Ageing aircraft like ageing spouses, Become more amd more nagging as they age. Having said that, may I explain.
Being an Air Force with limited resources PAF has a record of pushing the limits on aircrafts life. Likewise, we do not retire our tools untill they beg for mercy killing, Whereas we should have respectfully buried those years before with full honours, and brought new ones in their place. It may be the nostalgia of keeping my favourite screwdriver untill the philips end changes to a chisel, or it could be my ingrained fear that parting with my lucky screwdriver would bring bad luck, or could it be the psyche at the back of our technicians’ mind that each screwdriver coasts a lot- that too in dollors. whatever the reason may be, we like our equipment to outlive us.
Comming back to nagging part, every day I see the Tweety Bird ( T-37) serving PAF’s traning flying like a speechless mule that has a mission in life. But it still does not nag – not loudly at least. Deep inside its heart, it also yearns for a retirement, giving that the first T-37 flew in 1955. It is hard to imagine how many pentagenarians are ready to have 2 adults ride on their shoulders and still try to land softly on touchdown after a high jump. A hard landing the Tweety takes in a stride and nag the Tweety does, albeit politely.
AirCraft is a complicated machine. it has a wide varity of components, ranging from metallic panels, to rubber hoses, to thin wires, to high quality HUD glasses and complicated avionics. The variety is bewildering. Reliability and maintainability of all this jumbles varies just as much, some components require huge test rigs to calibrate, while others are hardwired using lasers. Some have lives just a fraction of the aircraft life, and some never get off the aircraft, ever.
With such an amalgam of componemts, it is but natural that as the aircraft ages, its maintenance workload increases. Parts that get old start to leak: Some develop cracks that were never anticipated. No aircraft is designed to operate 50 years, and yet we make it to. But with the decision to fly the aircraft for so long, we must weign the accompanying increase in risk, workloadin its upkeep and operating cost. Statistically the flight safety risks, maintenance workload and the cost of spares, all increase with the age of the aircraft. Obsolescence also adds to the cost of spares as they become uneconomical for the manufacture old technology components. Late upgrades to pre-empt failure coast more on ageing aircraft.
nevertheless, the decreasing MTBF ( Mean Time Between Failure) is not uniform across the components over a long life. There are components such as tyres and drag chutes that are designed for a limited number of sorties, and there are aircraft panels that are designed to last thousands of hours. Life expired aircraft pitched in park and in rounabouts even road side in Lower topa and my sabe has a pole stuck up its *** in the front off Peshawar Mucipal building and these are testimony to extremely strong materials in construction of their basic structure, skin and panels.
On top of all this therer are unplanned factors such as FOD, accidents, excessive aircraft stresses, weather phenomena, etc. The bolt from the sky , the birds in the sky, or the nut and bolt on the ground that just come out of nowhere , causes the maintance crew an additional headache, for no fault of theirs. but agian the bolt on the ground is someone’s fault. A technician thinking about flood water entering his village in Mardan or thinking how to convince his wife so he can get laid because she is pissed at him that there is no money left for her to buy a dress or something and the tec will forget his tools in, of all the places , the engine intake. These issues cannot form a major part of the design philosophy or maintenance of an aircraft part.
And that, preciely brings in a serious dilemma faced by today’s maintenance engineers. As long as the aircraft are new they perform like the ferrari that comes with a 50,000km unconditional warranty. But on the ageing aircraft the warranty is long forgotton promise. the big question for the aircraft is how to predict and avoid failure of a component without losing an important part of its life? It is easy to remove a component and put it in a repair cycle, or altogather reject it, thinking that it might fail in a couple of weeks. But how to make that judgment without knowing the complete effects of that decision? The manufacture gives a certain life to an aircraft based on certain operating conditions. The design engineer does not know how is he going to operate the aircraft while it flies in Risalpure, Samungli or the corrosive Masoor. Thankfully the taxpayers who are not so many in Pakistan have faith in PAF not to throw away their hard eanrned money. But with his luxury comes the enormous burden of ensuring its best utilization and balancing cost of maintenance against life of a pilot.
With such Varience between the design and operating conditions of ageing aircrafts, arises the silent whimpers of the ageing aircraft, Which show a little material failures that never happened before. Every new crack, every new leakis saying that the aircraft needs more than regular care. It needs meticulous inspections like never before. It needs that second look just in case you missed the silent tears from the sobing fuel hose, or th ebleeding from the hydraulic fluid connection in your first glance.
And the most important aspect is that we dont have that kind of cash that we can simply say retire these and by 50 new ones , with all the sanctions placed on us, We should be proud of our PAF that it has done so well that it has the reputation of being one of the best. we only talk about the pilots ans thats it but we forget that the men who work on them are the real heros.
So next time you pass by an aircraft past its prime years, eye it closely to look for signs of ageing, Which will not show easily, but still would be there to warn you of the impending catasrophe.
Nagging is not something you should miss out or brush off as trivial. And you could relicate it in your life, with your wife , when your better half is past 40- if you wish to live long.