Tail strike info

[JammedStab]

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.

[JammedStab]

I guess this gives the answer on what action to take in this situation. It appears that the tailstrike happens because people keep on pulling aft when the aircraft does not lift off.

"An Air France Boeing 777-200 freighter, registration F-GUOC performing freight flight AF-6724 from Paris Charles de Gaulle to Mexico City, was accelerating for a balanced takeoff from Charles de Gaulle Airport's runway 26R when the crew detected the aircraft was not accelerating quickly enough and firewalled the engines. The aircraft took off without further incident, while the crew discovered their takeoff weight had been programmed 100 tons below actual takeoff weight, which had caused the incorrect takeoff power and reference speed computations. The flight completed a safe landing in Mexico City about 11:15 hours later.

The airline reported: "Air France confirms that a data insertion error on take-off of cargo flight AF6724 operated by a Boeing 777 F from Paris-Charles de Gaulle to Mexico on May 22nd 2015 led to insufficient acceleration at the beginning of take-off. The crew, who noticed this slow acceleration, immediately reacted by applying full thrust. The aircraft took off normally and the flight continued to its destination. The crew spontaneously declared this event by ASR (Air Safety Report) and informed their superiors." The French BEA was informed.

On Jun 2nd 2015 the French BEA reported in their weekly bulletin that the crew used 243 tons of takeoff weight instead of 343 tons for computation of their takeoff performance, the resulting speeds were input into the flight management system. During rotation for takeoff, the crew noticed the aircraft did not become airborne, firewalled the engines, established maximum pitch possible without tail strike, lifted off, climbed out to safety, and continued to destination. "

[de facto]

Dont force it up...if you feel it doesnt come up then just maintain the pitch you have until you feel its ready to continue back up.
Fast increase of tailwind at low altitude,too foward CG.,negative gusts..many instances when if the feel isnt right dont force it.

[Lord Spandex Masher]

Did it really take you four and a half years to find the answer?

[JammedStab]

Actually, I had the answer the whole time as seen in the original post. But it took four years to find a written report of someone who got into such a situation and was able to get themselves out of it with no damage.

Any other useful info to add. Didn't think so.

Thanks de Facto. Obviously, you have proven the difference between a professional in your career and.....not.

[Lord Spandex Masher]

Any other useful info to add. Didn't think so.

Actually plenty, but I don't think I'll bother you with it.

[JammedStab]

Gee, how smart you must be. I suspect that really you have nothing to add(as proven by both your posts).

Anyways, thanks de Facto.

[Lord Spandex Masher]

Perhaps a winky face would have helped you see the, obviously too subtle for you, attempt at humour in my first post. Your condescending replies elicited my second and this, my final, post.

Now you'll never know how much useful information I could have given you, despite what you may suspect.

Well done.

[JammedStab]

Now you'll never know how much useful information I could have given you, despite what you may suspect.


As previously said about you providing useful info....

I don't think so. Proven correct so far.

Well, we do get a chance to get some insight into the personality of an undesirable co-pilot.

This is how providing useful information is done...

http://www.boeing.com/commercial/aer...7_article2.pdf

Boeing says what the AF pilots did..."If, after reaching the normal takeoff attitude, the airplane is not airborne, avoid the tendency to
increase rotation rate. Either slow or momentarily stop rotation rate. Many tail strikes on takeoff occur when or just after the main gear is airborne"

Apparently though, this is not done on occasion as we have seen through the years. Perhaps there is a natural instinct to keep pulling.

[Lord Spandex Masher]

Perhaps if you keep attempting to goad me you'll be more likely to receive the information you desire...

[JammedStab]

It would appear that I always had the information I desired as seen in my first and last post.

Nary a useful post from you yet.

While I am not an Airbus driver here is some info for those who are...

http://skybrary.aero/bookshelf/books/180.pdf

[Lord Spandex Masher]

You have one, quite basic, answer about avoiding tail strikes on take off. Your Airbus link is about landing and your Boeing link doesn't work.

You asked why it happens...

[JammedStab]

Your replies elicited my second and this, my final, post.

This was supposed to be your last post(unfortunately not).

You claim to have useful information(which has proven completely untrue so far).

The Airbus info is relevant for the overall subject of tailstrike avoidance(and my passing it along could possibly prevent one). I thought you might have picked up on the fact that it was an example of the concept of making a post that provides useful information but obviously not.


This Boeing link about Douglas products hopefully works as more useful information.
AERO : Tail Strike Avoidence (http://www.boeing.com/commercial/aeromagazine/aero_04/tr/tr01/index.html)

The associated quote provided with the earlier article(with the failed link) was the important information anyways. "If, after reaching the normal takeoff attitude, the airplane is not airborne, avoid the tendency to increase rotation rate. Either slow or momentarily stop rotation rate. Many tail strikes on takeoff occur when or just after the main gear is airborne".

Seems like straight forward info on what to do when in a critical situation but obviously these incidents have repeatedly happened so should be emphasized.

Anything useful to add.:rolleyes:

[Lord Spandex Masher]

This was supposed to be your last post(unfortunately not).
Oh well, sue me.

You claim to have useful information(which has proven completely untrue so far).
The only thing proven is that I haven't posted what you want.

Anything useful to add.:rolleyes:
Yep. Ask nicely.