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Engine Failure at Takeoff

by K.Haroon: Last Update on 25th October 2005

If an engine fails at or after attaining V1, the take-off has to be continued. Since Fokker F27 has four different take-off types, namely Flaps 16 Wet Power, Flaps 0 Wet Power, Flaps 16 Dry Power and Flaps 0 Dry Power, there are four different clean-up procedures involved. It might be easy to remember and recall these procedures under normal training sessions, which give you ample time to revise your procedures before practicing them, but an actual case of engine failure after V1, without any prior warning with high stress levels in the cockpit, might become very challenging in terms of recalling and applying the correct procedure. Therefore one should keep in mind the overall picture of what is required and to remember those steps which are less in number but comprehensive.

All what you need after an engine failure is lots of power to go up and a clean aircraft configuration to reduce drag. You can achieve this with MCP (15000 RPM & 850^oC TGT for Dart Mk 532-7 engine) and retraction of the gears and the flaps respectively. Divide this into two stages, one before the acceleration height and the other after it. Power is needed for taking the aircraft up and cleaning-up is required to reduce the drag and accelerating the aircraft once it has reached the acceleration height. If you have this gist in mind then it would be much easier to recall and apply the correct procedures. Secondly an important thing to keep in mind is to know whether you are taking-off wet or dry, because power application depends on this. This is not difficult since you can register this in your mind just before commencing the take-off roll.

Now if you are taking-off wet and the engine fails at V1, continue the take-off. When positively airborne call GEARS UP. Now you need to do two things that were discussed above i.e. application of power and cleaning-up the aircraft. Since you are below the acceleration height you need to think about applying the power first so that you go up. The good news incase of a wet take-off is that you dont need to do anything regarding the power. This is because in a wet take-off, the TGT is 860^oC i.e more than the MCP which is 850^oC and the RPM is already 15000 on the live engine, set earlier for take-off. Thus you already have sufficient power for going up. So now you only need to clean-up the aircraft. For that climb to the Acceleration Height and accelerate to V_FC. Crossing V_FR call TRIM UP 25% (incase of Dart Mk 532-7 engine) FLAPS UP and WATER OFF (when Flaps are up). Then reset MCP. Just to remember the sequence it is Fuel-Flaps-Water. Thats it. Carry out the rest of the drill while climbing to MSA (Minimum Safe Altitude) or CA (circuit altitude).

The book says, accelerate to V_FR, trim up 25%, flaps up, water off, reset MCP, accelerate to V_FC. Main and vital thing in such a situation is the coordination between speech and motor skills i.e. you have to fly the airplane along with calling out the correct commands and cross checking whether they have been executed correctly or not. This can be achieved in a much better fashion if the workload is simplified, streamlined and kept to minimum. For all practical purposes VFR and VFC are so close together (min 4 knots difference at lower weights and max of 6 knots difference at max weights) that if the pilot monitoring forgets to call out the V_FR speed then it would be much easier to accelerate to V_FC first and then give the clean up call outs.

For a 0 Wet take-off the book says, upon reaching acceleration height trim up fuel, water off, reset MCP, accelerate to V_FC. These two procedures can be combined to just one, for the sake of simplicity and reducing the pilots workload. Whether its a 16 Wet or a 0 Wet take-off, at 'Acceleration Height' accelerate to V_FC, trim up the fuel, retract the flaps, switch off the water and reset MCP. Two issues can be raised regarding this. One regarding the call for 'Flaps Up' when the take-off was already without flaps. Second regarding not switching off the water methanol and accelerating with wet power all the way from V2 till V_FC. For all practical purposes, I think these issues do not jeopardize the safety e.g. in a 0 Wet take-off, if the pilot flying accelerates to V_FC and says Flaps Up, then the pilot not flying will just confirm that they are already up. If they are not (like in a 16 Wet take-off) he will simply retract them.

Regarding the second issue i.e. accelerating with wet power from V2 till V_FC, the only concern that I can think off is the TGT. Though in my opinion it should not be a problem because from V2 till V_FR it is perfectly alright to accelerate with wet power, as the book allows it (refer to 16 wet take-off). The question mark will then only be applicable to the condition of accelerating with wet power from V_FR till V_FC.

Considering the average the difference between V_FR and V_FC to be just 5 knots, according to my estimate this acceleration should not take more time than the time required for flaps to retract completely. If TGT is not a problem while waiting for flap retraction before switching off the water (as in a 16 wet take-off) then it should also not be a problem when accelerating with wet power from V_FR to V_FC. However there is another interesting point to consider. Please refer to single engine go-around procedure in the operating manual. There is a note mentioned in the procedure, which says:

" In case of Wet Power at V_FC, increase the fuel trimmer setting of the operative engine by 25% (40% for 532-7R) and call W/M OFF and reset the fuel trimmer to the temperature limit for M.C. power " [Ref: F27 Operating Manual 1.3.22]

This means that in a single engine go-around, the book requires the water methanol to be switched off after accelerating to V_FC, unlike a single engine 0 wet take-off which says to switch off water methanol before accelerating to V_FC. This will yet be another procedure to learn and apply. But as discussed above, if we accelerate to V_FC first and then do the rest of the stuff, we can streamline all the procedures without compromising safety (in my personal opinion).

If the take-off is dry and the engine fails at V1, continue the take-off. When positively airborne call GEARS UP. Now again you need to do the same two things i.e. application of power and cleaning-up the aircraft. Since you are below the acceleration height you need to apply the power first to go up. The TGT is 810^oC in a dry tak-off, less than the MCP which is 850^oC, so you need to trim up for MCP here. As the RPM is already 15000 set on the live engine for take-off, just call TRIM UP after calling GEARS UP so that the TGT is set to 850^oC. Now you need to clean-up the aircraft. For that climb to the Acceleration Height and accelerate to V_FC, crossing V_FR call FLAPS UP, Recheck MCP. Carry out the rest of the drill while climbing to MSA or CA.

Following is a summary of steps involved in an Engine Failure after V1, as discussed above:

Wet Power Take-Off	Dry Power Take-Off
Positive Climb GEARS UP	Positive Climb GEARS UP + TRIM UP MCP
Climb at V2 to Acceleration Height	Climb at V2 to Acceleration Height
Accelerate to VFC	Accelerate to VFC
TRIM UP 25% FLAPS UP & WATER OFF	FLAPS UP
Reset MCP & Climb to MSA / CA	Recheck MCP & Climb to MSA / CA

Disclaimer: Information in the article "Engine Failure after V1 in an F27 Takeoff" is a personal feedback, opinion or suggestion by the author that does not sanction any pilot to violate his Company's Standard Operating Procedures, Aircraft Manuals or Manufacturer's Recommendations.