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fujii
24th Sep 2016, 05:46
In the back of hangar where I keep my plane, there is a C150 which hasn't flown for years. Each time I push my plane back I had to manoeuvre the tail plane between a roof pillar and the vertical propeller of the Cessna. Today it occurred to me, turn the Cessna's prop horizontal. My plane went in easily. Why didn't I think of this ten years ago?

Ogre
24th Sep 2016, 07:17
Jujii

Welcome to the "D'oh" generation....

Some people (me included) seem to go through life not making any ripples, and will adapt to suit our surroundings. Sometimes our surroundings need to change to adapt to us!

SpringHeeledJack
24th Sep 2016, 09:30
Sometimes we adjust our behaviour to suit the surroundings, other times not, and in the OP's example the adjustment was a repetition of the initial internal decision. The job of prepping the plane took precedence over the invisible conundrum and so it went on until the eureka moment…. :-) By chance yesterday I was able to help a neighbour fix their gas hob saucepan plates that had for over 3 years 'not quite fitted' causing pots to slip whilst cooking. It turned out that the saucepan plates needed to be turned 90degrees and the problem was solved. Because most hobs/cookers have plates that go North/South as it were, both the neighbour and myself had never considered them going East-West….I only found out by finding the ID plate and seeing a promo film online!

As mr Ogre said, some people are of the 'tread lightly' type and there are others who do the opposite. You can tell a lot about someone in how they close a door ;-)

VP959
24th Sep 2016, 09:41
Worth remembering that a 2 blade wooden prop (not the case here) needs to be kept horizontal, anyway, so the internal moisture content is equalised and the prop stays in balance.

I was taught, very many years ago, to always leave 2 blade props parked horizontally, so for me, looking at one sat vertically would raise a red flag, anyway.

stevef
24th Sep 2016, 09:53
In hangars at least, it's second nature to leave two-blade props vertical or diagonal. Horizontally, they get in the way when working around the aircraft and secondly it #&8%@# hurts when you walk span-wise into a tip.

VP959
24th Sep 2016, 10:06
In hangars at least, it's second nature to leave two-blade props vertical or diagonal. Horizontally, they get in the way when working around the aircraft and secondly it #&8%@# hurts when you walk span-wise into a tip.
All I can say is that my aircraft always sat with it's two blade wooden prop horizontal in the hangar. It did have red blade tip covers to try and prevent hangar rash more than anything else. All the other 2 blade props were usually parked horizontally, for the same reason; wood props go out of balance if left vertical, or at an angle.

If someone had turned my prop and left it vertical, and if the damned thing went out of balance as a result, then I'd have been damned angry about it. I doubt it would have ever happened, though, as 90% of the other aeroplanes in the hangar had wood props, too, so everyone knew about the potential problem.

Pinky the pilot
24th Sep 2016, 10:47
If I remember correctly after all these years; when I was flying "Bongo Vans' (BN2's) in PNG years ago we were informed that it was Company Policy to have the blades in a vertical position when parked overnight.

The reasons given were;
(A) If during the wet season, the rain would not be able to collect in the hub but just run straight through.

(B) When you carried out the DI at 'O-dark Hundred' with the usual massive Hangover you would not walk into the prop, and possibly damage it!:E

I have no idea re the validity of reason (A).:hmm:

As for reason (B); The CP who instructed us newbies to the Company was a non-drinker! Make of that what you will...:}

UniFoxOs
24th Sep 2016, 10:50
A normal 4-cylinder engine will usually stop in one of two positions, 180 degrees apart. Depending on the position of the prop relative to the pistons it will therefore tend to always end up in the same position. All the pictures I can see with a quick google (*) show the prop at "10 to 4" looking at the plane, so I guess one parked with the prop in a different position has been adjusted by the pilot/owner/engineer after stopping the engine.

* It's so long since I flew them that I couldn't remember

VP959
24th Sep 2016, 11:18
The wood prop thing is just about natural moisture in the wood and gravity. If you park a wood prop vertically, the moisture tends to migrate downwards over time, so the lower blade ends up slightly heavier than the upper blade.

It takes very little to throw a wood prop out of balance. I used to periodically balance mine by taking it off, hanging it on a prop balancer (basically a bit of string with a boss that fits the prop centre hole) and balance it by applying varnish to the tip of the lighter blade.

For those who've never flown behind a wood prop, and are only used to alloy or composite props all this chat about balance and leaving 2 blade props parked horizontally is probably irrelevant. It's only those of us who had to live with the foibles of these things that tend to be bothered by them. And yes, I did have to always turn the prop horizontal, as it would never stop naturally in that position.

chevvron
25th Sep 2016, 09:31
At Blackbushe, 3 Counties Aero Club policy was to leave props horizontal after a taxiing Cessna damaged its wingtip on one which was vertical.

DeltaV
25th Sep 2016, 12:05
The reasons given were;
(A) If during the wet season, the rain would not be able to collect in the hub but just run straight through.

I have no idea re the validity of reason (A).
My little aeroplane has a wooden, fixed pitch EVRA prop and EVRA state that their props should not be left horizontal. The reason given is to prevent water accumulating behind the metal leading edge protection on the down-pointing blade. Perhaps not really a problem if parked in a hangar but I do tend to just leave mine where it rests at about 5 past 7.

racedo
25th Sep 2016, 13:01
In the back of hangar where I keep my plane, there is a C150 which hasn't flown for years.

Course I would ask the obvious. WTF is the playing taking up valuable space ?

Jhieminga
25th Sep 2016, 19:09
And another question: was the engine on the 150 inhibited in any way? If it was, turning the prop may have scraped some of the inhibiting gunk off the cylinder walls.