bilby54 Posted November 10, 2009 Posted November 10, 2009 The issue with no intentional spins is overstress on recovery which is quite easy to do. Also are you capable of recovery, training cannot be done on RAA aircraft and most GA instructors can't/won't do it. There perhaps needs to be some clarification here as a spin will rarely over stress the airframe. The aircraft is essentially stalled in a pretty untidy situation so it has relieved itself of most of the wing overloading and will continue that way until it either recovers or hits the ground. A recovery from a spin is also mostly a non event as the aircraft is moved into its normal flying condition. The problem most usually occurs when the pilot tries to recover from a steep nose down attitude after an "how did that happen?" encounter and the ground is rushing up at an alarming rate. The rate of vertical descent can be alarming compared to the normal cruise speed so the pilot will pull steadily back on the stick after it has gone well past VNE and then the wings come off. Recovery from a deep spiral dive can achieve the same result but by doing it through more legal means. Spin recovery (or incipient spin recovery) in RAA aircraft is quite legal and is practised more than most realise. How do you recover from a stall in a climbing turn? Or as so eloquently worded, a stall with wing drop. The problem for most manufacturers is legal liability and the wording is left open to interpretation, usually by a bloke with half a sheep skin hanging off his bald head and saying things like "as your worship pleases"
farri Posted November 10, 2009 Posted November 10, 2009 This is a question that I have been meaning to get clarification on for some time. The Jab POH says NO INTENTIONAL SPINS. I take it from the wording that UNINTENTIONAL spins are OK, otherwise the note would read NO SPINS. This is the only possible, logical interpretation of the note. Comments?? Qwerty Querty, I know this won`t answer your question however it might give you some idea of what I`m trying to say. I had reason to ask CASA to give me a clear definition of the wording, "Periodical Survailance", which was in the first edition of the AUF/RAA operations manual that CASA had approved and it governed the responsibility of a CFI`s survailance over a satilite training facility. Because of my demand and the ambiguity of those two words a second edition of the operations manual was writen,the wording was changed and they made the AUF the sole interrpreter of the operations manual,it no longer mattered what we thought any of the wording meant,we needed to get a definition from the OPS manager. I think you`ll find that this is still the case today. Cheers, Frank.
djpacro Posted November 10, 2009 Posted November 10, 2009 I guess I started with a question about grammar and semantics, ie The only reason to differentiate between intentional and unintentional spins rather than just stating "NO SPINS"...MUST be and i repeat my self here it MUST be that unintentional spins are OK. On grammar and semantics - the FAR 23 requirements are very specific in the words required on placards: § 23.1567 Flight maneuver placard.(a) For normal category airplanes, there must be a placard in front of and in clear view of the pilot stating: “No acrobatic maneuvers, including spins, approved.” (b) For utility category airplanes, there must be— ........... (2) For those airplanes that do not meet the spin requirements for acrobatic category airplanes, an additional placard in clear view of the pilot stating: “Spins Prohibited.” That text seems to be preferable than the text required by other regs i.e. Jabiru probably didn't have the option to choose the words. As for everything else, as usual, I agree with facthunter.
dunlopdangler Posted November 11, 2009 Posted November 11, 2009 My two cents worth: Part of the certification process is that the aircraft recovers from a developed spin or it is demonstrated that it has a equivalent level of safety (such as cirrus with the chute) The reason the cirrus did not complete the spin testing is because the wing design actually stops the spin scenario from occuring..so to meet certification they came up with the BRS chute as an alternative which was accepted.. As far as Jab is concerned test pilots actually spun and recovered quite well and passed certification. Most aircraft are certified under the normal or utility categories and under utility you will see that some aircraft are certified for certain aerobatic manouvers. remember a intentional spin is deemed aerobatic.(see djpacro's post above) and an unintentional spin is a result of bad piloting in the normal sense. that is why during our pilot training we a taught to identify and recover from an induced spin. Hope that answered your question qwerty:drums:
Guest Qwerty Posted November 11, 2009 Posted November 11, 2009 Nope, not clarified. djparco quoted FAR 23, "SPINS PROHIBITED",.... this is clear and unambiguous and is almost impossible to missunderstand.. It is apparent to me that Jabiru mean something other than "Spins Prohibited" because they chose to use different words. I am trying to come to an understanding of exactly what meaning they are trying to impart. The best I can do right now is that unintentional spins are not prohibited as Jabiru have gone to the effort of excluding unintentional spins from the prohibition by the wording that they have chosen to use.
Al B Posted November 11, 2009 Posted November 11, 2009 What's the point of prohibiting ANY unintentional maneuver? If you unintentionally enter a spin, it doesn't matter what the placard says - you didn't set out to disobey the placard. They may as well say 'unintentional engine failures prohibited'. Forgive me if I'm reading this incorrectly, but I get the impression you are trying to find a loophole that will let you spin a jab. If not please ignore the rest of this message. Occasionally in accident reports, you'll read about a pilot who did something foolhardy and killed himself. After the investigation, it'll turn out that other people knew the pilot had a history of pushing the limits but didn't say anything about it. Please don't be that pilot. If not for your sake, then for your family and friends.
Yenn Posted November 11, 2009 Posted November 11, 2009 Facthunter. I have done only a few spins and mostly with an instructor. Flat spins take a while to develope and equally as long to get out of as far as I found, and they use a hell of a lot af altitude. I wouldn't want to do them now without an instructor alongside and I can't spin the Corby for legal reasons although they do in the US and NZ
Guest Qwerty Posted November 11, 2009 Posted November 11, 2009 Thanks for your concern, I appreciate it. I am really trying to understand why the restriction is "No intentional spins" instead of "no spins". The implication really is that unintentional spins are OK. I am not looking for a loophole. Come to think of it, I don't think loop hole is applicable it it??? I am not actually aware of any specific legislative prohibition on spinning. Please correct me if I have missed something. Spins may well be prohibited but I can't think where off the top of my head.
facthunter Posted November 11, 2009 Posted November 11, 2009 Spins Dual. Fair enough too, Yenn. In that situation the instructor is PIC and there should be no confusion. The point that I wished to make in the Chipmunk, is that they are a bit unpredictable,(and that was generally accepted). SOME had a larger rudder fitted. IF they flattened out, they were likely to be difficult to recover from the spin, and as I say, some didn't. Nev
farri Posted November 11, 2009 Posted November 11, 2009 I am really trying to understand why the restriction is "No intentional spins" instead of "no spins". The implication really is that unintentional spins are OK. . I got the impression that was the question also and the way I read it is that it`s yet another example of incorrect wording that should be changed. Frank.
Guest Qwerty Posted November 11, 2009 Posted November 11, 2009 Come on,...... I can't remember where the reg is about spinning. I have a vague recollection that bank angles over 60 deg are also prohibited. Someone must know??? Turboplanner??? Facthunter?????
farri Posted November 11, 2009 Posted November 11, 2009 Appart from the CAOs and CARs, RAA registered aircraft opperate under the RAA operations manual and spins have been prohibited for as long as I`ve been flying. A spin is an aerobatic manoeuvre and can not be peformed by an RAA aircraft therefore it`s only the wording " No Intentional Spins " that should be the issue here. Has something changed that I`m not aware of ?. Frank.
DarkSarcasm Posted November 11, 2009 Posted November 11, 2009 I may be showing ignorance here...but does the "No intentional spins" sign have to be placed in VH registered Jabirus as well? I'm just thinking that if it's only required in RA-Aus registered aircraft then it's a way of saying that spins are possible (i.e. the plane won't disintegrate in the sky or something if it happens), but you're not allowed to do them on purpose because of the RA-Aus regs Just a suggestion anyway...
djpacro Posted November 11, 2009 Posted November 11, 2009 Per my earlier post - the regulations are very specific on the wording of placards so the manufacturers don't get a lot of choice. The actual words used would follow from the certification requirements for the particular type. The JAR-VLA requirements borrow a lot from FAR normal category. It has the same limitation of 60 deg bank angle as FAR 23 normal category. It has the same spin test certification requirements as FAR 23 normal category. It is also very specific on the wording of the spin placard but differs from FAR 23 (refer my earlier post): The following placards must be plainly visible to the pilot: ...... (b) A placard stating ‘This aeroplane is classified as a very light aeroplane approved for day VFR only, in non-icing conditions. All aerobatic manoeuvres including intentional spinning are prohibited. See Flight Manual for other limitations’. It seems that similar offending text is also in the LSA regulations (sorry, I don't have a direct quote).The bottom line is that they should be treated like normal category aircraft i.e. don't spin them.
DarkSarcasm Posted November 11, 2009 Posted November 11, 2009 Alternatively the placard isn't as badly worded as people think Basically, "No intentional spins" means that, no you can't spin it ok, but if you scr*w up that badly and do spin it, it's not going to fall to pieces But note that I have never done a spin so I can't really comment on anything to do with that, I'm just saying how I would interpret the placard
djpacro Posted November 11, 2009 Posted November 11, 2009 Basically, "No intentional spins" means that, no you can't spin it ok, but if you scr*w up that badly and do spin it, it's not going to fall to pieces ... and you will be able to recover from it if you don't let the spin develop and use the appropriate technique.
farri Posted November 11, 2009 Posted November 11, 2009 ... and you will be able to recover from it if you don't let the spin develop and use the appropriate technique. And if you do let it develop and use the wrong technique to recover,you will most likely die when you make contact with the earth. Frank.
Exadios Posted November 11, 2009 Posted November 11, 2009 ... and you will be able to recover from it if you don't let the spin develop and use the appropriate technique. Some aircraft enter a spin very quickly in certain configurations. And, having entered a spin I doubt whether the average pilot could recover sufficiently fast without practice. Spins are quite disorienting.
turboplanner Posted November 11, 2009 Posted November 11, 2009 Alternatively the placard isn't as badly worded as people thinkBasically, "No intentional spins" means that, no you can't spin it ok, but if you scr*w up that badly and do spin it, it's not going to fall to pieces But note that I have never done a spin so I can't really comment on anything to do with that, I'm just saying how I would interpret the placard No, there is no implication in the wording that structural damage will not occur, and no implication that unintentional spins are OK. The wording is clear to anyone not looking for a loophole to put their life, the lives of others, and the safety standards of RAA at risk. It means don't deliberately put the aircraft in a position where it will spin. The placard most probably has the more specific wording as a result of clever dicks who love playing semantics criticising the simpler "No Spins" by pointing out that the placard should include "No crashes", "No stalls", No running out of fuel", No navigation errors etc. And no Qwerty, you were not accused of being a "Spin Lunatic", it was someone else, who I believe was wrongly accused because the accusers didn't know the difference between a spin and an incipient spin, but had been scared out of their wits.
DarkSarcasm Posted November 11, 2009 Posted November 11, 2009 The problem is that by putting the word 'intentional' in there then it is arguable that they are implying that it could survive an unintentional one if you were dumb enough to do that... One day someone is going to spin one and have an accident and lots of lawyers will be paid lots of money to argue about this placard...and it is potentially arguable both ways so a lot of lawyers could have a very interesting time in court
Guest Qwerty Posted November 11, 2009 Posted November 11, 2009 Darky, My point exactly. Turbo, the hypothetical "No Spins" placard has no bearing and no impact on other prohibitions, you are being mischieviouis to confuse the question with irrelvancies. If you are sincere then your logic equally applies to the existing placard and you should ( according to your own argument) be advocating "No intentional crashes", "No intentional stalls", No intentional running out of fuel", No intentional navigation errors etc. I submit to your honour that Turbo's argument is fatally flawed. How many times do I have to say I am not looking for a loophole, I am trying to understand what I percieve to be STUPIDITY.
DarkSarcasm Posted November 11, 2009 Posted November 11, 2009 The purpose of these placards is (apart from trying to keep the pilot safe) largely reducing liability on the manufacturer so if something does happen the manufacturer can claim that they tried to stop it so they're less liable that it did happen With potentially ambiguous placards like these (i.e. are unintentional spins ok in that your aeroplane won't disintegrate in mid-air or something) they are leaving themselves open to potential liability when someone does eventually spin their plane and have an accident It's not the same as having ones like "no crashes" and "no running out of fuel" because the normal reasonable person would know that obviously doing these things would be rather bad for their health. Something like a spin is less clear than these and therefore more warning is needed Darky is showing her lawyer side...
Guest Qwerty Posted November 11, 2009 Posted November 11, 2009 Lets clear up any ambiguity about jabs and the actual spin. Jabirus spin and recover perfectly OK. I know this to be a fact. There is no physical, structural or aerodynamic reason why one should not spin a Jabiru.
farri Posted November 11, 2009 Posted November 11, 2009 One day someone is going to spin one and have an accident and lots of lawyers will be paid lots of money to argue about this placard. To me,the wording,"No Intentional Spins" in an an aircraft that is not approved for spinning,is incorrect,it implies that if a spin occurs, "Unintentionally",then it, "May", be safe for the spin to occur,it does not imply anything about the integrity or strength of the aircraft. A more appropriate wording would be " This Aircraft Is Not Approved For Spinning", it then leaves the pilot with "No Doubt". In an RAA registered AC the placard should be changed. Frank.
Guest Orion Posted November 11, 2009 Posted November 11, 2009 You know if you spin it and you die. what the damn sign said won't be of any use to you at all. you will still be dead. The rules say don't intentionally spin, so don't can't undertand all the hair splitting going on here.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now