Photon

I've never done/teached nor heard of anyone who teaches this.
Nor would I teach it to a student with less than 50 hours in a multi

Phantom Flyer

In all of my years of operating aircraft from DC-3's to the B-777, I've only used it once or twice in a DC-3. NEVER in a turbo-jet aircraft. In a B-727, with a very strong direct cross-wind (usually 15 knots or more) an accepted technique was to bring # 1 and 3 up and then slowly increase the thrust on #2 because of the "S-Duct" to prevent compressor stalls;however, all 3 had to have the take-off thrust set by 60 Knts.

On landing....NEVER !!

Directional control in a turbo-jet aircraft is maintaine with ailerons, rudder or a combination thereof.

Just my two cents Mates....G'Day

aviatorhi

Used it all the time in a 1900 when landing on ice in anything over about 20-25 knots of x-wind component.

Phantom Flyer

Didn't know the 1900 was a turbojet, which I believe was the subject of the original posting.

In a propeller driven aircraft, perhaps, depending on the type aircraft and airport/runway conditions. That technique was used in a large tail dragger, such as the DC-3.

Hmmmmm

G'Day Mates

KC10 FATboy

I've flown the 1900 ... still don't know why you guys are suggesting this is a safe technique.

If you aren't using the rudder, you are either increasing your yaw to the runway and/or not killing your drift ... depending on which engine (upwind or downwind) you pull.

See my previous threads if you need more explaination.

aviatorhi

Ever landed it on an ice surface runway (not a contaminated runway, specifically an ICE runway)? You'd understand that "drift" and "side-load" matters less than "directional control".

Also, regarding the 1900 not being a jet, my apologies, didn't notice the question was specifically asking for jets, just saw a lot of bickering back and forth with one side talking about how it works in practice and the other side saying how it doesn't work on paper.

Ever landed on a contaminated paved or gravel runway with crosswind components exceeding 40 knots?

The reason the technique is used is because it works, it's worked for decades and it will continue to work, day in and day out up here, we make due with the conditions and equipment we have.

Radials Rule

I had to do a few landings in the DC-3 in which asymmetrical thrust was required to maintain directional control....especially when loaded towards the aft CG limits and especially during the landing roll-out with the tailwheel on the ground.

There is nothing improper about using asymmetrical thrust for xwind landings, piston or jet.

aviatorhi

I agree, and I think what people are forgetting is it's not the power plant that would make a maneuver appropriate or inappropriate... it's the type of wind/airfoil... supercritical wings dislike certain things that "inefficient" wings don't mind.

shdw

Some of the people here saying "no no no no no" over and over to asymmetrical thrust for landing would have no problem executing a single engine go around in their jets. Riddle me that one.

jungle

Asymmetric thrust is most commonly used in fairly lightly wingloaded aircraft as a technique to get a little more crosswind capability from an aircraft that has run out of rudder and can't land in a crab. It just adds a little directional control when there isn't enough rudder.
Some heavy jets can land in a crabbed or partially crabbed condition and this may even be preferable in a low friction situation. It also serves to increase the crosswind capability.
I have never seen a jet flight manual recommend asymetric thrust as a landing practice, or a takeoff practice. Would it work? Sure, but they don't want you doing it. Just like they don't want you exceeding crosswind limits or landing on an icy runway with no effective braking. Most of us don't want that recorded on the data recorder or having to explain why we were experimenting with an unauthorized method.

Most anyone can touchdown in any crosswind within reason, the tough part is what happens after touchdown, keeping control of direction after touchdown in a jet is a little different than a light twin and there is less margin in runway width, reverse and braking requirements.