Skip to comments.777 Crash at SFO (San Francisco)
Posted on 07/06/2013 12:02:24 PM PDT by FreedomPoster
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“Are you familiar with a “Wing Slip” or a “Wing Slide” ?”
Is that were a pilot yaws the plane around a little so the lifting shape of the wing is less effective?
If so, I hope this flight crew was not trying get that fancy. The approach at SFO should be void of such dramatics since it is so straight forward.
Whether we are speaking about a side slip used to counteract cross-wind drift on landing, a forward slip used to lose altitude, or a slipping turn used to lose lots of altitude, the essential technique is the same. With a combination of aileron and rudder inputs, we induce the aircraft to fly sideways through the air. We transfer some of the lift from the wings to the fuselage and create a significant amount of drag in the process.
When we use a slipping technique to counter cross-wind drift on landing, we point the nose of the aircraft with rudder input to keep the longitudinal axis of the machine parallel to the centre-line of the runway or landing area. We apply aileron to maintain lateral position. Rudder points the nose; aileron slides the aircraft right or left as needed. Of course, we use elevator and trim to control our approach speed and power to control our rate of descent.
When using the slip to lose altitude, we normally enter from a power-off glide. All too often on a flight test, we see people enter a slip to lose altitude with cruise or only slightly reduced power. This defeats the technique. With enough power, we can fly the aircraft with full rudder and opposite aileron without losing any altitude at all.
We establish the aircraft in a glide, normally at best glide speed as specified in the POH. Once in the glide, it is very important to establish a clear visual reference so we know where we are headed. I like to pick out some obvious and prominent feature on the ground ahead—about where we would touch down if we continued our descent—and maybe even say out loud or to myself, "That’s where I’m going."
We also want to take note of the aircraft’s attitude. Once in a slip, depending on the aircraft we are flying, the airspeed indicator can become unreliable. The pitot tube and static port are now meeting the relative airflow at an unusual angle.
If we work from the attitude of the aircraft by looking outside, we won’t be confused or fooled by inaccurate indicated airspeed readings.
With our eye on our reference point and an appreciation of the attitude of the nose, we can apply aileron in the direction we would like to establish our slip. Left aileron results in a slip to the left and visa versa. We roll the aircraft with aileron and stop the turn with opposite rudder: roll left; right rudder. Roll right; left rudder. Particularly in the early stages of learning this manoeuvre, gentle application of control inputs is easier to understand. No big hurry. Strive for elegance rather than speed.
As we enter the slip, the aircraft may have a tendency to raise its nose. We are increasing lift by exposing the whole side of the aircraft to the relative wind. Maintain the attitude we observed in the glide with elevator input. Keep our eye on our ground reference point so we continue to know where we’re heading.
Many students are worried about stalling the aircraft and producing a spin because of the cross control inputs and have a tendency to point to nose excessively downward. This simply increases speed and reduces the effectiveness of the slip.
Most light aircraft are very reluctant to spin from a slip. If you are really worried about it, give yourself plenty of altitude in a safe area and try it. Put the aircraft into a slip and gently raise the nose until she stalls. Most light aircraft will shake and buffet and lose altitude at a great rate, but will not show any interest whatsoever in entering a spin.
In the early stages of learning a slip, I encourage students to use full rudder input and "steer" the aircraft with aileron. This simplifies things by giving the pilot only one input to worry about and control. Two variable variables result in just so many combinations that it’s easy to get confused. Keep things simple and success is more easily obtained.
If there is a wind blowing, we normally set ourselves up with the lowered wing towards the wind. This is particularly important when using a slipping manoeuvre on landing. With limited altitude, we don’t want to increase our vulnerability by giving the wind an opportunity to get under the raised wing and toss us into an unusual and potentially dangerous attitude.
To turn our side slip into a slipping turn, simply increase aileron input. A slipping turn can be a very effective tool for losing altitude in a hurry and can be a very nice little trick to store in our forced landing kit or our landing kit for fields with difficult or obstructed approach paths. We can really keep our base in close by making use of the slipping turn in an effective manner.
Whether you are an experienced pilot or a new arrival to the activity, honing and developing your skills is not only an excellent plan, it’s a lot of fun. Slips can be extremely useful in a variety of situations. Familiarity and comfort with the maneuverer is a fine addition to your repertoire. Flaps fail; cross-winds occur; engines catch fire; difficult situations arise. Keep your skills sharp and they will be there for you when you need them.
I remember when the puddle jumpers were so small there would not even be a flight attendant on board. Just the P and Co-P. When landing they would pull back the curtain (no double locked secure doors back then!). You could then watch the landing through the front windshield from the passenger compartment.
During heavy cross winds the side slip maneuver was obvious as the runway would be to one side or the other and we would ‘tack’ into it on decent.
I have never sensed that maneuver being used as a passenger in the 737s and 757s at SFO. Landing at SFO were always just a long, steady decent at steady speed that started south of San Jose - no matter the wind conditions.
Just received this from a friend. I have no attribution, but it does provide, if true, insight into Korean pilots and their ability to take training.
Low-down on Korean pilots
After I retired from UAL as a Standards Captain on the 400, I got a job as a simulator instructor working for Alteon (a Boeing subsidiary) at Asiana. When I first got there, I was shocked and surprised by the lack of basic piloting skills shown by most of the pilots. It is not a normal situation with normal progression from new hire, right seat, left seat taking a decade or two. One big difference is that ex-Military pilots are given super-seniority and progress to the left seat much faster. Compared to the US, they also upgrade fairly rapidly because of the phenomenal growth by all Asian air carriers. By the way, after about six months at Asiana, I was moved over to KAL and found them to be identical. The only difference was the color of the uniforms and airplanes. I worked in Korea for 5 long years and although I found most of the people to be very pleasant, its a minefield of a work environment ... for them and for us expats.
One of the first things I learned was that the pilots kept a web-site and reported on every training session. I dont think this was officially sanctioned by the company, but after one or two simulator periods, a database was building on me (and everyone else) that told them exactly how I ran the sessions, what to expect on checks, and what to look out for. For example; I used to open an aft cargo door at 100 knots to get them to initiate an RTO and I would brief them on it during the briefing. This was on the B-737 NG and many of the captains were coming off the 777 or B744 and they were used to the Master Caution System being inhibited at 80 kts. Well, for the first few days after I started that, EVERYONE rejected the takeoff. Then, all of a sudden they all got it and continued the takeoff (in accordance with their manuals). The word had gotten out. I figured it was an overall PLUS for the training program.
We expat instructors were forced upon them after the amount of fatal accidents (most of the them totally avoidable) over a decade began to be noticed by the outside world. They were basically given an ultimatum by the FAA, Transport Canada, and the EU to totally rebuild and rethink their training program or face being banned from the skies all over the world. They hired Boeing and Airbus to staff the training centers. KAL has one center and Asiana has another. When I was there (2003-2008) we had about 60 expats conducting training KAL and about 40 at Asiana. Most instructors were from the USA, Canada, Australia, or New Zealand with a few stuffed in from Europe and Asia. Boeing also operated training centers in Singapore and China so they did hire some instructors from there.
This solution has only been partially successful but still faces ingrained resistance from the Koreans. I lost track of the number of highly qualified instructors I worked with who were fired because they tried to enforce normal standards of performance. By normal standards, I would include being able to master basic tasks like successfully shoot a visual approach with 10 kt crosswind and the weather CAVOK. I am not kidding when I tell you that requiring them to shoot a visual approach struck fear in their hearts ... with good reason. Like this Asiana crew, it didn’t compute that you needed to be a 1000 AGL at 3 miles and your sink rate should be 600-800 Ft/Min. But, after 5 years, they finally nailed me. I still had to sign my name to their training and sometimes if I just couldnt pass someone on a check, I had no choice but to fail them. I usually busted about 3-5 crews a year and the resistance against me built. I finally failed an extremely incompetent crew and it turned out he was the a high-ranking captain who was the Chief Line Check pilot on the fleet I was teaching on. I found out on my next monthly trip home that KAL was not going to renew my Visa. The crew I failed was given another check and continued a fly while talking about how unfair Captain Brown was.
Any of you Boeing glass-cockpit guys will know what I mean when I describe these events. I gave them a VOR approach with an 15 mile arc from the IAF. By the way, KAL dictated the profiles for all sessions and we just administered them. He requested two turns in holding at the IAF to get set up for the approach. When he finally got his nerve up, he requested Radar Vectors to final. He could have just said he was ready for the approach and I would have cleared him to the IAF and then Cleared for the approach and he could have selected Exit Hold and been on his way. He was already in LNAV/VNAV PATH. So, I gave him vectors to final with a 30 degree intercept. Of course, he failed to Extend the FAF and he couldnt understand why it would not intercept the LNAV magenta line when he punched LNAV and VNAV. He made three approaches and missed approaches before he figured out that his active waypoint was Hold at XYZ. Every time he punched LNAV, it would try to go back to the IAF ... just like it was supposed to do. Since it was a check, I was not allowed (by their own rules) to offer him any help. That was just one of about half dozen major errors I documented in his UNSAT paperwork. He also failed to put in ANY aileron on takeoff with a 30-knot direct crosswind (again, the weather was dictated by KAL).
This Asiana SFO accident makes me sick and while I am surprised there are not more, I expect that there will be many more of the same type accidents in the future unless some drastic steps are taken. They are already required to hire a certain percentage of expats to try to ingrain more flying expertise in them, but more likely, they will eventually be fired too. One of the best trainees I ever had was a Korean/American (he grew up and went to school in the USA) who flew C-141s in the USAF. When he got out, he moved back to Korea and got hired by KAL. I met him when I gave him some training and a check on the B-737 and of course, he breezed through the training. I give him annual PCs for a few years and he was always a good pilot. Then, he got involved with trying to start a pilots union and when they tired to enforce some sort of duty rigs on international flights, he was fired after being arrested and JAILED!
The Koreans are very very bright and smart so I was puzzled by their inability to fly an airplane well. They would show up on Day 1 of training (an hour before the scheduled briefing time, in a 3-piece suit, and shined shoes) with the entire contents of the FCOM and Flight Manual totally memorized. But, putting that information to actual use was many times impossible. Crosswind landings are also an unsolvable puzzle for most of them. I never did figure it out completely, but I think I did uncover a few clues. Here is my best guess. First off, their educational system emphasizes ROTE memorization from the first day of school as little kids. As you know, that is the lowest form of learning and they act like robots. They are also taught to NEVER challenge authority and in spite of the flight training heavily emphasizing CRM/CLR, it still exists either on the surface or very subtly. You just cant change 3000 years of culture.
The other thing that I think plays an important role is the fact that there is virtually NO civil aircraft flying in Korea. Its actually illegal to own a Cessna-152 and just go learn to fly. Ultra-lights and Powered Hang Gliders are Ok. I guess they dont trust the people to not start WW III by flying 35 miles north of Inchon into North Korea. But, they dont get the kids who grew up flying (and thinking for themselves) and hanging around airports. They do recruit some kids from college and send then to the US or Australia and get them their tickets. Generally, I had better experience with them than with the ex-Military pilots. This was a surprise to me as I spent years as a Naval Aviator flying fighters after getting my private in light airplanes. I would get experienced F-4, F-5, F-15, and F-16 pilots who were actually terrible pilots if they had to hand fly the airplane. What a shock!
Finally, Ill get off my box and talk about the total flight hours they claim. I do accept that there are a few talented and free-thinking pilots that I met and trained in Korea. Some are still in contact and I consider them friends. They were a joy! But, they were few and far between and certainly not the norm.
Actually, this is a worldwide problem involving automation and the auto-flight concept. Take one of these new first officers that got his ratings in the US or Australia and came to KAL or Asiana with 225 flight hours. After takeoff, in accordance with their SOP, he calls for the autopilot to be engaged at 250 after takeoff. How much actual flight time is that? Hardly one minute. Then he might fly for hours on the autopilot and finally disengage it (MAYBE?) below 800 after the gear was down, flaps extended and on airspeed (autothrottle) . Then he might bring it in to land. Again, how much real flight time or real experience did he get. Minutes! Of course, on the 777 or 747, its the same only they get more inflated logbooks.
So, when I hear that a 10,000 hour Korean captain was vectored in for a 17-mile final and cleared for a visual approach in CAVOK weather, it raises the hair on the back of my neck.
“The Slip is a maneuverer that can get you in trouble fast, if you don’t know what you’re doing, and I DON”T recommend it.”
No kidding! It can lead to as cross-control stall and a spin “out the bottom” as I recall from my flight training. It’s one thing to do a forward slip in a Cessna 150 with it’s low wing loading and stall speed, but it’s another matter with a swept-wing air transport. With the availability of spoilers on transports, there really is very little if any need to perform a slip. The neat thing about spoilers is that you don’t have to change any of your other control inputs or make changes in power settings. I flew gliders for a while. The spoiler is a very useful control feature on a glider to help you “make the runway” when you don’t have an engine!
“I was just wondering if the Korean pilots were trying a “slip maneuverer” to lose some altitude fast in this 777 crash, ,,,,,”
Someone posted the vertical speed data on the Asiana flight from some service that can provide you with altitude data for the entire flight. If that information is correct, the plane was never in a “stabilized” decent. The data presented showed that the rate of decent varied from more than 1300 ft/ min down to less than 300. It can be best described as a “yo-yo.” Evidently they were high at the FAF (the Outer Marker) so they pulled power, and nosed the plane down to position it properly. But they never got it stabilized at around 600fpm. It looks as though they were always behind in being where they needed to be on the glide slope. With something this big, you can’t be making large corrections in attitude, because the plane is incapable of responding. They simply ended up at the runway threshold with too high a rate of decent and too little airspeed, and when they tried to pull the nose up to stop the decent they simply stalled, banged the tail down first, tore the gear off on the seawall, and became wreckage moving at about 100 mph. along the ground. As far as slipping the plane, they would have more likely been using the spoilers to adjust their decent rate. That said, at the end of the flight a slip would have been counterproductive to their situation, because a slip is used to loose altitude. My flight instructor used to say that there are two things that are useless to a pilot 1) The runway behind you and 2) the sky above you.
“Slip maneuver” in a swept wing jet? No way Jose, or Kim. It just is not done, PERIOD! Please do not cross pollinate civilian experience with military or commercial jet flying.
Here I am again...you just do not slip a swept wing airliner!
Tom Brown?? He is right on the mark. Great observations and he does a great job of writing what I have been saying from the beginning. “The dreaded visual approach”, truer words were never said. One cause of pilot deficiencies in “stick and rudder” or hand flying is that the companies discourage hand flying because the autopilot does a better job economically. One wag in my company said, “if you want to fly, go rent an airplane”. Sort of bit Asiana in the ass, huh?
I would say it bit the passengers as well.