Its friggin awesome I tell you hwat :P For engines that are in the range of a car engine, averaging a tenth or a ninth of the displacement and/or inertial mass, the inertia starter would be maybe almost ten times heavier than the tiny lightweight starter motor? Its far too expensive to include as vehicle mechanical bulletproofing though, don't want cars to last too long eh? Otherwise nobody would buy new cars to feed money into the industry XD
Not too bad - have you ever seen a chain of men grabbing a propeller blade and running to crank a 3500 hp radial aircraft engine ? I have. Near-suicidal. Only guys without children were permitted to be the last guy in the chain in case he got sucked into the prop.
Hi, van I use your video in a video I'm making about the Boeing Model 100 (P-12)? I want to show how the inertia starter works. You will be given full credit.
Two questions: 1/ What is it he touches at 0:59? External magneto switches? What's the exact name for it? 2/ Is it possible on this engine to start by hand swinging the propeller, or do you have to use the crank handle? Many thanks.
The control he touches behind the crank handle engages the starter clutch which cranks the engine. What you don’t see because it’s off screen is that there has to be someone in the cockpit operating the magneto switches and throttle. Hand propping is technically possible but not really practical on an engine this large. That’s why they saw fit to include an inertia starter. It’s easier and much safer.
@@singleproppilot I have solo-cranked R-1830 Pratt Whitney engines as part of a three man team, and R-3350 once as part of a five man team. I could still prop a an R985 and when I was 25 could prop an R1340. Solo.
What is the biggest aircraft that anyone knows of that can be started by a mechanic turning a cranking handle in the side of the engine like the one in this clip? Any really big four engined aircraft? If so, which?
I don’t know about cranking by hand, but there were a number of large aircraft that used electric inertia starters. The Boeing B-29 Super Fortress is one example. So instead of some poor sap having to go spin up this heavy weight by cranking a handle, an electric motor did the cranking, then the clutch would engage and spin the engine just like you see here. In the B-29’s case, power to spin the electric inertia starters came from an Auxiliary Power Unit (APU). The B-29 was the first airplane to have an APU.
@@paulmurphy42 Yes I worked for Braniff Airlines and many times four or five of us would join hands and - biggest guy first, littlest guy grabbing the prop - we would all run and pull sideways (from starboard to port) on the bottom prop blade. Probably 30 times from 1951 to 1964 we had to hand-prop R-2000s on DC-4's. R-2800s on DC-6s, and R-3350 Turbo Compounds on DC-7Cs. Usually just two big guys would pull it through with the mags cold during priming (the "suck-in" phase) but anytime the mags were hot it was the whole chain at a dead run to so that in case it started we would be away from it and the hand-joining was to prevent Shorty from being sucked back in to the prop-arc. Once we got one engine to run it's generator would eventually charge up the ship's 32 volt battery bank enough to electrically start the next and so on. Hurry up and ask me any other questions because I am 92, capiche ?
@@patrickshaw8595 Wow, that's a great answer Patrick, thanks! I didn't think any team had ever hand propped a DC7! But what do you think is the biggest engine/aircraft that could be hand propped by one man alone?
When I was young and wiry I hand-propped an R-1830 Pratt mounted in a test cell solo once. That was at aircraft mechanic's school on a bet. The 3-bladed prop lost a blade a few seconds after startup and it disappeared. Running pretty good power with only two blades the prop hub's center was describing about a 20 inch circle despite being solidly mounted to about a 5 ton concrete block. I didn't know which way to run and I'm told I did a deer in the headlights impression. The nose casing for the gear reduction and whatnot broke off and the entire thing also took off straight up (thank you Jesus) and landed about 25 seconds later a quarter mile away in a huge parking lot with a clang.
