Archive for February, 2011

Photo flights and tail rotors

Monday, February 21st, 2011

The unique ability of a helicopter to slow down and hover out-of-ground-effect makes it an ideal platform for taking pictures or video. To safely perform these types of flights requires a complete understanding of the issues involved with maneuvering a helicopter at slow speeds. One of these areas is understanding the limitations of different helicopter’s tail rotors.

Older model Bell 206B Jetrangers have a smaller tail rotor with a symmetrical designed airfoil that makes it more susceptible to what’s referred to as Loss of Tail Rotor Effectiveness (LTE). According to FAA Advisory Circular AC90-95, any maneuver which requires the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind creates an environment where LTE or an unanticipated right yaw may occur. It also advises of greater susceptibility for LTE in right turns and states the phenomena may occur in varying degrees in all single main-rotor helicopters at airspeeds less than 30 KIAS. 

Another light helicopter that is very popular for photo flights is the Robinson R44. Frank Robinson is a tail rotor expert and designed the R44’s tail rotor to be highly efficient using an asymmetrical airfoil. The R44’s tail rotor is strong and although a lot less likely to encounter LTE pilots still need to exercise caution especially at high gross weights and high density altitudes.

Robinson Helicopter issued the following Safety Notice (SN-34) in March 1999, titled “Photo Flights – Very High Risk.” It describes the problems encountered when the pilot slows the helicopter below 30 KIAS and then attempts to maneuver the helicopter.

“The helicopter can rapidly lose transitional lift and begin to settle,” it states. “An inexperienced pilot may raise the collective to stop the descent. This can reduce rpm, thereby reducing power available and causing an even greater descent rate and further loss of rpm. Because tail rotor thrust is proportional to the square of rpm, if the rpm drops below 80 percent nearly half of the tail rotor thrust is lost and the helicopter will rotate nose over. Suddenly, the decreasing rpm also causes the main rotor to stall and the helicopter falls rapidly while continuing to rotate.” The safety notice recommends photo flights only be conducted by well-trained, experienced pilots.

Instrument flying

Thursday, February 10th, 2011

When I got my CFI rating in 1981, instrument flying in helicopters was very rare. In fact, back then very few companies required it for employment as a commercial helicopter pilot. Today it is much different. An instrument rating is required for most jobs and all professional training programs include the rating. Moreover, any pilot who begins their career instructing (as most do) will need a CFII.

Thirty years ago instrument flying was airport to airport. Now with GPS, approaches can be designed inexpensively to almost anywhere, making IFR helicopter operations more reasonable. However, there are some limitations with helicopters. One of them is range. Helicopters typically carry about 3 hours of fuel. With a large weather system it can be very difficult to fly to your destination, find a qualifying alternate and maintain the required fuel reserve.

Because of the unique characteristics of helicopters, the CFRs provide some help with the range limitation. Helicopters are required to have a 30-minute fuel reserve as opposed to 45 minutes for airplanes (CFR 91.167 (3)). Regarding the weather at the destination used to determine if an alternate airport is required, CFR 91.167 (b) (2) provides lower minimums for helicopters.

(i) For aircraft other than helicopters. For at least 1 hour before and for 1 hour after the estimated time of arrival, the ceiling will be at least 2,000 feet above the airport elevation and the visibility will be at least 3 statute miles.

(ii) For helicopters. At the estimated time of arrival and for 1 hour after the estimated time of arrival, the ceiling will be at least 1,000 feet above the airport elevation, or at least 400 feet above the lowest applicable approach minima, whichever is higher, and the visibility will be at least 2 statute miles.

Also, under CFR 91.169 (c) (1) IFR alternate airport weather minimums are different as well.

(i) For aircraft other than helicopters: The alternate airport minima specified in that procedure, or if none are specified the following standard approach minima:

(A) For a precision approach procedure. Ceiling 600 feet and visibility 2 statute miles.
(B) For a nonprecision approach procedure. Ceiling 800 feet and visibility 2 statute miles.

(ii) For helicopters: Ceiling 200 feet above the minimum for the approach to be flown, and visibility at least 1 statute mile but never less than the minimum visibility for the approach to be flown.

The regulatory relief has helped helicopters use the IFR system more often.

Finding training money

Wednesday, February 2nd, 2011

One large problem facing the helicopter training industry is a lack of funding for students. When the credit crisis hit several years ago, lenders such as Sallie Mae and Key Bank stopped making educational loans for non-degreed programs like flight training. Although this affected both fixed-wing and rotor-wing schools, the higher cost of a professional helicopter program (about $80,000) caused quite a drop in student enrollment.

There are a few options available, such as Pilot Finance, Inc. (www.pilotfinance.com); however, its loans are limited to about $15,000. Personal loans, home equity loans, and credit cards are options, yet with tougher credit requirements and the high cost of a professional helicopter pilot program these most likely would not provide enough funding.

Prospective students who served in the US military have somewhat better options. The Montgomery GI bill pays 60 percent of the training cost for ratings above private. However, this still leaves an out-of-pocket cost of over $40,000 for a professional helicopter pilot program. Prior to this year the Post 9/11 GI bill would pay 100 percent if the training was taken through an institute of higher learning (a degree granting institution) and as a result several flight schools partnered with local colleges to qualify. This was a costly and time-consuming process. The flight training industry regained some optimism when a bill was introduced last year to directly include flight schools in the program. However, the optimism was short lived when the bill recently passed with a $10,000 per year cap on flight training.

With entry level helicopter pilot jobs hard to find some might argue that training more pilots is really not needed. Maybe in the short term, but five or 10 years from now there could be a shortage of helicopter pilots.