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#11
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barrel roll in 172
Utility category allows some limited acro maneuvers, and a
list of approved maneuvers is on the placard on the side wall of the cabin and in the POH. If you want to do rolls, snap rolls, etc, rent or buy an airplane designed and tested and certified as such. Can the 172 do acro, sure, with Bob Hoover doing the flying. Can some ham handed 100 private pilot do it with out falling out of the roll, and pulling 9 Gs in the recovery? Probably not. Parachutes are required when you exceed certain attitudes, the mental attitude being the most important. § 91.303 Aerobatic flight. No person may operate an aircraft in aerobatic flight- (a) Over any congested area of a city, town, or settlement; (b) Over an open air assembly of persons; (c) Within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport; (d) Within 4 nautical miles of the center line of any Federal airway; (e) Below an altitude of 1,500 feet above the surface; or (f) When flight visibility is less than 3 statute miles. For the purposes of this section, aerobatic flight means an intentional maneuver involving an abrupt change in an aircraft's attitude, an abnormal attitude, or abnormal acceleration, not necessary for normal flight. [Doc. No. 18834, 54 FR 34308, Aug. 18, 1989, as amended by Amdt. 91-227, 56 FR 65661, Dec. 17, 1991] § 91.307 Parachutes and parachuting. (a) No pilot of a civil aircraft may allow a parachute that is available for emergency use to be carried in that aircraft unless it is an approved type and- (1) If a chair type (canopy in back), it has been packed by a certificated and appropriately rated parachute rigger within the preceding 120 days; or (2) If any other type, it has been packed by a certificated and appropriately rated parachute rigger- (i) Within the preceding 120 days, if its canopy, shrouds, and harness are composed exclusively of nylon, rayon, or other similar synthetic fiber or materials that are substantially resistant to damage from mold, mildew, or other fungi and other rotting agents propagated in a moist environment; or (ii) Within the preceding 60 days, if any part of the parachute is composed of silk, pongee, or other natural fiber, or materials not specified in paragraph (a)(2)(i) of this section. (b) Except in an emergency, no pilot in command may allow, and no person may conduct, a parachute operation from an aircraft within the United States except in accordance with part 105 of this chapter. (c) Unless each occupant of the aircraft is wearing an approved parachute, no pilot of a civil aircraft carrying any person (other than a crewmember) may execute any intentional maneuver that exceeds- (1) A bank of 60 degrees relative to the horizon; or (2) A nose-up or nose-down attitude of 30 degrees relative to the horizon. (d) Paragraph (c) of this section does not apply to- (1) Flight tests for pilot certification or rating; or (2) Spins and other flight maneuvers required by the regulations for any certificate or rating when given by- (i) A certificated flight instructor; or (ii) An airline transport pilot instructing in accordance with §61.67 of this chapter. (e) For the purposes of this section, approved parachute means- (1) A parachute manufactured under a type certificate or a technical standard order (C-23 series); or (2) A personnel-carrying military parachute identified by an NAF, AAF, or AN drawing number, an AAF order number, or any other military designation or specification number. [Doc. No. 18334, 54 FR 34308, Aug. 18, 1989, as amended by Amdt. 91-255, 62 FR 68137, Dec. 30, 1997; Amdt. 91-268, 66 FR 23553, May 9, 2001] -- James H. Macklin ATP,CFI,A&P "Bob Moore" wrote in message . 122... | Morgans wrote | I'll bet he is not going to wear a parachute, either, which is | required. | | Where does it say that? | | The answer to rolling a normal category plane should be no, always. | | The C-172 that I fly is a Utility Category airplane, if I want it to be. | | Bob Moore | ATP CFI |
#12
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barrel roll in 172
"john smith" wrote Certified? No. Possible? Yes, but you will finish much lower than where you started. Don't encourage that type of behavior with a yes. If he had to ask, he is probably not a competent aerobatic pilot, and a blown barrel roll could stall the plane, or overstress it, so it fails then, or later. I'll bet he is not going to wear a parachute, either, which is required. The answer to rolling a normal category plane should be no, always. We don't want his, or someone else's blood on our hands. -- Jim in NC |
#13
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barrel roll in 172
Don't encourage that type of behavior with a yes. If he had to ask, he is
I'm slightly disappointed by how quickly you've assumed my complete brainlessness. Yes I know what FARs say, and what POH says, and no, I'm not going to read this newsgroup and go break my neck the next morning. What I was hoping to hear was an opinion of someone who's familiar with what is involved in test-flying for normal/utility category and how much it covers the type of stress imposed on the airframe and systems in a barrel roll. Andrey |
#14
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barrel roll in 172
Possible? Yes, but you will finish much lower than where you started.
So, basically it's just because of a low-hp engine that the maneuver can't be properly executed? Andrey |
#15
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barrel roll in 172
Andrey Serbinenko schrieb:
I'm slightly disappointed by how quickly you've assumed my complete brainlessness. If this surprizes you, then you don't read this group often. Stefan |
#16
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barrel roll in 172
A properly done mild acro maneuver is well within the limits
of even a normal category airplane [3.8G], but it is easy to botch a maneuver and then the recovery can require much higher forces. They only test using qualified and competent pilots and they only test for maneuvers they intend to certify the aircraft to do. Some airplanes may be certified for "flick" maneuvers or accelerated maneuvers entered at higher speeds, such as snap rolls. Some aircraft are approved for unlimited maneuvers and they sometimes break. see http://www.faa.gov/regulations_polic...a_regulations/ § 23.151 Acrobatic maneuvers. Each acrobatic and utility category airplane must be able to perform safely the acrobatic maneuvers for which certification is requested. Safe entry speeds for these maneuvers must be determined. Browse Previous | Browse Next § 23.221 Spinning. (a) Normal category airplanes. A single-engine, normal category airplane must be able to recover from a one-turn spin or a three-second spin, whichever takes longer, in not more than one additional turn after initiation of the first control action for recovery, or demonstrate compliance with the optional spin resistant requirements of this section. (1) The following apply to one turn or three second spins: (i) For both the flaps-retracted and flaps-extended conditions, the applicable airspeed limit and positive limit maneuvering load factor must not be exceeded; (ii) No control forces or characteristic encountered during the spin or recovery may adversely affect prompt recovery; (iii) It must be impossible to obtain unrecoverable spins with any use of the flight or engine power controls either at the entry into or during the spin; and (iv) For the flaps-extended condition, the flaps may be retracted during the recovery but not before rotation has ceased. (2) At the applicant's option, the airplane may be demonstrated to be spin resistant by the following: (i) During the stall maneuver contained in §23.201, the pitch control must be pulled back and held against the stop. Then, using ailerons and rudders in the proper direction, it must be possible to maintain wings-level flight within 15 degrees of bank and to roll the airplane from a 30 degree bank in one direction to a 30 degree bank in the other direction; (ii) Reduce the airplane speed using pitch control at a rate of approximately one knot per second until the pitch control reaches the stop; then, with the pitch control pulled back and held against the stop, apply full rudder control in a manner to promote spin entry for a period of seven seconds or through a 360 degree heading change, whichever occurs first. If the 360 degree heading change is reached first, it must have taken no fewer than four seconds. This maneuver must be performed first with the ailerons in the neutral position, and then with the ailerons deflected opposite the direction of turn in the most adverse manner. Power and airplane configuration must be set in accordance with §23.201(e) without change during the maneuver. At the end of seven seconds or a 360 degree heading change, the airplane must respond immediately and normally to primary flight controls applied to regain coordinated, unstalled flight without reversal of control effect and without exceeding the temporary control forces specified by §23.143(c); and (iii) Compliance with §§23.201 and 23.203 must be demonstrated with the airplane in uncoordinated flight, corresponding to one ball width displacement on a slip-skid indicator, unless one ball width displacement cannot be obtained with full rudder, in which case the demonstration must be with full rudder applied. (b) Utility category airplanes. A utility category airplane must meet the requirements of paragraph (a) of this section. In addition, the requirements of paragraph (c) of this section and §23.807(b)(7) must be met if approval for spinning is requested. (c) Acrobatic category airplanes. An acrobatic category airplane must meet the spin requirements of paragraph (a) of this section and §23.807(b)(6). In addition, the following requirements must be met in each configuration for which approval for spinning is requested: (1) The airplane must recover from any point in a spin up to and including six turns, or any greater number of turns for which certification is requested, in not more than one and one-half additional turns after initiation of the first control action for recovery. However, beyond three turns, the spin may be discontinued if spiral characteristics appear. (2) The applicable airspeed limits and limit maneuvering load factors must not be exceeded. For flaps-extended configurations for which approval is requested, the flaps must not be retracted during the recovery. (3) It must be impossible to obtain unrecoverable spins with any use of the flight or engine power controls either at the entry into or during the spin. (4) There must be no characteristics during the spin (such as excessive rates of rotation or extreme oscillatory motion) that might prevent a successful recovery due to disorientation or incapacitation of the pilot. [Doc. No. 27807, 61 FR 5191, Feb. 9, 1996] "Andrey Serbinenko" wrote in message ... | Don't encourage that type of behavior with a yes. If he had to ask, he is | | I'm slightly disappointed by how quickly you've assumed my complete | brainlessness. Yes I know what FARs say, and what POH says, and no, I'm | not going to read this newsgroup and go break my neck the next morning. | What I was hoping to hear was an opinion of someone who's familiar with | what is involved in test-flying for normal/utility category and how much | it covers the type of stress imposed on the airframe and systems in a barrel | roll. | | | Andrey | |
#17
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barrel roll in 172
No, poor pilot skill.
-- James H. Macklin ATP,CFI,A&P "Andrey Serbinenko" wrote in message ... | Possible? Yes, but you will finish much lower than where you started. | | So, basically it's just because of a low-hp engine that the maneuver | can't be properly executed? | | | | Andrey |
#18
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barrel roll in 172
In article kMMvg.78923$ZW3.78738@dukeread04,
"Jim Macklin" wrote: Parachutes are required when you exceed certain attitudes, the mental attitude being the most important. Read it again. Parachutes are not required if you're solo. |
#19
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barrel roll in 172
Andrey Serbinenko wrote
I'm slightly disappointed by how quickly you've assumed my complete brainlessness. Yes I know what FARs say, and what POH says, and no, I'm not going to read this newsgroup and go break my neck the next morning. What I was hoping to hear was an opinion of someone who's familiar with what is involved in test-flying for normal/utility category and how much it covers the type of stress imposed on the airframe and systems in a barrel roll. First Andrey, you will probably find much disagreement on this group as to what actually constitues a "barrell roll". If conducted as normally accepted in the aerobatic community, it consists of a combination loop and roll which at most, places about 3g's on the airframe. The g loading is not the problem in the utility category C- 172, its lack of power to complete the loop portion is what makes it particularly difficult. Below, I have copied a description of a "barrell roll". This may or may not be the maneuver that you have in mind. It would obviously be much easier in one of the higher powered 172s than in the O-300, 145hp powered version that I fly. :-) After reading the following, you might find that you really didn't mean to say "barrell roll". :-) BTW the two following descriptions are how I was taught to perform the "barrell roll" in Navy flight training. :-) From: http://acro.harvard.edu The Barrel Roll is a not competition maneuver. The barrel roll is a combination between a loop and a roll. You complete one loop while completing one roll at the same time. The flight path during a barrel roll has the shape of a horizontal cork screw. Imagine a big barrel, with the airplanes wheels rolling along the inside of the barrel in a cork screw path. During a barrel roll, the pilot experiences always positive G's. The maximum is about 2.5 to 3 G, the minimum about 0.5 G. And another description from Kershner's Flight Instructor's Manual: THE BARREL ROLL • Preparation. It's almost impossible to draw a barrel roll on the chalkboard, but a model will give the desired results. Have the trainee study the references. •Explanation. The barrel roll is a precise maneuver in which the airplane is rolled around an imaginary point 45° to the original flight path. A positive-g level is maintained throughout the maneuver, and the ball in the turn indicator should stay in the middle. You may wonder why the barrel roll is taught this late, since it appears to be so simple. Well, it is a precise maneuver requiring particular airplane attitudes at particular reference points, which is difficult for the average trainee to do properly at first. This maneuver might be considered an exaggeration of the wingover, but instead of starting to shallow the bank at the 90° position, the pilot must steepen it continually until the airplane has rolled 360° and is back on the original heading. The rate of roll must be much greater than that used for the wingover because the airplane must be in a vertical bank at 45° of turn, and it must be inverted at 90° of turn. The roll and turn is continued until the airplane is headed in the original direction with the wings level. Compare the barrel roll in Fig. 23-12 with the same view of the wingover in Fig. 20-7. From behind the maneuver looks as though the airplane is being flown around the outside of a barrel. This is a very good maneuver for gaining confidence and keeping oriented while flying inverted in balanced flight. Good coordination is required to do the barrel roll properly and the trainee will show an improvement in that area after a session of barrel rolls. The barrel roll is generally more difficult and precise than the aileron roll, and he may have to work on this one awhile. Why- The barrel roll is one of the best maneuvers for improving orientation. Unlike the other acrobatic maneuvers covered thus far, the barrel roll requires a constantly changing bank and pitch (with attendant changing airspeed) and a radical change in heading (90°) while the airplane is rolling. The average trainee probably will be looking at the wing tip at a time when he should be checking the nose, or vice versa. When he is able to stay well oriented in the barrel roll, he is ready to move on to the reverse Cuban eight or reverse cloverleaf. How- You might use the following explanation, or develop your own: (1) Make sure the area is clear, then pick a reference on the horizon off the wing tip as in the wingover and lazy eight. (2) Set the throttle to low cruise rpm and ease the nose over to pick- up about 10 K more than used for the wingover or set up the airspeed used for a loop, whichever is higher. Power adjustment should not be necessary during the maneuver. You might have some of your sharper trainees apply full power as the airplane approaches inverted and then remind them to throttle back as the airspeed picks up in the last part of the maneuver. (3) Smoothly pull the nose up and start a coordinated climbing turn (note that it will have to be at a much faster rate than was used for the wingover) toward the reference point. (Assume that at first the roll will be to the left.) (4) When the nose is 45° from the original heading, it should be at its highest pitch attitude and the left bank should be vertical. (5) When the nose is at 90° from the original heading, you should be looking directly at the reference point that was originally off the wing tipfrom a completely inverted position (momentarily). (6) When the airplane heading is again 45° from the original, the bank is vertical but you will be in a right bank as far as the ground is concerned; that is, the right wing is pointing straight down at this instant of roll. The nose will be at its lowest pitch attitude at this point. (7) The roll is continued to wings-level flight as the nose is raised back to the cruise attitude. The maneuver must be symmetrical; the nose must go as far above the horizon as below. The barrel roll requires definite checkpoints to ensure that the airplane is at the correct attitude throughout. It is interesting to note that if the barrel roll is to the left, all of the airplane's path is to the left of the original line of flight and the airplane's nose is always pointed to the left of the original flight line (until it merges again at the completion of the maneuver). The opposite occurs, naturally, for the barrel roll to the right. Another method of doing a barrel roll is to pick a reference on the horizon, turn the airplane 45° to the reference point, and proceed to make a wide roll around this real point. One disadvantage of this method for the newcomer is that it depends on the pilot's own judgment of how large the orbit around the point should be. For an introduction to the maneuver, the first method is usually better, but you may prefer the second and work out your own techniques of instructing it. Demonstration. Try not to lose the reference point yourself while demonstrating this one. You may find your explanation is not keeping up with the airplane, which usually results in sputtering and stuttering while the maneuver proceeds to its foregone conclusion -and then you have to do a new demonstration. Don't worry, this will happen plenty of times during your career of instructing aerobatics -when your mouth can't keep up with your brain or the maneuver-and it can ease tension if you react to it with humor. Usually the trainee is surprised to see the same wing tip back on the reference point and may confess that, like the first snap roll, the earth and sky were blurred and he had no idea where the reference was during the maneuver. Practice. You may rest assured the trainee will "lose" the reference point during the first couple of barrel rolls. He'll usually stare over the nose, seeing nothing but blue sky or ground and not really seeing the point at all. Common errors during barrel rolls include these: 1. Not pulling the nose high enough in the first 45° of the maneuver, which means that the highest and lowest nose positions are not symmetrical to the horizon. 2. Not maintaining a constant rate of roll. Usually things are fine at the 45° position; the nose is at its highest pitch and the bank is vertical. As you approach the position of 90° of turn you will probably find that he is not going to be completely inverted at that point and will have to rush things a bit to make it. The usual reason is that he did not maintain a constant rate of roll. Remember that the nose is up and the airspeed is slower in this segment of the maneuver, so the controls must be deflected more to get the same rate. This is where coordination comes in. Watch for it in particular. 3. Letting the nose drop after passing the 90° point; losing too much altitude and gaining excess airspeed. 4. Failure to roll out on the original heading; having the wing tip well ahead, or well behind, the reference when the maneuver is completed. Evaluation and Review. Review each barrel roll briefly in the air, and have the trainee use the model on the ground. This one can be hard to "see," so go over it again as necessary after getting on the ground. By the time a half-dozen barrel rolls have been practiced, the average trainee should be oriented throughout the maneuver even though he may still have minor problems of heading and symmetry. After a dozen rolls he should be starting to work on a constant roll rate and starting to ease his heading problems. After several hundred, he may begin to be satisfied with his barrel rolls but will realize that constant practice is required. |
#20
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barrel roll in 172
Possible? Yes, but you will finish much lower than where you started.
So, basically it's just because of a low-hp engine that the maneuver can't be properly executed? The answer is not that simple. Low horsepower engine is one, design and strength of the airframe is another, skill of the pilot is a third, design of the airfoils selected, design of the the control system, design of the engine systems, etc. Many factors contribute to "how" a maneuver can be flown. |
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