WARBIRDS WORLDWIDE
HISTORIC FLYING FEATURE
Between 1925 and 1960 some 34,966 Pratt & Whitney R-1340 piston engines were built by their East Hartford, Connecticut, and Longueil, Quebec, Canada, facilities. The R-1340 was the first as well as the last P&W piston engine built. In service it powered almost every type of aircraft imaginable.
Today, in the 1990's, the majority of these engines, and the P&W R-985's (of which some 39,027 were manufactured between 1929 to 1953 to power 63 types of light transport, sport and helicopter aircraft) are used in agricultural aircraft. In fact this is Covington Aircraft Engines mainline business. But don't be fooled - this is a large and serious business in the United States. The strong interest in the AT-6 Texan and Harvard, both R-1340 powered has meant than an increasing number of engines for these aircraft are passing through the Covington facility; 25% of the business is in overhauling engines for Warbirds, Beavers, Otters, Stearmans and other collector aircraft. Covington Aircraft Engines specializes in the overhaul of Pratt & Whitney R-985-AN1 or 14B and R-1340-AN1 or AN2 engines. It currently operates out of a clean, modern air-conditioned facility: 20,000 square feet. In addition to overhaul and engine repair work the company also handles engine installation and carries a large inventory of parts including magnetos, carburetors and cylinders.
Bob Covington founded the company in 1972. He had several years of experience working on radial aircraft engines and was instrumental in doing the groundwork for the company. Covington's first customers were largely Twin Beech operators - mainly freight and mail haulers. 'The first R-985 overhauled by the company' - says Covington President Paul Abbott '...sold for $2700.00 in 1972.' Paul Abbott started working for Bob Covington in 1972 when the business was launched. He worked as Bob's Foreman until 1975 when he bought 50% of the business. Paul's right hand man, Frank Prentice, has been with the Covington's since 1974. He has worked in several areas of the operation and was once Shop Foreman. As Vice president he now works sales and procures parts.
The company also overhaul magnetos. Other accessories are sent out for overhaul. One interesting fact is that 25% of the engines are exported outside the United States. Paul reports that they have noticed a big increase in the number of AT-6 engines coming in for overhaul. They have recently sold R-1340s to Norway, Germany, and the UK. The company has started to cater more extensively to warbird customers '...we know that most of our AT-6 customers like to show their aircraft, so we pay particular attention to the engines we build. We recently sold five R-1340 engines to Lufthansa German Airlines to use in the restoration of their Junkers Ju-52! Paul Abbott is always on the lookout for spare parts - in the late 1980s he purchased 90 engines from Yugoslavia and some 550 cylinders from South America. In February 1988 Paul Abbott was interviewed for an article in Tulsa World. He made the comment that '...right now I wish I had a bunch of 1340 crankshafts because usable ones are really getting hard to come by.' Over the years, because the R-1340 Wasp was (and still is) a workhorse, high use overhaul parts started to become scarce. Manufacturing of items, such as pistons and rings, were taken up by various PMA parts companies (the FAA acronym for Part Manufacturer Approval). Due to the looming scarcity of crankshafts, and the obvious demand for the same, another U.S. based company, Air Tractor decided that it was time to manufacture new replacement crankshafts for the Wasp. Work began on the replacement crankshaft in September 1989 at the hands of a highly qualified mechanical engineer and consultant Jim Corning. After some consideration and not a little research 26 rolls of microfilmed P&W engine parts drawings were obtained form the Smithsonian Institute - they also suggested the Jim contacted the United Technologies Archives in East Hartford. UT informed him that they had some 50 boxes of drawings from Wasp engines to their early jets. After agreeing to sort these drawings for the archives it was agreed that Cornig could obtain copies of any drawings that looked interesting. He soon found that this material was invaluable. He discovered that the engineers who designed the later engines like the R-2800 knew of the shortcomings and difficulties associated with the Wasp. This enabled Jim to produce a part that was physically identical to the original, but one that was an improvement over the shortcomings of the unit. One example of this is where the original R-1340 cranks were machined form a variety of fairly mild steels, the new units were to be made from the same material as that used on the R-2800 units. To add to this Corning obtained a copy of the specification for the original R-1340 crankshaft material and this had been declared obsolete in 1946 - not recommended for use in new parts design!
Following the successful manufacture of a new unit, arrangements were made with Covington to test it in an engine in their test cell. Covington staff put the engine together in one day and ran it on the stand the next day without problems. The new crankshaft was put through a rigorous test cycle at various power settings (some not recommended under normal circumstances!) and then the engine was run at the highest vibration condition until the crankshaft had 10 million stress cycles on it; 10 million cycles at take-off power! On September 11th 1991 the endurance testing was complete and the test engine torn down for inspection. The FAA verified the new crank had met the post test inspection criteria and approval was given for new units to be manufactured - they are currently in progress.
Covington Aircraft Engines is an FAA Certified Repair Station, certified to rebuild R-985 and R-1340 engines. The company is also certified in non-destructive testing and ultrasonic testing of parts.
At the Okmulgee, Oklahoma, facility one engine is overhauled per working day. The company likes to have the customer's engine 45-60 day's for complete turn-around. Paul points out 'this allows us time to send out the cylinders for rechroming and any other parts that may need outside work.'
When the engines first arrive at Covington Aircraft they are assigned a work order. Each engine is then taken apart an cleaned. The magnesium and aluminum parts are then zyglowed and steel parts are magnafluxed to check for cracks. All engine parts are then thoroughly inspected for signs of abnormal wear, pitting and galling.
With such a large number of engines passing through the facility each engine assembly line is set up with quality and efficiency in mind. Each mechanic goes through a thorough training program in whatever area they are going to work. Their assignment is then to build that particular part of the engine whether it is the blower section, crankshaft, or sub-assembly and final assembly. During this engine overhaul process quality control is a paramount consideration. Chief Inspector at Covington's is Kelly Neal - he inspects and signs off the assembly of the engine as it is being accomplished
Heading up the machine shop facility is Bob Abbott. All parts that require machining - such as line reaming link rod bushings and fitting up cams to the cam drive gear are undertaken in this particular area. Importantly, all the parts fit up to original Pratt & Whitney specifications.
Many customers, in order to save on down time exchange engines rather than wait for their original unit to go through the facility. Currently, Covington has in the region of 50 R-1340 and 40 R-985 cores in stock.
Shop Foreman at the facility is David Hamilton. David has been with the company for 17 years. He received his A & P License from the Spartan School of Aeronautics. He worked his way through the production line up to cylinder shop foreman. Three years ago he was promoted to shop foreman. Ron Hollis is the company's Field Representative. He is available to answer any technical questions that the customer may have, and is also available to undertake field service calls if required. The company utilizes a Cessna 206 to travel within reasonable distances of the company HQ.
In order to aid the constant, high quality out-put of work, all the assembly areas are air-conditioned. It is the company philosophy that the more comfortable the employees are, the better the quality of their work. Paul Abbott; '...quality is our top priority and we will continue to strive to do our best. We have some top-notch people here who are dedicated to their jobs. We are currently considering the possibility of overhauling PZL engines - we have had several customer requests to overhaul these engines.'
Once the engines have passed through shop ad have been signed off they enter the unique Covington's state-of-the-are test cell. Each engine is test run for three to four hours. During the test the oil pressure is monitored at three different locations on the engine. The fuel and oil consumption is also monitored and several analogue and digital instruments are utilized for monitoring the powerplants during the test runs.
Since 1972 the company have overhauled approximately 3521 engines. Two hundred sixty engines per year is the working norm - that is one engine per working day. Their engines are proven workhorses - and the help they are providing the T-6 and other owners is commendable. If the number of first class reports we receive at Warbirds Worldwide is anything to go by they have a bright future in front of them!
