[SkyKing]

Ernie,

I trust you have already acquired "The Bibles' for your particular airplane, i.e., the Cessna Service & Parts Manuals for this 1973 "G" model!

Now, your 1973 normally aspirated "G" model Service Manual may have different numbered sections than the one for the P-model series (1973-1980), but in our P-model's Section 5, "Landing Gear, Wheels, Brakes And Hydraulic System", you will find a "Troubleshooting " chart to go thru and eliminate each possible cause. Since the power pack is running but nothing is happening, yes, you could have a defective squat switch or the oleo is not extending all the way for it to properly close, but I'll just bet that's not the case as these are fairly trouble free.

If you'll recall earlier threads that GMAs went through on the gear, on the later power packs (1973 and later) you have TWO solenoid operated valves... the one next to the pilot's right leg is the DOOR Solenoid and the one next to the co-pilot's left leg is the GEAR Solenoid. You can check that the DOOR solenoid is operating properly when you turn on the master... you should hear a familiar 'clunk' as it energizes.

Now, in flight, if the power pack is running and under strain, and the doors are not opening... and you should be able to discern a difference in the sound of the air slipstream if they were opening... then it's possible you may have a door solenoid valve jammed or stuck in the 'DOOR CLOSE' position. Does yours have the later solenoids -- as recommended by Cessna for changeout --that have the removable tops so the plungers can be cleaned?

Now, if the doors are opening but no gear movement and the power pack is under strain, it could very well be that you have a gear solenoid valve jammed or stuck in the 'GEAR DOWN' position.

Finally, IF the doors open but the gear does not cycle, THEN you may indeed have a faulty squat switch or perhaps the nose strut is stiff and not extending all the way to close it, but I doubt this is the case.

Try this: Block the main wheels so it won't roll, jack the nose up using the jackpoint just aft of the nose gear wheel well area and jack the nose off the ground so that the nose wheel is not touching the ground... an inch should do. Then, with an external power source applied to the ground service plug receptacle to supply 28vdc (use a spare battery and a charger hooked in parallel), reach in through the pilot side window and move the gear handle into the up position. You should have power pack initiation, doors then opening and the nose gear should begin moving up. You can stop the process at anytime through the cycle by pulling the landing gear circuit breaker... be ready for that. Since the mains are on the ground with weight on the wheels, nothing should happen with them, and since you're not going to allow the cycle to continue, the power pack won't be placed under addtional strain.

Now, if when you move the gear handle to the up position and nothing happens, cycle the gear handle switch a couple of times to see if you can get it to initiate... and if you get the doors open but the powerpack starts straining and the nose gear doesn't start moving, reach in and pull the landing gear breaker for a moment so the powerpack stops operating, then engage the breaker again. By doing this a couple of times you're allowing the gear solenoid to get a zap of electrical current and if the gear solenoid is stuck, this might break it loose.

But... if you haven't cleaned the door or gear solenoids, and they most likely haven't been touched because most shops won't take the time to remove all the plastic around the lower pedestal, you really should check these first and make sure they're clean and without any dried 5605 fluid keeping the plungers from working properly.

Hope this helps. BTW, remember that landing gear systems from 1973 and on are completely different than the earlier variety.

SkyKing