# Tag Info

62

That is crazy. DON'T just rely on an person who's new to airplanes and only training is 5 minutes of showing them what to do, who may or may not react correctly when it springs to life, as the only thing preventing the plane from heading off somewhere while you try to dive clear. Don't. Do. It. Tie the tail. To something. Anything. Use the passenger and ...

57

Is it practically possible to do that? Is it okay in terms of weight, CG? Bikes (depending on make and model) are not all that heavy and in this picture they are more or less center mass and would most likely fall in the CG range. aerodynamics Again this depends on the bikes and the placement but with proper care you could be ok. Admittedly a bit ...

54

We will take the case of an unsupercharged piston engine, as used in most small Cessnas and Pipers. All engines need the oxygen in air to burn their fuel. As an airplane climbs, the air thins out and so there's less oxygen available, so the engine can burn less fuel and so it produces less power. There then comes an altitude at which there's not enough power ...

46

Firstly, to understand the answer, we need to understand that the Cessna 152's and 172's run a 4 Cylinder, Horizontally-opposed Engine. Each Cylinder has 2 spark plugs, one on the top side of the cylinder head, and one on the bottom side. The spark plug ignites the fuel/air mixture that has been sucked into the engine, and causes a controlled burn to push ...

42

There is an old saying "If you put a big enough engine on it, you can make anything fly." The Lockheed Starfighter was a classic example of that. With its short stubby wings it is basically a guided jet engine / missile. With small wings you have two issues. Obviously, the sheer lack of lift at low speeds, but also the lack of control surface area at ...

41

You can, but you have to live with the consequences. There are several things that can happen: Depending on the vertical gusts ahead, you might not even get close to v$_{NE}$. There is another speed limit for gusty weather called v$_B$, and exceeding this will run the risk of overstressing the wing structure. Going above v$_B$ will overstress the wings in a ...

40

Those are called "Lightening Holes". The name refers to the weight reduction brought about by removing part of the material—lightening—and should not be confused with anything to do with electrical discharge—lightning. From the FAA's AMT Airframe Handbook, in Chapter 4, page 4-82: Lightening holes are cut in rib sections, fuselage frames, and other ...

34

Just eyeballing your image, the CG looks OK, and it's possible to put that much weight into the interior of the plane just fine, so the weight is OK. The aerodynamics on the other hand - yeah, no. Imagine the bikes are not strapped down and you have to hold them in place - in a 120 MPH wind. That's a LOT of drag and the turbulence from it could easily ...

33

I will take this from a more general perspective. A Cessna 172 is part of the CS-23 category (in EASA land, see the equivalent Part 23 for FAA land). In the relevant document, point CS 23.143, we find the maximum forces a pilot might be required to exert on the control columns so that the aircraft can be certified. As the Cessna 172 is certified, we then ...

31

These engines are not designed to run at maximum horsepower output all the time with a lean mixture. They are designed to cruise at 50-75% of their rated max power, and deal with that level of internal heat and friction over the long term. Even this is fairly hard compared to a car that runs at perhaps 20% of rated power when cruising at 60 mph. Running ...

29

You're not wrong, but a fixed pitch two-blade prop has a pretty big advantage: it's cheap. Cheap to buy, cheap to install, cheap to maintain, cheap to repair. 172s are predominantly trainers in FBO fleets, and cheap is the winner. The efficiencies of a better prop are lost when you're just doing pattern work and short cross countries. Also, when you're not ...

29

I'm pretty sure you have encountered "nose wheel shimmy". For reference, see this video on Youtube: c172 M Nose wheel shimmy [sic]. The shimmy can occur for a variety of reason, most likely due to some imbalance in the tire/wheel combo, loose bearings and just the right caster angle induced by your braking (and thus pushing the nose down). While it ...

28

Flaps out will reduce the ground run, but you're forgetting that they also increase drag. This is why you don't climb all the way to cruise altitude with flap extended. A 172 will climb better without flaps. With a take-off, you have to consider both the ground run and initial climb. After all, the take-off distance required is defined as the distance ...

28

This is real easy, no explanation required: Tell your student to stick their hand out the window of the car driving 25mph in the city and rotate it like an aileron. Then have them do it on the freeway doing 60mph. Feel the difference? Did smaller movements produce larger effects at higher speeds? Practical examples are typically more effective at driving a ...

28

You shut the components off to protect the sensitive electronics from electrical surges that may occur during start up of the engine. Circuit breakers are designed to trip open if too much current in amps is drawn from the power source by the electrical components or a short circuit downstream of the circuit breaker. They do not necessarily protect the ...

27

What limits a small plane to be able to fly at a much higher altitude? Money. Power and lift on an aeroplane both decrease with increasing altitude, as shown in the image above, from my paper copy only old uni book of prof. Wittenberg. At 20,000 ft about 60% of take-off power is still available, at 40,000 ft about 35%. Solution 1: install a turbo From ...

26

It is not common to call out the height above ground level when landing in a small aircraft. The main reason for this is that there simply is no way to measure it: A radio altimeter, which could directly measure the height, is not typically installed on a small aircraft. A pressure altimeter is not accurate enough. With the correct QNH reference pressure ...

25

Consulting your handy POH (or one for a 172N that I Googled up) you'll find the fuel system diagram looks like the one below (click to enlarge - most high-wing gravity-fed fuel systems are similar). So there are a number of ways you could wind up with uneven fuel burn with this plumbing. The most common ones are: (Uncoordinated) Turns If you're flying lots ...

24

Yes hand on throttle when starting, always, except on engines with fuel injection where you have to have it on the mixture because you start on idle cutoff and move it up as the engine catches. In any case, you shouldn't be reading checklist items during the start; you just learn what to do and do it so you can be in total control. Back to the checklist ...

23

You should check your POH but it may just be that the instructor in question was recently flying a lot of Pipers and it was force of [bad] habit. This POH for the 172S is in agreement with you. BEFORE LANDING .... Fuel Selector Valve -- BOTH. You should consult the checklist in the POH that is with the airplane in question to be sure.

23

The main problem lies in the behavior of the coils inside the starter. As all inductors, they build up a magnetic field - this stored energy will cause a high spike in voltage while disconnecting. Though it can be dissipated, there is still a slight chance of damaging sensitive electronic devices. And in aeronautics one does not take chances...

22

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 ...

22

It depends on what you mean by "strength". In general, it is "not much". I've flown a lot of sims and also flown a real Cessna 172. It is true that most sim controllers (especially joysticks) require almost no effort to move at all. In that perspective, then yes, flying a real airplane takes some strength, especially if you compare the force required to ...

22

I’ll second John K’s answer. Do not attempt to hand prop an airplane without receiving professional instruction on how to do it safely. It is a real easy way to get seriously injured or killed, as this idiot almost found out. It should also involve two competently trained people, one to do the hand propping, and the ...

22

This shaking is the infamous Cessna nose-wheel shimmy. It is a result of the bungee connection between the nose wheel and the rudder pedals, which is required due to the way you work the rudder of a Cessna in a side slip landing*. There is a shimmy damper on the nose gear, but they often aren’t maintained as well as they should be, and even in perfect shape ...

19

You can exceed the never exceed speed $V_{NE}$, but doing so will most likely result in damage to the structure. From FAA handbook of pilot knowledge: $V_{NE}$ —the speed which should never be exceeded. If flight is attempted above this speed, structural damage or structural failure may result.

19

The absolute ceiling, or the maximum height an aircraft can fly to, is usually not published; manufacturers usually use service ceiling as the benchmark. Service ceiling is the maximum altitude which the aircraft can attain flying in air at Standard Temperature and Pressure (29.92" Hg and 15° C at MSL) and still be able to climb at a rate of at least 100 ...

19

The drips only after shutting down means fuel is coming from somewhere it shouldn't and is being pulled into the engine while it's running, and when there is no intake flow, the fuel dribbles out the other direction until the level of fuel at the source drops below the leak point. This is supported by the low static RPM, that suggests an over-rich mixture. ...

18

Provided you meet ALL of the requirements for utility category operation as spelled out in the POH (within W&B limits for the utility envelope, no aft passengers, empty baggage compartment, and anything else you may find in the Limitations and W&B sections of your POH) a Cessna 172 is approved for intentional spins, and may be used for spin training. ...

18

It's pretty much to limit imbalance when parked on a slope, and if the tanks are full, stop fuel from the high side tank from forcing fuel out of the low side tank's vent or seeping out the fuel cap if it isn't completely fluid tight. On the '68 Cardinal I used to own, the vents went straight to the wing tip on each tank's side. If parked on a side slope ...

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