Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
Good stuff. maybe someone here knows why that Strikemaster had that rough coating on the wing leading edges.
Was it on the Saudi one? Could have been an anti-abrasive rubberised coating? I've seen similar on tailplanes of aircraft operating off sandy/stony airstrips to protect them from damage.
I'd thought maybe it was for rough-field ops, and even suggested it may be some sort of coating to disrupt air-flow at certain angles in a hot climate, although I'll admit that was a very 'outside guess'.
I took a couple of shots specially to show this (I hadn't noticed it before, during previous visits), and I'll post them tomorrow, as I haven't downloaded the 'extras' from my other cameras yet.
The T Mk5 had tip tanks but no nose strakes (they were originally converted from T Mk4 airframes), when the aircraft were upgraded to T Mk5A standard (an avionics upgrade of single VOR initially and later a DME) the tip tanks were removed.
This caused 2 related aerodynamic problems. Firstly directional control at high angles of attack was poor and, associated with this, the aircraft's spin performance was unstable and very oscillatory.
Secondly there was little or no stall warning buffet and stall entry was rather sudden (which could bite the unwary).
Neither of these problems were desirable in a basic trainer!
The spin problem was caused because removal of the tip tanks resulted in a greater fuselage weight (and thus inertial moment) relative to the wings (something known as the 'B : A Ratio'). This was cured by the fitting of the strakes to the nose (the strakes around the engine intakes are there for a different reason and are common to all JP5 types).
The stall problem was cured by the fitting of a roughened leading edge surface to the outboard part of both wings (the grey area ahead of the red on the models). This was an adhesive coating that actually felt like rough concrete! The idea being that this would increase the pre-stall buffet and result in wing drop at the stall (ie the tips stall before the main part of the wing), thus giving a more defined stall entry.