Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
Considering the chaps are firing the pom pom right over your shoulder and Italian bombers are dropping ordinance over head getting that Seafire back in the air is a must. But in reality how quickly can that job be done under fire? They must have been short on Seafires that day.I've seen that before. I guess if you're under attack and the engine starts you have no choice, but that is a huge risk
Changing the prop or changing an engine? The prop change isn't that long but you may have to make adjustments so you're getting the right pitch settings at a given RPM and manifold pressure.Considering the chaps are firing the pom pom right over your shoulder and Italian bombers are dropping ordinance over head getting that Seafire back in the air is a must. But in reality how quickly can that job be done under fire? They must have been short on Seafires that day.
As long as there's no impact load to the prop you're ok but any type of prop strike, be it static or dynamic and be cause for an engine teardown.So, a follow-on question: what if you prop-strike on a deadstick landing? I'm assuming the damage will be much less, but there's still going to be gearbox or prop-shaft issues.
That might be a considerationI wonder if the FAA preferred that type of composite prop because the tips shattered and had a way of guestimating the engine damage from damage to the prop tip?
It doesn't necessarily need to cause damage to the prop either. Here's Lycoming's definition:As long as there's no impact load to the prop you're ok but any type of prop strike, be it static or dynamic and be cause for an engine teardown.
A propeller strike includes:
- Any incident, whether or not the engine is operating, where repair of the propeller is necessary
- Any incident during engine operation where the propeller has impact on a solid object. This incident includes propeller strikes against the ground. Although the propeller can continue to turn, damage to the engine can occur, possibly with progression to engine failure
- Sudden RPM drop on impact to water, tall grass, or similar yielding medium where propeller damage does not usually occur
When I was at the academy one of the instructors taxied off the runway and "thought" he taxied over grass. He read that definition and wanted us to do an engine teardown. We told our customer that unless there was an RPM drop, this was un-necessary. After much argument and finger pointing we discovered the grass this guy taxied over was shorter than the prop clearance to the ground! 20-30K of US tax dollars saved!It doesn't necessarily need to cause damage to the prop either. Here's Lycoming's definition:
I was a docent at a Hanger for aircraft from WW2 and prior. It wasn't a museum because all of the aircraft flew. Then it got killed by covid, but I digress. We researched all the aircraft and delighted in presenting a previously unknown fact about one of the aircraft to our fellow airplane geeks. (Old men with not much else to do.) What became part of the presentation for our Spit was that it had wooden props so they would break off during a belly landing and save at least some of the engine. Supposedly, the props were milled on lathes purchased from Germany before the war.Much is salvageable from Belly Landing in Propeller Plane in WW2. I believe there were many Frankenstein Lancaster s containing components from their crashed brethren.
But the articles always seem to refer to sections of the fuselage or systems from the planes. There does not seem to be mentions of the engines.
So I am thinking does the force of the hard stop of the propellor when the plane pancakes get transmitted into the engine, wrecking the bearings and twist the engine casing?
Would this vary according to whether this was an inline or a radial engine?
I dont know enough about engineering or know of the history of mechanical salvage, so I am hoping that the forum are able provide some answers.
As always thank you in anticipation of your answers.
Money well spent.I was a docent at a Hanger for aircraft from WW2 and prior. It wasn't a museum because all of the aircraft flew. Then it got killed by covid, but I digress. We researched all the aircraft and delighted in presenting a previously unknown fact about one of the aircraft to our fellow airplane geeks. (Old men with not much else to do.) What became part of the presentation for our Spit was that it had wooden props so they would break off during a belly landing and save at least some of the engine. Supposedly, the props were milled on lathes purchased from Germany before the war.
Someone mentioned the cost of a rebuild for a Merlin. During a PE on our Spit our A&P mechanic found metal slivers in the oil. We had to fly two mechanics from RR in England to do an inspection and take the engine off of the aircraft and box it up for shipment to California. This took a week; hotel, car rental, etc. on us. Three months later the engine came back and the Brits returned to install the engine. We didn't have a proper jig so the alignment and installation were done with a fork lift. Funny, it was nothing when I watched it happen, just another day at the office. Now that I write about it was pretty amazing. No one ever gave an official final cost, but the rumor mill produced a figure just North of $500 K.
Also many RAF planes had CS propellers with Jablo (Heine) reinforced wood/composite blades during the SWW. Maybe especially Spitfires.I wonder if the FAA preferred that type of composite prop because the tips shattered and had a way of guestimating the engine damage from damage to the prop tip?
Still have to do a teardown inspection per S/B and Airworthiness Directive if they had a prop strikeA friend of mine just groundlooped his Aeronca Chief yesterday. Messed up the Right gear a bit and I guess the prop too, because they dialed the crankshaft this morning and found it was Okay.
its not just the crankshaft. All of the accessory drive gears have had the same shock loading through them.A friend of mine just groundlooped his Aeronca Chief yesterday. Messed up the Right gear a bit and I guess the prop too, because they dialed the crankshaft this morning and found it was Okay.
Don't matter - you have to do a teardown inspection per Continental SB and FAA AD. You have to do inspections on the cam and crankshaft and to do those inspections you have to get them out of the crank case!The Accessory drive gears usually are turning at some multiple of the crankshaft speed, so the impact on them usually is greater.
But on that engine, a C-75, you can usually pull the rear cover and access the accessory drive gears with it still on the airplane.