POH C172 RG

[graziani]

I am currently training for my CFI Initial in a C172RG and have a technique question to run by everyone:

When flying the traffic pattern in a complex aircraft, do you teach to raise and lower the landing gear every lap in the pattern? Or teaching lowering the gear when entering the pattern and then leaving it down for the duration of the touch and goes, minimizing configuration changes, and wear on the gear system.
what is the meaning on
the Cessna POH procedure ?

[TheOddOne]

You must have a reason for doing this in a complex type, not sure what might be, please do tell. Teaching ab initio flying in a complex type heightens to likelihood of it all ending in tears, I'd have thought.

In the UK, we set great store by using a checklist, especially in complex types. Our after-take checklist would include undercarriage raised. The call is generally 'no usable runway remains, positive rate of climb, brakes on/off, undercarriage up'.
The pre landing checks we teach are
Brakes off
Undercarriage down
Mixture rich
Prop fine
Fuel sufficient for a go-around
Fuel pump on (if called for in the POH)
Flaps as required
Instruments - in the green
Harness secure
Hatches closed
Height as required - a great reality check
Heading as required (at this stage, normally reciprocal of runway, another great reality check you've got the correct runway)

On final of course,
Red - Mixture rich
Blue - prop fine
Green - confirm undercarriage down and indicated
White -landing light on

TOO

[Big Pistons Forever]

Every takeoff should be the same therefore the landing gear should always be raised if if only a circuit is planned. Leaving the gear down is negative training as it doesn't reinforce the gear down as part of the prelanding check. You are inviting a gear up landing for a new pilot in this situation. As for ab initio training I don't see any reason why not as it is flies the same as a regular C 172. The stude will need a little extra training for the VP prop and retract gear but that is not a big deal.

[BigEndBob]

Poster is the pilot.
Normal to raise gear, i assume from memory the 172rg gear doesn't produce much drag, but if you are using a retract would be a bad habit not to raise and lower!

Lowering gear on downwind is not always appropriate for some aircraft.

[graziani]

What is the meaning , By Cessna?

…………POH C 172 RG : ………BEFORE LANDING

In view of the relatively low drag of the extended landing gear and the high allowable gear operating speed (140 KIAS), the landing gear should be extended before entering the traffic pattern. This practice will allow more time to confirm that the landing gear is down and locked. As a further precaution, leave the landing gear extended in go-around procedures or traffic patterns for touch-and-go landings……………


This procedure conditions some CFIs adopting it during training …..

[Jhieminga]

I suspect that this POH was written during a time when retractable gears were not as common or reliable as today... at least that's what it seems like!

You're training to be a CFI and one of the things you'll be dealing with is the discrepancies between POHs, SOPs and common sense.
- In this case the POH is written for the early 1980's GA pilot, someone who may have trained on fixed gear types and is prone to forget the gear handle is there. Especially as 98% of the C172 fleet doesn't have a gear handle.
- A POH is different from an OM in that it should be adhered to, but it leaves a lot of room for the development of club or company specific SOPs that further specify how a particular type should be operated. While the note in the POH is clear, it describes something that Cessna labels as a best practice. It is not an absolute in my view. I would write up a SOP that covers a more common approach to gear use for this type.
- Common sense is that you should consider all aspects of the operation before deciding on a single course of action. One is the student's point of view: everything you do is copied by the student, so someone who is taught this practice on a C172RG will no doubt carry out the same procedure on a higher drag retractable later on. Performance wise, pulling the gear up once you can no longer set down on the runway improves your climb performance and cuts down on your fuel use. As for the maintenance issue, good of you to think of it, but as a pilot, think about the fragility of your own neck before considering the depth of the pockets of your employer. Unless you get a direct order to follow these instructions to cut down on maintenance costs, I would pick the safest option for myself first.
- Another thing to think about: how long does it take for the gear to travel up and down? I have not flown a C172RG and don't know the times, but if it's a slow system and you're flying short circuits... the timing may mean that it's easier just to leave the gear down, but I would always clearly state the deviation from 'normal' during the flight. So "Gear up... non-standard, leaving it down" and "Gear down... non-standard, it's already down" at the appropriate times.

As a CFI, get used to thinking of all the angles and all the factors that influence aircraft performance and human performance. The fact that you're using an 'interesting' type for your training helps, in that it sets you up for dealing with all the other strange POHs out there!

[janrein]

Tinkering with the C172RG Gear Pump Circuit Breaker flying circuits ..... this is what may happen

Anecdotal evidence as follows.

FI (=CFI) is conducting flight training to a candidate-FI on the C172RG doing circuits. After some circuits flown, after rotation the FI pulls the Gear Pump Circuit Breaker. Student: "What are you doing?". FI: "That's my business, you fly the aircraft, keep operating the gear lever per checklist as before". Now after selecting gear up the green light remains on, no red transition light shown. Several more circuits are flown. In the debrief student ask "what was that with the CB?". FI grumbles: "The RG is prone to gear-mechanism wear, we must not do too many circuits in sequence".

Later, with the student now become an FI, and having performed instruction several weeks on C152 and C172, a lesson is scheduled on the C172RG, the lesson detail is circuits. With two circuits completed the FI pulls the Gear Pump CB and tells the student to keep operating the gear lever per checklist as before. And on climbouts to action and call out "gear up, no lights", on every downwind to action and call out "gear down, green light", imagining the gear lights to go off and the green light to come back on, ignoring the green light remaining on continuously. The practice is explained as a compromise limiting gear-mechanism wear while following the checklist as much as possible. On the next final "green light" is observed and called out. Touch-down is made properly on the mainwheels first, then comes down the nose. The nose keeps going down until chin on the runway and the aircraft comes to a grinding halt, then silence .... The gear lever is down, the green light is out.

I am the FI. When I see the CFI the next day he tells me "I should have told you to push the circuit breaker back in before every landing".

The aircraft is jacked up in the hangar and present are maintenance personnel, investigation commision, and myself. Several tests are performed. With gear retracted, the circuit breaker pulled, green light on, the mainwheels are being hit from below simulating some of the dynamics of the landing, and the nose wheel downlock releases, green light comes off. The C172RG apparently needs the oil pressure to secure the downlock.

With a manual gear extension you manually pump the gear down, forward into the airstream then slightly up until the stop, so the pressure is there. POH says whenever the gear pump fails to cut out you must pull the GP CB, but insists it being pushed in prior to landing.

I have since then refrained from tinkering with the gear pump circuit breaker flying circuits.

jr

[PerArduaAdAstra]

Type specific requirements and maintenance issues aside, I would take the view that when considering what to teach somebody who is new to aircraft with retractable undercarriage, it would be helpful to give them as much practice as possible with retracting and extending undercarriage. Thinking back at the flying I have done over a number of years, I would say that the modal activity would be teaching a circuit pattern in an aircraft with retractable gear. My organisation always cycled the gear on each circuit.
.
(I had to look it up before I used a mathematical term, the mode or modal value of a data set is the most frequently occurring value. It's a measure of central tendency that tells you the most popular choice or most common characteristic of your sample.)