As I stated in my last article (“Heliport Standards: Where the Bears Live,” May 2013, page, 48), I think the issue of the new heliport design guidelines given in FAA Advisory Circular 150/5390-2C need a bit more sunshine. Without restating the whole article, I think it’s worthwhile to reiterate the point, that while it is true that an AC is not a regulation, many of the states, which do have the authority to write the requirements pertaining to heliport design in their jurisdiction adopt the federal AC in whole or part. So in fact the FAA folks that produce this AC are, in effect, writing law. Think about it: What state regulator wants to try and explain in court why they wrote less-stringent standards than the published federal advisory standards? As stated in the last article, Emergency Helicopter Landing Facilities (EHLFs) are being included in the FAA’s heliport database as private heliports. This will lead to confusion. These EHLFs are meant for emergency use only on the specific building that they are installed on. One of my sources for this article now informs me that the Los Angeles County Fire Department helispots used for firefighting and EMS operations are now included in this database. This is just plain wrong. The vast majority of these areas, which are for a different purpose than EHLFs, are located on private property with limited permission to conduct LACOFD operations under emergency conditions only.
This AC also changes the computation of the size of the Touchdown and Landing Area (TLOF), the load bearing landing area. As an example, under the old AC, the TLOF for a Sikorsky S-76 on a hospital rooftop heliport would be required to be a 44-foot diameter circle. The new AC changes this to 52.5-foot circle based on the length of the helicopter. As I was schooled by the design engineers on the new University of Southern California Hospital Heliport project several years ago, an increase of one square foot of load 12 stories up is a lot more money than one might think. When the load mitigation for this considerable increase is translated into building costs, the costs start from the foundation of the building upwards.
Another requirement of the AC is an increase in the length of the Final Approach and Takeoff Area (FATO), the safety area around the TLOF based on the heliports elevation above 1,000 feet MSL.
A new concept called the Heliport Protection Zone (HPZ) has been added to the hospital heliport requirements. This clear area on the ground is projected out 280 feet from the edge of the FATO whether it’s a rooftop or ground-level heliport. The AC discourages this area from having any potential for public assembly.
Since around 1994, the FAA has steadily tried to make the heliport design guidelines consistent with the airport design guidelines, because for the most part, the people at FAA who wrote this document are airport engineers, with all of their experience in airport design. Look at the two examples in the proceeding paragraphs the HPZ listed above is the Runway Protection Zone (RPZ) used in the Airport Design guide.
So, once again kind readers, we – the helicopter community – are being saddled with airplane think, instead of thoughtful consideration of the differences between the physical requirement differences between helicopters and airplanes, before the rules are written. My favorite, or should I say least favorite, example of this are the rules concerning fuel systems on multi-engine airplanes that were adapted for twin-engine helicopters. The MBB105 as produced in Germany had a single fuel cell, a couple of pumps, two fuel valves and away we go. When the aircraft was brought to the U.S., FAA took exception to this and required that the MBB105 have separate fuel systems for each engine thus requiring two separate supply tanks. When the MBB105’s fuel system was adapted to this standard, the complexity of the system – the cost, weight and manhours for maintenance all went up, the only thing that decreased was the safety of the aircraft.
I fully understand that this subject is difficult to relate to. Its full of unusual acronyms that only specialists in the area fully understand. It’s not a subject that the helicopter industry has on its short-range radar. I guess the thing that draws me back to this issue is my love for helicopters and the future of helicopter flight. Also if I truly believed that all of these additional requirements were adding to the safety of flight in a proportional manner consistent with the risk being mitigated, I could see the sense of it, but driving helicopter rules with airplane mentality has never and will never work.