Originally Posted By: Win
Originally Posted By: Astro14
.... She crashed the airplane because of poor flying skills.
She was too close abeam the carrier when she began the approach turn. To compensate, she skidded the airplane .... As the airplane rolled out on final, it was nearly 20 knots slow ....
Once the decision was made to push a bad position, only to wind up in an even worse one, was it still possible to avert the crash? Or do you get out then and there while you still have some control?
Win - Simply, you have to act early to maintain control of the airplane/situation. If you allow a situation to continue to degrade (like this one, or Air France 447) you can arrive at a place where the airplane is still in the air, but the crash is inevitable, where it cannot be saved or recovered.
If an engine fails on an airplane while it is slow, and configured for landing, you have to immediately increase power on the operating engine and, in many airplanes, reconfigure (adjust flaps, airspeed, etc.) immediately in order to maintain control.
IF an airplane slows below VMCA (Minimum control speed in the take-off configuration, a.k.a. air minimum control speed or minimum control speed in free air), you simply, by definition, cannot go to full power on the operating engine. While VMCA is defined at takeoff power (full thrust) it is ALSO defined at 5 degrees or less bank.
As the airplane increases in bank angle, the load factor, and hence, Angle of attack (AOA) increase, and a loss of control can happen at an even higher airspeed, because the AOA is also critical in controllability. In the F-14A, VMCA was 140 KIAS with one engine in full AB. VMCA was much slower for an engine at full dry (non AB, AKA military power) thrust. Closer to 120 KIAS.
Another critical bit: L/D max. In the drag curve, which looks like a big valley, there is a spot at which drag is the minimum. That spot is L/D max and it is the very floor of the valley.
Faster than that velocity (above L/D max) you are speed-stable, meaning that an increase in speed results in an increase in drag, which slows the airplane, while a reduction in speed reduces drag, which allows the airplane to accelerate. So, above L/D max, add power, and the airplane flies a bit faster. Minor changes in airspeed are dampened out by that speed stability.
It gets ugly below L/D max... because the curve rises (drag increases) as airspeed decreases. As you slow, the drag goes up, causing the airplane to slow even more. So, a slight power reduction, or a slight change in airspeed, suddenly requires a lot MORE power to keep the same speed. The farther to the left of the curve, the worse it gets.
Note that the L/D max numbers and curve change with a change in aircraft configuration (flap setting, gear, etc.), but the basic principle is true whether you're flying flaps up, or full flaps for landing, or something in between.
So, you slow the airplane below L/D max, then it takes a LOT of POWER to fly at that speed. If you've simultaneously slowed below VMCA, you're in deep trouble. You don't have the flight control authority to handle the thrust asymmetry, but you NEED that extra thrust to stay in the air.
Commercial airliners fly well above L/D max when on approach, so they are speed stable.
Navy fighters are different. There are structural limitations on a Navy landing, including arresting gear engagement speed (which puts load on the tailhook and airframe). For example, 119 Knots was the max gear engagement speed for an F-14 at 54,000# landing weight. So, they generally fly pretty close to L/D max when on approach, to minimize the landing speed.
Which means that you can't get slow on approach, or it's hard to get out of the L/D max drag situation.
As an example, in the F/A-18, if you lost an engine when fully configured, you had to move the flaps to 1/2 immediately. The airplane could not maintain altitude on one engine with gear down and full flaps. There was simply too much drag (a point I learned in the simulator - it simply wouldn't fly, not even in max AB on the one good engine...) from the fully extended flaps and drooped ailerons.
So, let's take a 767 for example - lose an engine on final, normal configuration (flaps 30) and you've got three choices: 1. add power on the good engine and land. 2. add power, retract the flaps to 20 degrees, increase the approach speed and land. 3. Go to full power, retract the flaps to 20, and raise the gear as you climb out. Simple, docile airplane. Lots of options. But all must be done immediately.
In the F-14 you must:
1. add power immediately. You cannot allow the airplane to get slow.
2. retract speed brakes (because of the steep approach angle, Navy fighters landed with speed brakes extended to increase drag, which allowed a higher engine power setting and thus, better engine response)
3. disengage DLC (direct lift control, which extended spoilers on the wing to allow for glideslope adjustment without using engine power since the TF-30 engine had poor response)
4. adjust AOA from 15 to 14 (15 is normal, but a lower AOA increases controllability).
It all had to be done quickly. Very quickly. Even experienced guys would likely take the airplane around (initiate a full-power wave-off) to sort through the reconfiguration, changes, and re-trim everything (I didn't even talk about trim in all this, but trim all changes with power and airspeed, and with an engine failure, rudder trim in particular has to be significantly adjusted, either through normal trim, or a heavy foot on the rudder on the operating engine side).
Very few pilots would re-configure the airplane while in the approach turn, adjusting speed, trim, configuration and AOA while maintaining the precision turn... As apoint of reference, your goal was to cross the ship's wake at 375' in a 27 degree angle of bank and roll wings level to arrive on final at 350'. If you were ten feet high or low, and more than one know fast or slow, the LSO (see more below on LSOs) would be able to see that and judge your corrections. The LSO is watching from the time an airplane arrives abeam the ship and begins the turn.
And even if you were able to manage all that with precision, a single engine landing requires a couple of arresting gear considerations/calculations, so you might not be able to land on that approach anyway.
In the case of Kara Hultgreen, no engine power adjustment was made after the engine compressor stall/failure. The airplane was rolled into a 27-28 degree angle of bank for the approach turn (which increased load factor and AOA, and increased the drag). As the airspeed bled off, the airplane was climbing the drag curve below L/D max and as it got slower, the drag rose, more and more.
When she rolled out on final, the LSO (A Landing Signal Officer (LSO) is a Naval Aviator specially trained to facilitate the "safe and expeditious recovery" of naval aircraft aboard aircraft carriers - I was an LSO, if that wasn't obvious) waved her off (told her to go around) because he could see how slow the airplane was - it was way outside of normal parameters...
But she was on the back side of L/D max...and full dry thrust on the good (right) engine didn't arrest the descent - because the drag was so high... The LSO called for "raise your gear" in an attempt to reduce the airplane drag. Some LSOs have said that he shouldn't have made that call because he was "flying her airplane" but I think it was a great call - it was clear that the LSO was the only one who WAS flying that airplane.
When the LSO called for "burner" - she selected it. But where was the that airplane? Below VMCA. Well below it. And well below L/D max. At that point, it could not have been saved if Chuck Yeager himself had been teleported into that cockpit. There was so much drag, and at such low altitude, there was just no time to reduce AOA enough, to reduce drag enough, to regain control and add the energy needed to avoid a crash.
The failure to maintain flying speed was a listed causal factor. She needed to add power when the left engine quit. She didn't.
What will forever be speculation: did she know that the engine failed? She should have. The airplane was getting slow. The engine instruments would've shown the loss of RPM and fuel flow. The compressor stall warning was on. It was all there...all the information.
But there was absolutely no action taken in response: no increase in engine power on the good engine. DLC remained engaged. Speed brakes remained extended. (note that both DLC and speedbrakes are retracted when either throttle hits the military power detent - the engineers ensured that the drag would be reduced for a go-around/wave-off and they both did when she went to full power on the right engine).
As I've said before in this thread and my F-14 thread, the Tomcat wasn't easy to bring aboard. I've explained the simple aerodynamics, but the F-14 was even more complex - with slotted flaps and slats, DLC, spoilers and stabilators for roll control, and the poor engine response of the TF-30s at approach power settings. The discussion above doesn't get into the nuances and complexities of an F-14 landing.
It's my belief that she was nearly overwhelmed by the airplane when it was operating normally, as evidenced by her training records and performance. She didn't get the airplane to the right position abeam the carrier - the very simple job of putting the airplane in the right place. When things started to go wrong, she was unable to respond. It was too much for her. She failed to respond to the engine failure (that she induced through skidding the airplane, again, a horrible technique) because she became task-saturated and unable to understand what was happening.
The system that allowed her to be in that airplane, the airplane that was too much for her skills and ability, was what ultimately killed her. The real failure in all of this was a failure in leadership.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/2911273/1
https://en.wikipedia.org/wiki/Landing_Signal_Officer