Informal Evaluation of the Cessna Model 185 and L-28A (Helio Courier Model 395) Airplanes

for the rear door. The rear door was of sufficient size to permit loading of such items as cases of "C" rations and 5-gallon cans. The rear seats (three) were readily removable; however, there were no cargo tie-down provisions. One litter patient could be transported. Each seat was equipped with a safety belt and the seats were compatible with the back- type parachute. The sole adjustment (vertical) of the pilot's seat was considered a limitation. Ground ventilation through the single window on the pilot's door was inadequate. In-flight ventilation through the individually adjustable inlets was adequate. Ground visibility over the nose was severely limited. In cruise flight, observation to the front and side from the forward seats was adequate. Overhead visibility was restricted due to the absence of overhead windows. Controls, knobs, and switches were accessible to the occupant of either forward seat. The single set of toe brakes located on the left side of the cockpit restricted ground operations from the right seat. Instrument and cockpit lighting was adequate. (2) Communication and Navigation Equipment. Each airplane was equipped with minimum essential flight instruments and radio aids for the conduct of instrument flight. (a) Cessna 185. The airplane was equipped with a commercial type VHF transmitter-receiver and an OMNI localizer con- verter indicator. Ninety crystal controlled channels were provided for transmission and 190 channels for reception. (b) L-28A. A UHF transmitter-receiver with 8 preset channels was installed for radio communication. A 190 channel VHF communication and navigation receiver was also installed. (3) Ruggedness. The all-metal construction (except for the fabric covered ailerons of the L-ZBA) should contribute to the durability 4 -pan 1PF-I.CIA UUE ItIH'_V ATBG-SEC AVN 663 SUBJECT: Informal Evaluation of the Cessna Model 185 and L-28A (Helio Courier Model 395) Airplanes of both airplanes. Based on numerous takeoffs and landings at design gross weight that were accomplished during the evaluation, it appears that the landing gear and braking systems of both airplanes are suffi- ciently rugged for field use. (4) Ground Handling and Taxiing. (a) At gross weight each airplane could be easily moved over smooth, firm surfaces by two men. The airplanes could be towed by a 1/2-ton truck. Neither airplane was compatible with the Universal tow bar because of the lack of adaptor units on the main landing gear. (b) Taxiing was accomplished primarily with the cross- wind landing gear of both airplanes in the locked position. No difficulty was encountered with either airplane in crosswinds up to 12 knots. The steerable tail wheel of the Cessna 185 aided in ground maneuverability. b. Flight Characteristics. (1) Cessna 185. The airplane was easily trimmed for straight and level flight, and control in light turbulence was maintained with little effort. Stalling characteristics were satisfactory. Warning of an impending stall was by means of a stall-warning horn which was activated approximately 10 knots above the stall speed. Buffet onset occurred at approximately 3 to 5 knots above the stall speed. There was a tendency during stalls for one wing to drop prior to the nose-down pitch. Normal recovery techniques were effective. (2) L-28A. Pitch trim was provided in the cockpit and was highly sensitive. Roll and yaw trim controls were not provided. As a result, control pressures were required to maintain straight and level flight under varying load conditions. The airplane was very sensi- tive to light air turbulence which resulted in excessive control manipulation to maintain altitude and heading. The airplane could not be stalled completely with any combination of power and flaps. With the stick full back, settling occurred within the IAS range of 30-41 knots, dependent on the power and flap settings. Although rudder control was limited, 5 ~O" 18,OAL USI.~L ATBG-SEC AVN 663 SUBJECT: Informal Evaluation of the Cessna Model 185 and L-Z8A (Helio Courier Model 395) Airplanes aileron control was effective throughout the stall. The airplane did not have a tendency to fall off on either wing and normal stall recovery procedures were effective. c. Performance. (1) Takeoffs and Landings. No unusual flight character- istics or control problems were encountered with either airplane during normal takeoffs and landings, to include limited crosswind operations. Accordingly, emphasis was placed on maximum performance takeoffs and landings at the design gross takeoff weight. Comparative perform- ance data is presented for the Cessna 185, L-28A, L-Z0A, and L-19E airplanes in inclosure 5. Inclosure 6 is a composite of four photographs showing the takeoff flight path of all four airplanes and is based on a common starting point. Inclosures 7, 8, 9, and 10 are attached as quick reference charts for all four airplanes. (a) Cessna 185. For maximum performance takeoffs, flaps were lowered to Z0 degrees and the brakes released after full power was obtained. Rotation was initiated at approximately 43 knots indicated air speed (IAS) and the climb was accomplished at 52 knots LAS. For landing, full flaps (40 degrees) and an IAS of 52 knots was used on the approach. The rate of descent was controlled with power. Minimum landing roll was obtained by retracting the flaps and reducing the power to idle immediately prior to touchdown and applying brakes concurrently with touchdown. Under the existing climatic conditions, takeoffs averaged 1, 115 feet and landing 959 feet over a 50-foot barrier. Control was adequate throughout. (b) L-28A. For maximum performance takeoffs, full flaps (40 degrees) were utilized and the brakes released after full power was obtained. Rotatirn- was initiated at 35 knots IAS and the climb was accomplished at the same IAS. For landing, full flaps were used while maintaining 40 knots IAS on approach and controlling the rate of descent with power. Approximately 20 feet above the intended touchdown point, power was reduced to idle and the roundout was com- pleted. Control was adequate throughout. Under the existing climatic 6 AR DPVICItAI "mr nMny ATBG-SEC AVN 663 SUBJECT: Informal Evaluation of the Cessna Model 185 and L-28A (Helio Courier Model 395) Airplanes conditions, takeoffs averaged 686 feet and landings 611 feet over a 50-foot barrier. The following undesirable characteristics were noted: 1. The maximum flap extended speed could be easily exceeded during climb-out due to the time required to raise the flaps (18 turns of the crank). Z. The nose-high attitude during the approach restricted the pilot's view of the intended point of touchdown. (2) Climb Performance. Climbs were made to a density altitude of 12,000 feet (climb to service ceiling was not accomplished due to the lack of oxygen equipment). The best rate of climb for the Cessna 185 was 850 feet per minute at an IAS of 8Z knots and for the L-Z8A, 900 feet per minute at an IAS of 78 knots (see inclosure 1). (3) Cruise Performance. (a) Cessna 185. Flights were made at a pressure altitude of 1,300 feet. The outside air temperature (OAT) was 83 0 F. With a power setting of 70 percent, an average true airspeed of 130 knots was achieved. Fuel mixture was adjusted to 13. Z gallons per hour (a computer was provided with the test airplane to aid in deter- mination of appropriate power settinga and best power mixture). (b) L-28A. Flights were made at a pressure altitude of 1,300 feet utilizing 70 percent power with an OAT of 77 0 F. The resultant average true airspeed was 1ZZ knots. The rate of fuel con- sumption was determined to be 15 gallons per hour. (4) Range and Endurance. The following is based on data obtained during the conduct of the evaluation and on data presented by the Operator's Manual for each airplane. (a) Cessna 185. The Cessna 185 with a crew of two and full fuel and oil has a maximum payload of approximately 690 pounds and a radius of action of approximately 385 nautical miles with 30 minutes reserve. The above is based on flights at 70 percent power and an average true air speed of 130 knots. As stated in the Operator's 7 r-,",n -rTI'IAL. LamE ONLY ATBG-SEC AVN 663 SUBJECT: Informal Evaluation of the Cessna Model 185 and L-28A (Helio Courier Model 395) Airplanes Manual the airplane has a range of 820 nautical miles at 144 knots, using 75 percent power at 7,000 feet, without reserve. When flown at the power setting corresponding to optimum range at 10,000 feet and no reserve fuel, an endurance of 9. 3 hours and a range of 1, 070 nautical miles is obtained. (b) L-Z8A. The L-28A with a crew of two and full fuel and oil has a maximum payload of approximately 100 pounds and a radius of action of 205 nautical miles with a 30 minute reserve. This is based on data obtained during the evaluation with 70 percent of power settings and an average true air speed of 122 knots. As stated in the Operator's Manual, the L-28A has a range of 570 nautical miles at 134 knots TAS at 6, 500 feet with no reserve. At the maximum endurance power setting at an altitude of 10, 000 feet, and at 61 knots TAS an endurance of 6. 67 hours and a range of 406 nautical miles is obtained. d. Servicing. In both airplanes, the gasoline filler necks, located on top of the wings, were of sufficient size to accommodate standard refueling nozzles, and grounding receptacles were provided. Neither airplane had steps to assist in reaching the filler necks. Access to the dip stick and oil filler caps was through doors on the engine cowl- ing. A step was required to reach the oil filler access door on both airplanes, however, the dip stick for the Cessna 185 could be reached from the ground. e. Maintenance. No attempt was made to conduct a mainte- nance evaluation of either airplane; however, the following adverse characteristics were noted: (1) Cessna 185. (a) There are no quick access provisions for inspection of the engine. (b) The engine cowling must be removed in order to drain the engine oil (approximately . 15 man-hours for removal). (c) Access to the avionics equipment requires removal of the upholstery in the after cabin area. 8 L .... . ... . . . _ .... ? m.. . . o, . u .. . .. ... . .. . .. . . . . .. ... .. -p' " . . . .. ATBG-SEC AVN 663 SUBJECT: Informal Evaluation of the Cessna Model 185 and L-28A (Helio Courier Model 395) Airplanes (d) There is no battery quick-disconnect. (2) L-Z8A. (a) Access to the engine oil drain valve requires removal of the engine cowling (approximately . 5 man-hours). (b) An external power receptacle is not provided. (c) There is no battery quick-disconnect and the battery is not readily accessible. 4. DISCUSSION. a. Addition of the usual electronic package for airplanes of this weight class, in either case, would reduce the payload substantially. Neither airplane offers a significant advantage over the Army's L-20 except for the landing and takeoff performance of the L-28A. There are no provisions for attachment of external loads for either airplane, although the Cessna Aircraft Company indicates the Cessna 185 can be provided with this capability. It appears that either airplane would be suitable for parachute jumping and aerial delivery of internally trans- ported loads. b. The 12-volt electrical systems of these airplanes would create additional supply and maintenance problems should they be procured for Army use. c. The data reported herein for the L-28A and Cessna 185 was obtained at the maximum gross weight of each airplane. Under these conditions, the Cessna 185 carried approximately 500 pounds more payload and 145 pounds more fuel than the L-28A. Following is comparative landing and takeoff distance for these two airplanes under the same useful load conditions, i.e., crew of two, full oil, 360 pounds of fuel (60 gallons) and a payload of 100 pounds. The data for the L-28A 9 r~j: ppigAL UU eWI ATBG-SEC AVN 663 SUBJECT: Informal Evaluation of the Cessna Model 185 and L-28A (Helio Courier Model 395) Airplanes was taken from the Fairchild Flight Analyzer. The data for the Cessna 185 is estimated for the same climatic conditions and pilot techniques, and using Cessna chart data corrected to conditions existing at Fort Rucker: L-28A Cessna 185 LANDING Over 50-foot barrier (ft.) 611 840 Ground run (ft.) 160 280 TAKEOFF Over 50-foot barrier (ft.) 686 855 Ground run (ft.) 355 510 6. CONCLUSIONS. It is concluded that: a. Neither the Cessna 185 nor the Helio L-28A is suitable as a replacement for observation and utility airplanes in the Army inventory; therefore they do not warrant further consideration for Army tactical use. b. The Cessna 185 could be used as a utility airplane for special missions where payload, range, and endurance demand primary consideration and takeoff and landing performance is a secondary con- sideration. c. The Helio L-28A could be used as a utility airplane for special missions where takeoff and landing performance demand primary consideration and payload, range, and endurance are secondary con- siderations. II md JO N L. ROWAN as Lt olonel, Artillery Acting President 13 "R-- I AL ft U. ,ONLY hid I ssNA 185 - eDR fftC=tTVSE ON LY IY C' CIO I 2 HELlO L-28A -R OFFIA1JUSE7ONLY Inci 3 CESSNA 185 --OR-fFfltAL--UYSE -ONtY- I 4 BELIO Lo-28k FOR OFFICIAL USE --NLY TAKE-OFFS & LANDINGS Average climatic conditions for the following were: Density Altitude - 1900 feet Temperature - 83 0 F Headwind Component - 2 knots TAKE-OFFS GROUND ROLL TOTAL OVER 50 FEET L-Z8A 355 686 Cessna 185 730 1115 L-19E 472 800 L-ZOA 608 896 LANDINGS L-28A 160 611 Cessna 185 389 959 L-19E Z88 100Z L-ZOA 434 1081 NOTE 1: The data presented above is an average of three take-offs and landings for each airplane obtained by use of a Fairchild Flight Analyzer. NOTE 2: All four airplanes were at their respective gross weights. C45_ ~ 04 "Wpm -It! -- il 0 I H 1w co no 64 7J-Wftr, Ind 6 ^fn ^ e I--%orl N wl I QUICK REFERENCE DATA CHART MODEL & TITLE: Cessna Model 185, Skywagon TYPE: Utility airplane CONFIGURATION: High Wing, single engine monoplane DESCRIPTION: The Cessna Model 185 is a high Wing monoplane of all- metal construction. It is powered by a Continental I0-470-F engine of 260 horsepower and a constant-speed Hartzell propeller. Maxi- mum seating is six place with alternate arrangements for cargo loads. A fiberglas cargo pack is available which attaches to the bottom of the fuselage for additional cargo carrying capability. DATA: 500 Gross Weight: 3200 pounds Empty Weight: 1625 pounds Radius 400 - of Useful Load: 1575 pounds Action 300 NM. Cruise Speed: 130 K @ 70% power P.A. = 1300 ft 200 - -, Max Speed: 149 knots 100 Cruise Fuel 13. 2 gallons (79. 2 Consumption: pounds) per hour 0 - 800 1000 1200 1400 Cruise Range: 800 nn Payload- Lbs. Fuel Capacity 100/130 84 gallons alt 115/145): (504 pounds) *,"Takeoff Distance Over 50 Feet: 1115 feet *Landing Distance Over 50 Feet: 959 feet *Measured under the following climatic conditions: Density Altitude Temperature Headwind Component 1900 feet 830 F. 2 knots ,. J QUICK REFERENCE DATA CHART MODEL & TITLE: Helio Courier Model 395, Super Courier TYPE: STOL Utility Airplane CONFIGURATION: High wing single engine DESCRIPTION: The Helio Model 395, designated the L-28A by USAF, Is a fully cantilevered highwing monoplane of all-metal construc- tion with the exception of the short span ailerons which are fabric covered. It is powered by a Lycoming GO-480-GlD6 engine rated at 295 horsepower and a three bladed constant speed Hartzell Pro- peller. Passenger accommodations are made for five with alter- nate arrangements for interior cargo provisions. DATA: 250 Gross Weight: 3,000 pounds 2 Empty Weight: 2,173 pounds 200 Useful Load: 827 pounds Radius 150 of Cruise Speed Action @ 1,300 ft hp: 122 knots NM. 100 A Max Speed: 153 knots 50 50\ Cruise Fuel Consumption: 15 gallons (90 0 - pounds) per hour ZOO 300 400 500 600 700 Fuel Capacity 100/130 60 gallons Payload - Lbs. Alt 115/145: (360 pounds) Cruise Range: 470 N. M. *Takeoff Distance over 50 Feet: 686 feet *Landing Distance over 50 Feet: 611 feet *Obtained under the following climatic conditions: Density Altitude Temperature Headwind Component 1,900 feet 830F. 2 knots ,q) " - it."., QUICK REFERENCE DATA CHART MODEL & TITLE: deHavilland L-ZOA "Beaver" TYPE: Utility CONFIGURATION: High wing monoplane DESCRIPTION: The L-ZOA utility airplane is an all-metal high wing monoplane powered by a single Pratt & Whitney Wasp Junior engine, driving a Hamilton-Standard constant-speed propeller. The airplane is designed to carry a pilot and five passengers. It utilizes a non-retractable landing gear which may be modified to accept a twin float installation for operation from water, or a ski installation for operations from snow and ice. DATA: Gross Weight: 5100 pounds Empty Weight: 3252 pounds 400 Useful Load: 1848 pounds Radius - Cruise Speed @ S. L. 109 knots of 300 Action Max Speed: 134 knots N.M. 200 Cruise Fuel 21 gallons (126 Consumption: pounds) per hour 100 - Fuel Capacity: 138 gallons 0 80/87 (Alt 91/96) (88 pounds) 600 1000 1400 1800 Cruise Range: 724 NM Payload - Lbs. " Takeoff Distance over 50 feet: 896 feet " Landing Distance over 50 feet: 1081 feet " Obtained under the following climatic conditions: Density Altitide Temperature Headwind Component 1900 feet 83 F. 2 knots COMMENTS: The L-20A (Beaver) has been a standard Army utility air- plane for approximately 12 years. The airplane has performed well in the combat environment to include courier service, messenger service, light cargo transport, light supply dropping and bombing, paratroop dropping, casualty evacuation, reconnaissance, photo- graphic missions, radio relay and column control, wire laying, and aerial observation. EP ICIAL UUV IMLY., QUICK REFERENCE DATA CHART MODEL & TITLE: Cessna L-19E, Bird Dog TYPE: Liaison Airplane CONFIGURATION: High wing, single engine monoplane DESCRIPTION: The Cessna L-19( ) is a high wing monoplane of all metal construction. It is powered by a Continental 0-470-11 engine of 213 horsepower and McCauley fixed pitch propeller. Seating accommodations are provided for the pilot and one passenger. A small baggage stowage compartment is available behind the passen- ger/observer seat. DATA: Gross Weight: 2i65 pounds (for barrier operations) Empty Weight: 1612 pounds Radius 250 Useful Load: 553 pounds of Action 200 Cruise Speed: 87 knots NM. Max Speed: 116 knots 150 Cruise Fuel 7.9 gallons 100 Consumption: (47.4 pounds) per hour Cruise Range: 435 NM 50 Fuel Capacity: 42 gallons (Z52 pounds) 80/87 (Alt 90/96) 0 *Takeoff Distance over 50 feet: 800 feet 200 400 Payload- Lbs. *Landing Distance over 50 feet: 1002 feet *Measured under the following climatic conditions: Density Altitude Temperature Headwind component 1900 feet 830F. 2 knots COMMENTS: The Cessna L-19( ) airplane is currently in the Army inventory and has proven itself under combat conditions. This air- craft will eventually be replaced by the LOH when it becomes avail- able. :.gc- _:AL4 L_5ML--- ........ T ... ±'.-.". ........... ... .... -- --- - - -4:7 ..... .......... 14-, .. .. . .. _ 7. 7 .. . . .. . . . T ~ 7 . .... .. : 1800 -fODR--0FF0 1 4L- -USE--ONLY