DETAILED DESCRIPTION

CERTIFICATION BASIS

The Gavilán 358 was designed to comply with the airworthiness requirements of the Federal Aviation Agency of the USA contained in Parts 23 (amendment 46) and 36 ( amendment 20) . There are few aircraft that meet these regulations given the fact that they were certified when the regulations were much less strict.

FUSELAGE

The structure of the fuselage is a truss made up of 4130 steel tubes. The attachments for the landing gear, wings and tail form an integral part of this structure. This means that the fuselage is very rugged and is well adapted for operations from rough runways. This method of construction is also very easy to repair.

The firewall is made from stainless steel and protects the cockpit from fire.

The fuselage is covered in aluminum 2024-T3 sheet and the thickness of the skins varies from 0.025" to 0.032". This skin is not part of the structure of the fuselage.

The windshield and windows are made from flat sheets of plexiglass. This means that they are inexpensive to replace.

The pilot and the front passenger each have a door. There is a large double cargo door on the left side of the fuselage through which the aft passengers and cargo are loaded. This door permits the loading of awkward items such as stretchers, drums and construction material. It is possible to carry a standard sheet of plywood (4x8 feet) flat on the floor.

CABIN

One of the main design objectives of the Gavilán 358 was to design a cabin that was well adapted to the needs of operators of utility aircraft. The rectangular shape of the cabin comes from the assumption that the best way to carry a box is inside another box, and this gives the Gavilán 358 its particular shape. The walls of the cabin are parallel and the floor is flat through- out the length of the cabin. 

PASSENGER AND CARGO COMPARTMENTS

The aircraft was designed for 8 people. The pilot and the front passenger have seats that are adjustable horizontally and vertically and that resist up to 26 g, complying with the latest requirements of FAR 23. Both have four point harnesses with inertia reels.

The rear passengers are seated in two rows of three seats. These rows face each other and the seats can withstand 21 g. 

The seats are mounted on brownline tracks that are the standard in commercial aviation.

The seats can be quickly removed so that the Gavilán 358 can be used for cargo. The brownline tracks can be used to fasten cargo down with a net and anchors which are offered as optional equipment.

The cabin of the Gavilán 358 lends itself to being used in an air ambulance version.

WINGS

The structure of the wings is formed by two spars that are made up from commercially available extrusions and ribs. It is covered with 2024-T3 aluminum skin riveted to the spars and ribs.

Each wing is supported by an external strut.

The airfoil is a NACA 4412. This section is characterized by having a smooth peak in the lift coefficient and a wide drag bucket. The aspect ratio is 8. This implies that the Gavilán 358has very docile handling qualities and has low induced drag during climb and descent, which contributes to the efficiency of the aircraft.

The wings are also made from aluminum and are of the single slotted 2-h type as per the definition of Abbot and Doenhoff.

Like the flaps, the ailerons are made out of aluminum and are attached to the aft spar of thewing with piano hinges. They have differential deflection to counteract the effects of adverse yaw.

The wings have 2.5º of twist permitting positive control of roll with ailerons right up to the point where the aircraft stalls.

TAIL GROUP

The Gavilán 358 has a traditional empennage located on the aft part of the aircraft. Even in the design of the tail aesthetics gave way to functional considerations, hence its rectangular shape.

The horizontal stabilizers are fixed and are interchangeable, left and right.

The elevators are interconnected through a torsion tube. The right elevator has a trim tab.

The elevators have aerodynamic balancing and counter weights.

The fin is fixed and the rudder has aerodynamic balancing and counter weights.

All the structure of the tail surfaces is made out of aluminum.

LANDING GEAR AND BRAKES

The landing gear is fixed.

The main landing gear is made out of 4130 steel tubes and each is attached to the fuselage at two points. Shock absorption is through tendons that are in tension and react against a stack of k-prene elastomers of low coefficient of restitution. This method of shock absorption is very simple as it does not require gas or oil chambers, is very robust and requires minimum maintenance.

The tires on the main gear are 7.00x6 and have disc brakes. The brakes on each side are independent and the brakes are actuated by the pilot pressing on the corresponding pedal. The reservoir for hydraulic liquid is located on the firewall.

The nose landing gear is attached to the engine mount. It is of the trailing link type which means that both vertical and drag loads react against the shock absorber. This permits the nose gear to ride over obstacles without submitting the structure of the aircraft to high stresses. By these means, the Gavilán 358 overcomes one of the main drawbacks of the operation of tricycle geared aircraft from rough runways.

Asin the case of the main gear, the nose gear uses k-prene shock absorbers, and in addition has a simple automotive shock absorber.Nose Gear

The nose gear is free to swivel through 360º. The pilot steers the aircraft on the ground using differential steering permitting him to maneuver it with ease.

ENGINE MOUNT

The structure of the mount is made of 4130 steel tubes with a dynafocal system designed to absorb vibration. The engine is attached to the mount through LORD type mounts that also help keep vibration down.

PROPELLER

The propeller is made by Hartzell, has three aluminum blades, and a diameter of 84 inches. It is of the constant speed type and the change of the pitch is accomplished by oil pressure acting against a spring in order to maintain the pitch selected by the pilot.

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FUEL SYSTEM

The normal fuel system has a capacity of 104 US gallons, contained in six rubber cells, three in each wing. There is a filler on each wing.

Fuel drains are located on two sump tanks located under the floor, and each sump tank holds about 1 gallon.

Fuel flows from the tanks to the sumps and from there it goes to a selector valve located in the center of the cockpit. This valve has four positions: Closed, Left, Right and Both. It is not possible for fuel to flow from one tank to the other as the system has check valves to keep this from happening.

The ventilation of the tanks is interconnected to ensure that consumption from each tank is the same when the Both position is selected by the pilot.

The ventilation system has lightning arrestors and the fuel caps are of the lightning proof non-siphoning type, bringing the system in line with the latest regulations of FAR 23.

For shipping, the complete aircraft will fit into a 40 foot shipping container. 

DETAILED SPECIFICATIONS

POWERPLANT

Manufacturer:Textron Lycoming

Model:TIO-540W2A

Type:Piston Turbocharged

Power (hp):350

R.P.M. at maximum power:2500

Number of cylinders:6

Manifold pressure at maximum power (ins):52

Recommended time between overhaul (hours):2000

PROPELLER

ManufacturerHartzell

Number of blades3

TypeConstant speed

Diameter (in/mts)80/2.03

OPERATING WEIGHTS

(pounds/kilograms)

Maximum take-off:4500/2,041

Maximum landing:4500/2,041

Standard empty:2800/1,270

Useful load:1700 /770

Weight/Power ratio (lb/hp):12.9

PASSENGERS:

7 + Pilot

DIMENSIONS:

Wing span (ft/mts):42 /12.80

Wing area (ft2/mts2):206.7 /19.25

Length (ft/mts):30 /9.14

Height (ft/mts):11.2/3.41

Horizontal stabilizer: (ft2/mts2)54/5.02

Wing loading (lb/ft2/kg/m2):21.8 /106.7

Wheel track (ft/mts):11/2.40

Cargo compartment capacity (volume-load)

(ft3-lbs/m3-kg)17-200/0.5-90

FUEL CAPACITY – 100LL TYPE FUEL

(gallons/liters):104/400

OIL CAPACITY

(gallons/liters):3/11.35

AERODYNAMIC DATA

Airfoil wingNACA: 4412

Airfoil tailNACA: 0012

1PERFORMANCE

DESIGN SPEED

(kts/kph-CAS)

Design cruise: 145/268

Maneuver:135/250

Dive:180/333

Maximum flap extended:105/195

OPERATING SPEEDS

(kts/kph-CAS)

Stall speed flaps: 0º65/128

Stall speed flaps: 40º58/107

Best climb:83/154

Best angle:74/137

CRUISE SPEED

(kts/kph-CAS)

At 10,000 ft

75% Power: 130/241

65% Power: 128/237

55% Power: 123/228

CLIMB RATE

(ft/min / mts/min): 800/244

RANGE

(Nautical miles/km)

With 30 min reserve

75% Power:712/1320

65% Power: 720/1334

55% Power: 738/1368

OPERATING DISTANCES AND ALTITUDES

(ft/mts)

Take-off run with 15º flaps:1119/341

Take-off distance over 50 ft obstacle:1790/546

Landing distance over 50 ft obstacle:1640/500

Landing run: 801/244

Service ceiling

-without high altitude kit:12500/3810