Take Off Briefing

[Sonia767]

Hi to all,

In the 767 QRH take off briefing and maybe in the other boeings as well in the take off briefing they say a rejected take off should be carried out if the aircraft is Unsafe or unable to fly.

This is apart from the engine failures,fires etc

So what other circumstances would be considered to fall under that Unsafe or unable to fly.................

Can someone unconfuse me please............


Sonia:)

[Departures Beckham]

I guess bird strike to the fuselage, shattered windows, hydraulic problems ... however my manual (B737) does state:

"at speeds in excess of 80 knots take-off will only be abandoned for an engine failure, any fire warning, a blocked runway or any other failure at Captains discretion".

[BlueEagle]

We used to say the reasons to reject, after a speed of 80kts had been reached, were: "Engine failure, fire, system failure or factors that seriously effect the safety of the aircraft".

Uncommanded and unexplained movement of flaps or other flight controls. Total Electrical or Hydraulic failure, sufficient multiple instrument failure to render the aircraft unflyable, a blocked runway, shattered windscreen, to name a few.

There will always be debate on the extent of system failure that prevents take off and requires a rejected T/O versus the extent of failure you can take into the air and sort out without compromising safety so your company SOP should be definitive in that respect.
:)

[quid]

At 80 kts you've only used about 2000' of runway. At that point, you've got plenty of pavement left. No way I'm going to commit to "fly" if there's a question of "unsafe or unable".

In addition to those reasons mentioned, how about partial power loss on two engines, hitting a flock of birds and losing power on one engine and partial power loss on the other, hitting a deer on the t/o roll, blowing a few tires around 80 or 100 kts, uncommanded rudder input - I can go on and on.

I'm involved in writing SOPs for my carrier, and there's no way to cover all the situations on takeoff. That's something that the Captain has to decide on the spur of the moment.

With all the discussion on "RTO"s and aborts in the last 10 years or so, most pilots are prone to "go" at V1. What you have to remember in real life is that most carriers use balanced field V speeds. In many cases there is excess pavement left. For example, the V speeds used on 31L (14,000+) at JFK may be the same as those used on 27 at BOS (7000).

No matter what SOPs I write, the FARs still charge the PIC with safe and responsible operation of the a/c, and the authority to deviate from any rulesregulations or SOPs if the situation demands it.

[Sonia767]

Thanks to the three of you for youre sensible replies.

Will bear those in mind...........Sonia :) :)

[Earthmover]

Sonia, Boeing uses this statement in their excellent RTO video in reference to rejecting the Take Off after V1. It goes something like "The only circumstance under which T/O may be rejected after V1 is if, in the opinion of the Commander, the aircraft is unsafe, or unable, to fly"

This happened about 10 years ago to a crew I know very well: At the "Rotate" call it became apparent that the elevator was jammed, apparently solid, and they rejected at about 15kts above V1. Fortunately they were on a very long runway. It transpired that 'maintenance' had been carried out to the elevator PCUs the night before this first Take-Off and there were multiple failures in the whole STAB/ELEV unit. It wasn't actually jammed solid, but tests showed that 6-10 times the normal stick force would have been needed to operate the elevator.

I think that this qualifies to be added to your list!!

Tot Ziens!

EM

[Sonia767]

Already been added Earthmover.Cheers ;) ;)

Sonia

[scanscanscan]

Even though the flight controls were checked full and free movement on the runway immediately prior to takeoff clearence a HS 748 had elevator controls locked at rotate and my friend died along with some passengers.
Was the full and free control check also done with the above Boeing prior to take off roll?

[calypso]

In my co. we will do an RTO before V1 for " any fire, engine failure (confirmed by two parameters), configuration warning, control malfunction or blocked runway."

[Earthmover]

Scanscanscan, yes it was ... and it wasn't a Boeing as it happens

[HOMER SIMPSONS LOVECHILD]

I'm a wee bit concerned at Quid's eagerness to reject above 80kts in the face of overwhelming historical evidence that "go" is the way to go! When are we going to learn?I can't recall the exact figures but the huge majority of smoking heaps in the field/harbour beyond the overrun turned out to be perfectly flyable aircraft.
If you've briefed that you'll stop for "a few burst tyres" "deerstrikes" etc then that's fine.If you've briefed the usual suspects then you should stick to that.Fire ,confirmed engine failure,blockage etc just about covers it.The vague "inability of the aircraft to sustain controlled flight" or whatever your company says means to me a serious collision or a total hydraulic failure.Try failing a genny just before V1 in the sim with no thrust loss and see how many stomp on the brakes.Been there ,done that ,learned the lesson (I hope)

[Johnman]

Also
- Windshear or downburst conditions is one of the reasons as well only if significant airspeed variations occur below indicated V1 and the pilot decides that there is sufficient runway remaining to stop the airplane.
- Reverser unlocked
- Sever Damage

[quid]

HSL-

Many of those horror stories re RTOs were from a/c attempting an abort from a speed greater than V1. Also, the guidance by Boeing mainly dealt with takeoffs at max gross weight for the runway. Many takeoffs are made at weights well below the max weight for the runway in use, and use the V speeds for the lower weight.

I'm certainly not eager to abort at high speeds, but I guess I'm even less eager to continue a takeoff with an aircraft that is "unsafe or unable to fly".

As I said before, at 80 kts, you've only used about 2000 feet of runway, at 100 kts it's less than 3000. Part 25 certified aircraft will take about 50% of the distance to stop that it used to get to that speed. In other words, if you've used 4000 feet to accelerate to a speed (whatever it is) you'll need approx. 2000 feet to get it stopped (max effort).

Look at the rubber patterns on the runways. Even though the data used for landing assumes a touchdown at 1000 feet, most of the rubber is between 2000 and 3000 feet from the landing threshold. That means airplanes are landing safely and turning off the runway from that point every day. The touchdown speeds are not much different from the V1 speeds in many cases. And....the 80-100 knot speeds on takeoff are happening at those same points. You certainly can get it stopped from there.

Pilots (and I've been one my whole life) want things simple. But...there are things that can't be made black and white. A blanket rule against aborts over 80 knots falls in that category. If I've only used 2000 feet of a 10,000 foot runway, there's no problem getting it stopped.

I know of one group that teaches, "with a fire warning 20 knots below V1, continue the takeoff". If I'm doing 100 knots at that point with a V1 of 120), and I've got 8000 feet of dry runway left, there's no reason why I can't safely get it stopped. (With thousands of feet to spare.) On the other hand, if I'm runway limited and have slippery surfaces and crosswinds to deal with, it's a whole different ballgame.

To summarize, each takeoff is unique. The pilot must evaluate each one, and make some plan before leaving the blocks. One size doesn't fit all.

Many have said - with the reliance on automation in the last decade, many pilots are not "thinking" as well as before. I agree.

Earthmover-

Exactly, and they're talking about aborts "after" V1.

calypso-

Sure, but there are many other reasons to abort at speeds slower than V1. What if you notice a violent shaking of the nose wheel (scissors disconnected for example) at around 40-50 knots? I doubt if they mean those are the "only" reasons to abort at "any" speed.

[HOMER SIMPSONS LOVECHILD]

Quid, my point is to brief for your abort items and stick to it.The "unsafe or unable to fly" one is always a tricky judgement call on the day and we've discussed that.
If you said that you will only stop above 80kts for fire,failure,blockage or the other one (those are fairly standard industry parameters)don't go stomping the brakes for a tyreburst or instrument failure or "deerstrike"(unless it causes one of the above).
The Boeing figures refer to high speed aborts BELOW V1 and they have found that less than maximum effective braking is carried out in the majority of cases resulting in the afformentioned smoking heaps.
The dissapation of energy at typical landing weights is a whole different thing from typical take off weights.Remember the energy is increasing exponentially.Out in the wide world of reduced thrust take offs from wee islands V1 is just that!
I'm not questioning your judgement, just saying that 120kts its not the time to change your mind about what you are aborting for.What will the other guy think?

[Johnman]

There was a mention of the 80 Knots speed several times . The speed of 80knots is not critical . Above 100 Knots and below V1 rejecting the T/o is a more serious matter , particularly on slippery runways.

[Zeke]

Johnman,

OEI full thrust on a slippery runway in a twin at slow speed is a serious directional control problem, at higher speeds you have rudder effectiveness.

Z

[BusyB]

Unsafe or Unable to fly is fairly precise-- If you're past V1 and the a/c stops accelerating for whatever reason ( greater contamination on RWY than reported, W/Shear) you would have to assess whether you are better to rotate early or face the obstacles at the end of the RWY. These things happen!

[Plastic Cockpit]

I personally dont think you will ever be able to detremine Go/Stop factors on a one off document. All I would say is that if you decide to stop at/after V1 you need to have a good picture of what you have in front of you. Likewise continuing before V1, you would really be thinking that trying to stop the aircraft is likely to cause you grief.
Speaking from my situation, we have a particular weight for which we cannot exceed given the current conditions. If you are well under this weight your particular TO roll may actually not only allow for a reject after V1, it may even allow for a reject after rotate or even airborne. So basically it is left up to the crew to decide given what the conditions are supplying as to whether stop or go. Fortunately our company also sees it this way and at the end of the day leaves the decision up to the commander.

[Flight Detent]

Hi all,
Do you all think that Fine Air DC8 freighter out of Miami would have been better off aborting the t/o at rotate, after they heard the cargo shift, (which was heard on the CVR), if they had realized the extent of their problem, I certainly think they would have!
Would have probably bent a few panels, etc, but how far do you take this question, I reckon the instant decision is essential, there are so many variations!
Prior thought is essential as to what it will take for you to do it!

thoughts!!!