Dear Mr. Wilson,

Arapahoe County Public Airport Authority

This letter is to let you how pleased we are at Centennial Airport (KAPA) with the Density Altitude Displays (DAD) you sold us.

As you lmow, we purchased two units for our parallel north-south runways but because of the positive response from pilots, we acquired a solar-powered DAD for our crosswind runway as well. Although DADs are not federally funded, given the high altitude at our airport in metropolitan Denver (5883' MSL), staff thought it beneficial that the airport acquire a supplemental density alert system for pilots flying Centennial Airport.

Every year, Centennial Airport experiences a number of density altitude related incidents and accidents, most involving transient pilots not familiar with high altitude flying, especially during the warm summer months. While DADs do not prevent density altitude related incidents, our focus was to provide supplemental safety information, much in the way an ATIS message might alert a pilot to local conditions. In fact, ATIS messages during the summer often contain the advisory "check density altitude." Providing an exceptionally visible clue in the run-up areas to all our runways in addition to ATIS advisories further enhances pilot safety. Our pilots are sufficiently pleased with the highly reliable read-outs, that our airport office and ATCT staff regularly receive positive comments from pilots about the new system.

With our first summer with operational DADs coming to a close, I can unequivocally tell you that they work and that pilots appreciate having a back up to their own calculations. More than one pilot has expressed surprise at the altitude read out registered on the bright LED display, thinking they were at a much lower altitude. The DADs have registered close to 10,000' MSL several times this past summer due to hot weather.

I have spoken to Benito De Leon at the FAA and I have encouraged the FAA to look into the benefits of the DADs as a supplemental aid to flight safety. The Density Altitude Displays are perfect for the Colorado plains as well as the Rockies, and having flown the Sierras and the high desserts of California, I can think of a lot more airports that would greatly benefit from this outstanding visual aid.

In the next couple of years we hope to compile comparative statistical data on the number of density altitude related incidents and accidents that have occurred at KAPA before and after installation of the DADs, however, my instinct tells me that the three DAD systems currently operational at Centennial Airport have already saved lives and reduced accidents.

Again, thank you for introducing me to your product and for allowing us to test and evaluate them before completing the purchase. No one should be without a DAD!

Respectfully Yours,

Robert P. 0lislagers Executive Director