744 GA After touchdown?

[noblues]

Has anyone experience of initiating a GA after wheels touching?

From my understanding the GA mode is armed for 5secs after going below 5ft RA?

Will the spoilers automatically deploy?

Is their a high risk of a tailstrike?

Going straight to F2O is OK considering might be below Vref at this stage of the flare?

Just my mind pondering, not having actually down one!

[rasobey]

It's possible, I saw it in the film Air Force One.

Couldn't resist, sorry.

[BelArgUSA]

Sorry friend - but I am 747-200 pilot (the real 747) -
xxx
The maneuver described is called a touch and go...
It was common in the days that a barrel of oil was only $15.oo...
Now - all that is done in simulators.
xxx
In my 747-200, we can make a touch and go... provided that -
(1) we dont arm the spoilers -
(2) we have not deployed reversers after touch down -
(3) autobrakes are not armed -
(4) autothrust not used -
xxx
I have done a few in my life - with above conditions as follows...
After touch down, the PNF moves flaps to 20 - and pitch trim to 5 Units
The PF moves thrust levers "UP", then commands "GA POWER" -
The F/E moves thrust levers to GA EPR (or N1) -
xxx
No problems with tailstrikes -
:)
Happy contrails

[NigelOnDraft]

Rather than getting lots of varied opinions/thoughts here, track down the QF 744 accident report for BKK. I am sure that will discuss a GA after touchdown, and/or shortly before, since in retrospect, it might have been the better option :oh:

NoD

[skiesfull]

From The 747-400 Flight Crew Training Manual,
press the TO/GA or set manual go-around thrust and select flaps 20 while rotating to the go-around attitude. As the thrust levers are advanced, auto-speedbrakes retract and auto-brakes disarm.
This is in the case of a rejected manual landing.
For an autoland, an auto go-around cannot be initiated after touch-down or if the airplane is below 5 feet radio for more than 2 seconds.
Only ever done it during simulator base-checks where the instructor selects flaps 20, winds the trim forward to approx. take-off setting and stands-up the thrust levers. While this is being done, the trainee keeps the aircraft on the centre-line and once the flaps are at 20 rotates on command from the instructor. Similar to the -200, except more tasks for the instructor!

[Shanwick Shanwick]

Once went around at LHR from about 30ft and the wheels touched. Smoothest touchdown I've ever experienced on the 400.

[noblues]

Think some people are getting confused here ... a touch and go is a totally different manouvre to a GA from a landing as the wheels touch

ie. say max X-wind, and gust hits you just as you touch.

So the 2 secs below 5 RA is only if its coupled?

The GA switches should always work until reverse is selected?

Dont know about my faith in the system with Autobrakes dis'arming and the spoilers retracting!

[skiesfull]

Noblues,
My posting above is from the official Boeing manual.Read it again and 'have faith'!

[Feather #3]

As to the tailstrike; yes, there is a possibility.

The answer is to hold the attitude at 5degNU until positively clear of the ground and climbing away [max 8degNU, but 5deg is easier to see on the ADI.]

This ensures that the attitude is not high enough for a tailstrike AND that should further ground contact occur, it will be on the main gear, not the nose gear.

Maintaining the attitude needs some work as once the speed falls below the trimmed Vref+5, significant forward stick displacement with what can only be described as "soggy" feel is required to stop the nose rising with the application of GA thrust until the speed recovers and the a/c retrimmed.

Hope that helps.

G'day ;)

[TheOddOne]

I witnessed what became something of a landmark incident at Gatwick in the early 1990s when an Air New Zealand 744 went around whilst in the flare, touching the runway in the process.

A storm had just gone through, leaving the runway wet and a slight tailwind for the runway in use (26L), as is often the case after the passage of a storm cell.

Whilst the aircraft appeared to be making a normal approach, there was considerable 'float' and the a/c hadn't touched the surface for some distance past the aiming point. I was in a vehicle on the Northern Runway (08L/26R) approximately abeam the aiming point. The engine note increased and the a/c pitched up. However, due to inertia, the a/c continued to sink slightly, the mains briefly touching the surface and running along for a couple of hundred metres before becoming airborne and climbing away. We never saw the a/c again, as it diverted to Heathrow, I guess not having sufficient fuel for another go with reserves.

The go-around seemed like a good call, with the tailwind and float and there had recently been a couple of over-run incidents elsewhere in the world.

This incident is still mentioned especially in ATC training at Gatwick illustrating the go-around decision-making process and that controllers can see an a/c touching during this manoeuvre.

I also use it as an illustration and practical now that I'm teaching other people how to safely approach and go-around in all configurations.

Cheers,
TheOddOne

[Hand Solo]

It can certainly be done and featured heavily in one of BA's recurrent sim checks about a year ago. From what I can remember the spoilers will automatically stow when TOGA is selected and you may get a config warning as the aircraft thinks you are trying to take off with flap 25 but apart from that it's really no big deal. There's no greater risk of a tail strike than a normal take off and you really shouldn't be below Vref at any stage of the flare!