Pilot's Operating Handbook Cessna 150 Aerobat

is going on or what will be happening next. Precision aerobatic pilots ⠀ practice hour after hour and know what is going to happen three and seven-tenths maneuvers from now." The high percentage of pilots involved in the cause of aerobatic accidents and the nature of their involvement (attempted operation beyond experience/ability level; failed to follow approved procedures, directives%; exercised poor judgment) further substantiate this point. Moreover, professional or competitive aerobatics are conducted only in airplanes designed and approved for aerobatic flight while a number of accidents in this study involved airplanes in which aerobatic operation was prohibited. AEROBATIC ACCIDENT STATISTICS The Safety Board's records reveal that there were 105 aerobatic accidents from 1972 through 1974. Seventy-eight aerobatic accidents (74 percent) were fatal and represented 3.76 percent of the 2,071 fatal accidents. One hundred and seven persons lost their lives in aerobatic accidents; 21 persons were injured seriously and 10 persons were injured slightly. Seventy-eight aerobatic accidents occurred in "noncommercial" kinds-of-flying--58 in pleasure flying, 16 in practice flying, and 4 in other noncommercial flying. Fourteen aerobatic accidents occurred in the "miscellaneous" kind-of-flying category, 9 of which involved airshows. Eight aerobatic accidents occurred during "instructional" flying--five in instructional dual flying and three during instructional solo flight. The remaining five aerobatic accidents occurred in "commercial" flying-- four during aerial application or crop control-related flights and one during power or pipeline patrol. i t C TUE a 3. The 105 accidents include the following specific first accident types: Twenty-seven controlled collisions with ground or water%3B 6 uncontrolled collisions with ground or water%3B 9 collisions with wires, poles, or trees; 13 stalls; 36 spins; and 10 airframe failures in flight. The two most significant broad cause/factor categories for aerobatic accidents are "pilot" and "terrain." The pilot was cited as a cause in 97 accidents and as a causal factor in 15 accidents. (More than one cause or factor may be cited in a single accident.) Terrain was a cause of two accidents and a factor in nine accidents. (See Tables 1, 2, 3, and 4.) Stalls and Spins Forty-nine of the 105 accidents involved a stall or a spin (36 spins and 13 stalls). Most of these were unintentional and were related to the performance of other aerobatic maneuvers at low altitudes-- altitudes which made recovery from the accidental stall or spin either difficult or impossible. Flights at these altitudes were in violation of 14 CFR 91.9, "Careless or Reckless Operation," and 14 CFR 91.71(d), "Aerobatic Flight" (except for those flights associated with airshows where the FAA had issued a waiver or letter of competence). The latter prohibits aerobatics below 1,500 feet above the surface. Accident- prevention efforts, therefore, should be focused primarily on enforcement-- an intensive and rigorous campaign by the FAA in which the certificate of any person found guilty of violating these provisions would be suspended or revoked. The conspicuous posting of notices to this effect at general aviation airports throughout the country might be effective. In addition, a regulation to restrict the performance of aerobatic maneuvers to persons holding an appropriate endorsement and the distribution of educational materials should also be considered as a solution to this problem. On the other hand, some of the spins were intentional and were initiated at altitudes which would normally have been sufficient to permit recovery. Recovery in these cases, however, was not effected either because of inadequate spin recovery techniques at normal recovery altitudes, or because the spin was otherwise prolonged to the point that insufficient altitude remained in which to recover. In some cases, the airplane hit the ground before the spin rotation stopped; in other cases, the airplane crashed after spin rotation had stopped, but before a pullup from the ensuing dive could be completed. Persons involved in these types of accidents had some previous spin instruction, but their overall knowledge and proficiency in spins is believed to have been minimal. For example, they probably were not fully aware of all of the adverse spin characteristics that could be induced through improper use TABLE 1 DETAILED CAUSAL DATA ("PILOT" and "TERRAIN" CATEGORIES, "MISCELLANEOUS ACTS, CONDITIONS") AEROBATICS - INFLIGHT PHASE OF OPERATION U. S. GENERAL AVIATION PILOT PILOT-IN-COMMAND 1972 - 1974 FATAL AND NONFATAL ACCIDENTS CAUSE FACTOR TOTAL Attempted operation w/known deficiencies in equipment Attempted operation beyond experience/ability level Exceeded design stress limits of aircraft Failed to see and avoid objects or obstructions Failed to obtain/maintain flying speed Misjudged speed, altitude, or clearance 14 Failed to follow approved procedures, directives, etc. Improper operation of flight controls Inadequate preflight preparation and/or planning Lack of familiarity with aircraft Mismanagement of fuel Exercised poor judgment Operated carelessly Misjudged speed and altitude Misjudged altitude and clearance Misjudged altitude Misjudged clearance Incapacitation Physical impairment Subtotal 29 10 -13232323 -22308-23 1 4 2 1 29 2 2 1 31 2 1 4 10 28 1 1 6 0 178 16 194 1532327932. 33 4 - TERRAIN Wet, soft ground Snow-covered High Obstructions Other TABLE 1 CONT. CAUSE FACTOR TOTAL 1 1 1 8 8 1 1 2 9 11 TOTAL "Miscellaneous acts and conditions" are often given to supplement other causal information such as the above. These were recorded as follows: Subtotal MISCELLANEOUS ACTS, CONDITIONS Disregard of good operating practice Seatbelt not fastened Unwarranted low flying Correcting lenses-not used Fatigue fracture Separation in flight Corroded/corrosion Fuel exhaustion Alcoholic impairment of efficiency and judgment Improperly loaded aircraft-weight-and/or CG Interference with flight controls Aircraft came to rest in water Overload failure Material failure Disconnected Flutter Jammed CAUSE FACTOR 1 33 16 -26- 1 13 - 229-13-783-032--- 49 31 3 503 02 10 1 2 1 1 - 5- TABLE 2 PILOT AGE BY PILOT CERTIFICATE AEROBATICS - INFLIGHT PHASE OF OPERATION U. S. GENERAL AVIATION 1972 - 1974 PILOT CERTIFICATE - 6 - 1 COMMERCIAL WITH FLIGHT AIRLINE INSTRUCTOR AGE STUDENT PRIVATE COMMERCIAL TRANSPORT CERTIFICATE 20-24 25-29 7 30-34 35-39 3 40-44 45-49 50-54 55-59 34594532 69593332 3 386 13 60 or 2211 - more AIRLINE TRANSPORT WITH FLIGHT INSTRUCTOR CERTIFICATE NONE (UNCERTIFICATED OR EXPIRED TOTAL 1 1 1 1 1 3 2 2 22132375 2 4 5 31 37 ☐ 5 24 1 2 105 TABLE 3 PILOT TOTAL TIME BY PILOT CERTIFICATE AEROBATICS - INFLIGHT PHASE OF OPERATION U. S. GENERAL AVIATION 1972 - 1974 PILOT CERTIFICATE COMMERCIAL WITH FLIGHT TOTAL TIME STUDENT PRIVATE COMMERCIAL AIRLINE TRANSPORT INSTRUCTOR CERTIFICATE LESS THAN 100 4 100-299 300- 599 10 600-899 900-1199 47022 1200-1499 1500-1799 1800-2099 2100-2399 2400-2699 2700-2999 3000 or More Unknown/ Not Reported 1 112 2312--22- 24321 4 2121 AIRLINE TRANSPORT WITH FLIGHT INSTRUCTOR CERTIFICATE NONE (UNCERTIFICATED OR EXPIRED) TOTAL 7 - 80685MNOTON 10 16 3 2 4 2 30 50 16 5 8 1 1 3 1 2 7 5 31 37 5 10 24 1 2 105 TABLE 4 PILOT TIME IN TYPE BY PILOT CERTIFICATE INFLIGHT PHASE OF OPERATION AEROBATICS - U. S. GENERAL AVIATION 1972 - 1974 PILOT CERTIFICATE COMMERCIAL TIME IN TYPE AIRLINE WITH FLIGHT INSTRUCTOR STUDENT PRIVATE COMMERCIAL TRANSPORT CERTIFICATE AIRLINE TRANSPORT WITH FLIGHT INSTRUCTOR CERTIFICATE NONE (UNCERTIFICATED OR EXPIRED) TOTAL 8 - LESS THAN 100 hr 4 19 10 3 100- 299 1 4 9 300- 599 05 600-899 1 1829 42 2382 900-1199 1200-1499 2 2 1500-1799 1800-2099 2100-2399 1 2400-2699 1 1 2- 2700-2999 3000 or More 1 1 Unknown/ Not Reported 6 11 4 2 24 31 37 5 24 2 105 9 - of the flight or power controls, or both, or of the essential need to use a precise technique appropriate to their particular airplane in order to optimize the recovery. The fatal spin accident, which involved a commercial flight instructor and a passenger in a Cessna Model 150J on November 24, 1974, near Morganton, North Carolina, typifies the above circumstances. A witness estimated that the spin continued for at least five turns. Apparently, the airplane had stopped rotating, but struck the ground in a near vertical attitude (File No. 3-3837). A number of accidents which include the above circumstances involved spins which were apparently initiated at altitudes that allowed little margin for error, such as inept application of recovery controls or a delayed recovery because a pilot misjudged his altitude or became disoriented. This situation is particularly hazardous in the case of the novice or relatively inexperienced pilot. The fatal spin accident on January 28, 1974, just offshore, near Melbourne, Florida, for example, involved a private pilot with less than 100 flight-hours who had been given several hours of aerobatic instruction (File No. 3-0118). He was flying a Cessna Model A150L. A witness who saw the airplane in a spin said the spin continued to a relatively low altitude. The pilot was observed to bail out and his parachute deployed satisfactorily; however, he drowned in rough seas. Another case involving two commercial pilots further illustrates the potential hazards of initiating spins at relatively low altitudes (File No. 3-3937). The probable cause of this fatal spin accident is cited as "pilot-in-command - misjudged altitude." An excerpt from the factual report describes the circumstances: At approximately 1600 c.s.t., a pilot and his companion were observed to board N8344M and depart the airport. Before departure the pilot had made the comment to persons at the airport that he intended to demonstrate spins to his companion. At approximately 1630 c.s.t., a witness, who was also a commercial pilot, saw an aircraft in flight from a point about one mile northeast of the crash site. The witness saw the aircraft do a series of wing-over maneuvers. After completing one of these maneuvers, the aircraft made a climb and went into a spin, rotating to the left. The aircraft was seen as it continued in a spin until it disappeared from the witness' view behind some trees. This witness estimated the aircraft's altitude to be approximately 3,500 feet when it began to spin. · 10 - A second witness, who was watching the aircraft in flight stated that the aircraft turned or spun seven times before it crashed in an open field. Both occupants of the aircraft were found in the cockpit with their seatbelts fastened and wearing back-type parachutes. Investigation disclosed no evidence of an in-flight malfunction or failure. All aircraft control surfaces and extremities were found within the immediate wreckage area. The weather in the area was described as clear of clouds with good visibility. Both occupants held commercial pilot certificates. The pilot was enrolled in a 10-hour acrobatic course and at the time of the accident had received 7.2 hours of dual instruction including spins and spin recovery. In one accident which resulted during an intentional spin, the airplane's spin characteristics or lack of response may have been a factor in thwarting the pilot's recovery efforts. On September 24, 1972, at Larkspur, Colorado, a Beechcraft Model C-23 airplane failed to recover from a spin despite repeated recovery efforts by a commercial flight instructor and his student. Both parachuted from the airplane. Airworthiness Directive 74-14-05 was issued subsequently to "prevent in-flight situations in which prompt spin recovery may not be assured." The AD applied to Beechcraft Models B-19 and C-23 which were originally approved in the acrobatic category and to intentional spins in the utility and acrobatic categories. The AD prohibited intentional spins in these airplanes and required that all placards pertaining to intentional spins and acrobatic flight be removed. In place thereof, a placard was required which prohibited intentional spins and acrobatic maneuvers except chandelles, lazy eights, steep turns, and stalls (except whip stalls). A Beech spin-improvement kit must be installed for these operating restrictions to be removed. Several flight instructors have complained of difficulty in recovering from spins in Cessna Model 150 airplanes. Detailed investigation by the FAA, however, disclosed that the problems were related to operational vagaries or anomalies, inadequate knowledge regarding the precise spin recovery procedures necessary for the airplane, improper application or misapplication of recovery controls, apprehension, and confusion. As a result of these incidents and past spin accidents, the initiation of spins at higher, conservative altitudes is being emphasized. For example, the 1976 pilot's operating handbook for the Cessna 150 Aerobat recommends that : C 0 e: ت نه ة ri me el ir e> pe at re re 33202- si em op di ha sp fl in "F th F. 11 - "Where feasible, entries be accomplished at high enough altitude that recoveries are completed 4,000 feet or more above ground level. At least 1,000 feet of altitude loss should be allowed for a 1-turn spin and recovery, while a 6- turn spin and recovery may require somewhat more than twice that amount. For example, the recommended entry altitude for a 6-turn spin would be 6,000 feet above ground level. In any case, entries should be planned so that recoveries are completed well above the minimum 1,500 feet above ground level required by FAR 91.71. Another reason for using high altitudes for practicing spins is that a greater field of view is provided which will assist in maintaining pilot orientation." While the frequency of spin accidents involving the operational circumstances described above is not unusually high, these accidents occur regularly and usually are fatal. Furthermore, in view of the expanding aerobatic interest in spins, the frequency of these accidents can be expected to increase unless steps are taken to prevent their recurrence. Based on the provisions of 14 CFR 91.71(d), on airplane spin mechanics and recovery requirements, and on the human potential for error, the Board believes that a supplemental schedule of minimum initial spin altitudes should be incorporated into 14 CFR 91.71. For example, no spin, regardless of duration or number of turns, should be permitted to begin below 3,500 feet above the surface and spins initiated at this altitude should not exceed a designated number of turns before recovery is begun. A conservative increment in altitude should be required for each additional spin turn or fraction thereof. In years past, spins and spin-recovery procedures have been over- simplified. Only recently have precise recovery procedures been emphasized for a particular airplane. There are, moreover, various operational circumstances which stem from confusion, apprehension, disorientation, and the misapplication of flight controls which may hamper the recovery process. Because some of the knowledge regarding spins and spin-recovery techniques has been attained only recently, flight instructors may not be aware of many of the operational implications. To disseminate recent spin information, the FAA's Central Region, in cooperation with the Cessna Aircraft Company, devoted most of its "Flight Instructor Bulletin" of August 1975 to spins, particularly as they relate to the Cessna Models 150, A150, 172, and 177. (See Appendix F.) - 12 - The FAA's Central Region also initiated a spin indoctrination program relating to the spinning characteristics of typical general aviation airplanes, particularly those used extensively for training. On August 16 and 17, 1975, the first of a series of stall/spin clinics was held at St. Louis, Missouri. The clinic was held to brief flight instructors on the precise spin characteristics of the Cessna 150 and, through actual flight demonstrations, provide appropriate operational indoctrination. A subsequent clinic dealt with the spin characteristics of Piper Cherokee airplanes. Collisions With Ground/Water, Wires/Poles, Trees There were four types of collisions which were associated with 42 (40 percent) of the 105 accidents: Twenty-seven were controlled collisions with the ground or water, six were uncontrolled collisions with the ground or water, two were collisions with wires or poles, and seven were collisions with trees. Again, many of these accidents reflect the hazards of performing aerobatics at low altitudes. While a few of these collisions occurred during an authorized airshow, most involved flights conducted in violation of one or more of the provisions of 14 CFR 91.71. Safety Board records show that some of the more significant causes or causal factors relating to these accidents are as follows: 0 Exercised poor judgment. 0 Misjudged altitude. 0 Unwarranted low flying. 0 0 0 0 Attempted operation beyond experience/ability level. Failed to follow approved procedures, directives, etc. Alcoholic impairment of efficiency and judgment. Misjudged altitude and clearance. Improper operation of flight controls. The remedial action necessary to reduce these types of accidents is identical to that previously discussed in connection with stalls and spins--an intensive enforcement compaign by FAA. Airshow Aerobatics Before conducting an airshow, the sponsor of the airshow must obtain a certificate of waiver or authorization from the Federal Aviation Administration. The operations authorized and the waived regulations are specified thereon such as aerobatic flights associated with an airshow, waiver of Part 91.71(c) (flight within a control zone or Federal airway), and waiver of Part 91.71(d) (acrobatic flight below an altitude of 1,500 feet above the surface). The certificate is accompanied by a list of special provisions pertinent to the operations - 13 - authorized and any participating pilot, if he is to operate below 1,500 feet above the surface, must also possess a current letter of competency indicating that he has demonstrated satisfactorily his ability to perform aerobatics for public airshows. This letter may contain limitations relating to minimum operating altitude, permissible maneuvers, and type of aircraft. As previously noted, there were nine accidents directly associated with the actual performance of aerobatics at airshows; three of these were fatal, five involved serious injuries, and one involved minor injuries. In addition, 7 of the 16 accidents which occurred in non- commercial practice flying were related indirectly to an airshow since their associated flight purposes involved the practice of maneuvers to be performed at an airshow at some future time. Six of the seven accidents were fatal; one involved serious injuries. (See Table 5.) The aerobatic maneuvers being performed included rolls or inverted flight at low altitude, snap rolls, and spins at low altitude. Airframe Failure In Flight Airframe failure in flight is one of the several primary types of accidents relating to aerobatic mishaps and was evidenced in 10 of the 105 aerobatic accidents. Five airplanes involved were experimental or amateur-built, three were certificated in the aerobatic category, one was certificated in the normal category, and one was uncertificated. (See Table 6.) The avoidance of such a failure is of special interest to aerobatic pilots since an adequate understanding and respect for an airplane's structural limitations are fundamental prerequisites for the performance of aerobatic maneuvers. To avoid exceeding an airplane's design stress limits, the aerobatic pilot knows he must stay within two structural limitations: One pertaining to airspeed, the other to load factor. Normally, the airspeed indicator is monitored routinely and, as an aid to the pilot in observing airspeed limits, a radial red line has been painted on the instrument to designate Vne--the never-exceed airspeed. The following comments regarding the never exceed airspeed and limit load factor are excerpted from the Citabria Owners Manual: "The never-exceed speed is equivalent to the limit load factor--it is the maximum speed expected in service. It is shown by a red line on the airspeed indicator, and, as the name implies, should never be exceeded. "NOTE: In a Citabria, a slightly mose-low attitude when inverted will allow a rapid buildup of speed. Watch the airspeed indicator when inverted to prevent exceeding the never-exceed speed.