Aeroplane moving - Airmanship

[18greens]

Just to jump on the back of Fireflybobs post about engine starting.

What about the way people move aeroplanes.

I often see planes being pushed/pulled by the propellor and often see 152s being spun around by pressing down on the tail.

Are these considered acceptable ways of moving planes and am I being overcautious.

My instructor always taught me to treat the propellor as if it is moving (ie never walk through its arc and never put your hand near it in case one of the mag earths had failed). I also read a note about cessnas being overstressed by pressing down on the tail.

What do we think?

[tonker]

When i worked at Kemble they not only had tow bars you attach to the nose wheel, but also an electric car for towing the aircraft around and out of the hanger.

This was not only a good labour saving device but better for the aircraft, and was really good fun to tear about the apron honking the horn at one thing or another.

Nonetheless i'm sure one day in the country that invented so much, all flying schools might one day own a towing bar all of their own!!!!!

It's always find it quite funny when people deridingly say that flying in the US isn't anything like flying here, yep it sure aint.

[Oktas8]

You might be better asking an engineer whether you're allowed to move a particular aircraft type by pulling/pushing on the propeller. AFAIK, moving a light aircraft with fixed pitch propeller in this manner isn't going to hurt anything, but one has to be more cautious with variable pitch propellers. (Naturally you have to have your hands close to the hub, not mid-span.)

Do I check the mags are off, prevent the propeller from rotating unless I'm ready for it to "kick over", and take care not to get under the propeller whilst putting my weight on it? Well, yes... :hmm:

One can lift the nosewheel of an Aerobat off the ground by pushing on the junction of the tailplane spar and inner rib with one hand, and an aft fuselage bulkhead with the other - you find them by looking where the rivets are. Other Cessnas? I don't think so, but am ready to be corrected. (I got this information from a manual, but can't remember which one, sorry.)

cheers,
O8

[rupetime]

ITs the propeller that pulls the aircraft along in the air so why cant it be used to pull it along on the ground, apart from the obvious earthing issue

rt

[Oktas8]

why cant it be used to pull it along on the ground

1) Because of the "do not push / pull on propeller" sticker the manufacturer put on the propeller.

2) Possibly (speculation alert!) because air loads are distributed along the blades evenly, while the crankshaft is rotating smoothly inside its bearings. Ground push/pull loads are quite different, especially if not applied quite correctly.

O8

[fireflybob]

A/c should be moved with a suitable towbar etc but trouble is they tend to go AWOL!

I teach never ever to touch the propeller or walk through the arc. In the days when it was common to teach prop swinging pilots were much more propeller aware. I was walking through the hangar at my local airfield a while ago and was horrified to see an aircraft owner pulling the prop through in the hangar.

When you turn a magneto off you are making a circuit by earthing the mag to the engine. This is inherently NOT "fail-safe" - if the circuit is broken or there is a malfunction in the key a mag will be live - yet another reason to always treat props as live. I speak as one who many years ago pulled a prop through on a walk round only for the engine to fire because yours trully had assumed the mags were off - luckily I lived to tell the tale!!

[homeguard]

Aircraft should always be moved using the towbar! They are easy to get made by a local metalworker, cheaply. We have a dedicated towbar for each of the aeroplanes that we operate.

Cracks to tail planes have been reported owing to people sitting on it in order to swing the aircraft around.

[hugh flung_dung]

Our spanner wielders tell me that, from an engineering viewpoint:
pulling/pushing on a fixed pitch prop is acceptable providing it's done only at the root
pulling/pushing on a C/S prop is NOT acceptable because it kna^&ers the bearings. Apparently the centripetal force when the prop is spinning tends to make the bearings much more "solid" and they can then accept the thrust loadings (and the nasty things that aeros do to them), this is not the case when stationary
it is acceptable to lift the nose by pushing down on the rear fuselage, providing it is done over a frame
it is NOT acceptable to push down on the tailplane

Your Spanners May Vary:D

HFD

[shortstripper]

I agree with HFD's engineers ....

No problem if very aware,
Towbars don't fit taildraggers very well ... well not for pulling forwards anyway.

That said ... I prefer to have two people, with one on each wing tip as I find trying to pull by the prop puts me at an angle to slip up easily anyway.

Anybody with a bit of mechanical/engineering sympathy instinctively knows what and where you can push/pull. Common sense really ... or is there really non of that left these days?

SS