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Understanding "Ferry Flights"

April 10, 2024

The massive expansion of private luxury jet hangars at Hanscom Field has been argued by the project proponents to decrease jet flights rather than increase them as common sense would expect. This is based on the theory that a significant fraction of flights today are what is called “ferry flights” due to an incapacity to store or house them at Hanscom. The developer claims to have identified 3,543 ferry flights in the prior year that the project would eliminate, but did not study detailed flight operations to determine whether they 1) had properly identified ferry flights; and 2) the identified ferry flights would be eliminated by the project. This document describes what kinds of ferry flights exist and how they should be examined to determine the veracity of any claimed decrease in flights.  A systematic independent study of ferry flights shows that only 3 aircraft exhibit ferry flights of the type that would be eliminated by the project, and that all of the other aircraft housed by the project would represent new operations and greenhouse gas emissions.

A ferry flight is the flight of an aircraft without passengers for the purpose of picking up a air-taxi customer, returning to base, delivery to a customer, moving from one base of operations to another, or moving to or from a maintenance facility for maintenance. For purposes of understanding how hangar capacity at Hanscom affects ferry flights, only a subset of ferry flights applies.

The only ferry flights related to hangar capacity are those which would have been avoided if Hanscom had the capacity to accommodate the aircraft, which is only a fraction of total ferry flights. Examples help illustrate the different types of ferry flights and which are related to hangar capacity:

1. A time-share flight drops off a person at Hanscom, and then receives instruction to pick someone up at Logan. This results in a ferry flight to Logan. Extra hangar space at Hanscom would not change this ferry flight.
2. A time-share flight drops off a person at Logan, and then receives instruction to pick someone up at Hanscom. This results in a ferry flight to Hanscom. Extra hangar space at Hanscom would not change this ferry flight.
3. A privately owned aircraft based elsewhere occasionally drops off a person at Hanscom, who intends to stay for a while. The aircraft may be needed for another purpose and returns to home base at its airport base. It returns later to pick up, resulting in two ferry flights for the round trip. Extra hangar space at Hanscom would not change these ferry flights.
4. A privately owned aircraft routinely flies the same passenger(s) from Hanscom, but there is no capacity to store the plane at Hanscom. The jet has a home base in Portsmouth (or some other regional jetport). For each flight it ferries from Portsmouth to Hanscom to pick up; when the passenger returns to Hanscom, the jet ferries back to Portsmouth. If there was available hangar space at Hanscom this aircraft could be based at Hanscom, avoiding two ferry flights per round trip.
5. A privately owned aircraft routinely flies the same passenger from Logan, but there is no capacity to store the plane at Logan. The jet has a home base at Hanscom. For each flight it ferries to Logan to pick up, and when the passenger returns to Logan, the jet ferries back to Hanscom. Extra hangar space at Hanscom would actually increase this type of ferry flight.

These examples show that many types of ferry flights are not affected by Hanscom hangar capacity. The only type of ferry flight that might decrease with hangar capacity is the subset, identified as #4 above, which we will refer to as “Hanscom incapacity ferry flights.”

Some types of ferry flights could increase with additional hangar capacity. If additional capacity is added at Hanscom it could serve as a base supplying ferry flights due to hangar incapacity at Logan, Martha's Vineyard, or Nantucket-- which have limited capacity compared with the level of service. Such ferry flights using Hanscom as a base are enabled by Hangar capacity.

There is no flight data which will directly identify Hanscom incapacity ferry flights. However, flight data patterns help identify which flights could be such flights. Some airports cannot be the destination of Hanscom incapacity ferry flights, because they are not a location conducive to storing an aircraft. It is highly unlikely that Logan, Nantucket, or Martha Vineyard would be a source of ferry flights due to Hanscom incapacity; Logan has no hangars for based private jets, and the other two have very limited capacity for private jets and are frequently overloaded.

Hanscom incapacity ferry flights supporting a particular aircraft are associated with a base airport from which that aircraft regularly ferries to and from Hanscom. The choice of such a base is nearby to save time and fuel. Presumably a base would be within 100 miles of Hanscom. It certainly could not be hours away. Such a base should also have available jet hangar capacity.

Some types of transient aircraft cannot be the source of Hanscom incapacity ferry flights such as air taxi service such as NetJets. These aircraft have ferry flights as a part of their business model; like any taxi system they frequently respond to calls to pick up customers and must often relocate empty to do so. These aircraft would not be based at Hanscom if there were additional capacity.

Hanscom incapacity ferry flights are an attribute of what are called “based aircraft;” which would exhibit a pattern of an aircraft with the same registration number having a repeated pattern over time of departing and arriving at Hanscom from the same regional airport. This data is available.

It is possible to analyze historic flight data using the above criteria to determine how many ferry flights due to Hanscom incapacity occur per year. It is further possible to identify the registration numbers of those aircraft and where they are based. Every round trip flight from base creates two operations from base, one takeoff and one landing; if the aircraft is ferrying through Hanscom, each such round trips creates four operations at Hanscom. Therefore, an aircraft routinely ferrying through Hanscom should exhibit twice as many operations at Hanscom compared to the base airport.

The systematic study of a years worth of flights by aircraft using Hanscom has been undertaken by an independent aviation consultant. Findings include:

• There is no aircraft that always ferries from base through Hanscom Field.
• Out of the thousands of aircraft using Hanscom Field, there are only three that ferry through Hanscom field over 50% of the time.
• These three aircraft would save 75 flights per year if they relocated to Hanscom Field.
• Other than these three, there are aircraft that exhibit occasional ferry flights to Hanscom. Operations of these aircraft at Hanscom would actually increase if any of those planes relocated to Hanscom.
• The required hangar storage area for the three jets exhibiting ferry flights is only about 15,000 sq ft, or about 3% of the hangar project capacity. Therefore 97% of the hangar capacity will be for approximately 75 new jets generating additional greenhouse gas emissions.
• The 97% of additional hangar capacity could allow Hanscom to become the base for additional ferry flights through Logan, resulting in a net increase in ferry flights.
• Any GHG savings due to ferry flights from the three aircraft will be dwarfed by the additional GHG associated with the new based aircraft.

The developer's estimate of 3,543 ferry flights was grossly exaggerated. There are multiple reasons for this, including:

• They incorrectly counted air-taxi operations, which are a major fraction of ferry flights. Additional hangars would not affect these flights.
• They incorrectly counted flights that are not ferry flights. They counted all aircraft that visited Hanscom for less than a day; this would include many day trips that had passengers and were not ferry flights. Additional hangars would not affect these flights.
• They counted flights of aircraft that only visited Hanscom on a few occasions per year. Such aircraft cannot be routinely ferrying from a local base through Hanscom. Additional hangars would not affect these flights.
• They failed to identify whether the candidate ferry flights had a regular local base. They counted all flights from any airport within 350 miles without attempting to determine its base.
• They counted all flights coming from an airport within 350 miles as coming from a possible base. An aircraft that ferries through Hanscom from a base would not be more than 100 miles away, due to cost and time delays. Many of their "candidate" ferry flights came from Teterboro in New Jersey, Westchester in New York, and from as far as Philadelphia; it is extremely unlikely that an operator would chose such distant and expensive airports if they were trying to base at Hanscom.
• They counted 600 ferry flights from Logan airport. Since there are no based private jets at Logan, none of those flights can be based there, or benefit from relocating to Hanscom

The data shows that while it is true that some aircraft do ferry through Hanscom, such flights represent a tiny fraction of operations. The increases in new based aircraft at Hanscom due to the hangar project would create additional emissions dwarfing any potential savings that might result form eliminating the small number of known ferry flights. Claims that a giant hangar project will reduce operations are shown to be false. Since Massport and the proponent have access to the flight data, their false claims are intentionally deceptive.

It is important to recognize that increasing hangar capacity could actually add ferry flights relating to Logan airport, impacting both Hanscom and Logan.

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