Ben wrote:
the nut on the other end of the bolt that connects the elevator trim tab to the trim worm got loos
Ultranomad wrote:
Anyone who has been torquing nuts for a reasonable length of time will tell you the right torque is easy to achieve by feel – I am not advocating the use of this practice where a torque wrench is mandated, but at least it’s reasonably safe when push comes to shove.
I can agree that doing it so many times helps but we are talking aircraft not T-34s. If a nut gets loos the aircraft might come down. A friend of mine crashed during his first flight after maintenance because the nut on the other end of the bolt that connects the elevator trim tab to the trim worm got loos and fall out, then, the bolt came out, the nose pitched up and my friend and his engineer had to push HARD (one with his feet) on the yoke to avoid the stall, they both walked away but the aircraft was totalled.
Ben wrote:
The disregard of Russian pilots and engineers for safety goes further.I saw a photo of a Russian airliner taking off with tires that the canvas below was exposed, is it a recipe for troubles?
I also saw how a Russian engineer torqued the bolts that hold the main rotor blades on an helicopter. The torques meters that were available were out of (calibration) date, so he took a metal tube, measured (by the eye) 1m arm and gave it yank and that’s it. When questioned he said that this is ok.Eastern Block aircraft are built like tanks but the safety culture is lacking. Now you know why I don’t fly with “Eastern Block” airlines.
As a person born and initially taught to fly in Russia, I can say that the safety culture is often direly lacking indeed, especially in two aspects: CRM and the culture of doing things exactly by the book. Sometimes things get eventually corrected, sometimes not. In this particular case, the resonance was huge, including a circular on deicing practices being issued by the Russian CAA. If I remember correctly, the pilots in question kept their jobs but were officially reprimanded and probably lost their bonus pay.
On the other hand, some instances appearing to be safety violations are actually fine – for example, the tires on most Russian airliners have an official wear limit down to the third layer of cord, which explains what you saw on the photo. Tightening rotor blade bolts without a torque wrench is probably not OK in this case, but I have seen similar procedures officially mentioned in older manuals – one instance I remember offhand is the T-34 tank, where one maintenance procedure says “extend the wrench with a 1.5-2 m length of pipe and tighten the nut with the force of two men” (that’s one big f*ing nut!). If the nut/bolt is secured with safety wire, a split pin or a similar device, the torque need not be very precise anyway. Anyone who has been torquing nuts for a reasonable length of time will tell you the right torque is easy to achieve by feel – I am not advocating the use of this practice where a torque wrench is mandated, but at least it’s reasonably safe when push comes to shove.
There have been incidents where the diluted slush that remains after de icing re-freezes around critical control components and has caused stuck flight controls.
To keep this from happening some operators specify a two-step de-icing procedure when certain areas of the airplane are affected by icing.
Someone has mentioned it above and I can only confirm that the airplane was dripping de- icing fluid for days to come.
I know it is not the most convenient, but in my opinion “de-icing” light airplanes is best done using covers that you just pull off in the morning. Maybe there would be a market for a super super lightweight fabric that you can easily apply and remove from surfaces that are affected
But frost and ice of parking outside and no hanger available.
Aviathor wrote:
Well, I once picked up a rental car at Gardermoen that had been washed and stored in sub-zero. I can tell you that I spent the better part of one hour getting the doors opened, the engine started and thereafter the driver door would not shut because the lock was frozen. Temperatures were -20°C
That has happened to me as well. It’s important to drive 15-20 minutes after you have washed it, so water and ice will evaporate.
Every morning I drive through the Hell tunnel to work (nothing to do with the English Hell). It’s a 3-4 km tunnel going deep into the mountain, and the temperature there is about +10, all season. If I take a car that is snowed down, then driving through the tunnel will thaw off every bit of snow and ice. Very practical. When on the other side, the temperature is of course subzero again, and everything freezes (theoretically). But, that has never happened in the last 20 years The reason is of course the wind from the speed will evaporate water, even if it freezes up when on the other side.
The major drawback of deicing fluid, (and by that I mean the stuff they spray on hot from a big truck, wasting hundreds of litres on the floor) is that for weeks afterwards you get deicing fluid seeping out from hinge lines etc. Wouldn’t stop me using it if it’s needed though.
LeSving wrote:
Yes. It makes no difference at “normal” temperatures. -40 deg C may be another matter though. We wash the cars here at subzero temperatures also, no problems with that either.
Well, I once picked up a rental car at Gardermoen that had been washed and stored in sub-zero. I can tell you that I spent the better part of one hour getting the doors opened, the engine started and thereafter the driver door would not shut because the lock was frozen. Temperatures were -20°C
denopa wrote:
If the part that stays and freezes is, say, around your control cables, you’d better do your pre-take-off checks diligently.
Of course. But this is always equally important in subzero temperatures (as it always is, in all temperatures for that matter). A spray bottle with deicing liquid that you can apply on certain areas and parts may also be a good idea? (never tried it though, but I imagine some adverse effects on oil and grease?).
I guess I am a chicken, but I keep the tap water (hot tap water) inside a shopping type plastic bag (or two inside each other) which I then drag across the surfaces I need to de-ice. Effective as long the airplane is not iced down completely.
If the part that stays and freezes is, say, around your control cables, you’d better do your pre-take-off checks diligently.
