Multi-Engine vs. Single: Really Worth the Costs?
11/20/2008
Perhaps the rating that most interests people who ask me about my flying of all my ratings is the multi-engine rating. It especially perks up the ears of my fellow pilots looking to fly an aircraft that is faster, flies further, carries more weight, has more room and is safer than a single-engine. But anyone seriously interested in going down this flightpath must first seriously ask themselves if flying a multi-engine aircraft would be really worth it for them. One thing that many pilots, especially recreational pilots have to consider is that my friends and I who have gone all the way to acquire the multi-engine rating have done so mostly because we are pursuing careers as professional pilots, whether in the airlines or in corporate aviation. To do this, we of course need to be multi-engine rated if we plan on building the needed multi-engine experience and proficiency in a light twin before moving on to flying a 747 or Lear 35. For the rest of the aviation community, however, the advantages of multi-engines may not be apparent unless you have a lot of extra cash to burn flying your own C421 or King Air around.
The primary disadvantage of a twin is readily apparent when the fact that it has two engines is considered. Obviously, if an aircraft has twice as many engines, it will burn twice as much fuel. This is even more the case with the Piper Seminole I flew, because while a single engine C172RG burns somewhere near 9 GPH in cruise with the same engine, the Seminole burns a little over 22 GPH, actually more than twice the single. Furthermore, maintenance costs in the form of annuals, complexity and frequency of mechanical issues may also increase by more than twice. Also, even the lightest twin will still cost you more wherever you may land and park overnight as many airports that charge a parking or ramp fee charge more for multi-engine aircraft. This is all in addition to the initial cost of earning the multi-engine rating, which can cost upwards of $3,000 and also translates to increased rental costs for those of you fellow renters out there.
Some other example comparisons are the C182 vs Seminole and the C210 vs Piper Aztec:
| C182 | Piper Seminole |
|---|---|
| Range: 930 nm | Range: 868 nm |
| Cruise speed: 145 ktas | Cruise speed: 155 ktas |
| Fuel burn: 12 GPH cruise | Fuel burn: 22 GPH cruise |
| Useful load: 1,140 lbs | Useful load: 1,456 lbs* |
*The PA44's useful load is 300 lbs greater, but more will be used for carrying fuel.
| C210 | Piper Aztec |
|---|---|
| Range: 1,000 nm | Range: 1,042 nm |
| Cruise speed: 205 ktas | Cruise speed: 181 ktas |
| Fuel burn: 16 GPH | Fuel burn: 30 GPH |
| Useful load: 1,550 | Useful load: 1,877 lb |
**Please note that these are all rough figures which will vary with aircraft age, condition, features and modifications.
Another consideration when flying twin engine aircraft is the greatly increased workload, which increases the likelihood of a serious accident or incident occurring if the pilot is not completely proficient with their aircraft. Because of this, insurance costs are also dramatically increased, with many flight schools choosing not to rent light twins altogether, let alone allow people to fly them solo. As you can see from the above comparisons, a good C182 will do the job of getting your skis to Tahoe or friends down to LA for the game just as well or even better for a lot less money and workload. Best of all, you also get to better enjoy the spectacular view outside instead of managing extra engine and fuel systems along with navigation, especially if you're flying IFR.
However, one common argument in favor of twins is that they are safer to fly in case of an engine failure, especially over high altitude or mountainous terrain. One instance comes to mind from a flight I did on Halloween night last year when my friend and I were flying from Reno to Sacramento to practice instrument approaches. A smart aleck airline pilot came on the radio, "Single engine over the mountains at night, you're a brave man." While he may have a valid point, one must consider whether the situation would have been any safer had we been flying a light twin such as a Seminole as opposed to our C172. While loss of our only engine would have left us with very few options, our odds would not have been much better if we had lost one engine on the Seminole considering that its single engine service ceiling is only 3,800 ft over mountains higher than 10,000 ft
So would we really have been safer? Another thing to consider about twin engine aircraft is when one engine is lost, the aircraft loses not just 50% of its total power, but in excess of 80% due to the increased weight of the aircraft as well as the additional drag created by the inoperative engine and its feathered propellor. Applying these concepts to the mountain flying scenario, it is quite possible that the sinkrate would have actually been greater than that of a single engine aircraft in the event of an engine failure. We would only have been slightly better off had we moved all the way up to the Aztec, with a single-engine service ceiling of 8,000 ft.
Finally, this article is not intended to suggest that there are no reasons or advantages to flying multi-engine aircraft. Sure, there are some, but for the most part they can only be fully realized when flying a much larger, heavier aircraft with operational costs outside the means of most recreational pilots. For example, when you reach the point of flying your own King Air the advantages of the second engine start to show, but even then there is still a strong argument that the Pilatus PC-12 can do almost everything that at least a King Air 200 can do for much less cost. There are some flights, especially overwater ones such as the hop between Los Angeles and Catalina Island where the safety of an extra engine would be a great asset to have. Otherwise, however, I must tell you even an an aspiring professional pilot that if it weren't for the requirement of a lot of multi-engine experience, I would be perfectly content if not even more so flying a good old C182 than a Seminole or Seneca on most days. The best question to ask of all, is even though a twin may offer some advantages, are those advantages actually worth the price to be paid? I think it will mostly be no, but there will be some times when it will be yes.
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