One engine take off

[skelsey 765]

 

 

Thurst aettings dont matter. When you get your takeoff thrust settings, de rated or full, thays what youll be using fkr the takeoff. VMC doesnt matter because v2 will protect you in that regard.

 

But it does matter if you are using de-rated thrust (TO1/TO2), because V_MC (and therefore V₂) is predicated on the de-rated thrust setting.

 

If you use speeds calculated for TO2 with full thrust, you may get in to bother, especially at the lower end of the speed schedule, and you cannot just firewall the thrust on the operating engine if you conducting a de-rated takeoff for the same reason (and even at higher weights the rate of change of thrust may be problematic given that the book V_MCA is flight-tested under relatively benign conditions).

 

An assumed temperature reduction is of course a different matter and can be safely removed with a single click of the TOGA switches if desired. But if you are using TO1/TO2 -- the second click that gives you max thrust may not be a good idea.

 

I absolutely agree that there should never be a situation where you should be in V_MC trouble in a Perf A jet if you have done the sums correctly, and really the safest course of action is to leave the thrust exactly where it is -- as you say, any de-rate/ATM reduction will have been calculated to provide a safe flight path.

 

There are, of course, handling differences between a light twin and a transport jet, but the basics -- stop the yaw, control the aeroplane and minimise the drag (which as pointed out above is of course affected by the roll spoilers, such that it is preferable to accept some sideslip in order to keep the ailerons/roll spoilers neutral) -- still apply.

[ahsmatt7 1,199]

But it does matter if you are using de-rated thrust (TO1/TO2), because V_MC (and therefore V₂) is predicated on the de-rated thrust setting.

 

If you use speeds calculated for TO2 with full thrust, you may get in to bother, especially at the lower end of the speed schedule, and you cannot just firewall the thrust on the operating engine if you conducting a de-rated takeoff for the same reason (and even at higher weights the rate of change of thrust may be problematic given that the book V_MCA is flight-tested under relatively benign conditions).

 

An assumed temperature reduction is of course a different matter and can be safely removed with a single click of the TOGA switches if desired. But if you are using TO1/TO2 -- the second click that gives you max thrust may not be a good idea.

 

I absolutely agree that there should never be a situation where you should be in V_MC trouble in a Perf A jet if you have done the sums correctly, and really the safest course of action is to leave the thrust exactly where it is -- as you say, any de-rate/ATM reduction will have been calculated to provide a safe flight path.

 

There are, of course, handling differences between a light twin and a transport jet, but the basics -- stop the yaw, control the aeroplane and minimise the drag (which as pointed out above is of course affected by the roll spoilers, such that it is preferable to accept some sideslip in order to keep the ailerons/roll spoilers neutral) -- still apply.

we are speaking the same language lol. I just had to point out that reduction of thrust will never happen. At V1 youre committed (i know you know that, youre a smart and well educated person).

[Guest]

I am keen to do some check ride things like V1 or V2 cut . However I always end up crashing. Guess thats why its a checkride item huh? lol  Anyway some hints and tips would be much appreciated, I dare not even suggest that its not simulated in the PMDG 737NGX!!

Hi Len, looks like you've got all the guidance from Skelsey here and all the background information. Some beef to back you up and how to physically fly a 737 NG during an EFATO! A few more tips for you, it’s what we teach cadets and reinforce during recurrent training and the differences between a light MEP and a Multi-Engine Jet.

 

Firstly and what might seem a bit obvious, reject the take off before V1. This is because V1 must not be lower than VMCG, VMCG (Velocity of Minimum Control on Ground) is the slowest speed with which there is sufficient rudder authority to continue a take-off in the event of an engine failure.

 

If the engine fails after V1 smoothly apply rudder to maintain runway centreline. There’s a big difference in how quickly you apply rudder depending on say an engine flameout and severe damage.

 

At VR (Rotation Speed) start a smooth continuous rotation to a target pitch attitude of 12.5 degrees at approximately 1.5/2 degrees per second (normal two engine rotation 2/2.5 degrees per second approximately 15 degrees).

 

Throughout the rotation maintain direction control with the use of rudder AND aileron. You shouldn’t need too much aileron if you have the correct amount of rudder input. After a positive rate of climb raise the landing gear.

 

Now the best tool you have is the flight director. The flight director after an engine failure will command a pitch to fly to maintain a speed between V2 and V2 + 20 depending at what speed the engine failure occurred. V2 is the minimum speed to fly to maintain the minimum required climb gradient and to maintain aircraft control.

 

At 400ft AGL we would select HDG SEL and initiate any memory items specific to the failure, for example an engine fire needs to be dealt with promptly but an engine flameout we can deal with later.

 

It’s worth quickly noting we would generally maintain RWY Heading after an engine failure at V1 and climb to the MSA. If terrain is an issue at the particular airport our company has specified Emergency Turn Procedures to comply with to keep us away from terrain.

 

This pitch attitude is maintained until reaching MFRA (Minimum Flap Retraction Altitude) and is typically 1000ft above aerodrome elevation. At MFRA, which we would have set on the EFIS MINS BARO, we BUG UP and retract the flap. This is the engine-out acceleration height and the flight director will now command an almost near level or slight climb. Whilst accelerating retract the flaps like you would after any departure.

 

Once the flaps are up we would then select LVL CHG and select Max Continuous Thrust in the FMC (NI Page and LSK CON) and then manually set thrust on the reaming engine to the N1 bug. You would then fly the UP speed until above the MSA.

 

Once above the MSA we would action the applicable QRH Non Normal Checklist, After Take Off checklist and decide on the best course of action!

 

Oh and a quick note regarding Engine Failure during Reduced Thrust (ATM) and/or Fixed Derate Thrust.

 

Skelsey is absolutely right, if you increase thrust after reducing the thrust before departure by fixed derate (for eg 22k or 24k) you could potentially lose directional control. This is because takeoff speeds consider VMCG and VMCA at the fixed derate level of thrust HOWEVER at the Captains discretion maximum thrust is available if in the opinion you might smash into the side of a mountain.

 

If thrust has been reduced by ATM you may increase thrust on the operating engine by setting N1 to the N1 reference bugs whilst maintaining direction control, this would provide an additional performance margin HOWEVER this shouldn’t be required as the take-off data is based on the ATM thrust setting. Unless you are massively mishandling the aircraft on one engine the extra thrust should not be required.

 

If you’re using a combination of both fixed derate and ATM the same applies if you were using just a fixed derate (don’t increase thrust unless there is a massive mountain in the way!)

 

That’s it in a very brief nutshell. As I always stress this is guidance based on Boeings FCTM and my operator and I hope you might find this information useful.

 

Oh and remember to turn off Autorudder in FSX settings! It might help!

[lencarne 6]

Well, thank  you all... I can now get the bird off the ground on one engine. Thanks to Sam, how nice to have someone explain an acronym in the first instance of use. I did see a glossary once...