Aces High Bulletin Board
August 31, 2014, 03:13:38 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   AHWIKI Help Calendar Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: P38L Lose its Dive Brakes?  (Read 610 times)
BadCompany
Zinc Member
*

Reg: Jul 2012

Posts: 6
Offline Offline

« on: July 20, 2012, 05:45:39 PM »

I have a yellow cockpit indicator that lights up, but I don't see anything on the airframe moving or deploying when I hit the dive brake switch.  I also didn't notice any performance change in or out of a dive when trying to deploy them via Shift C key, thought the cockpit indicator does light up and go off with each press of the key.

Maybe I'm just too new to it to notice the performance change, and maybe they're out of my sight.  Or have they been removed/disabled?
Logged
Tracerfi
Silver Member
****


Reg: Feb 2012
Location: Somewhere other than here

Posts: 1612
Offline Offline

« Reply #1 on: July 20, 2012, 05:59:43 PM »

Bad I have not been playing lately but I think it may be a bug or you are new and i never see any change with them deployed either 
Logged

It's Over 9000!!!!!!!!
FLS
AH Training Corps
Platinum Member
******


Reg: Jan 2002

Posts: 5049
Offline Offline

« Reply #2 on: July 20, 2012, 06:10:19 PM »

When you're on the runway, in the training arena, or offline, you can use F3 for external view and look under the wing.
Logged
BadCompany
Zinc Member
*

Reg: Jul 2012

Posts: 6
Offline Offline

« Reply #3 on: July 20, 2012, 06:15:07 PM »

Aha, external view, and UNDER the wing!!! And I'm too new to notice the performance change, I reckon.

Thanx guys!
Logged
JOACH1M
Plutonium Member
*******


Reg: Jan 2010
Location: St.Clair MI

Posts: 8237
Offline Offline

« Reply #4 on: July 20, 2012, 06:23:57 PM »

Aha, external view, and UNDER the wing!!! And I'm too new to notice the performance change, I reckon.

Thanx guys!
I don't notice it either but I just deploy it when landing.
Logged

My YouTube Videos
++Blue Knights++
"I am the kid with the motor mouth. I am the one you should worry about."
R.I.P Sean Parsons & Andrew Davis
clerick
Silver Member
****


Reg: Nov 2006
Location: Eagan, MN

Posts: 1742
Offline Offline

« Reply #5 on: July 20, 2012, 06:53:13 PM »

Plus, they aren't dive "brakes" like you think they are. They were just there to help with compressibility issues by modifying the airflow around the wing, not actually slow it down (IIRC).
Logged

Karnak
Radioactive Member
*******


Reg: Dec 1999
Location: Hutto, Texas

Posts: 22311
Offline Offline

« Reply #6 on: July 20, 2012, 06:56:23 PM »

Yeah, "Dive Recovery Flaps".  They push the nose up.
Logged

Petals floating by,
      Drift through my woman's hand,
             As she remembers me-
Drano
Silver Member
****


Reg: Apr 2001
Location: Wilmington (Milltown), Delaware

Posts: 1713
Offline Offline

« Reply #7 on: July 20, 2012, 06:59:02 PM »

Don't try to think of them as dive brakes in the conventional sense as if on a dive bomber. On a dive bomber the dive brakes are designed to keep the plane from building speed in a dive by creating a lot of drag so they can aim a bomb before they might hit the ground or not be able to pull up. On a P-38 they act differently as they have a different purpose. The P-38 was such a slick airframe that using it in the verticle downhill was very risky. You'd enter compression easily and many of the early Lightning pilots found out the hard way that it might not pull out at all. The Howard Hughes episode comes to mind. It took til the L model to add the flap under the wing. What that flap does is deflect the airflow at high speeds farther under the center nacelle pod and also back so that it wouldn't slam onto the elevator as it would without the flap. This was found to be causing the lockups at high speeds. It's not very large so it doesn't produce much drag--like a dive brake does. All it does is deflect the airflow. Even so it's only good for a certain speed range. If you apply too late it's not gonna save you. Have it in mind as you're diving if it looks like you're going downstairs fast. Also if you're going to fly the 38 I'd strongly suggest acquainting yourself with the "k" and "i" keys to have better control over your elevator trim.

Test the dive brakes in level flight. You'll find they don't slow you down much if at all. Now try them on any dive bomber--you'll see the difference.

Here's a cool video about the 38:

  http://www.youtube.com/watch?v=Y3nddCJbcdI&feature=related  

Pay attention at about 2:50 where the flap is explained and demonstrated.  Sadly the guy in this video, Jeff Ethell, was killed not long after this was filmed when he crashed this plane.

Good luck flying the 38. <S>
« Last Edit: July 20, 2012, 07:02:59 PM by Drano » Logged

"Drano"
80th FS "Headhunters"

S.A.P.P.- Secret Association Of P-38 Pilots (Lightning In A Bottle)


FSO flying with the 412th Friday Night Volunteer Group
Ack-Ack
Radioactive Member
*******


Reg: Oct 2002
Location: لقد حصلت على تذكرتين إلى الجنة

Posts: 22447
Offline Offline

« Reply #8 on: July 20, 2012, 07:28:31 PM »

As noted in another reply, the only way you'll see the dive flaps deploy is if you're on the runway and hit F3 and look under the plane as you deploy them.  You will not see them deploy sitting in the cockpit.

I also didn't notice any performance change in or out of a dive when trying to deploy them via Shift C key, thought the cockpit indicator does light up and go off with each press of the key.

The dive flaps work as intended and will assist in recovering from a high speed dive.  The problem with a lot of players is that they usually deploy and use the dive flaps incorrectly.  A lot think that the flaps are intended to help you recover from a dive by acting as a brake and slowing your plane down enough that you can pull out of a dive.  That is 100% incorrect.  As you can see in the diagram below and in the photo with the dive flaps deployed, the dive flaps are a very inefficient design to act as a dive brake, why?  Well, that's an easy answer because the dive flaps weren't designed to act as brakes but instead as someone else mentioned to change the airflow over the leading edge of the wings.





For the dive flaps to work properly, you need to be in a certain window where they are beneficial to get the most out of them.  The dive flaps only work at high speeds, they are pretty much useless at speeds below 350mph IAS and you won't see any real effect if you deploy them at speeds lower than that.  The best time to deploy the flaps is when you're about to enter the dive, though you can sometimes get away with deploying them shortly after you've started your dive.  New or inexperienced P-38 drivers tend to deploy the flaps at the onset of a high speed buffet and by that time it's usually too late and the dive flaps aren't as effective and you'll need to manually trim to recover.  As soon as you complete your dive recovery, retract the dive flaps.

A little trick you can do with the dive flaps that was used by real life P-38 drivers.  The dive flaps can aid in high speed turns, just deploy them at the start of the turn and retract them as you finish the turn.  

Now the brutal honest truth...if you have to deploy the dive flaps to recover you messed up.  It's that simple.  Properly flown, the P-38 (all models) can safely dive if you understand what compressability is and how it effects the P-38 without neediing to use dive flaps.  Remember, compressability happens when the air over the leading edge of the wing reaches critical mach speeds, which means the higher you fly the P-38, the increased risk of entering compressability in a dive.  The lower you fly the P-38, the risk decreases dramatically the lower in altitude you go.  In other words, the P-38 will not enter into a compresability state below 20,000ft, the air is too thick for the air over the leading edge to reach critical mach.  The P-38 will suffer from sluggish and hard controls below 20,000ft but that is due to regulary aerodynamic forces pushing on the control surfaces and not the phenomena that is compressability.  

To safely dive the P-38, you need to control your speed and you can do that by decreasing throttle and using your rudders to "skid" the plane in the dive.  Using this simple technique you can easily reach speeds up to 475mph IAS in a dive and still retain control (although sluggish) to pull up out of the dive without having to use dive flaps.

I don't notice it either but I just deploy it when landing.

Why?  They don't do anything at low speeds and even if they did wouldn't be smart to deploy them on landing.  Besides, you don't need flaps to land a P-38.

ack-ack
« Last Edit: July 20, 2012, 07:30:29 PM by Ack-Ack » Logged

"If Jesus came back as an airplane, he would be a P-38." - WW2 P-38 pilot
titanic3
Persona Non Grata
Platinum Member
******


Reg: Jan 2007

Posts: 4235
Offline Offline

« Reply #9 on: July 20, 2012, 08:19:39 PM »

You don't need flaps to land anything. Do a flat turn over the field and land. Quick, easy.

Besides, you don't need flaps to land a P-38.

ack-ack

Logged

<br />  the game is concentrated on combat, not on shaking the screen.<br /><br />semp<br />
JOACH1M
Plutonium Member
*******


Reg: Jan 2010
Location: St.Clair MI

Posts: 8237
Offline Offline

« Reply #10 on: July 20, 2012, 10:33:05 PM »



Why?  They don't do anything at low speeds and even if they did wouldn't be smart to deploy them on landing.  Besides, you don't need flaps to land a P-38.

ack-ack
I like to play how slow I can I go when I'm landing.  Smiley joystick
Logged

My YouTube Videos
++Blue Knights++
"I am the kid with the motor mouth. I am the one you should worry about."
R.I.P Sean Parsons & Andrew Davis
Ack-Ack
Radioactive Member
*******


Reg: Oct 2002
Location: لقد حصلت على تذكرتين إلى الجنة

Posts: 22447
Offline Offline

« Reply #11 on: July 21, 2012, 12:34:36 AM »

I like to play how slow I can I go when I'm landing.  Smiley joystick

Dive flaps aren't going to help you.

ack-ack
Logged

"If Jesus came back as an airplane, he would be a P-38." - WW2 P-38 pilot
JOACH1M
Plutonium Member
*******


Reg: Jan 2010
Location: St.Clair MI

Posts: 8237
Offline Offline

« Reply #12 on: July 21, 2012, 09:15:07 AM »

Dive flaps aren't going to help you.

ack-ack
I figured since they help flush the nose up a little bit in a dive that it would help bring the nose up a tad more when pulling pull back scraping my tail on the ground before the gears hit.  Hehe!
Logged

My YouTube Videos
++Blue Knights++
"I am the kid with the motor mouth. I am the one you should worry about."
R.I.P Sean Parsons & Andrew Davis
Pages: [1]   Go Up
  Print  
« previous next »
 
Jump to:  

Design By simply sibyl And Free Forum Hosting
Powered by SMF 1.1.19 | SMF © 2013, Simple Machines