Bell 407
Introduction
The B407 is a single engine “light” helicopter.
The fleet has accumulated over 6 million flying hours.
The helicopter’s primary roles are in law enforcement, EMS and utility markets (including sightseeing) particularly in North America. The B407 also has secondary roles in VIP and offshore O&G.
History and Development
In 1993 Bell started development of a replacement for their highly successful Bell 206. Just three years later in 1996 the Bell 407 was certified in Canada and the USA.
In contrast to the Bell 206, the Bell 407 has a larger cabin (and larger main cabin windows) and a four bladed main rotor head. The composite rotor head and blade components used on the Bell 407 give better performance and a smoother flight experience when compared to the Bell 206. Furthermore, the more powerful FADEC-controlled engine further enhanced performance, especially in hot and high conditions.
In 2010 Bell developed the “plus power” STC which increases the MTOW by 400 pounds.
In 2014 Eagle Copter in Canada developed a STC for the installation of a (much more powerful) Honeywell HTS 900 engine in the Bell 407 creating a new product type – the Eagle 407HP.
Safety Performance
The Bell 407 has a good safety record. Most of the accidents and incidents on the type have been a result of human error or maintenance oversights and are unrelated to the design or maintenance planning of the helicopter. A number of incidents demonstrate the capability of the helicopter to safely perform an autorotation emergency landing after an engine failure.
Most Bell 407 design-related or maintenance-planning incidents have related to the engine or the engine-to-transmission driveshaft.
In 2011 a Bell 407 operating in the Gulf of Mexico suffered a fractured KAflex engine-to-transmission driveshaft resulting in Bell issuing a service bulletin requiring the installation of a new driveshaft with a 1,250-hour overhaul interval.
In 2011 a Bell 407 operating in eastern Spain suffered a fatal crash while on a firefighting mission. As a result of this incident an AD was issued resulting in changes in the maintenance schedule of the helicopter in respect of the hydraulic system.
In 2012 a Bell 407 operating in the US yawed left and a “loud howling/grinding sound” emanated from the aircraft. The pilot performed a hard landing. The investigation by NTSB showed the probable cause to be fatigue failure of two turbine engine blades due to vibration. The engine manufacturer plans to release design changes that will increase the operating speed natural frequency margin and improve the vibration margin.
In 2015 an accident occurred during an EMS flight at San Antonio, Texas. The pilot heard a loud bang, and the helicopter began a right yaw due to a failure of the no.3 tail rotor adapter and shaft due to a loss of torque on the retaining nut. As a result of the incident the maintenance manual was updated to include enhanced inspections of the tail rotor assembly in the recommended maintenance planning documents.
In June 2020 a Bell 407 on a private flight in Warwickshire, UK, went on fire after making an emergency landing. The AAIB described this as an “un-contained engine failure”.
The Future
New production
The Bell 407 continues in production today as the Bell 407GXI which comes with Garmin G1000H NXI cockpit avionics and the Rolls Royce 250-C47E engine.
Law enforcement
The Bell 407 is likely to remain standard equipment for law enforcement agencies throughout the United States and Canada for the foreseeable future. It is however likely that this role may come under some pressure from drone technology which will reduce the number of helicopters required by law enforcement by offering overhead surveillance at a fraction of the cost.
VIP
The Bell 407 is a very popular VIP aircraft and it is likely to remain strong in this sector for decades to come. The aircraft offer its classic “club seating” arrangement, has a competitive direct operating cost and is one of the best in its class for range at higher loads (full pax).
Utility and Tourism
The Bell 407 will remain a suitable helicopter for general utility tasks such as construction support and tourism. It is somewhat on the small side for most dedicated tourist flight operations but works well for operators who may wish to combine tourism with other roles.
EMS
The Bell 407 can be considered a cost-effective single engine solution for limited budget HEMS projects and should keep its position in this market in the years to come.
Summary
The Bell 407 is the quintessential general-purpose helicopter. Many of the world’s plethora of small helicopter operators will have either a Bell 407 or AS350 in their fleet. The type does not have the question mark that hangs over most larger helicopter types due to the decline in demand from the oil and gas industry. The question mark for the Bell 407 is the long-term implication of drone and EVOTL technologies. These have the potential to displace the traditional helicopter, but this is far from a certainty and the timing is unclear.
Costs and Values
A “per hour” rental price for the Bell 407 is appropriately US$4,000 per hour.
A dry lease rental price for a Bell 407 is in the range of US$10K to US$35K per month. However, caution is needed regarding these dry lease rates as the dry leasing market for the Bell 407 is less developed than for larger types such as the AW139. Few dedicated leasing companies have the Bell 407 in their fleet and so most leases are ad-hoc affairs between operators.
The Bell 407 has historically provided the best residual value performance in the light long single class, with resale values being 95% of acquisition cost across a 15-year timeframe.
Maintenance
Inspections
The primary maintenance events on the Bell 407 are as follows.
Airframe inspection intervals are:
- 300hrs, 600hrs, 1,200hrs and 2,500hrs
- Calendar inspections at 12 months and 24 months
Engine inspections intervals are at 300 and 2,000 hours.
The engine itself does not have a prescribed overhaul limit, but the sub-assemblies of the engine have the following inspection and overhaul intervals:
- Turbine - Overhaul – 2,000Hrs
- Fuel Nozzle - Overhaul - 2000hrs
- HMU - Overhaul –2,500hrs
- Engine Gearbox Assembly - Inspection – 4,000hrs
- Compressor Assembly - Inspection – 2,000hrs
Power by the hour products
Airframe:
Bell Helicopters offer its Customer Advantage Plans (CAP) support agreements for airframe component support.
Engines:
Rolls Royce offer their brand-named TotalCare support package offering full engine coverage.
External Links
The Bell Helicopters home page for the B407:
https://www.bellflight.com/products/bell-407
The Wikipedia page for the B407:
https://en.wikipedia.org/wiki/Bell_407
A description of the Bell 407 by AircraftCompare:
https://www.aircraftcompare.com/aircraft/bell-407/
A product sheet for the Bell 407 by Business Air News summarising the various variants, charter operators, maintenance centres and type rating training providers.
https://www.businessairnews.com/hb_aircraftpage.html?recnum=B407
Product page for a cargo hook offered for the Bell 407:
https://www.onboardsystems.com/product/200-403-00
A law firm site providing more detailed information on Bell 407 accidents:
https://www.slackdavis.com/aviation-accidents/helicopters/bell-407-fadec-engine/
Articles
A look back on 25 years of the Bell 407 (May 2021)
https://helihub.com/2021/05/20/looking-back-on-25-years-of-the-bell-407/
An announcement regarding the first single pilot HEMS flight with a Bell 407 (Arrow Aviation for HALO flight):
An announcement regarding the sale of 200 EMS Bell 407s to Air Methods (2015).This was one of the largest sales ever achieved by Bell.
An announcement by Rolls Royce regarding the upgraded M250-C47B/8 engine (2015):
An announcement regarding a new polycarbonate windshield for the Bell 407 (2014).
An article regarding increased high and hot capabilities for the Bell 407 (2014)
https://verticalmag.com/press-releases/faaapproveshotandhighincreaseforbell407/
A description of the Bell 407 by Business Jet Traveller (2012):
https://www.bjtonline.com/business-jet-news/bell-407
A general description of the Bell 407 by Business Jet Online including a summary of certain available upgrades (2012):
https://www.bjtonline.com/business-jet-news/bell-407