For something different here are some pictures of a plane undergoing a maintenance check of it's retractable landing gear. This is a Cessna model 172RG with the RG obviously standing for retractable gear (a duh moment here). Being a high wing, and with the jack points on the wings, tall jacks are needed. Since the plane balances tail heavy when on jacks a stand is used to prop up the tail. I had put sandbags on the tail and stand just to add stability. Observant members may note that the twin engine plane in the background, a Piper Seneca, is also up on jacks but since this plane becomes nose heavy, a weight is placed on the tail. A truss assembly that the Seneca nose gear mounts to had broken and had to be removed for repair. Airplanes do two things: they fly and they break, but I digress.

The first two pictures show the jacks positioned under the wings. Believe it or not the jacks will not raise the plane high enough so wood blocks are placed under them for additional height, as shown in picture three. Observant members may note that the plane has been jacked up slightly in three. This is so someone, like myself, could conveniently get under the plane and lube the gear.

 

interesting! Thanks for sharing

 

I'm not sure how to add commentary to additional pictures in one post so I'm writing multiple posts.

The next two pictures are of the plane jacked up as high as possible. There is a reason why the plane must be this high - just look at my next post.

 

When the gear retracts on a 172RG, it swings down this far as shown in the pictures. As one can see, there is only a couple of inches of clearance at best between the wheels and the floor. That is why the jacks need to be blocked up. This system is common on Cessna high wings airplanes such as the 182RG and 210. They all look like birds with broken legs when in flight and retracting their gear.

The gear is retracted, and extended, hydraulically. The hydraulic pump is driven by an electric motor. What I did here was to start retracting the gear till the main gear "broke" free of it's down position. I then pulled the circuit breaker to the electric motor to stop the gear retraction. At this point I swing the gear myself to confirm that the gear will clear the shop floor. If the plane was not high enough, and the gear retraction was not interrupted, the plane could be knocked off the jacks. Ouch! Since the nose gear is lighter it begins to retract before the main gear does.

 

Sonoronos, you broke up the flow of my posts! Ugh!

Anyway, the next two pictures show the gear completely retracted. Earlier Cessna planes had gear doors to fully enclose the main gear like the nose gear. But these doors were maintenance nightmares so Cessna eliminated them on later models. Even Cessna can get something right occasionally.

We try to get the planes off the jacks as soon as possible because you never know when the big one will hit. Even a moderate earthquake could possibly knock a plane down. Then again, *that* would make for a great picture!

 

While the plane is jacked up the emergency extension system is tested. When the gear control lever is place in the DOWN position the gear breaks free and the hydraulic system rotates the gear to their extended position. If there is a problem with the electric motor a hand pump can be used to extend the gear. Note that the hydraulic system is used by both the electric motor and the hand pump. So if there is a problem with the hydraulic system, not the motor, what does one do? Well, one merely uses a cane or other suitable appendage to hook the main gear strut and pull it to the extended position. Oddly enough, instead of opening a door in flight and attempting to wrestle the gear down, all the while trying to fly the plane, most pilots elect to belly in.

The first picture is of the handle to the hand pump. The handle telescopes and has been pulled out and up for the picture. It is normally stowed collapsed and flush to the floor. Note that the seats have been removed for inspection under the cabin floor. Also note the tuna fish can used to hold hardware, etc.

I included the last three pictures just to keep the first one company. An intrepid individual spent a good part of Sunday waxing this fixed geared Cessna 172. This same intrepid individual will for now on pay someone else to spend a good chunk of their Sunday waxing said plane. I deliberately upped the exposure on the one picture to better see the shine and that's why the outside view is blown out. Mike-in-Orange will be pleased to learn that Meguiar's QuickWax was used and a fine job it did.

Hey! How did that Crossfire get into the pictures? I don't know about the rest of the forum members but I think that a Crossfire and an airplane makes for a lovely couple.