American Airlines Two Planes Grounded After Tail Strikes
 

From Wall Street Journal, Jan. 20, 2011 page B4:

Two Planes Grounded After Tail Strikes
By ANDY PASZTOR
A recent spate of safety lapses by American Airlines, including a Boeing 757 that apparently took off at an unusually slow speed and slammed its tail on a California runway last week, are prompting concerns among federal safety officials as well as some of the carrier's pilots and mechanics.

None of the incidents resulted in injuries, though two planes suffered enough damage to warrant temporarily taking them out of service. An airline spokeswoman said "we take each incident very seriously," various internal reviews are under way to understand the causes, and American usually works together with labor and government officials "to make sure these types of incidents are mitigated."
She didn't provide details of what precipitated the operational problems.
Federal officials are conducting their own investigations into a number of incidents ranging from last week's takeoff error at Los Angeles International Airport to a botched landing in late December that resulted in a jet carrying 181 people running off the end of a snowy Jackson Hole, Wyo., runway.
The takeoff mistake in Los Angeles ended with the Hawaii-bound Boeing 757—piloted by a senior-management captain who is the chief pilot for 757 crews based in Los Angeles—quickly returning to the field. The aircraft may have suffered significant damage from what is called a "tail strike," which usually happens when the takeoff angle is too steep and the rear portion of a departing jet's underbelly hits or drags on the runway.
The heavily loaded Boeing 757 was taken out of service and may need repairs to its rear bulkhead, according to people familiar with the details.
The plane was ferried to American's Tulsa, Okla., maintenance base earlier this week, without passengers and under rules requiring the pilots to fly at lower altitudes in order to reduce structural stresses from pressurizing the fuselage.
A Federal Aviation Administration spokesman said the agency is investigating the Los Angeles tail strike and safety experts are "assessing the extent of the damage to the bulkhead." The National Transportation Safety Board also has looked into the incident. Tail strikes occur from time to time, mostly on longer models such as Airbus A340 or Boeing 767 and 777 jets, but safety experts said they are particularly unusual during takeoffs of 757 jets.
Greg Smith, the management captain who was in command of the flight, didn't respond to questions, and the American spokeswoman said employees aren't authorized to speak to reporters.
In the past few weeks, the AMR Corp. unit also experienced a separate tail strike at Los Angeles Airport involving a Boeing 737 taking off for Canada. American said it didn't tell U.S. or Canadian investigators about the event because the damage wasn't significant enough to warrant such reports. The plane, however, remains out of service, pending a decision slated for next week by American's engineering and maintenance experts. At a minimum, according to people familiar with the matter, the aluminum skin around the plane's tail was damaged.
In early January, yet another American jet, this time a Boeing 767 wide-body aircraft, had to return to New York's John F. Kennedy International Airport shortly after takeoff, when its nose gear wouldn't retract. After making a safe but overweight emergency landing, it turned out that mechanics had failed to remove a pin installed during overnight maintenance.
The New York incident has attracted attention from American pilots and mechanics because such pins have red-and-white streamers attached to them, reminding crews to "Remove Before Flight." None of the mechanics, baggage handlers or other ground staff noticed the pin prior to the plane's beginning its taxi for takeoff. The aircraft's pilots, who are responsible for visually checking the condition of every aircraft prior to flight, also missed the pin.
The American spokeswoman said the airline doesn't publicly "discuss corrective actions" affecting pilots.
At least three of American's recent incidents featured some unusual factors, and that's partly why they have sparked intense scrutiny from different groups.
The staff of the safety board, for example, appears especially interested in figuring out why the experienced captain in the Jackson Hole event failed to manually deploy panels on top of his jetliner's wings to help decelerate the speeding plane after touchdown. The panels failed to deploy automatically as the cockpit crew expected. Investigators are examining whether a maintenance mix-up contributed to that failure, and somehow also may have helped delay deployment of devices at the rear of the engines intended to slow the jet by reversing the direction of engine thrust.
Initially, the pilots of the Boeing 737 that scraped its tail climbing away from Los Angeles didn't realize anything unusual had happened. But during the flight, according to people familiar with the details, flight attendants alerted the cockpit crew that they had heard sounds of creaking metal after the jet's tail smacked the runway.
The Boeing 757 damaged during takeoff from Los Angeles may have been climbing at a speed of less than 120 miles an hour, according to people familiar with the details. That's markedly slower, these people said, than such a 110-ton jet typically would be flown in order to lift safely off the ground.
Write to Andy Pasztor at [email protected]
Copyright 2011 Dow Jones & Company, Inc. All Rights Reserved

Investigation over. :E

mercenary pilot... seems to know how things really are.

I would like to know if the rate of rotation was too quick on the hawaii bound plane.

but seriously...if the plane wasn't loaded as the weight and balance info (numbers) said, the trim setting may have been wrong for takeoff.

that bit about the nose gear pin is a bit disturbing though. we kept our pins onboard the plane , checked them on the walk around and counted them in the cockpit.

I recall some Boeing data, several years ago, which showed a cyclic pattern to 757 tailstrikes. IIRC this was against fleet flight-hours which at that time equated roughly to a two and a half year period. Boeing were investigating reasons for this, some of which were that pilots progress through the industry, training programs evolved to match new priorities, and that humans (management, training and crews) forget the context or priority of safety initiatives.

I have seen and generated similar safety data which showed a cyclic pattern. Patterns probably can be found in any data, but with some circumstantial correlation from the items above, I wonder if there are any other safety patterns or studies which might help the safety of our industry.
The items all appear to be aspects of change, thus is the pattern a function of change management?

So true. What's the saying - those who can't, manage? That is the biggest threat, a manager at the controls. :eek:

I hate to quote journos, but it sounds like rotation at the wrong speed;

Again, this is coming from a journo. but a Hawaii bound 757, or even a lightly loaded one should not be climbing out at 120 (assume he means rotation?). Maybe this management genius mistook the V1 call and began rotating? I've seen it happen before with new pilots when they are nervous, which could happen to someone out of their element (ie, flying only enough to stay current.)

Anyway, tailstrikes on a 75 do seem quite rare. :confused:

American Airlines...again.
It should be remembered that it was a 'senior management pilot' that crashed his MD-80 at Little Rock, trying to land in a thunderstorm.

Perhpas...management pilots need to stay firmly in the office, or...have a bit more regular line flying experience.:rolleyes:

411A:

Depends on what the management pilot does. If he gives line checks all the time he (she) is probably fine. If, however, he/she is a "chief pilot" office paper shuffler, then watch out.

At my airline the latter type usually were smart enough to assign a "F/O" to their occasional currency flight who was, in fact, a sharp check airman.

I always interpreted a management pilot to be one who exhibits strong personality traits and opinions without the currency of flying the actual product.

Much like the opinions we often see posted on PPrune:E

Since I have never flown aircraft long and powerful enough to whack their tails, can somebody explain to me what causes tailstrikes?

Yes, I understand that overrotation "causes" the strike, but what leads to the overrotation? Simple carelessness? Pulling too hard/fast? Not paying attention to the proper pitch indication? Nervousness about too long a takeoff roll? It seems so simple that if 10 degrees is a proper rotation and 12 degrees will hit the tail, you don't let the little veebird go past 10.

Or am I missing something?

Lack of sufficient a/s, (Lift) to leave the ground. Once committed, one gets airborne, or plows ahead into the Autobahn, Beach, Snow bank. 100 knots probably not enough velocity, imo.

These incidents/mistakes happen frequently.

In our airline we had a summary about it. To make it short, mostly it was due to wrong inputs in the FMS e.g. wrong weights, or wrong flap settings, or a combination of both.

When I was an apprentice pilot I recall being admonished for rotating to quickly in an L188c aircraft. fortunately that type of machine just got up and flew, but the admonishment stuck in my memory core right thru my career thru to the big heavies.
The growling I received from a long deceased crusty old Captain was
"When-you-rotate-you-will-count-to-three!"
I even used it when were were running out of cement at Gatwick, right on the last 500ft mark before the piano keys.

bbg - a better technique would be to use the 'NY decimal' system for your 'count'

That's a one...
That's a two...
That's a three...

By then the plane will have left the ground and the tail would be clear of the runway. :ok:

pei3721

re: cyclic: it all boils down to ''fundamentals''...you are never too good to practice the fundamentals in the sim.

I prefer the Lawrence Welk counting method to the NY method...ahoneannatwoo anna you know what to do

I'll have to agree with that statement. The 75 is not that light in pitch compared to other planes I've flown. Also, the tail clearance is fairly generous for a long aircraft.

A couple of the classic causes for takeoff tail strikes are setting the airspeed bugs wrong and trying too agressively to achieve the 'ideal' 2 degree per second pitch rate they harp about in the sim.

When you fly once a month as a management pilot you are at the same proficiency as a line pilot flying once a month. Striking a tail out of LAX with about 12,000 feet of runway would never happen with a line pilot. I don't care how mistrimmed it was if the W&B was off. I thought it was an SNA take off when I heard about the tail strike. But at LAX?

I had a friend that had his captain screw up and not set the flaps in a 737 out of LAX one day when maintenance pulled the takeoff warning circuit breaker to not hear that annoying sound about flaps everytime they advanced the thrust levers. They didn't get a tail scrape but did a stick shacker on lift off. My friend should have caught it too but he didn't. Unless I was flying out of SNA I let the airplane fly itself off the runway with proper pitch and not worry because I had 8,000 ft in front of me at rotation. I guess management guys know something we don't.

It seems that frequently when someone in a large jet tries to takeoff erronously with the flaps up or with V-speeds much lower than they should be for their heavy weight, that they end up with a tailstrike. A good example is the 727 in Dallas many years back.

So here is my question. Why does the tail strike happen. I assume that these particular pilots know not to exceed a certain pitch angle. 10° nose-up on the 727 was about the max you wanted with the mains still on the ground.

So is it because the pilot flying rotates, does not lift off and then tries to force the aircraft in the air. I don't think that a pitch instability would be involved as the tail is probably flying fine. If I ever happen to encounter this situation on the 727 where I am at my 10° noseup attitude and not lifting off, aside from adjusting thrust, what do you recommend in terms of pitch. I might be tempted to lower the nose.

Just curious.

This is worse than a string of bad luck. Something isn't right at AA and they need to get to the bottom of it.

Best,
GC

I think China had a TS not too long ago, in a 340. At the end of the Runway, and with bugs missing a few legs, Captain had to get airborne or plow through the fence and into some buildings. He chose flight over certain death. 30-50 million dollars and possibly a Hull loss, he did what he had to do. Keep pulling until it gets off the ground. the alternative is to not raise (or even lower) the nose, and start virtually over. Reject the T/O when you cannot stop in time, or cost the Company an airplane, or at least a gazillion Euros, (Yuan). Live, and learn Bartending.

I seem to recall that the 727 has a tail skid (retractable)...so does the DC9 series, though it is called a bumper.

ok, a managment pilot bumped the tail...its the old line:

1 week away from flying and I FEEL IT
2 weeks away from flying and my copilot feels it
3 weeks away from flying and my passengers feel it
4 weeks away from flying and a tail strike happens.
5 weeks away from flying and they make me a chief pilot

In theory, any aircraft could suffer a tail-strike during Take-off or Landing (except taildraggers).

A tail-strike occurs when the horizontal stabilizer (Tail) is capable of generating a sufficient downward force that the lower tail section of the aircraft is brought into contact the ground before the aircraft is able to fly. Think about basic flight theory - angle of attack and stalling.

In other words, exceed the "Ground" angle of attack and a tail-strike occurs, just like the exceeding the "Air" angle of attack will cause a stall.

It generally happens when the aircraft is either rotated, or flared, at a speed below optimal for the conditions (Vr, Vref, etc) It can also happen if the pilot is aggressive on the controls (Over-rotation,etc), but in this case the tail-strike is caused by aircraft's geometry over reaction time, not really by the aerodynamics.

Some aircraft would appear more prone than others based on their design. The 727, some 737's, 767 and some others, have limited tail/runway clearance and subsequently were manufactured with a "Skid" which would offer at least some damage protection.

Yup, but true to form at AA, they are in the deny/deny/deny mode.
Isn't going to change, either, unless the FAA suspends their operating certificate.

I'm pretty sure that this was an Emirates A340 taking-off from Melbourne, Australia.

tailstrike
 

We had a tail strike at our outfit(737 NG) about a year back on takeoff accompanied with stick shaker as the copilot had made wrong takeoff speed calculation( max Reduced thrust) at max takeoff weight and the relatively new captain didn't notice the error in his haste to get going.

Luckily, other than structural damage and a few frightened pax , the aircraft made it OK. Both pilots were grounded for a while and after investigations and corrective training are now flying. A rule of thumb I use(taught to me by a senior check pilot) to cross-check the speeds is the V2 speed set in the MCP window should be approximately 20 knots less than takeoff weight ...eg. if T/O weight on the -800 is 70 tons ( 70-20=50) , therefore 150 knots approx. For the -700 , reduce by 25 .

masalama.

the rule of thumb is a good idea however some of the recent tailstrikes have occured due to incorrect weight being entered in the first place... garbage in...

Captain Greg Smith is the LAX Director of Flight. Which makes him the big cheese for the base.

No reason to put his name on internet, is there?:= (Next time it's you!)
BTW, what is he called now?:}

His name was in post #1 which means it was also in the WSJ.

The 757 rotation technique as taught at AA is to smoothly begin rotation AT VR trying for 2.5 degrees per second to 10 degrees. The aircraft should be airborne during those 4 seconds and rotation is smoothly continued to maintain V2 +15 which requires 18-20 pitch attitude.
At VLO and 10 degrees pitch, the 757-200 tail (All AA 757's are -200s) is about 33 inches above the tarmac with the struts extended. Tail contact takes about 12.5 degrees with struts extended. With struts fully compressed, which they would NOT be for any TO the tail will contact at 10 degrees.

Sorry, thought they were only talking about "the chiefpilot". Later on in the article his name was indeed mentioned.

Tail strikes are not limited to takeoff situations – they occur during landings as well. As PappyJ very correctly states:
However, I don’t completely understand the balance of PappyJ’s comment …
Any tail strike involves aerodynamics – the way the controls are manipulated to influence the aerodynamic characteristics of the airplane. For example, if the controls are moved abruptly, not giving the airplane a chance to be influenced by the changing airflow … like a continuing rotation on either takeoff or landing … and the airplane may well achieve a pitch attitude that would place the tail structure appetizingly close to any “airplane-eating runway” on the planet.

Certainly it can’t be the training at AA, as all airlines in the US are required to comply with the training that is contained in part 121 of the FARs … and that would include AA, right?

As a sidebar comment, I know of at least two airlines which provide the crew with flight data information right after takeoff and after landing. The speed, RA, pitch attitude, pitch rate (deg/sec) throughout the maneuver), Vertg, Descent Rate are all provided to the crew for their examination if they wish. Providing this information to the crew immediately, gives them something to learn from if a rotation or a flare was slightly outside normal. This use of flight data has already reduced tailstrikes at these two airlines. This data remains the crew's to use/dispose of as they deem.

Typical FOQA Programs have events which track how close an aircraft came to tailstrike on liftoff or on the flare at landing, as well as monitoring rotation rates, (almost all the events I've seen were very slow rotation rates...between 0.8 and 1.5deg/sec and took a long time to get the pitch to 15deg +).

Tailstrike on the approach is most certainly aerodynamic in nature - we have seen higher risk of tailstrike with a quartering tailwind and the airspeed right on the bug, (Vref +5 or Vapp on the 'bus). There is a FOQA event that monitors flare times as well; Any flare longer than 8 to 10 seconds can be an indication of higher risk of tailstrike and here is where aircraft geometry can come into play.

Both the FOQA events and the data link information to the crew are attempts to deal with the problem of tailstrikes and are obviously preventative. Of course, in any actual incident, all data is available to the airline safety investigation team and flight ops to see if there are training issues.

Many years ago, demonstrating new aircraft to airline and military operators around the world, while trying to make the demonstratee look (and feel) good, we always used the maxim: "watch out for Chief Pilots and Colonels".

Scene 1: lined up on the departure runway, CP of a developing world airline in the left seat, very thorough briefing complete, T/O clearance received - Me "Any questions?" - He "Yes, which one's the airspeed indicator?"

Scene 2: CP of a legacy flag carrier in the left seat, CAVOK day, calm wind, very light weight, no issues. The result - the hardest landing I ever experienced in my career and, - it happened a flash!

Chief Pilots and Colonels! And then I were one.....

While “flair time” may be a decent data point for discussion, it seems to me that anyone who is still “flaring” any airplane (i.e., continuing to move the nose to a higher position) after anything approaching 8 to 10 seconds is indicative of the fact that the pilot has no idea of what attitude he/she wants for the airplane to land. Said differently, that pilot likely knows not what he/she is attempting to achieve, or if he/she is just pulling on the controls “until it lands” which would be a classic case of the airplane flying the pilot. To avoid speculation, the attitude that should be sought is the attitude that would achieve level flight for the airspeed and airplane configuration at THAT time. There should be no way that the level flight attitude of any airplane, particularly when in ground effect, would require such a nose high position that it would risk a tail strike. Pulling the nose up above the attitude that would maintain level flight is only inviting something that no one would desire. Transport category airplanes are not expected to be landed “in a full stall” condition. Unless someone flies final approach at something like 8 – 10 degrees nose LOW, there is almost zero chance that a change in airplane attitude (i.e., flare) should take anything approaching 8 to 10 seconds to achieve a level flight attitude. It would seem to me that any review of FOQA data that shows any pilot flaring for something approaching 8 to 10 seconds will have already demonstrated the need for additional training – tail strike or not.

So, "flair" is the culprit. Hunting (waiting) for liftoff after initiation (rotation) or T/D (landing) is not a stabilized approach. Rather simple. Is that it? Poor speed control?

I've worked for three small airlines and one really big airline. AT no time was their a discussion of "Flare" techniques or concepts.

It took seperate study on my part to learn the following:

1. Learn and be aware of the visual clues that can lead you to ''flaring'' too long. For example, when on a runway sloping downhill, if you ''keep flaring'' you will keep floating as the runway is moving away from you...

I was going to write an extended explanation, but have decided I enjoy talking about other people screwing up and if they actually learned something, the whole pprune thing would get dull.

Interesting. I had assumed that all tail strikes happen as a result of overrotation on takeoff. Never occurred to me that you could have one on landing.

Over rotating on take off is poor pilot technique because you did it to yourself with no outside forces. Landing and hitting the tail is poor pilot technique with outside forces. The pilot flying shouldn't be getting a tail strike unless he or she really screwed it up. I can see it happening after a bounce and screwing the recovery up but not a normal landing, no matter what the wind component is. When you fly to Hawaii once a month and get one or two landings anything can happen.

My biggest challenge was landing uphill on a short strip in Honduras in a 757 and landing in a climb. Firm landings were quite common there. It took a while to figure the climb angle needed to get a smooth touchdown.

That would be what we used to call Tegoose.

But wasn't it fun? Landing uphill at TGU rarely happened because of the prevailing wind so we got really good at landing north. Landing south seemed so easy, uphill, but our best landings were downhill turning final at about 100 ft to miss the hill. I really miss that place. Had a reverser not work one day but no big deal. I am waiting for the report to see how this could have affected one of our arrivals. The 757 is a wonderful airplane, lots of power and you can override everything manually. I like it as much as my beloved Lear Jets. It is hard to kill yourself in machines like that if you pay attention.