Twin Otter Ingenuity and Adaptability

In these unsettling times, we have found that focusing on ingenuity and adaptability has kept us strong and positive.  Regardless of what is happening, we are maintaining our high standards of quality and are appreciating the depth of knowledge in our staff, and the resources that we can rely on.

It turns out that innovation and ingenuity have not been stymied as a result of the pandemic. Developments that were underway have been brought to completion and can now be shared.  See our Emergency Roof Escape Hatch

Adaptability is evidenced in our response to supply chain and logistical challenges, while new Service Bulletin (SB) requirements on top of Covid-19 operational requirements have been met with in-house solutions and resources.  See our Exchange Flight Controls

It may be difficult to be optimistic given the very real challenges faced by our industry, but a “glass half full” look at uncertain times can see opportunities for increased versatility, profitability and reliability in operations.  See our Avionics upgrades

DHC-6 Taking Flight
Twin Otter Taking Flight

Twin Otter Emergency Roof Escape Hatch

For Twin Otter operators who because of regulatory requirement, or operational needs, still have the OEM Viking cabin roof escape hatch. Are you experiencing problems with fitment, delamination or other unserviceability?  Have you had no option but to continuously carry out time consuming repairs as the hatch is no longer available?

Cabin Roof Escape Hatch
RMA-C6FS2413-11

Rocky Mountain Aircraft have recently received TCCA STC approval for a replacement cabin roof escape hatch. The replacement hatch is manufactured from aluminum sheet unlike the OEM balsa core material, so is immune from delamination.

The replacement part RMA-C6FS2413-11 along with the STC are in stock and ready to ship.

AOG for Twin Otter flight controls?

Did you know? Rocky Mountain Aircraft keeps most Twin Otter Flight controls in stock ready for exchange, purchase or as loaners if we are repairing yours.

Viking SERVICE BULLETIN V6/0066 for Aileron Structure Inspection requires borescope inspection equipment that many operators don’t possess and those that do may discover significant repairs required. Minimise aircraft downtime with an economical exchange from Rocky Mountain Aircrafts stock.

Flight Controls
Flight Controls

Spending a fortune on analog instrument repair and gyro overhauls?

The old electro-mechanical instrumentation that has served the Twin Otter fleet well for over fifty years has reached the end of their economical life. Attempting to coax a few more years of service out of these systems is only going to cause heartache and expense. It’s time to invest it reliability and modernity.

Modern avionics systems will increase profitability, versatility and reliability. Isn’t it time your cockpit looked like this?

Avionics Cockpit
Avionics Cockpit

Don’t Just Kick the Tires and Clean the Windscreen

As air travel and aviation in general start to take the first tentative steps to emerge from the Covid-19 lockdown, the reactivation of aircraft that have been parked for the past three of four months needs to be addressed.

Storing aircraft, even for the short-term is nothing new for most major airlines. However, for smaller regional airlines, corporate flight departments, and other commercial operators this may have been a new experience.

So were the aircraft properly stored and were measures taken to safeguard the aircraft’s ultra-sensitive avionics systems? All apertures and openings through which environmental factors – sand, dirt, water, birds, and insects – can find their way inside an aircraft are wrapped up and made watertight. That includes engines and air data probes – such as pitot, static, temperature, angle of attack sensors – engine intakes and exhausts, and APU intakes and exhausts.

Were maintenance or maintenance control staff furloughed? Have calendar-based inspections lapsed? Are the CVR/FDR, ELT, Altimeters, Transponders overdue recertification?

Emirates Airlines estimates that It may require around 4-5 dedicated employees and at least 18-24 hours to put just one of its aircraft back into service.

With the aircraft now ready to fly, what about the aircrew? Recency will have expired for most aircrew unless they had access to a simulator, proficiency checks will be overdue for some.

Start-up procedures will have to be carefully managed to ensure that public confidence in air travel, already at historic low because of the pandemic, is not further compromised.

At Rocky Mountain Aircraft we have some unique expertise at reactivating aircraft from years of improper storage or even abandonment. With our own aircraft back online we are happy to offer advice and assistance to enable our industry to soar back into the skys.

Time to reactivate - Sleeping Plane

Twin Otter Autopilots

It may appear that Twin Otters and autopilots don’t mix. That would be the conclusion you would come to looking at a survey of the number of Twin Otters with an installed autopilot. So what is the history and why do operators shun autopilots in the Twin Otter?

The first production aircraft left the Downsview factory with an option for the Honeywell H-14 autopilot. This system used large pneumatic servos to control the aircraft. This was a popular option at the time however as the aircraft and autopilot aged the maintenance involved in keeping the system serviceable resulted in many operators disabling or removing the system. Other approved autopilot options followed, the Bendix M4-C, Collins APC-106 both these systems while having dispensed with the pneumatic systems and being fully electric still required regular scheduled maintenance to keep them airworthy, the regular overhaul of the servo’s being particularly onerous.

The last autopilot system introduced by DeHavilland was the Collins APS-65. Introduced in 1989 the APS-65 was one of the last analog autopilots designed prior to the shift to digital. This highly capable autopilot had one main drawback, it was hugely expensive and thus not a popular upgrade or option.

For operators requiring an autopilot, a retrofit autopilot was introduced by S-TEC, the System 65, this is a basic two-axis autopilot a lot less capable than the APS-65 but at a fraction of the cost. The System 65 has become the “go-to” autopilot for operators who need an autopilot since it was first certified in the
Twin Otter 25 years ago.

New state-of-the-art retrofit autopilots are being certified in many different airframes at an incredible rate.

Manufactures like Avidyne, Garmin and Genesys (S-TEC) are regularly expanding their approved model lists. The capabilities of the new digital autopilots compared to their 50 year old predecessors is vast, modern autopilot do much more than keeping an aircraft on a preset heading and altitude. They can almost fly the aircraft independently from take-off to landing. That capability should not be taken lightly. A pilot must still be completely aware of exactly what it is the autopilot system is or isn’t doing.

So why are these maintenance free, inexpensive, multi-function, safety enhancing autopilots still missing from Twin Otters?

It appears we have a chicken and egg situation here, no autopilot manufacturer is investing in a Twin Otter approval because there is no perceived demand among operators, but there is no demand because there are no systems available.

So who will break this impasse, which manufacturer will be the first to follow the “if you build it they will come” philosophy?

Well, the answer is Genesys Flight Systems who will be certifying their 3100 digital autopilots on one of Rocky Mountain Aircraft’s Twin Otters. Installation and approval are expected by the summer of 2020. A full review of the installed system, its performance and capabilities will be posted on this blog. Stay tuned.

Modern Technology – a Lifesaving Backstop in Aviation

Rocky Mountain Aircraft had staff attending Heli-expo in Anaheim this week.

Why would a company specializing in Twin Otter and other similar twin turbine aircraft attend a rotorcraft convention you may wonder? Well, plenty of equipment designed specifically for rotorcraft can be a great fit for the special mission Twin Otter conversions that Rocky Mountain Aircraft excels at. FLIR systems multi-mission audio, tactical radio suites, night vision cockpits for example, that started off exclusively for rotorcraft have been STC’d into Twin Otters.

Garmin Integrated Flight Display
Installed Garmin Integrated Flight Display

There was a lot of talk and speculation at the convention about the tragic crash that killed Kobe Bryant, his daughter, and seven others. While the cause of the accident is still under investigation, the lack of a terrain awareness system (TAWS) on the helicopter could have been significant.

The TAWS systems, mandated for the majority of commercial aircraft, are tried and trusted technology credited with saving hundreds of lives. It is also comparatively cheap to retrofit. A California congressman has now introduced a bill to make TAWS mandatory in all helicopters. What will it take before all aircraft owners and operators voluntarily carry out safety audits on their aircraft?

Universal Avionics Terrain Awareness (TAWS) Display
Universal Avionics Terrain Awareness (TAWS) Display

Modern avionics have made flying safer than ever, terrain awareness, traffic and collision avoidance systems, large graphical displays for situational awareness, real-time weather information have significantly reduced accident rates.

The latest generation of digital autopilots with their envelope protection, unusual attitude recovery, straight and level functions are so advanced compared to the old analog autopilots it’s like comparing a Sony Walkman to an iPhone 11. Automatic landing autopilots, in the case of pilot incapacitation, are now being introduced to the market.

While pilot training, proficiency, flying skills and good decision making along with a properly maintained aircraft are always going to be the primary safety feature of any flight. In the event of failure, modern technology should always be installed as the lifesaving backstop.

Garmin Product Announcements

Garmin came out of the starting blocks strongly in 2020 with two big product announcements.

First was their fourth generation navigator, the GTN Xi series. Powerful dual-core processors boost the GTN Xi series graphical display capabilities — with faster zooming, panning, and map rendering on the display. With almost double the pixel count of its predecessor, the GTN Xi series features wider viewing angles and one of the highest-resolution displays ever offered in this class of avionics.

Image of Garmin - GTN-750Xi
GTN-750Xi

Within a week, another product introduction. Garmin introduced the GI 275 Bright, reliable, high-resolution touchscreen instruments that offer all-purpose digital upgrades from traditional round mechanical instruments. As your primary flight reference instrument, GI 275 features an integrated display to support all the essential readouts — attitude, altitude, airspeed, and heading. Configurable for a multitude of functions

Image of  Garmin - ADI with Autopilot Integration

ADI with Autopilot Integration

For select aircraft and glass cockpit systems, GI 275 can function as a standby flight instrument with MFD capability2 for mapping, traffic, weather and more

Image of Garmin -  MULTIFUNCTION DISPLAY
Multifunction Display
Image of Garmin- Animated Nexrad
Animated Nexrad

ANIMATED NEXRAD

When paired with an optional GDL® 69 SiriusXM® receiver, the MFD-configured GI 275 offers display capability for satellite weather coverage with graphical NEXRAD imagery.

Image showing Garmin - Wireless Data Streaming instrument
Wireless Data Streaming
Image of Garmin - Radar Altimeter
Radar Altimeter

RADAR ALTIMETER

For applications that require precise tracking of aircraft altitude above the terrain, GI 275 can provide display capability for select radar altimeters, including the Garmin GRA™ altimeter series.

WIRELESS DATA STREAMING

Use built-in wireless connectivity to share data between the GI 275 and compatible mobile apps. Import databases. Stream weather, traffic, attitude information, EIS and more4.

Image of Garmin - Moving Map
Moving Map
Image of Garmin -  traffic and weather mapping
Traffic and Weather

MOVING MAP

Within the MFD configuration, a dynamic moving map page offers views of terrain features, airports, airspace boundaries, navaids, flight plan routings and more.

TRAFFIC AND WEATHER

With select ADS-B “In” datalinks, GI 275 MFD pages will support subscription-free U.S. weather and traffic displays, including TargetTrend™ and TerminalTraffic™ technologies.

As an approved dealer for Garmin, Rocky Mountain Aircrafts Avionics team can get you set up with the right configuration to support your aviation needs. Contact Us to see how we can help.

Transitioning from Radar to ADS-B

What is ADS-B you ask;

  • Automatic in the sense that it operates without external stimulus (unlike radar)
  • Dependent in the sense that the surveillance information is derived from onboard systems
  • Surveillance in the sense that it’s primarily intended to provide surveillance information to other parties
  • Broadcast because it transmits to all listeners without knowing who those listeners are, there is no two-way communication

The capability of an aircraft to transmit ADS-B signals is called ADS-B OUT, the capability of an aircraft to receive ADS-B signals is called ADS-B IN. The Garmin GTX-335 is an example of an ADS-B OUT only transponder, while the GTX345 is ADS-B OUT and ADS-B IN.

ADSB-how-it-works for ADS-B - Transitioning from Radar
ADSB-how-it-works – from FAA

ADS-B data contains information about the identity, position, altitude, and velocity of the aircraft. The position and velocity information is derived from GNSS (GPS).

ADS-B is a surveillance technology whereby the aircraft broadcasts information about its identity, position, altitude, and velocity of the aircraft to any interested party. The position and velocity information is derived from GNSS (GPS).

TCAS

ADS-B is not intended to replace TCAS, although in the future it will augment TCAS. The TCAS algorithm currently only uses distance and altitude to calculate whether there is a conflict and to determine the best conflict resolution strategy. With the more accurate ADS-B position available to the system as well, the number of TCAS interrogations can be reduced (the surveillance radio frequencies are getting congested in some areas) and the performance of TCAS can be improved. A new standard for this hybrid approach was published in 2013.

It may also be possible to have a passive TCAS-like system that does not require active interrogation but is purely depending on ADS-B. Currently, a technical standard for a new Airborne Collision Avoidance System (ACAS, the generic name for TCAS) is being developed in a joint RTCA / EUROCAE committee (RTCA SC-147 / EUROCAE WG-75), which will take advantage of more data offered by ADS-B. This new standard will eventually replace TCAS II.

ATC

The purpose of ADS-B is not to replace ground-based ATC. It will change the way ATC is done. ADS-B IN will improve the situational awareness of pilots; they will have a display of accurate positions of other aircraft. New procedures will allow pilots to maintain separation from other aircraft in marginal Visual Meteorological Conditions (VMC), where they currently would often lose sight of other traffic. More advanced usage of ADS-B will be flight deck based interval management (FIM) where ATC will be able to instruct aircraft to ‘follow that plane XX seconds behind for landing on runway YY’.

ADS-B is not a replacement for all radars, although it will allow the number of radars to be reduced. For remote areas that currently do not have radar coverage because of the associated high costs, ADS-B will be a cost-effective alternative.

The display of ADS-B IN requires a compatible cockpit monitor. The Garmin GTN series of navigators can display ADS-B targets blended with TCAS whereas older models of navigators and MFDs will only display TCAS traffic. The Garmin GTX-345 contains a built-in Bluetooth transmitter that can broadcast ADS-B traffic information to a handheld cockpit display such as an IPAD.

Canadian Maintenance Organizations (AMO’s) are approved under a bilateral agreement between the FAA and Transport Canada to complete ADS-B installations and return n-registered aircraft to service.

Rocky Mountain Aircrafts Avionics team can keep you equipped to stay airborne in 2020. Contact Us.