Is McDonnell’s Jet Still the Quietest of Them All?
They were, McDonnell Douglas proudly claimed, “the quietest commercial jetliners in the world.” It was 1980, and the DC-9 Super 80s that began rolling off the assembly line and down the runways of the nation’s busiest airports were heralded as the ultimate answer to airport noise problems.
Within a few years, almost the entire fleet of aircraft serving John Wayne Airport--widely acknowledged as a frontrunner in noise abatement--had converted to the Super 80s. Orange County’s entire noise regulation and airline entry program revolved around the amazingly quiet, highly efficient new airliners that could clear the noise monitor south of Bristol Avenue at less than 98.5 decibels.
The new airplane was up to 67% quieter than conventional jets.
“We made the claim that we were the world’s quietest commercial jetliner, and we’ve been able to make that claim undisputed for four years,” McDonnell Douglas spokeswoman Elaine Bindell said recently.
But there are new kids on the block.
British Aerospace Inc., in a flurry of brochures and color-coded noise graphs, says its new high-winged, four-engined BAe-146 is “the quietest jet airliner in the world.”
And purchasers of the new Boeing 737-300 are calling that aircraft “the quietest jet in the world.”
88-Decibel Talk
Both manufacturers are making noises about crossing Bristol at 88 decibels.
In the world of airport noise regulation, that’s big news. An airplane that’s 10 decibels quieter is only half as loud.
On Wednesday, the Orange County Board of Supervisors revamped its entire airline noise regulation program in hopes that the two manufacturers can make good on those claims. For the first time, the county will offer incentive flights to a new class of aircraft, those that can take off at 89.5 decibels and below.
It was a highly controversial decision--bitterly fought by McDonnell Douglas--and it has set the scene for a technological war to determine who will be awarded the new incentive flights. County officials say the decision could ultimately test the outer limits of their legal ability to clamp noise controls on air carriers.
“You’ve got to watch these guys. It’s big money involved in selling aircraft, and it seems to me it just makes prudent sense to make sure you have a bird in the hand before you make any commitment,” said John Wayne Airport Manager Murry Cable.
Claims Exceeded Performance
“We went through all this with the Super 80s. The manufacturers’ claims were more than the actual performance, even though we’re very happy with the airplanes, they’re what allowed us to meet state noise regulations for the first time,” he said.
In expanding total departures at John Wayne to 55 daily, the board provided that each airline could trade in some of its regular flights on a 2-for-1 basis for the new, quieter jets, up to a maximum of three for each carrier during the first year and a total of 16 flights daily.
But while the decision was heralded as an important step toward alleviating noise problems around the airport, several doubts remain about the ultimate success of the effort:
- Neither the BAe-146 nor the Boeing 737-300 have ever been tested at John Wayne Airport, so no one is certain that they will be able to meet the 89.5-decibel requirement.
- Even if they did, and the maximum level of 16 daily flights were converted to the quieter jets, the average noise level near the airport would be lowered by only 1 decibel.
- Although manufacturers question the findings, it is generally believed that both the BAe-146 and the Boeing 737-300 are noisier on approach to landings than the Super 80.
- Both airplanes are smaller than the Super 80. The Boeing craft seats 141 passengers, compared to 155 for the Super 80. The BAe-146 seats 100. And a number of noise experts say privately they doubt that either craft will be able to meet the 89.5-decibel level without limiting either fuel or passengers. Thus, critics say the incentive flights will serve fewer passengers for each noise event.
County supervisors were aware of some of the potential drawbacks of the incentive program when they made their decision. But the idea of encouraging the latest technology in quiet aircraft--and the Federal Aviation Administration’s constant push for freer airline access to the airport--were deciding factors, several supervisors said.
The BAe-146, at least, has had some experience at other airports. PSA, one of the airlines serving Orange County, has six in service and 20 more on order, with service at Burbank, Ontario, San Jose, Los Angeles, San Francisco, Phoenix, Las Vegas, Reno and Portland.
“Everybody seems to be very impressed,” said Chuck Zeaman, assistant airport manager at Ontario International Airport. “When it takes off, you can’t even hear it. You literally have to be looking at it to know it’s coming and going.”
In noise tests Jan. 16 at Long Beach, with the decibel meter set to measure only noise above 75 decibels, the BAe-146, loaded with 60 passengers and enough fuel for an hourlong flight, did not register, according to PSA spokeswoman Marjorie Craig. Other readings during the test included 100.1 for a Boeing 737, 98.9 for one Super 80 and 99.8 for another Super 80.
In another test at Burbank, the BAe-146 measured 82.3 decibels at takeoff, compared to Super 80 readings of 98.3, 95.9, 90.3 and 97.6.
However, Orange County officials emphasize that none of those readings are useful for Orange County because of variations in where noise monitors are placed and load factors used during the tests.
The Boeing 737-300 hasn’t been officially tested anywhere. After AirCal ordered 12 of the jets--$300 million worth--last year however, a demonstration jet flown into John Wayne took off at between 87.7 and 90.9 decibels. But it was far below normal gross weight for an airliner in service, county noise abatement officials say.
So far, three other airliners serving John Wayne--Western, Continental and America West--have placed orders for the new Boeings. No other carriers beside PSA have ordered BAe-146s.
PSA spokeswoman Craig said she is not certain whether the airline will seek the new incentive flights or when it will schedule noise tests to determine whether it qualifies.
“We believe the airplane speaks for itself or doesn’t speak for itself. It’s a very quiet airplane, but until we get in there to have it tested, because each airport is different, I would just be speculating,” she said.
AirCal is tentatively set to test its new Boeing 737-300--the first of which is scheduled for delivery Feb. 9. County officials will require the craft to take off with both full- and partial-passenger loads, then make a determination of whether it qualifies for incentive flights, said Ken Hall, an aide to Supervisor Thomas F. Riley.
If it only qualifies when partially loaded, that could introduce a new thorn into the regulation picture. While the county can probably impose takeoff weight restrictions, it is much less likely that it can implement the weight restrictions by limiting the distance each plane flies, which makes some legal challenges possible, county officials said.
Meanwhile, McDonnell Douglas is making its own technological advances, which the manufacturer claims will keep the Super 80 competitive with both new airplanes.
A new takeoff procedure certified last year by the Federal Aviation Administration allows the Super 80s to reduce takeoff power at 500 feet above the ground, effectively lowering noise as the planes begin to cross neighborhoods south of the airport.
However, even those results are open to question. McDonnell Douglas originally claimed the cutback procedure would reduce takeoff noise by up to 6 decibels, but American Airlines, the first carrier to win full certification for the procedure, has registered less than 1 decibel quieter at the nearest noise monitor, and 2 decibels quieter at other stations.
Republic Airlines, which has only used the procedure for a short time, is producing almost twice the noise savings with the 500-foot cutback, according to the county’s noise abatement office.
