Global Hawk Hard Landing Explained

Maj. Gen. Eichhorn tells the story of the Global Hawk's hard landing at Edwards...

Commentary by Maj. Gen. David Eichhorn Commander, Air Force Flight Test Center 6/2/2009 - EDWARDS AIR FORCE BASE, Calif. -- Men and Women of the Air Force Flight Test Center, Actually, it all started while you were probably watching prime time television or perhaps you were having dinner. You may have even been reading your kids a bedtime story. It started for me at the civ-mil dinner at Club Muroc. We had just gotten our food on Thursday night, 28 May when the Test Wing Commander pulled me aside for a word. The word was that an aircraft that had been flying for hours had a spoiler malfunction. It was Global Hawk and a spoiler problem is a major problem for that aircraft. So some of you are asking, what are you talking about? Here it is. Spoilers exist on virtually all modern jet aircraft. Just as the name suggest, they're there to "spoil" the lift of the wings and cause more drag. They're needed so aircraft can slow down and descend efficiently. Modern, very slick aircraft really need spoilers or they will float for a long, long ways just as any glider floats. (Contrast this with the F-4 which "floated" like a brick - now before the Phantom drivers come after me, understand, I loved that aircraft too but engine out, we all agree, it could fly formation with a brick.) Back to the sick Global Hawk, what to do, what to do? Letting the aircraft land "normally" would result in failure of the landing gear. Why? Because the lack of spoilers would cause the aircraft to touch down too fast and then bounce back into the air. It's the next landing that's extremely nasty. The aircraft would float up and up and then nose over to come back down. The subsequent landing would be hard enough to fail the gear and crunch some very, very expensive sensors on board. The team at Edwards worked for hours with company engineers in Rancho Bernardo to find some way to safely recover what had never been safely recovered. They decided a lakebed landing was the better way to go. Now this would not be an option with a manned aircraft since the lakebed runways are unlit but the unmanned Global Hawk wouldn't know the difference. About 11:30 o'clock p.m., to get the aircraft to shed the extra airspeed, it was also decided to shut off the engine. So Global Hawk landed the same way the Shuttle landed on Sunday with no go around capability - dead stick. We committed 100% (all in) to landing for good or ill. It was a daring plan! It worked! The 452FLTS/UAV CTF did fantastic, as well as the entire 412OG team! What a scramble in the dark to make this all work! Kudos! Only Edwards could have recovered the aircraft safely that night. The aircraft floated (without spoilers remember) far further than anyone expected. Anywhere else and it would have been past any sort of proper landing service. But not at Edwards and on Rogers Dry Lakebed. It landed about 6 maybe 7 miles down the runway. The right main gear hit an obstacle and was badly damaged, but I must say, I was impressed with how well it withstood the damage. It didn't collapse for several more thousand feet. This saved the sensors. The most expensive part of the aircraft. So instead of a multi-million dollar mishap, (no threat to life but a lot of money is a lot of money) we are keeping our fingers crossed that this one will be less than a million dollars worth of damage and we gained a wealth of information on how to safely recover the aircraft when this happens again. Priceless! And that, ladies and gentlemen, is why Edwards is here -- talent tightly coupled with natural resources.