CESSNA 414 / 414A
The pressurized, twin-engine, 6 - 7 place Cessna 414 was certified in September of 1969. This aircraft had (2) 310 HP turbocharged Continental engines. Maximum takeoff weight was 6350# and maximum landing weight was 6200#. The 6 – 8 seat C414A came along in September of 1977 also with (2) 310 HP Continentals but numerous other changes. The C414A had a maximum of 6750# takeoff and landing weight.
QUIRKS
Probably the weakest part of the airplane is the landing gear system. Be sure that this system is looked over by someone very acquainted with the Twin Cessna landing gear.
I’ve noticed that the emergency gear extension system does not work on some aircraft I have conducted training in.
The second item is the fuel system, especially if you have the wing locker tank on the left side only. Let’s say you have the 31.5 gallon aux tanks and you take off with full fuel. You need to fly for 1 ½ hours prior to switching to the aux tanks. The excess fuel that the engines do not use is returned to the main (tip) tank so that the fuel level in this tank increases more the longer the aux tanks are selected. Once the aux tanks are nearly empty you switch back to the main (tip) tanks. When the left tip tank gets low enough on fuel you can then turn on the wing locker fuel pump which pumps its fuel to the left tip tank. This causes the left wing to become heavier than the right wing and so you need to crossfeed fuel from the left tip tank to the right engine and the excess fuel goes to the right tip tank! Another thing, you can’t crossfeed fuel from one aux tank to the other engine, so that it is imperative to empty the aux tanks as soon as possible so that in the event of an engine failure you have access to all the remaining fuel. Any time you switch from using fuel from the aux tank to the tip, or the tip tank to the aux, you need to enrichen the mixture momentarily and then re-lean as the head pressure is different between aux and tip tanks. In the twin Cessna’s with tip tanks, they found that if you were low on fuel and in a fairly steep nose down attitude the fuel pump could not pick up that last ~ 5 gallons of fuel from the front of the tank. The solution was to put a transfer tube at the front of the tip tank - and have a constant running electric fuel pump draw fuel from that area and put it next to the fuel pump. The operation of these pumps should be checked during preflight – just turn the battery master switch on and go out and listen to these “ticker” pumps (located at the rear of each tank) operate. If no noise – no go. They are required to be operating to fly
Another item that can be confusing is the nomenclature. The main (tip) tank pumps are called aux pumps, the pumps downstream of the auxiliary tanks are called in-line pumps and the pumps transferring fuel from the wing locker tanks are called transfer pumps. The pumps located at the rear of the tip tanks are also called transfer pumps. Tell the line crew to add fuel to the “Tip” Tanks – not the main tanks as they may believe that the aux tanks are the Main tanks.
Why would some Twin Cessnas have a wing locker fuel tank only on one side? There is a good reason. We’ll discuss that later.
Fuel selector – The fuel selectors can leak. Even if you have the fuel selector in the proper detent, fuel can drain from the tip tank to the aux tank if the aux tank is not full.
The C414A fuel system is differs significantly from that of the C414. This can be discussed in class.
Exhaust – the exhaust system needs to be inspected for deterioration, cracks etc.
Wing spar – fortunately at least for now the wing spar AD does not apply to Twin Cessnas with Tip tanks. The purchaser of a C414A though would need to look at this significant AD to see what would need to be done to comply with it and how soon and how long the airplane would be down for and determine the cost.
Be cautious of engine cases & cylinders cracking. Be very gentle with power changes. We’ll discuss in ground school ways to reduce the incidence of engine cracks.
You may find that you need to burn more fuel during cruise than recommended by Cessna unless the engines were converted by RAM and you use RAM’s power/altitude/Fuel Flow recommendations.
MY OPINION
RAM Aircraft, LP of Waco, TX has done wonderful things to Twin Cessnas. For example, they can upgrade the C414 to 335 HP engines and add VGs, larger turbos and better induction system. The takeoff weight increases to from 6350 to 6765 and twin engine climb performance and single-engine climb performance is increased. The C414A with the same changes increases its takeoff weight from 6750 to 7105 and twin engine and single-engine climb performance increases slightly even with the increased weight. How about 215 TAS at FL 250 at 70% power!
A well maintained C414 converted by RAM to the VII mod would be a great airplane to own! The shop maintaining the 414 or 414A would have to know the airplane well for me to think seriously about purchasing this aircraft. Another option I could take before I’d consider purchasing a specific aircraft would be a thorough pre-purchase inspection by someone who knows the aircraft extremely well who could determine the value of the airplane and indicate how much money I’d have to put into it to bring it up to my standards. The Cessna 414 & 414A with its wider cabin is much more comfortable to ride in than the C340 but about 12 – 15 KTAS is sacrificed with the same engines and hourly fuel burn. If the Wing Spar AD did not affect “my” C414A, it would probably be my first choice in an aircraft unless I could afford the TBM 850 or some other hot rod. Be very careful about buying a stock C414 or 414A. There is a LOT that can be wrong with these airplanes and the fix may be cost prohibitive. Any older airplane which is not maintained correctly can be cost prohibitive to bring up to your standards.
OBSERVATION – The last C414A was built about 1986. You may find one with a data plate later than that but I’m quite sure it was built prior to 1987 but the data plate was not put on until the aircraft was sold. The FAA mandated that aircraft with engines powered by AvGas, as compared to Jet fuel, could not have fuel in the wings closer than ~18” from the tips. Therefore the C414 was discontinued and the C414A came along.