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San José Airport / Downtown Airspace and Development Capacity Study Frequently Asked Questions
1) What did the City Council approve on March 12, 2019?

  • Council approved City staff’s recommendation to allow buildings in Downtown San Jose – both in the Downtown Core and Diridon Station Area – up to height limits determined to be safe by the FAA.
  • Council evaluated the Steering Committee’s analysis which found that setting development heights in the greater Downtown area up to the height limits determined by the FAA to be safe is achievable without significantly impacting flight operations when conditions require aircraft to take-off from SJC to the south over the Downtown area (known as “south flow”), which occurs, on average, 13% of the time.
  • Council directed the Administration to provide refinements in the City’s development review process to incorporate these findings.
  • The Steering Committee also recommended that Council direct the Administration to work with the private sector to establish a community-funded Air Service Support Fund. This fund could be used to help mitigate any potential economic impacts to airlines that may result when their flights must depart SJC to the south over taller Downtown structures.

2) Why is it important to allow taller buildings in the Downtown area?

  • Allowing taller buildings encourages development by allowing developers to add more square footage of usable work and living space on the same amount of land.
  • This increase in density provides economic benefits to San Jose residents and businesses by increasing the number of people who can live and work in Downtown, which translates into more foot traffic past local businesses, more downtown area spending and the ability to add more, much needed housing.
  • More development in Downtown San Jose is also expected to generate more demand for air service from the airport.

3) How much taller could buildings get under the plan City Council will consider?

  • Setting development heights in the greater Downtown area up to the height limits determined by the FAA to be safe would make it possible to increase the maximum building height in the Downtown Core by 5’-35’ and the in the Diridon Station Area by 70’-150’.

4) What are these economic benefits and what does this recommendation mean to the development of Downtown San Jose?

  • The most significant economic gains resulting from setting development heights in the greater Downtown area up to the height limits determined by the FAA to be safe are expected to occur in the Diridon Station Area.
  • Development capacity in this area under the Study scenario recommended to Council (Scenario 4) is estimated at a net building addition of 8.6 million square feet, resulting in net new construction value of $4.4 billion and net new annual property tax revenue of $5.5 million, once all 8.6 million square feet of new capacity has been built out.
  • Assuming a 90/10 split of residential and commercial construction of this new square footage, this results in a potential net increase of 4,700 employees and 12,800 residents in the Diridon Station Area.

5) Why is this study being undertaken now?

  • In June 2017, the City Council directed staff to update the City’s 2007 Airport Obstruction Study and include an economic analysis to identify the trade-offs between maintaining the aircraft protection and potential increased building heights to support aircraft operations in south flow.
  • Given the current surge of development interest in San Jose, it’s critical that the Council evaluate all opportunities using current data, metrics, and analysis from all stakeholders, including airlines operating at SJC.

6) How often do aircraft depart over the Downtown area?

  • South flow operations occur on average 13% of the time, and most often during winter months and morning hours, according to an analysis of weather over the past 15 years.

7) What are the impacts for SJC and its current and future flights if the Council approves City staff's recommendation to allow taller buildings under proposed Scenario 4? Is there a risk of losing air service to Europe, Asia and possibly the East Coast?

  • The study determined that there would be minimal, if any, impact to flights departing to key East Coast, European and Hawaiian markets.
  • SJC flights departing to some cities in Asia (e.g., Beijing) using certain types of aircraft (including the Boeing 787 Dreamliner currently operated by Hainan to Beijing) may be required to operate with fewer passengers and/or less cargo during the rare times their flight departs during south flow operations.
  • To compensate for this, the Steering Committee recommends to Council the creation of a community-funded Air Service Support Fund to be available by 2024, to offset any potential airline economic losses that result from weight restrictions during south flow operations.

8) Is there a public safety concern with the City’s recommendation to raise building heights in the Downtown area? How do you respond to critics who say Scenario 4 poses a safety risk if planes flying in "south flow" lose an engine? Are we compromising safety in any way?

  • No. The safety margins between and aircraft and the buildings, which are mandated by the FAA, are not changed by the recommendation before Council.
  • Setting development heights in the greater Downtown area up to the height limits determined by the FAA to be safe in the Downtown area will result in airlines revising their operational procedures and aircraft weight and balance during the approximately 13% of time when flights must take off to the south. These adjustments will allow for aircraft to safely operate over taller buildings in the event that one aircraft engine should become inoperable at take-off.

9) When will the proposed flight operations changes take effect?

  • The recommendation will establish maximum building heights. It will then be up to developers to propose and gain approval for any new buildings (which would require a separate public permitting process).

10) Where can I find more information?