Atlas Tail Strike

[domani]

parked today next to an ATLAS CLASSIC N505MC in ATL that arrived from STN,had a tail strike on Take off and decided to continue across the Atlantic ,not a good idea.:eek:

[flyboyike]

Duly noted.

[Earl]

Ouch! Not a good thing if true!

[canadair]

more likely:
had a tail strike on Take off,
crew had NO knowledge of this,
continued across the Atlantic,
maint discovered on turn around.

You make it sound as if the crew knew or was informed of the TS, and chose to continue regardless, by use of the word decided.

is this a fact as you know it?

[mumbo jumbo]

Depending on the severity of the tail strike, they may not even have known they had had one until they arrived at their destination.

Once again we see here the amateurish way some people jump in with their assumptions. Now you can see why you didn't train as a lawyer or a detective. :rolleyes:

[Dan Winterland]

Historically, tail strikes are very difficult to detect from the cockpit in a 747. The crew are usually notified by the cabin crew at the back who heard the scrape. They wouldn't have known in a freighter, IMHO.

[nitro rig driver]

Start by getting the route right first
PIK-ATL

[HZ123]

We are having a late summer and all seems well with part of the world. If it were not for the mistakes and assumptions there would be nothing to read. All of you have a nice day.

[JJflyer]

Tailstrike or a tailscrape. As someone said it is very hard to detect from the cockpit. A friend of mine flying in Africa was saying that their company had 2 tailscrapes within a few weeks on 767. Apparently next crew and maintenance only saw it on the tailskid during their walkarounds. I am not familiar with the 767 at all but I understand that with a good dragging of the tail feathers this strut will compress. I was told that a pad at the bottom of the skid had just some paint missing, no other damage.

The 747 on the other hand does not have a tailskid even as the tail clearance is only a few inches.

JJ

[Rainboe]

It should be understood on a heavyweight take-off in a 747, the tail can easily get to within 18" of the tarmac- about 45cms, so it is especially important to maintain correct rotation techniques. Too fast definitely frowned on, too slow also. A tailscrape will most likely not be detected by anybody- there are no warnings, and nobody in the rear cabin is likely to hear or feel it in the full acoustic blast of the engines and the shaking on take-off. I was once right next to an Eastern A300 at MIA having a spectacular tailscrape- a big flash, smoke and sparks. The pilots were unaware until I told them. They are invariably just a gentle scraping contact, not a jarring bang.

So not a bad report, apart from:
*Route wrong
*Expression 'tail strike' instead of 'scrape'
*Assumption that 'decided to continue....'- didn't know
*Criticism after the event: 'not a good idea'- see previous!
*WHY THE GODDAM SMILEY? We are grown up experts here- can we please leave the Smilies out?
5 pieces of criticism in a 1 1/3 line report. Worse than a tailscrape! This is a discerning, expert audience, please get it right.

[Avman]

And, I note, it was domani's 1st post on PPRuNe too.

Reading the above, out of interest is there not a case for some a/c to be fitted with some sort of sensor warning the FD of a tail strike/scrape?

[Perrin]

There was the L1011 that had a ram with pad on end which came down with landing gear. It was always easy to see if it had been hit on t/o and with Saudia there were a few.

[HotDog]

Correct, colloquially called "The donkey's dick". Old hat really, the Convair 880 had a small tail skid with a hole in it which accomodated a piece of lock wire that broke if the aircraft suffered a tail scrape. Much cheaper than Lockheed's contraption.

[Golf Charlie Charlie]

What is the difference, please, between a tailstrike and a tailscrape ? I had always thought the two words meant pretty much the same thing.

[Bullethead]

I think the inference is that a 'tailstrike' is a harder impact than a 'tailscrape', but you're right thay are basically the same thing.

Regards,
BH.

[domani]

rainbow
-sorry for the wrong route, that's what I was told
-I saw the damage and it look to me like a tailstrike
-the crew knew something was wrong because twr reported seen sparks during rotation , cvr was pulled later on, you tell me why,you are the expert.
-was it a good decision to continue?
-and for your info the icon is not a smile, this is a smile:)

Domani

[Hoolet]

The 'scrape' was 157m long through the numbers and the rivet/screw heads were recovered on the rwy.
The crew were told by atc of possible damage. The a/c was 2000kgs under mtow and the wind was calm.
Fact.

[-8AS]

Tail scrape - only damage is to the tail skid or similar device that provides protection for the aft fuselage during takeoff. If the device is not 'crushed' beyond limits, event can be descibed as a minor tail scrape. (no aircraft damage, only requires maintenance inspection).

Tail strike - fuselage strikes the runway or the tail skid is compressed beyond limits indicating possible fuselage damage.

[Spanner Turner]

Reading the above, out of interest is there not a case for some a/c to be fitted with some sort of sensor warning the FD of a tail strike/scrape?



OVER-ROTATION WARNING SYSTEM GENERAL - SP ONLY
General
The over-rotation warning system, although originally designed for
all 747 series aircraft was found unnecessary in all except 747-SP
aircraft. On earlier 200 series aircraft the system has been
deleted and on later 200/300 series the system was never installed.
The following graphic is a simplified diagram of the over-rotation
warning system as fitted to B747-SP series aircraft.
The system is instructed to operate a stick shaker on the captain’s
control column to warn of over-rotation during take-off.



The SP is quite sensitive in Pitch and can be over-rotated easily with a heavy handed 'pull' of the column during take-off.
Basically, the SP has an over-rotation computer that becomes active at nose-wheel lift-off. It has inputs from ADC and from #1 or #3 IRS and it compares pitch angle and rate of rotation to determine if a tailstrike is imminent. If 'YES" then it causes the stick-shaker to operate to alert the pilots.


As you suggest though, it doesn't alert you if a scrape HAS actually happened. I don't know of a system that does this, but could be a good idea.

[rubik101]

Just how expensive and complicated would it be to fit a micro-switch in the tail skid or a pod under the tail to indicate ground contact?
In a new build, about $25.00 I should think.
Light on after take-oof, land at nearest suitable airport for check/rectification.
That would of course, preclude proceeding to the destination overseas!!

[Lexif]

rubik101,

Wouldn't perhaps a wrong positive indication happen much more often than a real tailscrape that would be dangerous, but not be noticed in the plane?
(I'm not a pilot. Just a thought.)

[rubik101]

In answer to Lexif's query; No more than false engine fire alarms, or open cargo or entrance doors, or failed hydraulic or electric systems or false airspeed or altitude indications and so on and so on. What makes you think that indication systems on aircraft are less reliable than anywhere else?
Does your TV switch itself on at random?
Does your door open light in your car come on as you drive along the road?
Does your oven switch itself on or off when you least expect it?
Enough?

[Lexif]

The underlying thought was just that it appears to me that tailstrikes that are not felt in the cockpit or at least the cabin are much rarer occurances than other safety problems for which warning systems have been integrated in aircraft - at least tailstrikes that were undetected, but endangered the safety of the flight or even caused crashes. I don't know if that's true, I just had the impression and wanted to introduce that angle into the discussion. And I surely don't want to be on the flight that makes a precedence.

I've surely heard of a lot more safety landings because of the failure of gear proximity switches or other devices that created an "gear unsafe" warning of sorts than of real landings with landing gears that failed in some way. (Thanks to the media that make a live TV event out of every airliner circeling to burn of fuel for an emergency landing. :ugh: ) So I feel that even these important sensors fail a lot. On the other hand, I don't know how often (cargo) door sensors have prevented accidents, as the problems they are inteded to detect surely happen most of the time on the ground, and in flight failures only seldomly make the news...and cargo doors that open for real in flight are even more rare.

I know it's cynical, but this question surely turns up when designing a tailstrike warning system for an airliner. I would sure feel better if such a system was an option on the airliner I'm flying on as a passenger, though.

Just out of humble curiosity...when was the last time an airliner had an accident that could have been prevented by an indication in the cockpit?

[hautemude]

A question of the saucepan calling the kettle black perhaps!