At the club I fly at, there is an older Cessna 172 that has a manual "Johnson Bar" that is used to put the flaps down.
In the newer 152, and I believe the rest of the planes (I have yet to fly them), the flaps are controlled via a electronic (or hydraulic?) lever.
It appears to me that the manual flaps are more reliable, more maintainable, and a hell of a lot more fun in my opinion. Additionally, the manually flaps don't require a lot of strength to operate IMO. Does anyone know why the automatic design is favored over the manual counterpart? Same question applies to car transmissions...
Nobody can definitively answer this for you except Cessna's 1965/1966 engineering team (the year they made the change), but there are two reasons I can think of:
Because switches are cooler than Johnson bars; or Because everyone else is doing electric flaps.
Much like with manual transmissions, some people just don't like the extra work of manual flaps, and for those folks electric "flip a switch and don't worry about it" flaps are a selling point.
In terms of reliability it's a trade-off (as are all engineering decisions), so let's look at a few of the factors:
+Flaps still work when the battery is dead.
+The pilot can control the extension/retraction rate to some extent.
+Usually cross-linked with a bar (so you can't have a "split-flap" condition)
+Simple to rig, adjust, and maintain.
-Actuation requires more pilot skill
-The failure mode is usually "Flaps Up"
+"Easier to Operate" (you don't need to reach down to the floor)
+Extension/Retraction rate is constant (governed by the motor)
+Fewer moving cables running through the fuselage (wires replace them)
+Typical failure mode (e.g. dead battery) is "Flaps stuck where you left them"
+Depending on the design they may save some weight over a mechanical system.
-You lose control of the flaps if the battery dies (no-flap landings are more likely)
-You have one or more motors to maintain/replace if they fail
-Depending on the design it's possible to have a "split-flap" condition
Cessna's engineers and marketing folks looked at those factors (and probably many others) and decided that electric flaps "made sense". On the other side of the GA fleet, Piper's engineers looked at the same factors and decided to keep the Johnson bar flaps (which are still found in the PA-28 series today).
From a manufacturing standpoint it makes sense for all of the aircraft a manufacturer produces to use the samecontrol mechanisms -- either all the planes use mechanical flaps or all the planes use electric flaps because it simplifies production and allows everything to run through on one assembly line rather than stopping at the flaps and diverting aircraft to different teams.
At the club I fly at, there is an older Cessna 172 that has a manual "Johnson Bar" that is used to put the flaps down. In the newer 152, and I believe the rest of the planes (I have yet to fly them), the flaps are controlled via a electronic (or hydraulic?) lever. It appears to me that the manual flaps are more reliable, more maintainable, and a hell of a lot more fun in my opinion. Additionally, the manually flaps don't require a lot of strength to operate IMO. Does anyone know why the automatic design is favored over the manual counterpart? Same question applies to car transmissions...
So the EGT gauge on the 172 (and other cessna singles?) doesn't have a numerical scale on it, just markings every 25 degrees. I know that one is supposed to use the EGT for leaning operations (ROP, LOP, what have you), but it's always stymied me that there are no actual numbers on it. Any reason why this is so?
Can someone explain why the aircraft would fly in an arc using the satellite as a reference point? Have I missed something?
— (1) Category A: Speed less than 91 knots. (2) Category B: Speed 91 knots or more but less than 121 knots. (3) Category C: Speed 121 knots or more but less than 141 knots. (4) Category D: Speed 141 knots or more but less than 166 knots. (5) Category E: Speed 166 knots or more. So an aircraft category never changes because it is always Vref at max landing weight. What if I fly an approach at a speed that falls into a different category? For instance, a jet may land at significantly less than this speed if very light, or more than this speed if landing with less
If an autobrake setting is chosen prior to touchdown, but after touchdown and nosewheel compression (i.e. after the autobrake has engaged) a different setting is required, is it safe to change the setting during the roll-out? What happens when the setting is changed in this manner? I know application of manual brakes disables the autobrake. Does the autobrake immediately match the new deceleration requested?
As technology becomes more advance airplanes are becoming less and less stable. In flight school I learned that it's dangerous to load a Cessna out of it's CG range, and now in college (for aerospace engineering) I'm learning about modern fighters and their fundamentally unstable designs. A lot of these unstable aircraft are supermanuveralble but rely on computers to fly them more than... kind of side affects might a pilot experience? The two conditions I can think of are No computer aid, but the control surfaces are still "responsive" The pilot loses all control of the aircraft
In some light aircraft, like a Cessna 172, the pitot tube is heated but the exterior static port isn't. The usual reason I've heard is that static ports are much less susceptible to icing, but why is that the case?
compared to car drivers, so they know a lot more of what they are doing. Hence they are more aware of the condition of the plane. Cars crash a lot more often than airplanes. It appears...It is normal to see older planes (20+ years) quite frequently. In fact, a few months ago I saw a plane over 50 years old (not in a museum but on a runway, about to take off). Comparing to cars, there are not many cars on the road which are older than 10-15 years. What are the reasons for this besides the following? Airplanes are very expensive. A new 172 would be over USD 300,000
It's easy to go online and look at prices of a Cessna 172, but what are some examples of how to breakdown the real world costs of ownership? how much other maintenance should you plan for? How much does an engine overhaul cost? Insurance hangar etc.. It would be great to also get some typical costs and ranges, since some element are more predictable than others. Obviously the costs will vary based on individual aircraft and location, as well as over time, but I'm looking for information that would help someone make the buy/rent decision. Prices can also vary geographically. I'm asking
as well land. But what about in a light, single engine plane (think Cessna 172 or Piper Cherokee)? Engine failures in small aircraft, for example, seem to be more common, so you have more... out? It seems like a somewhat practical solution, yet I have never heard of anyone doing it. Why do pilots often try to find a road to land on or a lake to ditch in when trouble strikes instead...There was another question that asked why commercial flights don't have parachutes. The almost ubiquitous response was that the parachutes would be useless because: Most accidents with commercial