Cutting Engines Mid Flight

[skorpion]

why do people even cut engines to slow down? if you just go to min. throttle and keep RPM all the way up, it acts like a brake as its at a fixed speed and not windmilling as it wishes. try it on a B17 or a P38. those are the greatest examples of "RPM-brakes"

[Ack-Ack]

why do people even cut engines to slow down? if you just go to min. throttle and keep RPM all the way up, it acts like a brake as its at a fixed speed and not windmilling as it wishes. try it on a B17 or a P38. those are the greatest examples of "RPM-brakes"

In the P-38? nope, just chopping throttle with full RPM isn't going to act like a brake.  The P-38 is quite aerodynamic and retains energy quite well.

ack-ack

[skorpion]

In the P-38? nope, just chopping throttle with full RPM isn't going to act like a brake.  The P-38 is quite aerodynamic and retains energy quite well.

ack-ack

what i meant is it slows down faster than just cutting engines. would you rather have a hardly any brakes or at least some control over it?

[Ack-Ack]

what i meant is it slows down faster than just cutting engines. would you rather have a hardly any brakes or at least some control over it?

Speaking as someone that exclusively flies the P-38, just chopping throttle isn't enough if I want to bleed energy quickly.

ack-ack

[icepac]

In the P-38? nope, just chopping throttle with full RPM isn't going to act like a brake.  The P-38 is quite aerodynamic and retains energy quite well.

ack-ack

The P38 has more drag than every single engine fighter of WWII.

The intersection drag is what kills it.

The p38 has 14 intersections while most single engine fighters had only 5.

The P38 also has two engine nacelles as well as cockpit pod counting toward frontal area.

This is one of the reasons the "pond racer" was not as fast as they though it would be.

[Ack-Ack]

The P38 has more drag than every single engine fighter of WWII.

The intersection drag is what kills it.

The p38 has 14 intersections while most single engine fighters had only 5.

The P38 also has two engine nacelles as well as cockpit pod counting toward frontal area.

This is one of the reasons the "pond racer" was not as fast as they though it would be.

NACA wind tunnels test of a YP-38 showed the Lightning to be an aerodynamically clean aircraft.  If you have any data that shows the P-38 didn't retain energy very well or was not aerodynamic, please post it.  Before you do though, I would suggest you read Warren Bodie's The Lockheed P-38 Lightning.  


ack-ack

[icepac]

Coefficient of drag must still be multiplied by frontal area.

Frontal area and intersection drag is what kills the P38.

The fastest qualifying lap ever for a p38 is 390mph in air racing.

That's 100mph slower than the mustangs.

http://aerofiles.com/nar.html

Some familiar names in those early postwar races at cleveland.

http://www.airrace.com/

[Wiley]

Back to the engine cutting for a moment...  I'd respectfully submit there might be another motivation for cutting it out.

On a few occasions the last little while, I've been tooling along and spied somebody all by his lonesome on climbout.  Having alt on them, I came in for the bounce, getting low six as I approached.  I don't like to fire outside 600 on such an attack, I usually wait for the icon to go to 400 and then open up.  What I've noticed in a lot of cases lately is right around the time the icon goes to 600, a guy that most likely can't see me from his canopy suddenly does a panic break.  Again, we're the only two in icon range.

After considering it a bit, it occurred to me that we can hear other peoples' engine noise between 800 and 600 over your internal engine sounds.

Might people be wanting to use it as a gamey measure to help sneak up on people?  On a related matter, I've never flown a single engine prop plane built for raw performance in close proximity to other aircraft, but I'm really having trouble believing you'd be able to hear another plane's engine 1/2 a mile away from you over your own engine.

Wiley.

[icepac]

I'm pretty sure that nobody flying a top line fighter in WWII ever heard the plane that bounced them.

[Ardy123]

I find it hard to believe that one could hear another's engine when one has 2000hp engine within 6 feet from oneself (in most single engine fighters).

[Tyrannis]

I find it hard to believe that one could hear another's engine when one has 2000hp engine within 6 feet from oneself (in most single engine fighters).

I find it easier to see that theyve turned their engines off rather than hear it.

When im in pursuit of an AC, i like to keep an eye on their nose. If i see the props slow down or stop spinning, it warns me they've shut their engines off alot quicker than trying to listen for it.

[Ardy123]

I find it easier to see that theyve turned their engines off rather than hear it.

When im in pursuit of an AC, i like to keep an eye on their nose. If i see the props slow down or stop spinning, it warns me they've shut their engines off alot quicker than trying to listen for it.

you misunderstood what I said.. I stated, that in RL you wouldn't be able to hear weather they had their engine on or off, thus turning your engine off to sneak up on someone is absurd.

I do agree its easier to see it than to hear it, but it doesn't change that turning off your engine is dumb and 'gamey'. There are much better ways to accomplish the same goal.

1) to sneak up on some one..
         come in below and behind them

2) Force an overshoot
         cut throttle, make a hard turn create some separation and an off angle between the nose of the attacker and you, then do a barrel roll and pop them as they try to pull up and match your barrel roll.

3)To bleed speed
     * cut throttle, point nose up
     * turn hard, cut throttle
     * slip the rudder, cut throttle
     * snap roll by forcing a wingtip stall
     * drop flaps and/or gear


      

[Wiley]

1) to sneak up on some one..
         come in below and behind them

Agreed on the other points, but they can hear you at that point, which is IMO equally absurd.

Maybe I wasn't clear in what I was saying.  I could see there being an advantage as the bouncer to come in with smash, get low six, and 800-1000 out kill the engine and put RPMs to 0 so I can glide in silently to shoot him.

Gamey as hell, but so is his ability to hear the guy on his low six.

Wiley.

[skorpion]

icepac, listen to ack, hes a g33k about his P38   he knows more about the P38 than most of us here. the P38 was just one of the planes that had just a smaller resistance to drag, its like saying cutting the engine in a P47 will slow it down in a dive instead of cutting throttle. either way, your still going to pick up some insane speed if you dive too quickly.

[Ack-Ack]

The fastest qualifying lap ever for a p38 is 390mph in air racing.

That's 100mph slower than the mustangs.

http://aerofiles.com/nar.html

Some familiar names in those early postwar races at cleveland.

http://www.airrace.com/

It's performance in an air race does not support your argument that the Lightning was not aerodynamically clean aircraft and wasn't able to retain energy very well.  The top speed of the P-38L was 443mph and the only thing that really limited the Lightning from able to achieve greater power were limited by the wing leading edge intercoolers until the J model arrived.

This is pretty good article on the evolution of the speed and climb of the P-38 and goes into considerable detail about it's aerodynamic and energy retention properties over at the WWII Aircraft Performance site.

The P-38 Lightning - Evolution of Speed and Climb Performance

ack-ack