Why no "Auto Take off" ?

[ARINC]

Given the sophistication of modern avionics and the proven ability to automatically flare, land, roll and Brake passenger aircraft safely time after time, why does the take off regime not have similar levels of automation.

TO/GA functions provide thrust and pitch guidance, FMC provides all the performance data V speeds etc (Including EO data) a simple matter to close the loop to the Autopilot and Auto throttle.

Perhaps it's a cultural barrier and not a technical one ?

[Old Smokey]

I would think, ARINC, that the barrier is not so much a cultural or technical one, but a financial one.

If you think back to the time of development of the Auto-Land system, many years of Research and Development, and millions of Pounds / Dollars were required to develop the system, with all of it's safety protocols.

Even in the present stage of Auto-Land's development, the ability to carry out an Auto-Land is a bonus, no operation is predicated upon the aircraft's ability to accomplish an Auto-Land. An Alternate Airport with weather minimums above the "human pilot" level is still required.

The closer that any collision risk exists, e.g. Takeoff and Landing, the greater the degree of back-up and "Fail-Operational" protection required. At Climb, Cruise, or Descent where much greater margins of Obstacle / Terrain seperation prevail, even a single simple Auto Pilot suffices. The pilot has plenty of time and airspace to intervene.

I have no doubt that it will one day be achieved, but, in the interim, Auto-Land provides great operational advantages and safety in allowing an already airborne aircraft to land, whilst the commander of an aircraft already on the ground may simply delay the departure and "Hold at the Gate".

There's many other considerations to be made, the "system's" ability to correctly handle a Rejected Takeoff, for example, but until some manufacturer can put up a valid case for any cost or safety advantage for such an "Auto-Takeoff" system, this will remain a manual phase of flight.

Regards,

Old Smokey

[Piltdown Man]

If we did, what would be the benefit? The majority of us can depart with 125M RVR already and you really need 75M to taxi, or are you suggesting "Auto-taxy" as well? Over my lifetime (see panel to left) I can probably count the days where visibility has been less than 125M on my external digits, ie less than 22. I'd suggest that the reason we don't is that there is no economic benefit.

PM.

[Superpilot]

I think it boils down to 'Takeoffs are optional, landings are mandatory'. Admitedly, I'm bit of an automation freak, love the idea of automation inside airplanes. But auto-takeoff is one thing I too cannot see any valid reason for.

[Mad (Flt) Scientist]

The benefits might be in reducing the incidence of tailstrikes, and obtaining more optimum takeoff performance, through being able to have more complex and precisely followed pitch attitudes and rates.

Unfortunately, those benefits may be 'real' but you'd never be able to take credit for them, because they are already assumed to be present when a pilot flies. One of the ironies of automation is that systems are assumed to fail, and for certification one must show how that failure is mitigated, in an acceptable fashion. Whereas pilots can be assumed to always do exactly what the flight manual says - even when we all know that isn't the case.....

[earnest]

We were told that most tailstrikes occur on landing.

[Mad (Flt) Scientist]

I'd expect that to be a very much type-dependent statement; both takeoff and landing strikes have occurred in-service on various types.

[Old Smokey]

Tail strikes are more likely statistically to occur on Takeoff than upon Landing.

Takeoff = Lower Flap setting = Less ground effect = Higher Pitch Attitude to achieve the same Lift, than upon Landing.

Regards,

Old Smokey

[McAero]

hence why the 777-300ER has a new semi lever gear system to help reduce the risk of tailstrikes on takeoff...

[Human Factor]

The "Reject" decision is not always black and white. Clearly for an engine fire/failure before V1, you stop. After V1, you go. A computer can be programmed to "Reject for A" or "Continue for B" but there will always be grey areas where it will not be clear cut, so the potential for human intervention will always be there.

A manual take-off can be performed safely (with the appropriate equipment and safeguards) to 125m RVR. I see no need for an automatic take-off.

Edited for brain fade.

[anybodyatall]

The real question is, would pilot unions support it?

In Hal 9000 we trust?!

[Piltdown Man]

I'm sure the unions would support it, like they have with every other properly introduced technical advance in aviation. However, if this means that you don't need pilots anymore - would the passengers support it? I'd bet a pound to a pinch of pooh that whilst the bean counters would think it fantastic, the aircraft would be empty as the freight would vote with it's feet.

[3Greens]

never going to happen at places that are working at max capacity like LHR. The reductionin flow rate when LVPs' are introduced causes mayhem. To be able to auto take-off, and the technology exists, you would need similar protection to auto-land. Nice idea, but not practical with everyday airline ops.