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KCDW
25th Nov 2005, 14:17
Quick question: can you hand swing/start a "normal" plane which has electrics, alternator etc? For example, as an alternative should you not be able to start with the key.

Would the process be the same as if you were hand swinging a cub, say?

stiknruda
25th Nov 2005, 14:37
The short answer is yes - you can hand swing electic start aeroplanes.

The complete answer is rather more engine/type specific!

I have hand swung C152/172/182, various Pitts Specials and the largest displacement was a Beech V35B - Wonderboem back in the early '90s, hot and very tiring!.

If the engine has an impulse mag, ensure that ONLY that mag is selected when the chap in the aeroplane hears you call CONTACT. Generally this is the LEFT mag but some aeroplanes do have impulses on both sides.

On normal key-start aeroplanes (Lyc/Cont) when you turn the key to START, it mechanically grounds out the RIGHT mag therefore allowing the engine to start only on the impulse mag. When the key is released back to BOTH, the RIGHT mag is energised.

Tricycle geraed aircraft are generally easier to start as the propeller disc angle is more vertical and consequently the thrust line is closer to the ground, so no long reaches a la Tiger Moth.

Hope that this helps,

Stik

KCDW
25th Nov 2005, 15:04
Thank-you!

Running on from this then, say you have flooded the engine of your C172, presumably you could then blow back with 4 pulls in the other direction, call "contact" (checking only the left mag is on), then give the prop a swing?

Shaggy Sheep Driver
25th Nov 2005, 15:25
Vacuum pumps fitted to some flat engines can be damaged by turning the engine backwards.

I have hand-swung 172s and the like, but I prefer not to. Whereas something like a Tiger Moth or Chippy, with a long stroke engine, just needs gentle pull over compression for the prop to flick around, the typical flat engine (with the exception the little 65 horse Conti in a Cub which is a deligh to swing) needs a more sustained pull for longer and doesn't 'flick over'.

I have heard it's possible to hand-swing a Yak 52. Now that, having spent a long time simply pulling these engines through before flight, is something I would never do!

SSD

shortstripper
25th Nov 2005, 15:43
KCDW,

From your posts I'm guessing that you've never swung any prop before. If this is correct then do get somebody who has, to show you how to do it properly first. Not that there is anything particularly difficult about it ... but props can bite! and it's not simply a matter of "call "contact" (checking only the left mag is on), then give the prop a swing I'm sure you probably know that, but it seemed worth mentioning.

SS

KCDW
25th Nov 2005, 16:02
Trainee Prop Swinger actually :} And fully respectful of them...

I was a bit glib with that description I know.

Thanks for caring though SS.

Brooklands
25th Nov 2005, 16:22
Its surprising how big an engine can be hand swung: I've seen the Shuttleworth Colletion's Bristol Fighter hand swung in the past, admittedly it did take three people !

Brooklands

Tinstaafl
25th Nov 2005, 18:02
We handswung a C402 once while ferrying the bucket of bolts for maintenance. Lucky me: I was the pilot for the flight so got to do the cockpit bit while the big, burly engineer did the hard work...

aerobatic_dude
25th Nov 2005, 18:04
Saw a 210 being handswung. Must say the guy was pretty wrecked after it.

hugh flung_dung
25th Nov 2005, 19:47
I used to regularly hand-swing a non-electric vagabond with a 65HP lycoming (I think) without problems. VWs are not too bad either. I once swung a Long-Eze (Lyc O-235) and ended-up with 2 broken fingers because the bod in the seat selected Both mags :{

HFD

Formally Known As
25th Nov 2005, 19:54
I have witnessed a 600 hp (R-1340) radial hand swung, by one man. Easy when the engine is cold. Almost impossible when warm.

When the first "pot ignites" there is ample time to get out of the way, before the second blade arrives.

soay
25th Nov 2005, 19:57
Starting the engine this way will not of course make the alternator charge a flat battery, so none of the electrics would work.

foxmoth
25th Nov 2005, 20:01
Starting the engine this way will not of course make the alternator charge a flat battery, so none of the electrics would work.

not if the battery is actually flat, but if it is just too low to turn over the engine then you should get the battery charging after start.

DubTrub
25th Nov 2005, 22:10
...and 3-blade props are interesting (watch the fingers)...4- blade props are a NO-NO!

fernytickles
26th Nov 2005, 03:49
Have watched one of the Aeroshell T-6 team members hand prop one of their aircraft. Rather him than me!

Say again s l o w l y
26th Nov 2005, 15:42
There are a number of reasons, first of all the alternator needs some power to it otherwise it won't produce any power itself, secondly a flat battery often won't actually take a charge, especially if the plates have been knackered.

Trying to charge a totally flat battery can wipe out the alternator as well, often the relays can get burnt out and you then have not only a flat battery, but a stuffed alternator also.

Basically if you need to hand swing a prop, have a think about why, if the battery is just low due to lack of use and it's a cold day, then hand swining may be an idea, BUT if the battery is actually dead, then at least try and recharge it with a trickle charger before going flying. If it is toast, then replace it, don't muck about with hand swinging just to get in the air.

This is especially true of turbine a/c that use battery starts. The lower the inital voltage, the higher the chances of a hot start and all the associated (expensive) problems. I've seen a couple of people damage £50k turbine sections because they've been too tight to put in a new £400 battery. Very stupid!

Make sure you always have a good battery, don't try to 'get away' with a duff one, it's a false economy.

ShyTorque
27th Nov 2005, 19:04
An alternator needs a field current to "excite" the field coils, before it can produce any charge. This needs to be provided by the battery and if it is completely flat, no current might be produced even though the alternator spins as normal. The charge / ignition light on an alternator equipped machine is a critical part of the system - if it doesn't light before start, there is a fault because it shows no "exciting" charge to the field coils - it's connected in series.

Conversely - starting, then flying, an aircraft with an almost flat Ni-Cad battery by other means might not be a good idea because IF the alternator DOES charge, it might cause the battery to overheat due to the very high rate of charge that will result.

Flik Roll
28th Nov 2005, 08:53
I was taught how to do it to a modern aeroplane...but I refuse! If it's got a start button I'm dam well gonna use it! I value my arms!

Always follow through with your arms:ok:

javelin
28th Nov 2005, 11:42
As my brother is rather old now and used to fly Shackletons for the Womens' Auxiliary Balloon Corps, he tells tales late at night over his Horlicks about sandbagging Shackletons down route. Not quite a hand swing but I would have liked to see it none the less.

Rod1
30th Nov 2005, 14:29
“If the battery is actually dead, then at least try and recharge it with a trickle charger before going flying. If it is toast, then replace it, don't muck about with hand swinging just to get in the air.”

This is an exact replica of a conversation I had with an instructor when trying to hand start a DR400/160, my other aircraft was a Nipper with no electrics. He was adamant I should not fly the DR400. I could not see the problem provided I kept the alternator turned off. The flight went very well!

Rod1

Say again s l o w l y
30th Nov 2005, 14:39
Well if you aren't actually going to use the electrics, that's a different story!

But if you are going to use lights, radios, pitot heat or Nav equipment, then having a serviceable battery is a pretty good idea.

In a Tipsy Nipper, it's a different type of flying, you can't use what you don't have, but in anything with a bit more kit, then I want to make sure it's going to work and continue to do so before I go anywhere.

Hairyplane
2nd Dec 2005, 08:31
I hand swung Will Curtiss's Sukhoi when he ran out of air last season. It went second go.

I have also hand swung an Aztec with flat battery.

2 of my old planes are 'handraulic' start

As long as you are careful and know what you are doing....

HP

Say again s l o w l y
2nd Dec 2005, 08:37
Will's a/c ran out of air? Surely he could have just talked at it?

Only joking...!

Onan the Clumsy
2nd Dec 2005, 17:58
I had to prop a 172 once. I wasn't very keep on the idea, especially as it was Winter, but I had to do it before the airport police showed up. I made sure I kept the old girl tied down while I did it though.


Biggest I've seen done was a 182 and I thought that was fairly large.

Pitts2112
4th Dec 2005, 08:06
Something else to consider depending on how you got to the handpropping decision. If the aircraft has a standard heavyweight starter (only type I have experience with) which has already engaged the starter ring for some reason, you'll have the devil's own job trying to hand prop with that dragging on it. It can be done but it is absolutely knackering. Ask John Tempest. Probably 20 blades it took to start my Pitts and I think he needed to have a lie down afterward!

Pitts2112