A1 skyraider

renrich · 07-02-2007, 08:54 AM

I don't know that it makes a lot of difference but I believe the AD was originally designed by Ed Heineman to be a replacement for the SB2C and was supposed to have the capability of dive bombing and therefore in the early stages of it's career those brakes were probably used as dive brakes. Linnekin, whose book I got the quote from was a career naval aviator, an aeronautical engineer, a test pilot and flew operationally, among others, the Stearman, SNJ, Hellcat, Bearcat, Corsair, Panther, Banshee, AD, A4, F8U, Phantom etc. He has quite a lot of credibility with me. His book, if you can get it would seem to be a good read for all who have the interests we have.

Graeme · 07-02-2007, 06:16 PM

Amazing what you find when you look.
The caption reads;
"Douglas AD-2 Skyraider extends the under-fuselage dive brake on an early developmental flight, 27 October 1949. The dive brake remained a standard feature of the attack bomber, although in Vietnam the brake was frequently wired shut to permit the use of a centreline fuel tank".
(Sorry about image quality)

spadguy · 07-03-2007, 12:03 PM

The AD-5 did not always have the three panels for the dive brakes. Usually the bottom one was not installed due to the radome ( AD-5W) or due to mods for center station weapons or pods.

The AD-6/7 had all three panels and you DID NOT want to use them in level flight because they could blank out the airflow over the fully movable elevator trim system. You had to have a definite nose down trim before deploying the brakes. You COULD trim nose down, physically hold the nose up and pop the brakes. You would almost stop. Very effective but a lot of work and you would stall if you left the brakes out too long. It took a delicate touch to use them.

They were extremely effective in preventing acceleration while diving at very steep angles. All the better to aim.

renrich · 07-03-2007, 02:50 PM

Thank you Spad guy. Very instuctive.

renrich · 07-03-2007, 02:50 PM

Instructive!

mkloby · 07-03-2007, 05:48 PM

Wasn't prop reversing already developed by then - initially for use in dive bombing for the same reason; to increase rate of descent and reduce A/S?

renrich · 07-04-2007, 06:32 PM

Matt, did not dive bombing go out of favor because of the effectiveness of triple a and aa missles?

spadguy · 07-12-2007, 10:29 AM

The Skyraider never had any form of prop reversing. That is a scary thought. In a high angle dive, steeper than 30 degrees, usually up around a 60 degree dive angle one would set the power to a nominal setting and the prop to around 2100 rpm. In the dive an automatic manifold pressure regulator prevented the manifold pressure from building as it will in any normal engine. It would reduce the pressure automatically then put the manifold pressure back to normal as you pulled out. It was just one less thing to worry about in a dive. It worked quite well.

High angle dive bombing, and some times it was very steep, worked becuse when the skyraider was designed not a lot of AA guns could elevate to those angles. One could dive in the cone where they could not get you. That did not last long.

Have you noticed the dive cowl flaps around the front of the engine. The operated like a camera iris to enclose the engine during long dives at low power to keep the engine from cooling off. They almost sealed it off. They reopened automatically when engine temp got to some limit.

They worked well to button up an engine at a dusty airfield ut that was very much an incidental use of the dive cowls.

In Viet Nam the presence of missiles, for which the Spad had little defense was a big factor in limiting the usage. The plane was in no way a dogfighter but it has won a few.

Given how oily and greasey the plane normally was we figured the development of an oil seeking missile was only a matter of time.

renrich · 07-12-2007, 05:32 PM

Good info, thank you. It is nice to hear from someone who actually has experience with the subject ac.