It looks like you're using an Ad Blocker.

Please white-list or disable AboveTopSecret.com in your ad-blocking tool.

Thank you.

 

Some features of ATS will be disabled while you continue to use an ad-blocker.

 

YF-23 Safty Question

page: 1
0

log in

join
share:

posted on Dec, 20 2006 @ 12:29 PM
link   
I'm not trying to argue oppinions with this thread, I want to find something out about the YF-23 and how it's engine placement might have an effect on safety!

On the YF-23 the engines were spread wide apart to improve stealth qualities. However, if for some reason, one of the engines were to fail in flight, could the engine spacing cause a flat-spin?


In case anyone isn't sure what I'm referring to, flat spin is when the aircraft goes out of control and enters a spin where the wings remain essentually level. The aircraft spins in a manner simular to a frisbee being thrown. You can see a flat spin in the movie Top Gun, when Mavric and Goose crash during a training flight out of NAS Miramar.

Do the spaced engines of the YF-23 make a simular accident possible?

Tim




posted on Dec, 20 2006 @ 12:57 PM
link   
im not a pro in this fielf of flight characteristics but I'd hazard an educated guess to say that due to the reasons you mentions the controlling of the aircraft would be harder but I doubt the fact that it would cause a flat spin



posted on Dec, 20 2006 @ 01:07 PM
link   
I would say the flight control system will prevent that. I don't know how the controls would do it, but I presume that a failsafe system will take control over the aircraft if the plane was loosing it... I don't think it ever was an issue specially with a sophisticated aircraft.

[edit on 20-12-2006 by carcharodon]



posted on Dec, 20 2006 @ 01:10 PM
link   
The YF-23 had it's engines spaced so far apart so that if one engine were hit, the chances of the other engine surviving would be better.

Regarding the flat spin; I'm doubtful that one engine going out would necessarily cause a flat spin particularly with a Fly By Wire, digital flight control aircraft.

Furthermore, I would think that the wider body caused by having engines so far apart could actually contribute to stability in case of other structural damage - in much the same way that the Israeli F-15 survived having it's wing sheered off in training a number of years back.

[edit on 12-20-2006 by intelgurl]



posted on Dec, 20 2006 @ 01:43 PM
link   

Originally posted by Ghost01
I'm not trying to argue oppinions with this thread, I want to find something out about the YF-23 and how it's engine placement might have an effect on safety!

On the YF-23 the engines were spread wide apart to improve stealth qualities. However, if for some reason, one of the engines were to fail in flight, could the engine spacing cause a flat-spin?



In a word... no.



Every aircraft with more than one engine has to take into account engine out when sizing the rudder area.



posted on Dec, 20 2006 @ 02:20 PM
link   
Almost everything was said. I just can add that every engineer that is designing multi-engine aircraft or helicopter must have in mind situation when some of the engines/engine failed. Just imagine the distance of the Boeing B777 engines. I know that aerodynamically it is the very different plane compared to YF-23, but....

I remember the DC-10 crash dozens of years ago, when one engine under the wing damaged all three hydraulic systems and pilots were forced to manoeuvre the plane only by using different thrust of the right wing and tail engine.



posted on Dec, 20 2006 @ 02:41 PM
link   
Thanks for the help everyone!

Tim



posted on Dec, 21 2006 @ 10:07 AM
link   

Originally posted by matej

I remember the DC-10 crash dozens of years ago, when one engine under the wing damaged all three hydraulic systems and pilots were forced to manoeuvre the plane only by using different thrust of the right wing and tail engine.


That was the Sioux City DC-10 crash, and it was the tail engine fanblade that fractured and cut all the hydraulic lines, with the pilots only having differential thrust to control the aircraft. There was another seperate DC-10 incident where the left engine broke free of its mountings on takeoff, severing the hydraulics, which resulted in a fatal crash with no survivors shortly after.

To answer the threads question - the flight systems will trim out the yaw automatically by setting the rudder offset, negating the possibility of a flatspin. Commercial aircraft have engine out emergencies fairly often, with engines much much further apart than the YF-23, and they dont immediately go into a flatspin. The possibility is muchly exagerated in Top Gun.



posted on Dec, 21 2006 @ 02:08 PM
link   
Hey guys as i was doing my normal avaition surfing i came across the XB-70 crash for the 100th time but in light of ths thread i actually thought about it. the plane entered a flate spin after the f-104 impacted its rudder.
so now my question (piggybacking Tim's) is if a dual rudder plane suffers a collision in which one of its rudders is destoryed. Is there a higher chance of a flatspin?



posted on Dec, 22 2006 @ 10:43 PM
link   
Well from what I understand, the plane should be fine as long as the plane is not entered a slip/skid or stalls. As long as the plane maintains that, it should be fine. Slips are normally safe to perform, but can cause spins in the right conditions, skids are dangerous.

If it is equipped with FBW, the FBW would prevent that.

Shattered OUT...



posted on Dec, 23 2006 @ 04:13 AM
link   

Originally posted by Canada_EH
so now my question (piggybacking Tim's) is if a dual rudder plane suffers a collision in which one of its rudders is destoryed. Is there a higher chance of a flatspin?



Defintely. The design required X amount of vertical rudder area, now you've only got X/2. Vertical fins are not an arbitrary size - there is a detailed process that goes into selecting the size.

[Its not quite X/2 but you get what I mean].



posted on Dec, 25 2006 @ 03:10 PM
link   

Originally posted by kilcoo316

Defintely. The design required X amount of vertical rudder area, now you've only got X/2. Vertical fins are not an arbitrary size - there is a detailed process that goes into selecting the size.

[Its not quite X/2 but you get what I mean].


Actually, yes it is! Think about it. The plane's Total rudder AREA is divided evenly between the two rudders. So if you loose one whole rudder, you would loose exactlly 1/2 of tyhe plane's total rudder surface area. The same hold true for the F-22, F-15, F-14, F-18, and every other plane with twin rudders.


Tim



posted on Dec, 25 2006 @ 03:22 PM
link   
Yes, you are right about area, but I think that kilcoo meant force movement produced by rudder. First rudder + second rudder is not exactly two times more power.



posted on Dec, 25 2006 @ 04:08 PM
link   
Thanks Matej,

Your clarification is very helpful. I get the impression the kilcoo, and I had two slightly different thought processes going at the time of our respective posts. I get the impression that he was factoring in mechanical loose in energy convesion or something simular.

I, on the other hand was focusing on control set up and force distrabution. Design force distrabution is Exactly 1/2. However, as kilcoo points out, when you factor in mechanical loss, the total force of both rudders together is slightly less than 100% of the original amount of energy input, which gives you slightly less then 50% of the imput force reaching each rudder.

Good Point, well stated!

Tim



posted on Dec, 27 2006 @ 11:20 AM
link   
thanks for the help guys. The website had stated that the AB-70 had entered a flat spin shortly after lossing the rudder and i figured that it had to do with the loss of control



new topics

top topics



 
0

log in

join