From Art Nalls/2-4-08
UPDATE 18
Well, as with the entire program, two weeks turned into two months. Lets hope it doesnt turn into much more than that. The two weeks comment has been a running joke since the beginning of the project and many of you caught it, but some actually expected us to be in the air in two weeks. It probably will be two weeks, but a day here and day there, spread out over several months. Note the banner after our first flight and please excuse the spelling. The spray can didnt have spell-check.
The airplane is back in the hangar and weve completed a detailed inspection. The damage is very minor on the outside and not much worse on the inside. The front reaction control, called a puffer duct by true Harrier people, concerned me the most. Its an extremely critical flight control, controls tons of very hot, high-velocity air and built to exacting specifications. I also dont know if any spares are available. Plus the airplane did actually contact the ground near this critical part. But once we cleared away the wrinkled sheet metal and actually removed the ducting, the nose reaction control is fine and not damaged. The engine also appears not damaged, through the first 3 stages, but were still waiting for a full bore scope inspection and ground runs to declare it safe for flight.
As we anticipated, the cause of the hydraulic failure surfaced immediately as we applied our hydraulic generator and 3,000 pounds of pressure. Bright, red fluid was vaporizing in the engine bay, from a split hydraulic line on the port side. The failure appears to be due to a previous modification, possibly for flight test. Those who are familiar with this airplane are aware that it was used as a flight test asset for British Aerospace. There was a tee welded into the line, then capped and no longer in use. Thats where the crack propagated, causing the leak. A new line should solve that problem.
Fortunately, we could access that line without removing the engine. All we needed was six-foot arms the size of pencils, twelve fingers, and eyes that can see around corners. This would be an easy job for a space-alien, slightly more difficult for normal people, but clearly not impossible. Engine removal would have been a MAJOR delay in the program. We were lucky.
That particular line, along with several other lines all dated 1970 - and the hydraulic pump, were shipped to a company in Washington State for evaluation. They claimed to be able to make anything. However, once they received the hydraulic lines, they said, we can make anything - except these.
The hyd lines have special ends and fittings that are attached to the tubing and are unique; at least weve never seen them. Like everything, they are Harrier-specific, there are no substitutes, and theres not much room for adapters or workarounds. Eventually, we will develop the capability to manufacture new lines in-house, so well need to locate a source for these ends and the couplings. From our experience, nothing has been simple, easy, or inexpensive and we dont anticipate these will be either, but it also is not rocket science.
The hydraulic pump was a surprise. Since it uses hydraulic fluid as a lubricant and coolant, and it ran for some time absolutely bone dry, we expected it to be toast. However, upon teardown inspection it was reported pristine. No visible damage at all. Were waiting for a full bench check and certification and I have absolutely no doubt that will be fine as well, since I just procured two expensive spares. If I couldnt have located any spares, Im sure the original pump would have been ruined, but since Ive now got some extras and paid dearly for them I probably wont need them. Thats also been part of the program. The spares will no doubt remain on the shelf indefinitely.
Immediately after the flight, we took some time to do a self-evaluation. What did we do wrong? We analyzed everyones performance from the top down, and have a list of improvements that well implement before we take to the sky the next time. Weve modified our briefing procedure, our emergency procedures, our ejection seat procedures and a whole lot of things that will help us do this better and safer. In only two flights, we demonstrated that our center of gravity is acceptable for handling from zero airspeed to 350 knots and up to 4 Gs, the reaction control system is fine, and all aircraft systems are operating just fine, except for a nearly catastrophic hydraulic leak. We also demonstrated that we could operate from our civilian airfield. Except for emergencies requiring a crash crew or pure vertical landings, which this emergency certainly did, we wont be using NAS Pax River. Eventually, we will build our own vertical landing pad at St. Marys and are beginning the application process for that.
I hope you have seen the video posted of the emergency vertical landing. Its available on our website. I am very proud of that landing, considering that I hadnt actually hovered a Harrier in 16 years. Although we were required to hover much earlier in the program that we had planned, we had planned for contingencies, such as this. Im very proud of the entire Sea Harrier TEAMs performance under extreme pressure. This was no simple emergency, if there is such a thing, and in conventional aircraft the outcome could have been quite different. In a Harrier, it was relatively minor.
No one panicked. There were no un-controlled bowel movements or decapitated-chicken dances. None. (Quite a change from the exploding GTS and subsequent fire, which I think had one of each.) Everyone did exactly as briefed and pulled together with fuel and options decreasing rapidly. That teamwork convinced me, more than ever, that this is an achievable objective. We may not have all the best tools, the best facilities, nor the supplies and spares that we could want. We certainly arent the Big Boys, and dont have unlimited pocket books, but we DO have dedicated professionals who want to be here and be involved, and thats enough for now.
Many have asked, why we didnt use the emergency blow down system? There is a very simple explanation - - - because we didnt have one. That system requires an explosive-actuated valve that is not available to us. There arent any available, so we made a calculated gamble to fly without it. We mis-calculated, obviously. But in some circumstances, the blow down system does not guarantee safe gear extension, and it may not in this one as well. Still, it would have been better to have it as an option. To that end, weve re-designed the system to incorporate an electrical solenoid valve that will allow us to extend the landing gear. That will be part of our next series of ground tests.
The hydraulic parts will begin arriving this week and well start reassembling the SHAR. After that, well service and test the hydraulic system, test the landing gear and the new emergency system. Well also take this time to modify the cockpit for a better camera installation and flight displays. Hopefully, none of this will delay getting back into the air, but while were waiting, we might as well continue to make improvements.
I dont have an estimate for returning to flight status, but as soon as I do, Ill post it in another UPDATE.
