Stalls and Radio Exam!

[boingk]

Aircraft without dihedral still have secondary effects, especially seeing as they're not limited to the rudder/yaw input. You will still get a tendancy to roll with yaw input and yaw with roll input, also a tendancy to yaw and/or roll with power. Yawing with roll input is especially craft dependant due to placement and operation of the ailerons.

 

One major reason you're using the rudder in a stall is because its in the propwash and not associated with keeping you aloft - the rudder is generally not stalled. Seeing as your wings are stalled your aileron will generally make the condition worse by increasing the apparent angle of attack on the downgoing wing. Thus, you rely on the secondary effects of rudder to help right the craft.

 

Thats it as far as I understand it. I really thought all this would've/should've been covered in ground school before you even touch an aircraft for the stall/spin lesson?

 

- boingk

 

 

[motzartmerv]

Oh ok.So yawing doesn't actually get you out of the stall?

 

And what happens if the engine is at idle?

 

 

[boingk]

If the engine is at idle then your airspeed will only build while you maintain a nose-down attitude, hence pushing the flight coloumn forward. As airspeed rises you gain more control authority.

 

Are you having a dig at me?

 

- boingk

 

 

[motzartmerv]

No, not at all.. Just trying to keep it clear what we are saying. Yawing does NOT help get out of a stall.. The rudder is more effective with power, but hardly if at all with power off.

 

Having the nose down does not ensure your not in a stall. Stalling has nothing to do with airspeed OR attitude.

 

Cheers

 

 

[Ultralights]

as i said before, a stall is a function of AOA only... and only reducing the AOA will unstall the aircraft. 15 dg AOA, not stalled, still flying as usual. 16 deg AOA, stalled, either both wings, or one or the other, but get it back below 16 deg, not stalled. and you will only find that a small elevator movement is the difference between 15 and 16 deg AOA. no violent nose down push, just relax back pressure on the elevator, and you will unstall. with practice, you can stall and recover with only a height loss of less than 10 ft. pull back hard enough at Vne, and you will stall. even inverted.

 

 

[boingk]

motzartmerv - No worries mate, I see what you were getting at know.

 

Ultralights - Bingo, Angle Of Attack, thos're the magic words. It is also sometimes (and incorrectly) referred to as 'G stalling' if flying at speed - you stall out due to the AOA even though well above traditional stall speed, generally while pulling considerable positive g. I've encountered this in my aforementioned simulator time, generally while flying a 1940's Yakolev 9 or one of its variants; very overlooked aircraft and hugely capable, they were even assigned a 'Do Not Engage' status for the Luftwaffe's 109's at one point. Usually you're shot down after encountering it as you're trying to evade somone, but you can use it to your advantage and pull throttle simulaneously to simply drop down and aft of your attacker if neccessary.

 

Now, where'd I put my brandy and leather flying cap?

 

- boingk

 

 

[djpacro]

a stall is a function of AOA only... and only reducing the AOA will unstall the aircraft.....

and important to know whether it is stalled or not stalled. Seems that many pilots (present company excluded) do not know how to tell whether an aircraft is stalled or not.

 

... pull back hard enough at Vne, and you will stall. even inverted.

Do you mean an inverted stall or being inverted and pulling?

[motzartmerv]

Lol, pull back hard enough at vne I reckon stallig would be the least of your worries..teehee

 

 

[boingk]

You see that a lot in the competetive flight sims as well; loom up behind a shiny BF109 in my Yak, he dives and tries to run. I follow. He tries to pull out before we hit the deck... goodbye wings! The 37mm cannon in the Yak T's spinner has a similar effect, come to think of it. Hahaha, good times.

 

 

[Ultralights]

and important to know whether it is stalled or not stalled. Seems that many pilots (present company excluded) do not know how to tell whether an aircraft is stalled or not.Do you mean an inverted stall or being inverted and pulling?

actually you can do both, over the top of a loop, easy to keep pulling, and hit critical AOA with positive G, or even flying inverted, push to0 far forward, and again you can hit the critical AOA, much harder though as the amount of forward elevator authority is usually a less then up elevator movement, but the reason for the stall is always the same, exceeding the wings critical AOA. and the simple way to unstall, is reduce that AOA.

 

 

[planedriver]

Time to reflect on that book called BAK

 

 

[lark]

I did my first stalls (and spins and spirals) in a Tomahawk, that gets the sphincter going!

yeah, have heard if u look back you can see the tail flexing!

 

 

[Jabiru7252]

yeah, have heard if u look back you can see the tail flexing!

I know they banned spins in the Tomahawk after a few lost their tails. They certainly made a lot of noise during stalls. Long time ago now.

 

 

[lark]

I know they banned spins in the Tomahawk after a few lost their tails. They certainly made a lot of noise during stalls. Long time ago now.

Not too many ac about with T tails. Is a T tail weaker than a more conventional type arrangement? (dosent look as strong) or are they not popular for other reasons?

 

 

[motzartmerv]

They banned spins in them/?...news to me!!!!

 

 

[Jabiru7252]

They banned spins in them/?...news to me!!!!

Yep, over 30 years ago. I did my PPL in Tomahawks (PA38), did stalls, spins and spirals. Then in the late 80s they lost a few during spin recovery in the States. They can now only be spun if they have had some mod carried out. I would think that a T tail would have the necessary structure to give it strength but I have seen a few other T tails (ie Dutchess) wobble like crazy during run ups. The Nomad had the horizontal stabiliser halfway up the fin, while not a T tail, they were grounded because they lost the tail. I do some flying in a Lear jet occassionally and they have a T tail. I hope the glue is still good because the one I fly in was built in 1977. This video

 

shows a Tomahawk spinning. The comments (to me) suggest that Tomahawk has the mods because he claims they can be spun. Anybody still have old copies of the Australian Flying or Aviation Safety Digest would be able to find the original articles.

[djpacro]

Somewhere I have copies of tech documents wrt Tomahawk stalling and spinning. No failures of tail structure and no mods required for spinning - spin approval was never withdrawn by the airworthiness authority (FAA). More than a few lost due to spinning.

 

One observation is that different examples behaved differently so not everyone encountered those with unacceptable characteristics.

 

 

[facthunter]

"T" tails do have a lot of load . The B 727 when first airtested experienced airloads many times higher than expected by the design engineers, who had to beef it up straight away.

 

On smaller aircraft I don't particularly like it as a feature as it's probably not necessary so makes problems that you don't need. Nev

 

 

[Jabiru7252]

What is the advantage of a T tail. Is it to move the stabiliser out of the prop wash? Move it out of the turbulence created when the wing is stalled? Stop clowns sitting their kids on it at airshows?

 

 

[facthunter]

I think it's a styling exercise in some cases. Same as rearward sloping tails in slow planes. Nev

 

 

[motzartmerv]

Yea, I didnt think so either. The wiki page on them is interesting, no mention of loss of spin certification, but did say they were designed as spinning training planes due to their odd characteristics and the need to be flown out of the spin.

 

 

[Jabiru7252]

Maybe I am thinking of the old washing machine. We could not get that to spin, had to dry everthing on the line. There was a great article on the Tomahawk in Australian Flying many years ago that compared the Tomahawk and the Beechcraft Skipper. The two planes looked so alike it was scary. They were designed as trainers with particular stall/spin characteristics because flying schools requested such a trainer. Both came out around 1977 but I have not seen a Skipper myself. I guess if you feed the same numbers into a black box with the same desires, similar outputs must occur. I used to fly MHO, BNT, DAR, AFI with Aircare at Parafield.

 

 

[fly_tornado]

http://www.acmp.com/blog/piper-tomahawk-vs-the-beechcraft-skipper.html

[Guernsey]

http://www.acmp.com/blog/piper-tomahawk-vs-the-beechcraft-skipper.html

I used to fly Tomahawks occasionally but never a Skipper. Thanks for the post, very interesting.

 

Alan.

 

 

[lark]

Seems 1981 models had inboard wing flow strips fitted to make the stall more docile. It is claimed that the T tail was to provide "superior handling and flight characteristics" Whatever that means!