Winding up old aircraft

Some old aircraft had a port in the cowling into which a ground crewman would insert a crank. After winding the crank, the engine could be started. What’s going on?
[ul][li]It’s cranking over the engine, like on a Model T? (If so, why doesn’t the prop spin?)[/li][li]It’s winding a spring that turns the motor over when the pilot releases a catch?[/li]It’s turning a dynamo that provides electrical power for a starter?[/ul]

At least two of the above, in my experience.

Pops Mercotan had an old Ryan PT-22 in the feckless days of youth, and the crank wound a spring when the catch was released.

He later got an old Fairchild PT-26, which cranked over the engine when I (being young and strong) was assigned to turn the crank. And the prop did turn as I turned the crank. Sometimes I’d get sick of turning the crank and just prop it.

I’m guessing that they are winding up a flywheel.

I have flown an aircraft where the start sequence involved flicking a swictch that spins up a flywheel and then, when the wheel is up to speed, you engaged the starter. The flywheel had enough energy to turn the engine over several revolutions.

Sorry, that should read “wound a spring which then turned the engine when the catch was released”.

In the case of the Stearman Pt-17 the crank is speeding up a flywheel. When it gets going fast enough a lever is pulled out which engages the flywheel to the engine crankshaft and turns it over.

In Army aircraft using radial engines, as 1920s Style “Death Ray” said, the wheel was spun up by an electric motor. In some there was one toggle switch that spun up the wheel while another switch engaged it. In others the toggle switch was a two throw, center off model. One direction of the bat spun up the wheel and the other position engaged it.

The specific image I have in my head is of an ME-109. Anyone know what system it used?

Thanks for the answers, guys. I didn’t realise that there would be more than one method of using the crank. I figured there was one standard way.

A peripherally related question: I recently saw Flight of the Phoenix. What was that shotgun-shell thingie they used as part of the engine-starting process?

The Navy’s WWII Gruman F4F and F6F used a shotgun shell starting system. I don’t know the details but what it did was provide a bunch of hot gas that would expand and drive some kind of motor that turned the engine over.

A Coffman starter. It certainly made for more drama than the inertial starter in the OP. Hey, they could have just kept cranking it by hand otherwise.

I was just about to post that I wasn’t finding a specific definition by searching on ‘cartidge starting system’ on google, and here you post the name of it! (And as soon as I read it I said :smack: ‘That’s what it was called!’

I was surprised to find out in my search that the system was also used on in-line engines and even jet engines. This page shows a B-57 Canberra being started with one, and includes an audio file.

I didn’t hear the Coffman starter. Just the turbine winding up.

The BF109 has an inertial starter (I’m not sure when or why they became “ME”.) From this BF109 manual (.PDF):

The US nomenclature for the 109 was ME-109.

Actually, I got curious and found this from

I used to be a stickler for calling it a BF-109 when I was a kid. Almost typed it in my previous post. But I’ve found that more people refer to it as ME-109 and it’s easier to use that nomenclature than to explain the BF.

When a German says the letters “M” and “e” in rapid succession, it will sound almost exactly like the english word “may”. …E is prounounced “aye”…the first letter of the alphabet being “ahh”

When a German says the letters “M” and “e” in rapid succession, it will sound almost exactly like the english word “may”. …E is prounounced “aye”…the first letter of the alphabet being “ahh”

From what I’ve read even after the BFW company changed their name to Messerschmitt their product was still officially called the Bf 109. It was only when a new model came out (I think the 109E model, but I’m not positive) that the official designation became the Me 109 since it was considered to be designed by the Messerschmitt company, not the BFW company. The '109s in use during the Spanish Civil War are definitely Bf 109s, but most models in use during WWII could properly be called the Me 109. Just like their twin-engine fighter was originally the Bf-110, it became the Me 110 in later models. So Me 109 is more likely to be correct (or at least more common) than Bf 109 if you’re talking about World War II. Interviews I’ve read and seen with Luftwaffe fliers also will usually refer to them as the Me 109.