Originally Posted by
Kengineer-130
That is possibly the most stupid comment I have ever heard
... I have been working and flying on Hercs for the last 9 years, If anything has system redundancy the Hercules has... 2 completely seperate duel hydrualic systems for the primary flying controls, then manual reversion, the utility system has full mechanical over-ride should the electrics fail, so you can still get the flaps and gear down, and also have manual wind-down for the flaps and landing gear. If it STILL dosn't work you can free fall the gear, and if it STILL dosn't work you can disconnect the screwjacks and allow the gear to fall under it's own weight....
The aircraft can fly on one engine at a push, and will work with zero power, as the engines are fully mechanical. So I think I would rarther be on a Herc than any other aircraft in dire straights.
Perhaps your Herc's are different than the civil ones I flew. Manual reversion? Our books said never to simulate loss of hydraulic boost assistance as it could result in "an unusual attitude and requirements for high manual forces to move the flight controls". Also, "Greatly increased forces will be required to move a control for which hydraulic assistance has been turned off"(such as after a booster assembly having failed in a hardover).
These examples are where you still have the hydraulic fluid in the lines but little or no hydraulic power available. When parked, try moving the flight controls on the ground with only the hydraulic suction boost pumps on and then with no hydraulic power at all. The first is not easy, the second is extremely difficult at best. Now imagine trying to do that with airflow over the flight controls...good luck.
Then there is the loss of all hydraulic fluid from your two independent hydraulic systems that power each flight control system for redundency. Unlikely situation perhaps, but there have been several Hercs that have thrown props that went in one side of the fuselage and out the other damaging other engines and hydraulic systems. As well, military operations increase the risk of this situation occuring. I am not aware of any mechanical backup to operate the flight controls(manual reversion).
So what to do? According to the book, use your electrically operated trim tabs and engine power with inboard engines(that blow air over the tail) for pitch control and outboards for speed control. Worked somewhat well in the sim on the several attempts that I tried it.....for a while, after finally gaining control. Usually I could get set up on approach. But at some point, each time I tried it, control would eventually be lost and I crashed. Perhaps this particular sim is different than other sims and for sure the airplane flies much better in real life but I sure wouldn't want to try landing after a complete hydraulic loss.
Personally, I thought Lockheed's hydraulic system design was poor. The gear, flaps, nosewheel steering and normal braking system(the one with anti-skid) are on the same hydraulic system(utility) which was run by engines 1 and 2. So when these two engines fail(and they always seemed to in the sim), you lose all these functions. So the gear has to be manually extended which may take a long time, the flaps have to be manually cranked down into the airflow with muscle power if you decide to use them and not more than 50%(That will probably take a long time as well but I have never talked to anyone who has done it). If you are fortunate and not too heavy and your second shutdown on the left wing gives you enough time, you can extend the gear and some flap while you still have that hydraulic system available. In the sim, we were always fortunate in terms of weight, altitude, temperature, runway length availability and time availability before shutting down the second engine. We would only extend the flaps to 20% allowing some flap with minimal drag plus increased rudder boost. So now we are landing with hardly any flap, high approach speed, no reverse capability(due to asymmetry) and no anti-skid. Why didn't they put at least one of these systems on the other(Booster) hydraulic system. Lockheed logic we called it.
On a separate subject but speaking about the main gear, there is no guarantee as far as I know that a gear will extend on their own, as preferred during a manual extension. Perhaps the screwjacks are dirtier than they should be and that is not unusual for typical herc ops. Or something such as a rag could be the problem, after all, that is what maintenance cleaned the screwjacks with so your gear would hopefully extend by themselves after pulling the big handle to release them. The alternative, 600 turns of the crank if a full manual extension is required. How much fuel did you say we have left?
So now you find out that you need to do an emergency gear extension on one of the main gears by disconnecting the screwjacks because the gear is so jammed. Special tools in a metal box riveted shut(so the tools don't mysteriously disappear on you over the yaers) are required. Somehow you have to smash the box open then spend however long it takes to disconnect the the screwjacks so the gear will freefall down. Remember to disconnect the bolts in the proper order or you may lose your hands in the process. And you won't be able to even attempt this if you have a heavy piece of cargo right near the gear area that doesn't allow access to the panels to do all this. After all, the plane was designed among other things, to carry cargo. As you can see in this C-130 gear up landing report, it took 30 minutes for the F/E and loadmaster to undo only two nuts in their failed emergency extension attempt.
200000618
Easily flying on one engine? Depends on a lot of things I'm sure.
As 411A mentioned, no stick shaker. In fact no artificial stall warning at all, however there was plenty of natural stall warning buffet. But no certification in the U.K.because it didn't have one fire bottle per engine? Neither does a 727.