And that’s exactly what the student should learn.
I have no idea about the rigidity, but i have also not heard about a failing t-tail on a Tomahawk
Unlike many GA types, the PA38 uses an electric oil pressure sender rather than being direct reading. As it’s measuring a very small current it may well be susceptible to big electrical power changes. A normal landing lamp will take 10A or so. Apart from going through the 30+ year old electrical system, if the oil pressure fluctuation on landing lamp selection worries you then you could consider replacing the lamp with a Whelen Parmetheus LED lamp which would use less than 1A.
On the PA38, the nose wheel steering is very direct. As there is no bungee or spring between the rudder pedals and the nose gear (as found on PA28s and Cesnas), it’s a simple rod, any small pressure on the rudder pedals will move the nose landing gear (NLG). Cross winds when taxying can put quite a side force on the PA38s big fin which may be counteracted by the rudder pedals without realising it which in turn moves the nose wheel and so on.
On take off/touch and go’s mean a bit of rudder work as the power is applied – if the nose wheel is on the ground then that results in nose wheel steering input – throw into the mix any cross winds and…
Make sure there is not excessive play in the nose wheel bearings, NLG torque links and the NLG itself in the engine mount or the steering bellcrank on top of the NLG. Tyre pressures can also affect things.
Main Landing Gear leg bolts should have their torque checked regularly. MLG wheel axles are shimmed. The MLG legs do start to flatten out over the years and of course this will alter the wheel alignment.
The 11000 hour airframe limit is for the wing spar and ‘associated structure’ – ie the wing carry thru spar in the fuselage. There are ‘fixes’ out there but the cost makes it almost not worth doing against the value of the complete aircraft. Other fittings in the fin/rear fuselage have separate ‘lifes’ but aren’t a major issue.
Thanks for all the responses!
Firstly, I want to say that because of the very salty air up here, the brake discs start to rust VERY quickly, and this could cause them to stick unevenly. But after a run down the runway and using the brakes, this layer of rust should be taken care of. Maybe a bit of WD40 before hand would help?
I think investing in an LED lamp would be a good idea for the long term. Will definitely look into that!
I did a couple of stalls in our Tommy on my check-out flight and yeah, if you keep her straight then there shouldn’t be much wing drop. But it’s hard to anticipate, I mean a wing drop can occur accidentally and then it’s good to know how to recover from a spin! (which in PA38’s is a slightly different technique than most other trainers due to it’s T-tail). I read that article in the CAA ‘clued up’ mag too, and that seems to have been an unintentional spin! I think they were below 4500ft.
Once after rolling out on landing, I noticed violent shimmy which shook the peddles like hell! That was at >20kts! The toque link nuts were loose. So we tightened them (not too much to allow movement), and that hasn’t happened again thankfully. I will check the rest of the nose gear connections though.
Finally, about the gauges. I checked the oil temp and press. connections. The were screwed down well. I cleaned and checked them and they looked fine too me, maybe the sensor on the oil temp is broken, because the needle fell over completely during flight!! Also, I noticed that on climb-out, the fuel pressure drops a fair bit, but I heard that is normal.
There is a thread on LED lamps here – do a search on “LEDS” etc. The 28V ones draw about 1-1.5A and the 14V ones about 2x that. They are awesome.
But this is nothing to do with the oil pressure indication being affected by the landing light. It sounds like there is a short (or bad wiring) around the oil pressure sensor, and its ground is passing through a piece of the airframe. The sensor needs to be wired directly to the instrument. The airframe should not be used for carrying any ground connection for that.
Lots of things can cause a shimmy, and it isn’t always fixable. My TB20 has always had a bit of a shimmy, from brand new. The best thing to start with is to check the tyre pressure, tyre type, and that all the linkages are not worn (are play-free). The last bit is likely to be a tall order on a 32 year old aircraft, and may not be all that cheap to fix using official parts.
Fuel pressure should not drop during climb. Why would that happen? Is it literally the case that if you fly straight and level at full power, read the fuel pressure, and then climb at 20 degrees UP, the reading changes?
Ok, I’ll check all the wiring again. It’s hellishly crammed in there though! haha But its good fun.
The tyre pressure and links all seem to be ok. I haven’t checked the connections on the top of the nose gear shaft, under the hood. Will do that.
Hmm… is it not? It helps when I turn on the electric fuel pump but I shouldn’t really have to do this. And yes, it is exactly as you described! When I’m straight and level the pressure usually goes back to optimal. I just want to say, though, that it doesn’t go out of the green, it just drops considerably.
The only thing I will add is that you proceed with caution. The aircraft is a certified aircraft and as such pilot/owner maintenance is limited to what is allowed by EASA.
The fact that there is no based licensed engineer is no excuse from not having the aircraft released to service by an appropriately licensed person post maintenance – and to carry out pilot/owner maintenance, one should have access to the current manuals (which include wiring diagrams….) and other continuing airworthiness data.
Fuel pressure indication often does drop at max rpm – the attitude of the aircraft should have no effect on that indication. Be very careful where and from whom you source information from….
The fact that you want to spray the brake discs with WD40 concerns me that your enthusiasm outweighs your knowledge.
Lecture over – I didn’t want anyone thinking I was encouraging anyone to go beyond what they are legally allowed to do. 
There should be licensed engineers in Orkney – not at a GA maintenance facility, but working for an airline operating piston engine airliners. The other aircraft owners in Orkney could put you in contact with someone.
Be wary of fuel pressure fluctuations. It could be first sign of a cheaply fixed problem, which if left could lead to a forced landing. Not on a Pa38, but I’ve had an air leak at the mechanical pump gasket cause fluctuations – and without fuel pressure indicator have had an engine almost stop due to a blocked finger filter in one fuel tank.
Do NEVER spray the discs or the calipers with ANYTHING. THat’s a big mistake. Dismantle and clean them, buy new brake pads if necessary, but never lubricate brake parts, not even the caliper parts.
AFAIK the wings were more flexible than certified, as they were built with fewer ribs. I haven’t heard anything similar for the tail thought it was meant to be like that.
Maoraigh, you’re right, there are Logan Air engineers up here for the BN2 Islander and the SAAB 340’s. I suppose I could ask them to take a look at our plane, but I think they are busy enough with all the bigger planes. You think the low fuel pressure on climb could be a sign of a clogged filter?
And don’t worry, I haven’t and I won’t spray the brakes with anything. WD40 evaporates after a while, but still I shan’t use it! haha
Also, in reply to aerofurb, we are very careful not to go too far with what we do (as my dad and I aren’t aircraft mechanics), so all we do is check stuff and only do very minor repairs. If something to do with the electrics or brakes needed repairing we would probably pop over to the Logan Air hangar and kindly ask the guys there to have a look. Apparently the are very friendly and approachable.
Cheers!
