Friday 22 November 2013

American Aviation AA-1 Yankee Two Seat Light Aircraft


American Aviation AA-1 Yankee Two Seat Light Aircraft Construction All models of the AA-5 have four seats under a sliding canopy, which can be partly opened in flight for ventilation. Entry for all four occupants is from the wing root over the canopy sill. Compared to competitive aircraft of the same era the AA-5s are noted for their light and pleasant handling characteristics as well as high cruising speed for the installed power.



As derivatives of the original AA-1 Yankee, the AA-5 series share the same unique bonded aluminum honeycomb wing and fuselage that eliminates the need for rivets without sacrificing strength. The main landing gear is fibreglass with a sprung steel nose gear tube. There is no nose wheel steering as the nose wheel is free-castering through 180 degrees. 


Steering is by main wheel differential braking operated by using one's toes to push the tops of the rudder pedals.


Development history

The Yankee was originally designed in 1962 by Jim Bede as the BD-1. The prototype first flew on July 11th, 1963 and featured folding wings for trailering and ease of storage. Bede formed a company to produce the aircraft, but the BD-1 never entered production. At that time the FAA was very doubtful about certifying an aircraft with folding wings, as it had never 
been done. Bede was ousted by his business partners and the company renamed American Aviation. American's engineers reworked the wing to a non-folding design with greater span, thus greatly easing FAR Part 23 certification. The company redesignated the redesigned aircraft as the AA-1 Yankee Clipper.




The AA-1 was certified under FAR Part 23 on August 29th, 1967 with the first production AA-1 flying on May 30th, 1968. The first 1969 models were delivered in the fall of 1968 at a base price of $6495.00, which was notabley lower than competative aircraft types were sold for at that time. American Aviation built 459 examples of the AA-1 Yankee Clipper between 1969 and 
1972 at their factory in Cleveland, Ohio.

In 1971 American Aviation added a leading edge cuff to the AA-1's wing, creating the AA-1A Trainer. The design change produced softer stall characteristics and permitted lower approach speeds. While this did tame the AA-1's sharp stall, it also reduced the cruise speed compared to the original AA-1. 470 AA-1As were built in 1971–72.

Grumman bought American in 1971 and sold the design as the Grumman American AA-1B Trainer for school use. The varient designed for the personal-use market was called the TR-2 and it featured a standard radio and trim package. The AA-1B was produced until 1978. 551 AA-1Bs were produced. All the AA-1s, AA-1As and AA-1Bs were powered by the Lycoming O-235-C2C low-compression engine which produced 108 hp.

The Grumman light aircraft line was then acquired by Gulfstream Aerospace in 1977 who formed it into their light aircraft division, Gulfstream American. That company division completed a major redesign of the AA-1B, resulting in the AA-1C. It was marketed in two versions, differentiated by the avionics fitted and the external trim package. The Lynx was targeted at private owners while the T-Cat was the flying school trainer. The AA-1C had a new tail and other significant improvements, including a 115 hp Lycoming O-235-L2C high-compression engine that brought the cruise speed back up to that of the original 108 hp Yankee. 211 AA-1Cs were produced.

The last AA-1C was produced by Gulfstream American in 1978. The type certificates are held by Tiger Aircraft LLC who produce the AG-5B Tiger. Tiger Aircraft have not announced any plans to place any of the two-seat AA-1 models back into production.

Overall, 1691 AA-1 family aircraft were built between 1969 and 1978. 


Features

All models of the AA-1 accomodate two people under a sliding canopy and are noted for their exceptionally light handling. The Yankee and its 4-seater siblings, the AA-5 series, feature a unique bonded aluminum honeycomb wing and fuselage that eliminates the need for rivets without sacrificing strength. The Yankee was originally designed to minimize the number of 
airframe parts used with the aim of simplifying production and saving money. As a result of this philosophy many parts were interchangable. Due to the use of a non-tapered tubular spar, which doubled as the fuel tank, and the lack of wing washout, the wings could be exchanged left and right. The fin and horizontal stablizers were interchangable, as were the rudder 
and the elevators. The ailerons and flaps were similarly the same part. While it did suceed in making production easier, this design philosophy produced many aerodynamic compromises in the design. For instance, because the flaps were the same part as the ailerons they were too small to be effective as flaps. The lack of wing washout, necessitated by the wing 
interchangability requirement, meant that stall strips had to be installed to produce acceptable stall charatertistics for certification. Over time this philosophy of compromising the aerodynamics in favour of a minimized parts count was abandoned. For example, the redesign of the AA-1B into the AA-1C by Gulfstream involved wider-span elevators and horizontal 
stabilizers that produced better longitudinal stability, but were no longer interchangable with the rudder and fin. Powered by the same 108 hp Lycoming O-235 engine as the Cessna 152, the original Yankee cruises twenty percent faster thanks to the cleaner wing and better aerodynamics. 

Specifications (AA-1)
General characteristics

    Crew: 1 pilot
    Capacity: 1 passenger
    Length: 19.24 ft (5.87 m)
    Wingspan: 24.46 ft (7.46 m)
    Height: 6.80 ft (2.07 m)
    Wing area: 98 ft² (9.11 m)²
    Empty: 1,018.1 lb (461.1 kg)
    Loaded: 1,500 lb, (679.3 kg)
    Maximum takeoff: 1,500 lb (679.3 kg)
    Powerplant: Lycoming O-235-C2C, 108 hp (80.6 kW) 

Performance

    Never Exceed speed: 170 kts (315 km/h)
    Cruise speed: 117 kts (217 km/h)TAS at 75% power, 8000 

feet
    Stall speed: 60 kts flaps up, 58 kts flaps down
    Range: 323 nm (599 km) with 30 minute reserve
    Service ceiling: 11,000 ft (3355 m)
    Rate of climb: 710 ft/min (217 m/min)
    Wing loading: 15.3 lb/ft² (74.6 kg/m²)
    Power loading: 13.9 lb/hp (8.42 kg/kW) 



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Regards,

Nidhi Jain [ MBA eComm]
Asst Project Manager [ eComm]
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