Buying a New Plane

by Philip Greenspun, ATP, CFII-MEI, CFI-H; updated March 2007

Site Home : Flying : One Article


Buying a car is easy. All cars will get you door-to-door in the same amount of time. Most cars will hold enough people and bags for 99 percent of your trips. All cars have sufficient range to get you from gas station to gas station. You can trade a car in on a new and different car in an afternoon.

Airplanes are much more varied in their capabilities. An airplane without de-icing will be grounded on cloudy days through the entire winter. There is almost no airplane that can carry a full passenger and a full fuel load at the same time. A fancier airplane may require a longer runway than the one at the airport near your favored destination. The speed differences among planes, combined with expected headwinds, can result in a difference of hours or days in transit time. When it is time to trade in, it could take 6-12 months to sell a plane without offering a steep discount.

Start by defining the mission

It doesn't matter how advanced the technology is, how seductive the advertising is, or how persuasive the magazine article is. A plane is either capable of your typical mission or it is not. Until you've defined your mission, you can't see if a plane fits.

Sample Mission Definition

Here's a sample mission and capability definition:

Specify a Trade-Off Procedure

Even if you have an unlimited budget, aviation is all about compromise. A Boeing Business Jet (converted 737) is a lovely airplane, but it can't land at small airports. You probably won't get everything on your list, so specify in advance a way of trading off one attribute for another. Example:

List the Crew

What resources are available for flying the new airplane? If it is just a newly minted Private certificate holder, that limits the search to some fairly basic airplanes. Here's an example of a crew specification:

Discuss some Example Aircraft

To see if the mission profile is specific enough, prepare a written evaluation of some airplanes against the mission specification.

Examples:

A 1987 Piper Malibu with a 4-blade prop would handle all of our requirements... except that we don't trust its Continental IO-550 piston engine (better than the Lycoming in the Mirage, but perhaps not good enough) and the entire airplane seems a little bit too fragile (e.g., tough to get the landing gear down after flying in the cold flight levels).

King Air E90. Same fuel burn and cabin as a C90, but with an extra 90 gallons of fuel (474 gallons versus 384 for the C90). F90 is similar, but supposedly requires longer runways. We would require the Raisbeck modifications ($100,000) that give us a 400 lb. gross weight increase and also interior quiet due to four-bladed props. Typical fuel burn is 70 gallons/hour, so on a VFR day this means about 6 hours of fuel with a reserve. 6 hours x 240 knots = 1440 n.m. still air VFR range (checks with the Raisbeck Web site performance chart for the E90). Full-fuel payload is around 600 lbs. for a Raisbeck ship. Seats-full NBAA range for a factory ship is 730 n.m. Tanks-full NBAA range for a factory E90 is 1337 n.m. Balanced field length is 4350'.

TBM-700. Interior noise measures 91 dBA at the pilot's seat. Range is supposedly around 1400 n.m., but that is with only a pilot and 100 lbs. of bags. We need to find out what the range is with 600 lbs. of passengers. TBM-700 should be at least $800,000 more expensive than the E90. http://www.caijets.com/tbm_operating.php shows that the TBM is at least $300/hour cheaper to operate, which will save $90,000 per year if we run 300 hours/year. The extra $800,000 capital cost, however, will cost us about $50,000/year in opportunity cost on the money, plus we'll be paying more for insurance (?), and finally the TBM-700 will be depreciating faster.

Think about the Plane and Seller

Write down the kind of plane that you would be willing to buy and the kind of owner from whom you'd be willing to buy. If you're an A&P mechanic, maybe you'd be willing to buy a plane that has been rusting on the ramp for 5 years and whose flying condition is unknown. Whatever your standards, write them down before starting to go through the classified ads.

Here's an example specification:

Start Shopping

Where to look for a new plane? There are the obvious locations: What is a non-obvious source of planes for sale? Write letters to the owners of planes that are not for sale. Aircraft registration is public information in the United States. Grab the FAA registration database, narrow it down to, say, 2003-5 Piper Meridians, and send all of those owners a letter saying "I would like to buy your plane." That's what airplane dealers do when they are asked to find a specific plane for a customer.

More


Text and photos (if any) Copyright 2007 Philip Greenspun.
philg@mit.edu