convair880mfan wrote:Can a jetliner go from takeoff thrust to climb power during a turn without reducing bank angle?
But what if an immediate turn is required after takeoff to avoid terrain? A steep bank is initiated but during the turn climb power is selected. Does the bank angle need to be reduced for safety reasons?
If I recall correctly, the aircraft are still at takeoff thrust when the turn is initiated. The bank angle seems [?] steep and the flaps are yet to be retracted. I can't recall if the bank angle is reduced when climb power is selected or whether it is maintained.
convair880mfan, so many questions . . . let's see.
First question, "can a jetliner go from takeoff thrust to climb power during a turn without reducing bank angle?"
Like GalaxyFlyer (Reply # 2) stated above, Yes.
With regard to your statement, "A steep bank is initiated but during the turn climb power is selected. Does the bank angle need to be reduced for safety reasons?"
A transport category aircraft in Part 121 (airline) operations is not going to be making a steep bank (greater than 45 degrees) turn. With all engines operating, turns are predicated on "standard rate" turns--approximately 30 degrees--and that takes into account operating at climb power. So, in the example you cited bank angle does not need to be reduced.
Concerning your statement, "aircraft are still at takeoff thrust when the turn is initiated." In many aircraft, depending on where you are seated, and on operating conditions (gross weight, temperature, altitude, etc.) it is occasionally difficult to determine when thrust has been reduced from takeoff thrust to climb thrust, so it may not be valid for you to say that aircraft are still at takeoff thrust when the turn is initiated. Thrust is generally reduced from takeoff thrust to climb thrust at either 1000 or 1500 feet AFE in the U.S.
In transport category aircraft, takeoff data and climb performance are predicated on the loss of an engine, with the requirement to maintain adequate obstacle clearance on the departure procedure. This will probably require the use of Maximum Continuous Thrust throughout the departure procedure and the use of half standard rate turns if required. However,
if all engines are operating, there will be increased performance, and therefore, it would be normal to reduce thrust from takeoff thrust to climb thrust at the normal point, 1000/1500 feet AFE and to make standard rate turns--not steep turns--at the appropriate points.
Now Albuquerque, with mountains to the east of the field--presents special challenges. Each air carrier may develop their own (FAA approved) departure profile to expedite their aircraft climbing to a safe altitude as quickly as possible. Such profiles may include climbing at Vx airspeed, rather than Vy, with flaps at the takeoff setting until reaching a certain altitude, or perhaps climbing at Vzf, rather than accelerating to 250 KIAS, until a certain point on the departure.
It looks like the eastbound departure procedures at Albuquerque (MNZNO and GRZZZ departures) departing Runway 8 require turns to the north or south--to avoid the mountains--until such time as the aircraft are high enough to clear the terrain and safely turn to the east. They eastbound SIDs also have restrictions of a maximum airspeed of 220 KIAS until above a specified altitude (close to Vzf for many aircraft depending on gross weight). This is designed to allow aircraft to climb higher more quickly (with respect to distance traveled) and also maintains a suitable ground track using standard bank turns so aircraft maintain a safe distance from the terrain. As you may have experienced, aircraft departing Albuquerque for points east, DFW/DAL for example, will turn either north or south until obstacle clearance is assured (above 11,500 feet MSL at MNZNO; above 12,100 feet MSL at GRZZZ) before turning back to the east.
In the event of engine loss, it would not be prudent to attempt to cross the mountains. Rather, a pilot would fly the departure procedure, using appropriate engine out procedures, and maneuver back to the west before returning to land at ABQ or proceeding to an alternate airport.
Airbus narrow body aircraft (A319/A320/A321) procedures are the same.
I hope I was able to address some of your questions and interests.
e38