Spinning a Warrior/Archer

[taff_lightning]

As an over zelus student pilot I was sent off solo to practice insipient spins in a "long wing" worrier. In my enthusiasm I did what I know now (as an aerobatic instructor) to be an academic spin entry. The ship turned me inverted then the stability took over, gently flipped me back over and went spirel. I have since spun many "slab wing" cherokees and even with a trickle of power and different flap settings I've found that they just don't stay in. 1 rotation at most then spirel.

So in answer to your original question I think it because that don't stay stalled and the ensuing and possibly un diagnosed spiral dive might put you through Vne.

Having now done my fair share of dumm stuff in light A/C I also strongly agree with the chap/chapess who said don't spin anything unless the ship is cleared and you have a chute.

[sevenstrokeroll]

genghis the engineer

thank you for telling me that you couldn't get hershey bars in England till recently.

NOW that is information!!!

With all the World War 2 movies I've seen, the Americans were always handing out Hershey bars all over Europe. Even in the post war era, they were dropping
Hershey Bars to children during the Berlin Airlift.

I would have thought all of Europe would have been addicted to hershey bars!

[Dan Winterland]

No. Compared with Cadburys, they taste like cr@p!

[Genghis the Engineer]

As Dan says, Hershey bars are chemical-laden rubbish.

Next you're in this neck of the woods buy a bar of Cadbury Dairy Milk, (or if you prefer dark chocolate, Bourneville) and reflect on (a) that this is the cheapest popular chocolate in Britain, and (b) Hershey sales in the UK are tiny.

In the war chocolate was rationed, fortunately that has not been the case for some time, so anybody given a choice wouldn't touch a Hershey Bar with a bargepole.


So we generally refer to early model PA28s as either "slab wing" or "plank wing".

G

[astir 8]

The question was asked earlier - quote

"If the worst happens & you really botch the recovery, what is better; exceeding Vne or busting the g limit? And without a g meter, how do you know when you're pulling too hard?"

As I understand it, the chances of very nasty things happening if you exceed VNE by a relatively small amount (look Ma, no wings) are much greater than pulling quite a lot of excess G (look Ma the wings bent a lot but they're still there)

At least that's how it works with gliders

So if you really get yourself into that corner, pull harder.

[Genghis the Engineer]

Broadly I agree.

Certification standards generally work on the basis of nothing really nasty happening until 11% above Vne, or until 50% above the g limit, which in a non-aerobatic light aeroplane is usually 3.8g (so 5.7g).

Although, the couple of times (both on flight test programmes) that I've exceeded either (in one case, both), I've landed and had the aeroplane thoroughly inspected before doing anything further with it. That said, both times, the aeroplane was fine.

G

[Pilot DAR]

A question for you DAR - how did you deal with the unrecoverable spin risk in those PA28s. I can guess what I might have done,

Well I'm going to have to hang my hat on the expectation that a certified aircraft (which is "very experienced" in service) will not be subject to an unrecoverable spin. It is a design requirements that all certified single engine aircraft be able to be recovered from a spin:

"(iii) It must be impossible to obtain unrecoverable spins with any use of the flight or engine power controls either at the entry into or during the spin"

So it's up to me to have the skill - and altitude! - to do it. The Caravan at full aft C of G was the most worrying, but it came out perfectly well.I mitigate risk by working up to the most rigorous spins in stages, observing changed behaviour along the way. If a recovery does not seem to be happening, I'd be adding power, but I have never had to do that.

I was required to show for the "...or engine controls..." portion of the foregoing requirement once in being told by the regulator to enter spins with 75% power on in a Lake Amphibian, which I was testing for an increased power engine. As I expected, against the engine torque, it would not even enter. With the torque, the result was predictably something like a snap roll (even with the slow deceleration entry). I decided that this type of aircraft should not be doing snap rolls, so I did not do it again! It was un-nerving looking forward at the horizon - upside down - with full rudder and nose up applied! It was time to recover right then! It came out very nicely - Lakes spin beautifully, if you do it power off!

nothing really nasty happening until 11% above Vne, or until 50% above the g limit

Yes but.... In each case, you are assured that a certified plane will remain flyable within those limits. However, you are not assured that at G between 100% and 150% you won't have some damage. Up to 110% of Vne, you are not going to hurt the plane, as long as you are very gentle on the controls, and do not hit turbulence. I have seen the wings of a Cessna 180 which were badly wrinkled outboard of the struts as a result of a careless jump pilot spinning it down through a cloud after the jumpers left.

I was faced with this decision (which has to be made very quickly!) in the Caravan spins. I did not have to exceed Vne and 2.8 G (with 3.5 being the limit), but it was looking like I might have to for a moment. I would rather have exceeded Vne a bit, than got to 3.5 or more G. Once at that high load factor, a bit of turbulence could be very bad.

All that said, I do not like spinning planes. I regularly spin spin approved planes for my proficiency, but other than that, I spin only as required for the testing work I do, and then in accordance with an approved test plan, precautions, and no more than I need to to achieve the objective.