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Faro
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Handling Qualities Widebody Vs Narrowbody

Wed Nov 11, 2009 9:59 am

I recall reading that the 747 when launched was deemed to have superlative handling qualities, much better than other models of the pre-widebody era.

Is this a general (or quasi-general) rule for widebodies vs narrowbody airliners? For the practicioners on Anet, which aircraft type that you have flown do you deem to have the:

- most responsive;
- most forgiving; and/or
- most harmonious

flying qualities about all axes?

Faro
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Starlionblue
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RE: Handling Qualities Widebody Vs Narrowbody

Wed Nov 11, 2009 12:47 pm

Widebodies have more inertia, so they will tend to resist changes of direction more. On the other hand, they have proportionally larger control surfaces to counteract the inertia.
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RE: Handling Qualities Widebody Vs Narrowbody

Thu Nov 12, 2009 3:23 am

I spoke with a test pilot comparing the 737 and 777. Although the 737 could outperform the 777 in almost every way, I was told that it is a clunker to fly compared to the fly by wire 777. The cable driven flight controls require much more finesse and are no where near as smooth as the electric controls on the 777. From having to physically force the landing gear lever in place to the spring loaded brakes, the 737 is an awesome plane, but it requires more effort to fly. Although they both have a yoke, the 777 is a beautiful plane to fly.
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DocLightning
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RE: Handling Qualities Widebody Vs Narrowbody

Thu Nov 12, 2009 6:15 am

Someone on this board described the MD-11 as "like flying a swimming pool half filled with water."
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TSS
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RE: Handling Qualities Widebody Vs Narrowbody

Thu Nov 12, 2009 3:21 pm



Quoting DocLightning (Reply 3):
Someone on this board described the MD-11 as "like flying a swimming pool half filled with water."

 rotfl 
That sounds like a Wilco-ism. Big grin
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Aaron747
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RE: Handling Qualities Widebody Vs Narrowbody

Fri Nov 13, 2009 12:33 am



Quoting Faro (Thread starter):
I recall reading that the 747 when launched was deemed to have superlative handling qualities, much better than other models of the pre-widebody era.

Well, essentially it has proportionally huge control surfaces - so there is really no excuse for it to handle poorly. If you ever have the chance, just stand at ground level under the aircraft and take in the size of the v-stab - truly massive.

I took these from ground level:



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PGNCS
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RE: Handling Qualities Widebody Vs Narrowbody

Fri Nov 13, 2009 7:00 pm



Quoting Faro (Thread starter):
I recall reading that the 747 when launched was deemed to have superlative handling qualities, much better than other models of the pre-widebody era.

Is this a general (or quasi-general) rule for widebodies vs narrowbody airliners? For the practicioners on Anet, which aircraft type that you have flown do you deem to have the:

- most responsive;
- most forgiving; and/or
- most harmonious

flying qualities about all axes?

Certainly earlier jet aircraft were less docile than more modern aircraft. The B-727 is notorious for dutch roll and has more yaw damper restrictions than most aircraft, for instance. I can't address the 707 or DC-8, but have flown the 727, 737, and DC-9, as well as the 747, and find the control harmony of the 747 much more pleasing than the 727 or especially 737. The DC-9 is a whole different creature with the cable drive tab architecture. I personally like the DC-9 control feel, though it does require more initial deflection (in roll especially) to obtain the same result present on the hydraulically boosted Boeings (one approach in manual reversion in the 727 or 737 will demonstrate the advantage of the Douglas design without question). Once you get into the spoiler augmented region the DC-9 is very responsive in roll. I personally think the DC-9 is better flying than the MD-80 family, as an aside.

In retrospect, I still think the 747 has very good control harmony, and is responsive beyond what most would expect. Of course it has a lot of inertia, too. I think the 747 has better control harmony than the 767 by far (way touchy in roll, especially slow and configured), but think the best Boeing for hand flying is the 757, which is extremely well balanced and maneuverable without being touchy in any axis. I have not flown the 777, so I can't address that comparison. In short, I think Boeing did a great job with the 747 controls (the 744 would be my second favorite Boeing to fly), but it's one good competitor in a very distinguished field; in other words, it's great, but so is most of the competition. The best control harmony and maneuverability I have personally flown in a large aircraft is undoubtedly on the L-1011, which was the most pleasing aircraft to hand fly I have ever known. It's as close to perfectly balanced as any airliner will ever be; I especially love the flying stabilator and DLC...talk about stable! As far as what's currently out there, I dramatically prefer the Airbus FBW aircraft for control harmony, stability, ease of control (especially in abnormal situations), and being very forgiving. B-737 is my choice for least enjoyable to fly in every regard, though plenty of people disagree.

This is, of course, my somewhat subjective, though informed opinion. Hope it's kind of what you were looking for.
 
Western727
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RE: Handling Qualities Widebody Vs Narrowbody

Fri Nov 13, 2009 7:10 pm



Quoting PGNCS (Reply 6):
I personally think the DC-9 is better flying than the MD-80 family, as an aside.

This perspective got my curiosity piqued. Is it because the MD-80's control surfaces have hyd boost like the Boeings you mention (and that's only my uneducated guess), and/or the greater inertia of the MD-80 family...or something else entirely?
Jack @ AUS
 
PGNCS
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RE: Handling Qualities Widebody Vs Narrowbody

Fri Nov 13, 2009 7:46 pm



Quoting Western727 (Reply 7):
Quoting PGNCS (Reply 6):
I personally think the DC-9 is better flying than the MD-80 family, as an aside.

This perspective got my curiosity piqued. Is it because the MD-80's control surfaces have hyd boost like the Boeings you mention (and that's only my uneducated guess), and/or the greater inertia of the MD-80 family...or something else entirely?

Hi Western!

Great question, and I don't think it has a simple answer. The MD-80 family has the same control tab architecture for roll and pitch control the DC-9 has; there are trivial differences in the systems. The MD-90 does have hydraulically boosted elevators, and I like its handling least. I have often wondered about the hand flying qualities of the DC-9 vs. MD-80, and it may just be a personal preference. It seems to me that the bigger, heavier MD-80 (late MD-80's could weigh twice what early DC-9's weighed) seem a bit more sluggish than the DC-9 per unit of control deflection. The rudder is powered on both aircraft, and is very positive and effective. The biggest difference I note in the handling is that the MD-80 seems heavier in pitch especially at low speeds, and especially when in landing configuration (Flaps at 28 or 40 degrees); part of this may be due to trim technique. I tend to trim further nose up on final than most of my contemporaries (judging from looking at the stab trim indicator after landing). It's an individual pilot-feel thing and different people trim differently in reality. I have never thought I didn't have good pitch control of the aircraft, though some people complain about pitch feel when configured and slow (i.e. in the flare). The MD-90 DOES have hydraulically powered elevators, but has a vaguer feeling at slow speeds...I don't know how to describe it other than there is less feedback to the pilot in pitch even though there is actually more control authority. It's not a problem it's just different...when I flew the MD-90 a lot, I didn't really notice it, but when I switch back and forth between the MD-80 and -90 I notice it more, much like guys who normally fly the 767 note the handling differences of the 757 when they get in it.

I hope this addresses your questions. If you want to know more let me know what you'd like me to address.
 
Western727
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RE: Handling Qualities Widebody Vs Narrowbody

Fri Nov 13, 2009 8:45 pm



Quoting PGNCS (Reply 8):

Fascinating. Thank you, PGNCS, for taking the time to write down your thoughts and yes, you addressed my question and then some. Your comment about switching between the MD-88 and the -90 as well as between the 757 and 767 reminds me of the experience I have driving the many rental cars I drive. Thanks again.
Jack @ AUS
 
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Faro
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RE: Handling Qualities Widebody Vs Narrowbody

Sat Nov 14, 2009 8:55 am



Quoting PGNCS (Reply 6):
The best control harmony and maneuverability I have personally flown in a large aircraft is undoubtedly on the L-1011, which was the most pleasing aircraft to hand fly I have ever known. It's as close to perfectly balanced as any airliner will ever be; I especially love the flying stabilator and DLC...talk about stable!

Many thanx PGNCS for your detailed and insightful input. I must say that the Tristar never ceases to amaze me, the number of times people have glorified it here on A.net is quite remarkable. Apart from all the innovations it introduced like 4D FMS, DLC, load-alleviating ailerons, etc (I recall reading somewhere on A.net that the Airbus FBW philosophy implemented starting with the A320 owes quite a lot to the Tristar legacy) it also flies superlatively well! I wonder if it were not for the Rolls Royce mess with the RB211, it may have been a major commercial success. That was one exceptional design.

Faro
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RE: Handling Qualities Widebody Vs Narrowbody

Sat Nov 14, 2009 4:34 pm

Limiting my judgement to those airliners I have actually flown in the front seat for more than a couple of trips [B737, B757, B767, F100, MD82/83/90]....

Quoting Faro (Thread starter):
- most responsive;
- most forgiving; and/or
- most harmonious

B752, B752, and... B752 (with B763 a very close second)
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