Arresting Engine Components

Question 0

What is the CROV weight selector

Answer 0

Makes it possible to adjust theCROV for aircraft of different weights by varying the valve opening. Bigger aircrafts get a smaller opening smaller aircrafts get a bigger opening.

Question 1

What is CROV

Answer 1

The constant runout valve

Question 2

What is the deck edge control station

Answer 2

Can retract barricades, a control lever to raise or lower the barricade and push buttons to raise or lower retractable sheaves

Question 3

What is a retract valve

Answer 3

Permits the controlled return of fluid from the accumulator to the cylinder, thereby returning the engine to battery position

Question 4

What is the valve body

Answer 4

A hollow steel casting with an Inlet port that is connected by pipping to the engine accumulator, a discharge port that is flanged and bolted to the engine cylinder outlet elbow

Question 5

What is the valve seat

Answer 5

Four vertical elongated holes are machined in the seat to allow fluid To enter the valve from the accumulator

Question 6

What is the valve stem

Answer 6

The valve stem is a round piece of machined steel with a shoulder machined midway between the top and bottom. This shoulder mates with valve seat and blocks fluid through the retract valves during arrestment and from the accumulator to the engine cylinder untile retraction is desired.

Question 7

What is the valve plunger

Answer 7

A round piece of machined steel that is blind bored at one end to receive the shank of the valve stem. Helps to shut off flow of fluid from the cylinder to the accumulator to bring craft to a stop.

Question 8

What is the valve retracting lever

Answer 8

Located at the deckage control station, provides a remote means of opening the retracting valve from a location where the operator will have full visibility of recovery options .

Question 9

Talk about the accumulator system

Answer 9

…Contains a FLUID LEVEL INDICATOR a device used to indicate to the engine room operator whether the system has the proper ammount of fluid. The fluid indicator registers the following three conditions DRAIN ( excess ammt of fluid in system) BATTERY ( proper ammt of fluid in system) and FILL ( insufficient ammt of fluid in system).
The engine cross head must always be in it’s battery position when the fluid level of the arresting engine is checked

Question 10

Talk about the fluid replenishment system

Answer 10

Consist of a 6 gallon stowage tank and hand pump. Used to compensate for leakage and expansion or contraction of the hydraulic fluid in the hydraulic system of the MK7 arresting engines.

If the engine cross head is in battery and the fluid level indicator reads fill, the supply valve is opened and the hand pump is operated untile the indicator reads battery.

If indicator reads drain, the return valve is opened and fluid from the accu drains into the replenishment tank. When indicator reads battery, the return valve is closed.

If overfill exceeds tank capacity 6 gal fluid transfer to a 700 gal engine fluid stowage tank is required.

Question 11

Talk about the fluid stowage system

Answer 11

A fluid stowage system is provided to stow fluid from the arresting engine during maintenance and to transfer fluid back to the engine after maintenance is complete. Has one common stowage tank (700 gal) that serves all the arresting engines installed on a ship

Question 12

Normal vs emergency recovery

Answer 12

Normal involves the recovery of air craft at the prescribed speed with no equipment failure or damage. An emergency is done in the same manner as a normal except a barricade webbing assembly transmits the aircraft a landing force to the purchase cables instead of a cross deck pendant.

Question 13

What is a cross deck pendant

Answer 13

A wire rope which spans the flight deck in the landing area. The force of the forward motion of the aircraft is transferred to the purchase cables that are reeved around a movable cross head of sheaves and a fixed sheave assemble of the arresting engine. Minimum breaking strength is 205,000 pounds .

CDPs are protected against salt water by applying prelube 6

Question 14

What is the fluid reclamation system

Answer 14

Provides a means of reclaiming hydraulic fluid removed from any engine due to venting or through leaks or spills. Has a 90 gallon reclamation. Tank located close to fluid stowage tank.

Question 15

Talk about the fluid cooler

Answer 15

To maintain extended pendant engine operation the fluid temperature is reduced by a fluid cooler. The maximum operating temperature for the arresting engines is 170 degree Fahrenheit. Prolonged operation at this temp limit is not recommended.

Engine fluid as it is returned from the accumulator to the main engine cylinder during retraction of the engine, flows through the fluid cooler body.

Question 16

Cross head and fixed sheave assembly.

Answer 16

Uses a block and tackle assembly. The purchase cables are reeves around the sheaves of the cross head and fixed sheave assemblies. All the sheaves in the cross head and the fixed sheave installation rotate on roller bearings. The cross head is provided with slipper liners as a bearing surface between cross head and cross head tracks.

The fixed sheave assembly is identical to the cross head except does not require liners

Question 17

Cable anchor damper

Answer 17

Used to eliminate excessive purchase cable slack between the cross head and fixed sheave assembly at the begin inning of the arrestment stroke.

Damper removes excess slack thereby eliminating vibration of the purchase cable and engine. Only used in pendant engines only.

Question 18

Sheave damper

Answer 18

Acts as a shock absorber to ease cable tension and lessen cable vibration.

The accumulator acts as a fluid stowage tank and has a high pressure air connection. The accumulator is charged to 750 psi and must have a reading of 2 (+1) inches of fluid on the fluid sight indicator when the sheave damper is in the battery position.

Question 19

Talk about the drive system

Answer 19

Provides a means of transferring energy from the arresting aircraft to the arresting engine components that provide a means of disseminating and absorbing that energy. The drive system consist of a sheave damper, purchase cable, fair lead and deck sheaves, cross deck pendants and wore support.

Question 20

Talk about retraction

Answer 20

Retraction to the sheave damper is automatic and happens when accumulator pressure becomes greater than cable tension. Retraction normally happens prior to full runout of the aircraft. The pressure buildup in the accumulator forces the fluid from the accumulator to the damper cylinder forcing the damper piston back to it’s batter position.

Question 21

Purchase cables

Answer 21

Wire rope reeved onto the arresting engine.Transmits the force of the landing craft to the arresting engine. All wire has a breaking strength of 215,000 pounds

Question 22

Fair lead sheaves

Answer 22

Used to accommodate 1 7/16 inch diameter purchase cable. Has three races, an Inner race, bearing race, other race. Contains a base and cover that retaines the sheave assembly .

Question 23

Retractable sheave

Answer 23

To provide a means of lowering deck sheaves that would interfere with the passage of aircraft and deck equipment when in the raised operating position. Operated by an electric motor unit Controlled by a deck edge push button station.

Question 24

Thru deck sheave

Answer 24

Mounted vertically and it guides the purchase cable between the sheave damper and the retractable sheave installation.

Question 25

Wire supports

Answer 25

Provide a method of raising the cross deck pendant off the flight deck to ensure arresting tail hook engagement of the incoming aircraft.

2inxhes minimum 51/2 inch maximum

Question 26

Impact pads

Answer 26

Upon initial arrestment of an aircraft, the terminal will impact on the pads instead of the steel deck, minimiZing damage to the firings, purchase cable, and cross deck pendants.

Question 27

Cushioning piston

Answer 27

Cushioning piston in the cable anchor is to prevent the operating piston from slamming Into the opposite end of the cable anchor damper assembly if the purchase cable should break or in the event of an extreme off-center landing.