Mechanical installation to allow an aircraft to roll on the ground and prevent propellers hitting it. Only the very first aircraft used skids, usually "legs" with attached wheels are used.
In kits: Check for correct length of the legs!
All aircraft have/had a suspended landing gear to prevent damage to the aircraft and the pilot. As the landing gear is compressed by the weigth of the a/c its length is reduced. So if the kit part with wheel attached fits exactly into the wheel well it's fine if it is to rest there. If the aircraft is to rest on its legs, the leg has to be shortened. Otherwise the model appears too stalky and in "tailsitters" is pointing its nose upwards in too steep an angle.
This may seem trivial, but I've seen quite a few kits and models with too long landing gear legs. They don't look right.
Another point are flattended wheels. Some years ago a smart modeler came with the idea when the weight of the aircraft compresses oleo legs the rubber tires are flattened too. In principle he was correct. But what is not correct are the exaggerations commonly seen today. No pilot in sane mind would man a plane with half flat tires. If they wouldn't blow due to the drag inflicted, take off distance would be exessive. In a landing half full tires would be compressed to the hub ("screeeeech!").
Therefore exept types destined to operate on soft ground aircraft tires are high pressure, especially on carrier based aircraft. In reality the flat area is very small, outward bulging minimal (hardly to be seen).
By the way: Check the tires of your car (or others on the parking lot) and remember: Pressure in aircraft tires is much higher!
Conclusion: Forget bulging tires. Sanding off a tiny spot on wheels is quite sufficient.
For painting wheels se page W.
Navigation-, position- and warning lights usually seen on aircraft are made very easy for model aircraft. All you need is a candle or another appropriate flame and some clear sprue from the kit parts.
Scetch and description see separate page.
pattern continues lengthwise
Printed colours on fabric covering of German WW I aircraft. Regardless of the many colours used there were two different shades: Darker for upper sides, lighter for undersides. This pattern was printed lengthwise but again differing considerably, those used on fighters mostly being irregular while on bombers regular hexagonals were usual. Depending on the individual aircraft manufacturer or type the layers of cloth went chord- or spanwise, the most common use however being chordwise on wings and horizontal on fuselages.
This covering had three functions: First of all to provide a lifting surface. Secondly to reduce drag. And finally to protect the wooden parts of the inside from detoriating. As fabric soaks up water easily it had to get a protective covering too.
After the fabric covering was applied it got a first cover of shrinking dope. The severaly layers of clear varnish (the first one containing some shrinking dope too). In the outcome the fabric covering was taut like a drumskin and of high gloss.
As ailerons and rudders were covered separately, the pattern wasn't uniform. Also when combat damage had to be repaired.
The usual waves found in kits are pure concessions to detail freaks (not so speak of "textile structure" in 1/72!). The only noticeable protusions in fabric coverings were thin fabric strips sewn over the ribs of the aircraft (not generally common in WW I).
recommended website: http://www.theaerodrome.com/forum/articles.php?action=viewarticle&artid=8
"Ageing" of fabric covering: A fairy tale! As most WW I-motors were of the two stroke type the used motor oil went out of the exhaust stacks covering all parts behind. Somehow functioning as a sealant. Secondly an aircraft in these days didn't live long enough to get an aged appearance. Besides: Rotating radial engines never spilled black motor oil centered on the underside of the fuselage).
If the kit model shows sagging fabric between the ribs simply fill in with putty and sand after this has dried. In the outcome narrow protusions will show just as in the real thing (plastic normally is harder than putty).
Exaggerated ribbing can be cured by simulating the fabric strips usually covering the threads fixing the fabric to the ribs. Slightly inscribe position of the ribs, then sand all off; transparent adhesive foil is placed over the wing and narrow strips cut out where the ribs should be. Mix putty with liquid glue and spread it evenly into the recesses cut out before. Let dry thoroughly then remove foil. If necessary carefully sand edges of the protusions simulating ribs and covers.
Alternatively: New wings or rudders are easily made, see page "fabric covering".