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QAVION
10th Feb 2002, 07:14
Just wondering what the procedure is for a tailstrike on rotation on a 777? (sorry if this issue has been covered before)

A fellow engineer reported seeing a Singapore Airlines 777 (ex-Sydney) strike its tail on departure a few days ago (huge rotation rate, showers of sparks, etc... presumably lots of noise in the cabin). Aircraft continued on its merry way. The authorities were notified, but the aircraft did not return to Sydney.

I believe SQ 777's have tailstrike sensors fitted(?).

Rgds.. .Q.

411A
10th Feb 2002, 08:13
Nothing new for SQ...recall many years ago a B747 had a tailstrike on departure from MEL and continued non-stop to SIN with weeds imbedded therein. Several more followed in LAX later on.. .I wonder why?

gas path
10th Feb 2002, 16:25
The crew would have been very aware of a tail strike as there is a sensor (blade type antenna)at the back end, as it got ground down it would generate a message on EICAS. . .The inspections for a tail strike besides the obvious skin damage are also a detailed inspection of the rear pressure bulkhead....need I say more!!!

donpizmeov
10th Feb 2002, 23:33
The -300 has a tail skid, which can scrape the ground and keep the paint looking pretty, with no effect, and not produce a "tailstrike" EICAS message. This would cause lotsa sparks but no damage (Good onya Mr Boeing!).. .The Tail Strike sensor is in a different location, and if it is made, EICAS will wake you up, and you will land at nearest suitable to change your undies!. .The -200 does not have the tail skid, but does have the tail strike sensor.. .So it is very possible that this crew did the right thing by continuing, and they got there moneys worth from landing fees etc but collecting some lights as well.

QAVION
11th Feb 2002, 05:04
"The -300 has a tail skid, which can scrape the ground and keep the paint looking pretty, with no effect, and not produce a "tailstrike" EICAS message. This would cause lotsa sparks but no damage (Good onya Mr Boeing!)."

Interesting... So you would have to pretty much put the tailskid through the fuselage to get the Tailstrike sensor to react? <img src="tongue.gif" border="0"> I was told recently that there are two sensing elements in the sensor. Both have to be damaged to generate an EICAS message (a bit like old-fashioned engine fire loops).

Anyway.... Thanks for the responses, gentlemen.. .Rgds.. .Q.

Superpilot
11th Feb 2002, 06:59
Side-stepping slightly, how easy/difficult is it for a pilot to scrape the tail along the tarmac? incorrect Vr calculations? ...surely not. Pardon my ignorance but from the experience I've had in real jet sims, it's pretty difficult to achieve <img src="confused.gif" border="0">

xyz_pilot
11th Feb 2002, 14:47
Is the tail skid set up for TO or LDG as the contact point is normally different?

7times7
11th Feb 2002, 20:29
if there was an EICAS msg TAILSTRIKE, they would have to turn back.

If none, then there's no big worries on the structure, just a tailscrape. Go back, laid out inspection, repaint and off she goes.

scanscanscan
12th Feb 2002, 00:11
Is there a " Tail strike" Eicas message available?. .I recall an Eicas message "Tail skid" meaning it is not in its correct position, this is a different situation to a tail strike, unless you have broken it off maybe!. .I think there is a fuel penalty also if the tail skid cannot be retracted after takeoff of around 6kgs a flight hour, beloved of line check captains.. .Also you hit the tail skid with more than 10 degrees pitch up on landing on a 767-300er and with a over rapid rotation on takeoff at about 8 degrees of pitch up.. .Someone with the Boeing training manual could correct these figures as it has been a couple of years.. .B767-3300er flight with a gear leg door missing also has interesting restrictions and penalties I also remember from one dark nights trip.

7times7
12th Feb 2002, 17:57
yes scan,

they have "TAIL STRIKE" eicas msg on the B777, which call for manual depressurisation of aircraft and plan to land at the nearest suitable airport.

btw they have "TAIL SKID" to on the -300.

eightn
12th Feb 2002, 20:42
Superpilot wrote,"Side-stepping slightly, how easy/difficult is it for a pilot to scrape the tail along the tarmac? incorrect Vr calculations? ...surely not. Pardon my ignorance but from the experience I've had in real jet sims, it's pretty difficult "

My experience hasn't gone larger than antique DC9-83's, so I can't speak to the 777; but in the MD80 you could get a tailstrike by having the trim setting a little off. Also, as you guessed, if you are off in our weight calculations, you could derive an incorrect rotation speed; which would lead to achieving the takeoff attitude before the aircraft was ready to fly. In this situation, you must maintain that attitude until the aircraft lifts off; if you attempt to yank it off, you will only drag the tail. . .My MD80 operating manual states: If rotation is abnormal and lift off does not occur at 6-8 degrees pitch, stop rotation at 10 degrees until lift off occurs to prevent tail strike&gt;. .regards

abeesley
13th Feb 2002, 08:39
Dunno about the 777 but our new shiny 757-300's have a tail skid which when hit, causes a few sparks. If the strike is severe, the sensor which looks like an antenna behind it scrapes, opening the circuit through it giving EICAS msg.

The tail skid has a crushable can inside it and the tell-tail markings should be visible on a walk round.

The -300 looks chuffin long compared to the -200! They have reduced the rotation angle to 15deg (instead of 17deg) At that angle there is only 26in clearance to the runway. To try and prevent tailstrikes Mr Boeing has added extra feel so that the stick-to-seat-interfaces don't pull so hard!