Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
But even with a car, the starter uses a lot more current than the generator/ dynamo can supply, especially at low rpm.
But being a aircraft, it's not going to want to carry all the extra weight of a giant battery, that you'd need for a difficult start.
Aircraft are like that still, if it doesn't start right the first time, go look for a auxially power unit.
BTW, the Bf 109 inertia wheel was always manual?
The inertia starter was a good idea, plenty of crew have been severly injured pulling a propellor around manually.
How do you think the crew would pull the prop manually? Are you referring to starting or to clearing hydraulic lock in a radial engine?The inertia starter was a good idea, plenty of crew have been severly injured pulling a propellor around manually.
Some WW II aircraft (like the P-39) also had electric landing gear, and/or flaps and perhaps an electric propeller. Getting the battery in a low state of charge and then taking off could cause real problems if there isn't enough battery left to operate the systems before the engine can recharge it. DC generators (not alternators) are also rather heavy and in order to save weight sometimes smaller sizes were used, like a 900 watt instead of a 1500 watt. The watts generated varied with the engine speed and sometimes a low cruise speed could not generate enough power to keep up with demand even during cruise let alone lowering landing gear and flaps.
In Germany, the Me 109 used the SAME inertia starter that we did. We supplied them through Switzerland to Germany. But THEY used crewmen to turn the inertia starter manually while we used a battery to spin it up. It added weight, but we did it anyway.
Some years back we restored a Messerschmitt Me 109E at Chino Aerro Traders and invited several former Luftwaffe Me 109 pilots to see the first flight.
The Me 109 was rolled out and the pilot got into the cockpit. The former German pilots were looking arounf for the "batman" when the pilot engaged the electric starter and started the DB 601. One of the former Luftwaffe Me 109 pilots was heard to say (in German), "My God, if we'd had those electric starters in WWII, we'd have won the war!" We were all quite amused at the comment after it was translated and after realizing the implications. They were all laughing at the electric starter ...
Don't know about that. The voltage regulator controls the load on the electrical system and how much charge is going to the battery. Once the generator(s) are on line there's plenty of electrical current to run the rest of the systems if everything is working properly. There is usually a electrical load requirement to have the generator(s) to be able to support the full load of the system then ususally something like a 5% safety factor (don't quote me on the latter) is built in.
GPUs are used to ensure a good start allowing plenty of current to the starter (which is actually good for it). On turbine engines, battery starts could result in slower spool up resulting in a hotter start, something you want to avoid.
Most ww2 voltage regulators were "carbon pile," a bit crude but they worked well.