputs.
Sorry to be rude but if I was the chief flying instructor at the school you worked at, we would have a one way conversation that would indicate any further attempts at playing test pilot would result in your immediate termination.
Extract from an article by Gene Beggs in Sport Aerobatics of October 1985:
"In my telephone conversation with Bill Kershner, he told me of a spin mode in his Cessna Aerobat from which he was unable to recover using my power-off, hands-off, opposite-rudder method of emergency spin recovery....…
If I placed the aircraft in a spin to the left with the power on as might happen with a student who did not correct for the “P” factor properly, and let it spin with the power on for two turns or more, and then cut the power off, released the yoke completely, and then applied full right rudder and held it, the aircraft would continue to spin and showed no sign of recovery evern after as many as 10 turns! I would then place the heel of my hand on the padded center portion of the yoke and briskly push it forward, and the aircraft would always recover promptly in one additional turn ....
I found that the Cessna 150 would spin very docile, as long as the ailerons were held neutral and the power completely off in either direction .. Trouble developed only in the spin to the left, either when the power was left on or when “in-spin” aileron was applied and the aircraft permitted to turn two turns or more ..."
Cessna produced a booklet in 1978 about spinning and much of that information is provided in this article in Flight Magazine. Most of this info is also provided in Kershner's book, The Basic Aerobatic Manual.
I see that FAR 23 now (well, for many years) has another spin placard mandated but only newly certified airplanes will have it. Worth noting as it emphasizes a limitation on the number of turns in a spin based on what was tested.
[(d) For acrobatic category airplanes and utility category airplanes approved for spinning, there must be a placard in clear view of the pilot--
(1) Listing the control action for recovery from spinning maneuvers; and
(2) Stating that recovery must be initiated when spiral characteristics appear, or after not more than six turns or not more than any greater number of turns for which the airplane has been certificated.]
Aerobatic category airplanes are normally tested to 6 turns and with a comprehensive spin matrix of configurations and modes so your favourite video on Youtube doesn't count for much. i.e. the recommended maximum number of turns in a spin is 6 (there are physiological effects on the pilot which also support that same limit).
I'm certainly wary of spinning, especially flat spins but I do like instructor trainees to get a taste for how aeroplanes can suddenly misbehave as distinct from the standard spin entry.
"In my telephone conversation with Bill Kershner, he told me of a spin mode in his Cessna Aerobat from which he was unable to recover using my power-off, hands-off, opposite-rudder method of emergency spin recovery....…
If I placed the aircraft in a spin to the left with the power on as might happen with a student who did not correct for the “P” factor properly, and let it spin with the power on for two turns or more, and then cut the power off, released the yoke completely, and then applied full right rudder and held it, the aircraft would continue to spin and showed no sign of recovery evern after as many as 10 turns! I would then place the heel of my hand on the padded center portion of the yoke and briskly push it forward, and the aircraft would always recover promptly in one additional turn ....
I found that the Cessna 150 would spin very docile, as long as the ailerons were held neutral and the power completely off in either direction .. Trouble developed only in the spin to the left, either when the power was left on or when “in-spin” aileron was applied and the aircraft permitted to turn two turns or more ..."
Cessna produced a booklet in 1978 about spinning and much of that information is provided in this article in Flight Magazine. Most of this info is also provided in Kershner's book, The Basic Aerobatic Manual.
I see that FAR 23 now (well, for many years) has another spin placard mandated but only newly certified airplanes will have it. Worth noting as it emphasizes a limitation on the number of turns in a spin based on what was tested.
[(d) For acrobatic category airplanes and utility category airplanes approved for spinning, there must be a placard in clear view of the pilot--
(1) Listing the control action for recovery from spinning maneuvers; and
(2) Stating that recovery must be initiated when spiral characteristics appear, or after not more than six turns or not more than any greater number of turns for which the airplane has been certificated.]
Aerobatic category airplanes are normally tested to 6 turns and with a comprehensive spin matrix of configurations and modes so your favourite video on Youtube doesn't count for much. i.e. the recommended maximum number of turns in a spin is 6 (there are physiological effects on the pilot which also support that same limit).
I'm certainly wary of spinning, especially flat spins but I do like instructor trainees to get a taste for how aeroplanes can suddenly misbehave as distinct from the standard spin entry.
Join Date: Nov 2009
Location: East Coast United States
Age: 86
Posts: 53
Likes: 0
Received 0 Likes
on
0 Posts
I'm certainly wary of spinning, especially flat spins but I do like instructor trainees to get a taste for how aeroplanes can suddenly misbehave as distinct from the standard spin entry.
It was noted correctly that specific aircraft were prone to specific spin behavior due to rigging, and especially cg consideration even to pilot co-pilot weight factors and differing fuel load.
As with most aircraft, it is entirely possible to see differing spin axis development in the 150/152 series as the inertia and aerodynamic factors in play for a specific aircraft in a SPECIFIC spin entry come on line during the maneuver.
This is especially true if outspin aileron is applied to accelerate the spin and power then added (in a left erect spin in the case of a 150/152 due to needed gyroscopic forces) to flatten the accelerated spin mode.
I would strongly note in addition to what you have already correctly said that pilots doing long time line extended multiple turn spins in these aircraft be COMPLETELY aware that these multiple turn stabilized spins were NOT part of the certification process and that in every such spin attempted there is a fairly reasonable element of increased risk involved.
I note from one poster's film clip such a spin entered holding inspin aileron and no parachutes being worn. THIS is a situation I would highly discourage were I privy to this pilot's ear.
Dudley Henriques
