CocoaJin, on 29 July 2014 - 11:57 PM, said:
I've heard anecdotal statements suggesting the A-10 slows down while firing its gun, and honestly, I don't doubt it. But I think its a bit of a stretch to say it'll eventually go backwards before spiraling out of control. It'll no doubt slow the aircraft enough to cause it to stall, but I can't imagine it could make the plane go backwards first. Now, once it stalls, if the pilot kept firing, it might off set the natural tendency of the plane's nose to drop, instead letting the tail drop and the the tail first descent eventually resulting in a spin or some other horrible lack of control, including a spiraling flopping mess. But I cant imagine the gun as enough recoil to ignore the aerodynamic forces inherent in the plane to over power them even briefly to allow for a short period of reverse flight. The A-10 is going to stall well before it gets close to even stopping, at which point it'll just flop with increased lose of airspeed due to the gun firing.
That being said, I could be wrong...though I'd like to hope my instincts as a Commercial/ATP pilot would be correct on the matter...not that we get the chance to fly backwards much.
MeiSooHaityu, on 30 July 2014 - 04:07 AM, said:
P.s. I also heard the A-10 slows down when firing it's auto cannon. That is why it fires in bursts instead of one continuous stream. It is also why the barrel is centered in the plane (so as not to pull the aircraft to one side when firing). If the pilot fired a continuous stream while the plane was in a low speed straffe run, it could stall the plane and crash it. That is why it burst fires. I am pretty sure that is the reality of that gun platform.
That's the thing -
TI's original statement/argument was, "If you've ever seen an A-10 do a strafing run with the cannon, they can only fire short bursts because the recoil from the gun is like slamming on the brakes in mid-air.
If they just held down the trigger, the plane would stop and begin going backwards for a brief time before it spun out of control."
This specific statement, barring very specific & strange/stupid actions on the part of the pilot, simply isn't true; the GAU-8 simply doesn't produce enough force through recoil to completely overcome both the thrust of its engines and the aircraft's momentum.
While the GAU-8's recoil force (44.5 kN, or 10,000 pounds -
source, from General Dynamics' own website) is indeed significant (for comparison, one of the A-10's two engines produces only 40.3 kN (9,065 pounds) of thrust -
source, from the USAF's own website), having both engines running together at even only 66% power (which produces a total of 53.2 kN (11,966 pounds) of thrust) is more than enough to overcome the recoil force of the gun on thrust alone; combined with the plane's momentum at the point at which the gun starts firing & the effects of gravity in a dive, the GAU-8's recoil simply isn't enough to reverse the plane's direction of travel as TI originally stated.
On top of that,
Stjobe even brought up a quote from an interview in
Stars and Stripes with an A-10 pilot with 3,500 hours in the cockpit (as of August 2011) that also dismisses the myth that the GAU-8 can reverse the A-10's direction of travel.
Quote
An old rumor that a reader recently asked about is the A-10's gun is so powerful that when fired the recoil slows the plane down almost to a complete stop.
But while the A-10's endurance and firepower are legendary, the myth that its cannon drastically decelerates the aircraft is pure "Hawg-wash," said retired Air Force Col. Steve Ruehl.
"I have fired as many as 500 rounds in one trigger burst, that takes just about seven, eight seconds, and [it had] no impact on the air speed of the aircraft," said Ruhel, who has logged 3,500 hours flying A-10s.
Thus far, TI has as-yet failed to provide any real, independently-verifiable evidence to support his original claim; by contrast, information from both the USAF itself and General Dynamics itself, along with documented testimony from an A-10 pilot, demonstrates that TI's assertion that "
the plane would stop and begin going backwards for a brief time before it spun out of control" is simply incorrect & a perpetuation of an urban myth.
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