Chapter 61. Propeller

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CHAPTER 61 PAGE 1 PAGE DATE: 4. June 2009

Chapter 61 Propeller

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GENERAL

The EXTRA 300L can be equipped with either a MTV-9-B-C/ C 200-15 (3-blade), MTV-14-B-C/C 190-17 (4-blade) or MTV-9-B-C/C 198-25 (3-blade) propeller. Maintenance work or overhaul of the propeller requires consultation of the propeller manufacturer MT-Propeller.

Proper control,operation and maintenance of the propeller is described in the Operation- and Installation Overhaul Manual E-124 of the manufacturer.

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PROPELLER

The MTV-Propellers are made of laminated wood encased in glass-fiber reinforced plastic, which is painted to make it waterproof.

N O T E For more information about the propeller refer to MT-Propeller Operation- and Installation Manual E-124.

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CONTROLLING

The pitch change is conducted by a propeller governor (refer to Figure 1). Once an engine rotational speed is selected it will be held constant at variations of airspeed and power. The governor itself is actuated via a vernier control cable ending on the left side of the rear cockpit. This cable is routed on the left side of the fuselage, penetrates the firewall, the rear air baffles and is then routed to the governor. The cable is attached to the fuselage by a clamp block at its front end and by self-clinching plastic straps in the cockpit area. The clamp block serves also as a means for rigging. The fire wall and air baffle penetration is covered with clamp sheets. The firewall penetration is additionally sealed with PRC-812 (Products Research & Chemical Corp., USA) firewall sealant.

Mechanical stops for low pitch and high pich limit the pitch change level. In case of the oil pressure of the govenor to be lost, the blades automatically return to high pitch, if the counterweights are installed. The oil pressure is single acting.

Figure 1, Controlling

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Governor

One of the following governors is installed:

MT-Propeller P-880-5, preset for a max. 2700 rpm MT-Propeller P-880-41, preset for a max. 2600 rpm Refer to the MT-Propeller Operation- and Installation Manual E-1048 for further information.

NOTE The lever position of the governor actuator is preset.

Do not change this position.

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RPM Vernier Control Cable

Removal

1 Ensure master switch is off.

2 Remove engine upper cowling per Chapter 71.

3 Remove main and bottom fuselage cover per Chapter 53.

4 Remove cotter pin, castle nut, washers and bolt from the rod end (1, Figure 2) to governor actuator (2) attachment.

5 Loosen counter nut and remove the rod end (1) from the vernier control cable (6).

6 Remove rod end counter nut and vernier control cable rubber parts (4).

7 Remove clamp block (5) attachment bolt.

8 Remove clamp block from the vernier control cable (6). 9 Remove clamp sheet attachment bolts on the rear air

baffle sheet and remove plastic grommets.

10 Remove clamp sheet attachment bolts on the firewall and remove plastic grommets.

11 Mark vernier control cable routing and remove the self-clinching plastic straps.

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12 Remove attachment nut (9) and washer of the vernier control unit (7).

13 Pull the vernier control unit aft (about 15 cm) and then inside the cockpit to remove.

14 Pull complete vernier control cable (6) aft to remove from aircraft. Secure clamp sheets.

Installation

Install in reverse sequence of removal observing the following items:

1 Thread the respective clamp sheets on the vernier control cable before penetrating the firewall and the rear air baffles.

2 Install rod end (1) with 8 rotations on the vernier control cable (6). Ensure thread is visible in the inspection hole. Apply inspection lacquer on the counter nut.

3 Renew the sealing of the bushing grooves and gaps at the engine side of the firewall. Use PRC-812 (Products Research & Chemical Corp., USA) firewall sealant. 5 Tighten the castle nut slightly. Ensure movability of lever.

Rigging

1 Bring vernier control knob (8, Figure 2) to the foremost position.

2 Check that the travel stop is reached, and if the gap between vernier control knob (8) and unit (7) is 5 mm (tolerance +/-1 mm).

3 If not, loosen clamp block attachment bolt and adjust the vernier control cable position in the clamp block (5).

4 Fasten clamp block attachment bolt. 5 Check full travel.

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b Loosen the counter nut and adjust rod end by turning. Ensure thread is visible in the inspection hole when fastening. Apply inspection lacquer on the counter nut. c Reinstall the rod end to the governor actuator (2).