Summary

The Cessna 170 is a four place single engine high wing aircraft built between 1948 and 1956. During the six years of production, over five thousand aircraft of three different models were produced with about two thousand remaining today.

In 1956, Cessna had plans to further improve the line with the 170C. She was to include a high aspect tail plan similar to the venerable 180 however the 170C never came to be. Market demands for a tricycle geared aircraft was too great and two competing models did not make economic sense at the time. The prototype 170C was converted to a tricycle geared aricraft and the 172 was born.

Model distinctions

The Cessna 170 has three models. Mention the L-19 Bird Dog being a derivitive but they are not the same airplane and mearly share a lot of parts.

170 'Rag Wing'

Although the first 170 was of the same size and capabilities of later 170 models, it probably had more in common with the 140 of the same era. The wing was fabric covered with jury struts like the 140 and the vertical stabilizer lacked the dorsal extension found on later 170s. To the untrained eye, the 1948 170 can easily be mistaken for a 140 at a distance however it is in fact a four place aircraft with the same performance numbers as the later 170s.

170A

The A model had many significant changes over the '48 but the most evident was the new all metal wing and the distincive vertcal stabilizer borrowed from the 195 that would grace the 170 for the remainder of it's prouction. The fabric wing was discarded for a new all metal design with zero dihedral, hinged flaps and a single strut.

170B

In 1952, Cessna made the next major change by replacing the wing with a newer design incorporating washout and dihedral to make stall chracteristics even more sedate as well as large semi fowler flaps. The '52 model was unique in that it posessed the new wing and rebalanced tail feathers however retained the early style instrument panel with piano keys as well as the lighter landing gear legs. In 1953, the 170B's instrument panel was upgraded and the landing geard was changed to a stiffer leg referred to as 'Lady Legs'.

Specifications

Throught all of the models of the 170, performance numbers remained effectively unchanged.

Performance specs

Notable issues

Parking brake

The 170's parking brake is like other Cessnas of the aera but the rudder cables added an interesting twist as the rudder stops were way back at the rudder. A mal-adjusted set of rudder cables combined with a thick firewall pad can create a situation where a parking brake tab on the master cylinder can be wedged in the locked position by applying full rudder deflection. Combine this with poorly maintained unlock springs on the master cylinders and it became possible to inadverdantly engage one of the parking brakes while flying only to realize the situation upon landing.

This has happened to me personally. Luckily, the brake was only partailly engaged and I was able to salvage the landing, barely. Others have not been so lucky.

It's recommended to remove the parking brake in its entirity. Not just disconnect the cable but remove the locking tabs on the master cylinder as well.

Slipping with flaps

This is a topic of much debate however it must be mentioned as it is the one abnormal behavior that can get a into real trouble if experienced at lower altitudes. It's real and has been documented in enough places.

The issue is specific to the 170B model with its large semi fowler flaps, fast back fuselage and relatively low aspect tail feathers. The issue does not manifest itself in the 170 nor the A model and was greatly reduced in later 172 models due to the higher aspect tail and later reduced fuselage side profile by adding the rear window and subsequently eliminated when flaps on the 172 were limited to 30 degrees.

In the 170B, it is possible to blank out or stall a significant portion of the horizontal stabilizer during a full flap descent and aggresively slipping the aircraft. When the tail stalls, the aircraft violently pitches down as it rotates around it's center of lift. This is not a wing stall but rather a tail stall. Pilots who have experienced the event describe being voilently thrown towards the windscreen. Early test pilots documented it and made the recomendation that slipping with flaps deployed should be avoided.

Corrosion

Common areas where corrosion is found in this aricraft. Most is the same as every other 100 Series aircraft. I dont know of a 170 specific issue.