Flight test: Cessna 170
- Credit: NA
Cessna’s first four-seater model — a taildragger, of course — is now seventy years old. We see how the 172’s grandaddy is bearing up. Words Peter Turner, photos Peter March
When Steven Moth invited me to fly his beautiful Cessna 170 I was absolutely delighted, even more so because the type was conceived and first flew in the year I was born! Steven’s company, Spirit in the Sky, specialises in importing, restoring and selling vintage aeroplanes, and the C170 is the second of these that I’ve been privileged to fly, the first being the 1942 Stinson Gullwing a couple of years ago.
I spent most of a day studying the comprehensive Flight Manual, making notes in preparation for the flight test. This is part of my ritual before flying any aircraft that is new to me. I stand by the six Ps: Prior Planning Prevents Piss Poor Performance.
I co-own a 1964 C172, G-ASSS, with Pilot contributing editor and photographer, Peter March, so I was especially interested in flying its predecessor. For once the weather played ball on the first day that we had earmarked, and we assembled at Dunkeswell for the sortie.
I was to fly the C170 with Steven, and Peter would do the photography from a Hughes 500 owned and flown by Andy Twemlow, boss of AT Aviation, the sales agent for the C170. N4063V is a stunning looking aeroplane resplendent in its gleaming bare metal finish accentuated by red stripes.
When I arrived one of Andy’s men was busy polishing it and I couldn’t help but think that keeping it up to scratch was some task. It sat on the apron on its rugged and maintenance-free sprung steel main undercarriage and beefed up tailwheel, looking eager to be flown.
‘63 Victor’ is slightly different from the standard C170 in that it sports an extra fuel tank in the port wing, boosting capacity up to 48 US gallons (24 each side) rather than the normal 36?a useful extra hour and ten minutes worth. It has also been fitted with a beefy, non-standard Scott tailwheel which castors 66 degrees either side of centre. This, with the assistance of independent toe brakes, enables the aircraft to be spun around almost within its wingspan.
The walkround revealed no surprises but two features did catch my attention. The aircraft has no vacuum pump to drive the artificial horizon, so there are two venturis on the starboard side of the nose to provide suction. As these have no effect until airspeed is achieved, the horizon will not function for a little while after takeoff, so departing in less than VFR conditions would not be a cunning plan. The other feature is an anti-bug flap on the pitot, something I have not seen for a long while!
Climbing into any of the comfortable seats is easy by way of the very large doors and, due to the excellent forward visibility over the nose, I didn’t need a cushion under my backside for once.
I quickly felt at home in the nicely presented and tidy interior, and the heather grey and brown fabric and the leather trim made it very pleasing to the eye. The two front seats have no vertical seat adjustment, just the usual fore and aft; and the back of the rear bench seat is easily adjustable, with four positions available.
Leg room in the back is very generous, and nowhere near the ‘knees up around your ears’ discomfort of some other four-seaters. The back seat can be folded flat to give access to the roomy baggage area, which has a very useful 120lb capacity, although loading anything heavy through the door and over the seat isn’t ideal and certainly not good for one’s back (there is a baggage door mod but this is not fitted to 63V).
After fastening the lap strap (no shoulder harness) and adjusting my position I performed my seat wriggle, a ritual I do on every flight ever since a hairy episode in my early days flying a Piper Tri-pacer. I was taking off from a short strip with a down-slope when, three quarters of the way along it and with insufficient distance remaining to abort, my seat shot back.
Being vertically challenged, the rudder pedals were now well out of reach so I had no directional control on the ground and we started to veer off to the left. I hauled it off as soon as I could, put in a hasty bank to avoid a tree and climbed away. It was a very close call. My future wife sitting in the right seat was not impressed! Similarly, if the rudder pedals are adjustable I always give them a firm push to ensure they too are locked. Another gotcha… but I digress.
The instrument panel is pretty typical of the era, i.e. the instruments are placed randomly although very symmetrically; the standard T-panel had not been thought of back then. See the redundant knob between the mixture and carb heat controls?
It is just there to keep the visual balance! Starting at the top are the flight instruments and two engine gauges?RPM and fuel pressure. Below them are the ammeter, clock, and oil pressure and temperature gauges. On the far left is the radio stack, an Apollo II GPS, a Narco Comm 812, and a Narco AT150 Transponder with mode C?basic but adequate.
There is an array of knobs below the sub-panel which control mixture, carb heat, the park brake, cabin heat and the starter, plus of course the dummy one. All the knobs are red except for the carb heat, a nice touch to differentiate it from the mixture control. The push/pull throttle is centrally located, with turn and bank and switches for the master, nav and landing lights underneath.
Below these are the circuit breakers and fuses together with a more modern switch for the retro-fitted rotating beacon. On the far right is a handy little glove box to store some of those small items that seem to accumulate in a cockpit. The headset sockets and intercom controls are located on the side window ledges. The overall effect is an uncluttered and easy to read panel.
Moving down to the brown carpeted floor is the fuel cock with four positions? ‘Off’, ‘Both’, ‘Left’ and ‘Right’ with the lever pointing at the appropriate selection. Immediately above that is the long armed flap lever with four positions: ‘Up’, 10, 20 and 30 degrees.
Just behind the fuel cock are the elevator trim wheel and indicator. Two smallish sidewall pockets complete the picture. All in all a good, practical and pleasant interior.
After a briefing with Andy and Peter, Steven and I strap in, with me in the left seat. Start-up is standard for the Continental engine with a one minute post-start run at below 800rpm before setting 12–1500 for the warm up.
The initial low rpm run is to give the oil time to circulate and do its job, and the Ts and Ps to settle. We taxi out to the short 400m grass R35 for takeoff. We’re using this runway to give Peter March the opportunity to capture the aircraft on a grass strip for the vintage ‘period’ effect, although when flying a taildragger new to me I prefer to familiarise myself with its takeoff and landing quirks on grass?it is so much easier to keep straight than on tarmac.
The 170 is delightfully easy to taxi, with the larger tailwheel, effective toe brakes and a totally unobstructed view over the nose. The low-slung engine and downsloping cowling give a view which betters some nosewheel types.
The book figure for the takeoff run is 232m at our takeoff weight of 1,825lb, an ambient temperature of 10°C and a light breeze?well within the 400m available. With a slight downslope I reckoned any allowance for grass to be unnecessary as the two factors cancel each other out.
The only slight concern was the very narrow strip, which was not much wider than the wingspan. But with a light quartering breeze and usable run-off on both sides it was highly unlikely I would embarrass myself!
With the checks complete and 10 degrees flap selected (zero is used on tarmac) I lined up, applied power, and checked the Ts and Ps and rpm. All was good and we accelerated at an acceptable rate down the strip. A firm push on the wheel got the tail up and after an effortless straight run a slight backward pressure had us unsticking at 50mph just past the halfway point as predicted.
With a recommended initial climb speed of 85mph I set up a gentle climb angle and waited. No zooming into the air in this baby! After a little while the speed was nailed and once above 100ft the flaps were raised. Passing 1,000ft I accelerated the extra 4mph to the recommended best rate of climb speed of 89mph.
Once in smooth air the rate of climb settled at a reasonable 650fpm?close to what the book says. Should we have needed to clear an obstruction the best angle of climb speed of 65mph would have been used initially, before accelerating to 89.
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Levelling off at 2,500ft I lowered the nose to what I thought was about the right attitude but, due to the sloping cowling, found I needed to lower it further. The cruise attitude is seriously nose down?rather nice really, giving an excellent view ahead. Cockpit visibility to the sides is pretty standard for a high-wing aircraft, great for looking down but rubbish for looking up, and it’s always best to raise the wing before starting a turn, just in case someone is lurking nearby.
At 120mph we reduced power to a cruise setting of 2,400rpm and trimmed the aircraft. The speed sagged a little to 115 and settled there. At this power setting and altitude we were burning about 10USG (38 lit) per hour. With four average-sized occupants (two male, two female) the aircraft can take full fuel and return an endurance of four and a quarter hours, and a range of around 490nm with a 30min reserve. This is quite respectable and way beyond most people’s comfort zone.
Waiting over the coast for the helicopter to join us gave me the opportunity to try some turns of varying bank angles. The roll rate and aileron response were certainly a little lacking. The rudder was effective enough but the aircraft was definitely heavy in pitch, a feature rectified in later models.
Not at all bad though, and in normal flight the heavy elevators would not be a problem as the very effective trimmer takes care of that. I say ‘normal flight’ because we were about to formate on the Hughes and reaching down to constantly adjust the elevator trim at lowish level in a little ‘chop’ is not a good idea.
The first of two shoots was to take place along the south Devon Jurassic Coast to get those glorious red cliffs as a backdrop. Meeting up off Seaton we started the first run to Sidmouth. Two beats later we had it in the bag and set off in loose formation to Upottery disused airfield to use the rolling green scenery of the beautiful Blackdown Hills as a contrast to the cliffs.
Fifteen minutes later all was done and we parted company. The Hughes set off back to Dunkeswell while we climbed to a safe altitude to try some stalls.
Levelling off I completed the HASELL checks (height, airframe, security, engine, location, lookout) and configured for a power off, clean stall. With the heavy elevator forces the urge to re-trim all the way back as we decelerated was strong, especially with my left arm aching a little from the effort of formation flying. Not good practice though, so I stopped trimming at approach speed and put up with the increasing force from there down to the stall.
The Flight Manual suggests a stalling speed of 59mph; ours occurred at around 54 with a slight buffet a few mph before. Holding the stick hard back there was a slight wing- and nose drop and we just mushed downwards?very benign. Progressively applying full power, selecting carb heat to ‘cold’ and lowering the nose just below the horizon produced a quick recovery and we climbed back up to reconfigure.
After a clearing turn, power and speed were again reduced, carb heat set to ‘hot’ and landing flap selected below the limiting speed of 90mph. The results were the same as before with a gentle departure occurring at fifty. Again the recovery was quick and, once climbing, the flaps were retracted.
Later that evening, I wondered about the discrepancy of around five mph between the book and indicated figures. Then the penny dropped. My guess is that, at the high angle of attack and low airspeed, the pitot tube’s anti-bug flap had partially lowered restricting the airflow. I wish I had thought about that in flight because a quick glance at the tube would have revealed all.
We stooged around for a while enjoying the scenery. I just love ambling around and peering down at the English countryside, and how better than from a high-wing aircraft? All too soon though it was time to recover to Dunkeswell and, with the descent checks complete and ten degrees flap selected, I slowed down to 75mph to join on a right base for 35 grass with one ahead for the hard.
After establishing wings level on final the landing checks were completed and, with thirty degrees flap, reduced to the final approach speed of 70mph. At this point Steven mentioned that the strip seemed rather short, which of course it is, but after reassuring him that we only needed 243m he seemed happy enough. I don’t blame him: he had never flown with me before and it was his toy I was playing with! I think I might have felt the same were our roles reversed.
In any event, if there is any doubt in your mind then speak up?a philosophy I’ve always encouraged in the cockpit.
The edge of 35 grass is some 200m inside the airfield which gives an obstruction-free approach. Crossing the airfield boundary we were right in the groove with the speed at seventy mph and full flap selected. The wind was light and after a short float we touched down smoothly. Very satisfying.
With the shut-down checks completed it was mission accomplished and smiles all round. In my case a big grin! So what would I change? Not much really?this is a 1947 design after all. A stick instead of the control wheel, probably a baggage door and the improvements that Cessna made to later models...
The Cessna 170 is a lovely benign aeroplane to fly. I cannot think of a taildragger that is so easy to operate, or so versatile, and this one is a beauty in every respect.
In 1948 it would have set you back $5,475. Today you will have to fork out around £60,000 to secure one like 63V and it would be worth worth every penny. But like all those who have the privilege of buying a classic you’ll never own it?you will just be the custodian.
Oh, and a proud and happy pilot.