PA-38 Tomahawk outboard stall strips

[Mister Geezer]

Just a quick question about the stall strips that are a feature on the PA-38. I can understand why an AD was issued for inboard stall strips since that would be promoting rootstall but I can not understand why a second AD was issued for outboard stall strips? I was looking at a PA-38 a few days ago and I can't think why you would want to promote a stall in a position which is directly in front of an aileron? I have seen that the official Piper answer is that it is there to 'reduce the rate of roll' since the PA-38 is renowned for a large wing drop! One person said that the stall strip creates a vortex on front of the aileron and prevents spanwise flow.

Anyone with any ideas or even the 'correct' answer!

Cheers

[El Desperado]

The PA38, as I'm sure you know, has unpredictable stall characteristics. The outboard stall strips were fitted to reduce the rate of roll in the event of a stall.

They don't stop a wing dropping, and PA38s will drop either wing, or none at all, depending on which particular airframe you have just climbed in to, but forcing both outboard sections to stall at roughly the same time gives the pilot more time for recovery.

So why don't both wings stall at the same time..... Piper used a standard aerofoil section (GWA-1 ?) on the PA38, but made it flexible. As I understand it, the 'oil-canning' effect (American term) of the non-rigid structure means that the aerofoil section being presented to the airflow is not necessarily constant from one maneouvre to the next, thus the unpredictability of the stall/spin characteristics.

I used to stall and spin them regularly. Armed with the knowledge I have now, I wouldn't dream of it :)

[Boss Raptor]

As an ex Tomahawk PPL and later an instructor with 1400 hours on them...and a great fan of the plane...

As I recall the outer stall strips and large wheels were standard on the 'Tomahawk II' but retrofits on the early version...some of our aircraft (in the UK) did not have either and some had been retrofitted...

It was a fun plane and needed/taught good handling technique...flew a 152 once only and hated it!

[El Desperado]

Sure... great trainer for the reasons you state, poor trainer for the reasons you state !

The PA38 is a love-it/hate-it aircraft. Much more room than the equivalent Cessnas, and pushes you harder when the going gets tough. In the hands of the right instructor, I can't think of a better trainer. In the hands of an inexperienced PPL or a poor instructor, I can't think of a worse trainer.

When you start bolting on bits of plastic to the LE in something as small as a PA38, something has gone wrong. As an aircraft designed to be flown by a low-hours pilot, the stall/spin characteristics are horrendous. Not that the average PPL can't cope with it, but they bite and the statistics prove it.

Dangerous...no. Unpredictable.. yes. I still fly one regularly, but I wouldn't even think about spinning it.

[Windy Militant]

Don't know if it's true but I was told that positioning the stall strips in front of he ailerons was done to produce a pre stall burble that could be felt through the yoke which gave more time to respond to the onset of the stall as well as the other reasons given here.

[El Desperado]

Seems unlikely - as you know, the buffet felt through the column on the stall is caused by turbulent airflow over the elevators, not the ailerons. I can't imagine stall strips producing 'aileron buffet', but I'm not an aero-eng so may very well be wrong.

What is factual, is the stall characteristics of this aircraft are unpredicatable, hence the ADDs and the stall strips. Learn to fly this aircraft and you will not ******-up a stall recovery in another light type !