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Should We Keep 121.5 Alive?


Photo: CC BY-SA 3.0

Pilots are trained to use the radio frequency 121.5 in the event of an emergency. Emergency locator transmitters (ELTs) broadcast over 121.5 to notify search and rescue of a downed aircraft. FAA radio facilities, Civil Air Patrol, and often pilots monitor 121.5 as a way to receive distress signals. So why does the FCC, and subsequently the FAA and NTSB, want to ban something simple that could potentially save lives?

The answer lies in the advancement of modern technology – the increased use of the more accurate satellite-based 406 MHz ELT, and the decision of major search and rescue company COSPAS-SARSAT to cease monitoring 121.5 in 2009. But does the introduction of a more reliable system mean that everyone should be required to use it? And should we go so far as to ban the use of an emergency frequency so commonly known to help pilots?

Since 1973, the FAA has required almost all aircraft to have an emergency locator transmitter (ELT) on board. ELTs are small transmitters that emit a signal and provide a way for search and rescue (SAR) to locate a downed airplane, increasing the survival odds for a pilot and passengers. They can transmit on either 121. MHz or 406.025 MHz. It’s commonly known that the 406 MHz ELTs are much more accurate, but a good portion of the general aviation fleet still uses 121.5 MHz ELTs.

121.5 ELTs
Many ELTs commonly used in aviation are designed to transmit an analog signal over the frequency 121.5 when activated, allowing anyone that is monitoring the frequency to hear the distress signal and notify appropriate search and rescue teams. These 121.5 ELTs are inexpensive and simple to use, but they aren’t without their problems.

If an ELT is in the ‘armed’ mode, it will become activated during a crash and transmit a noisy alarm over the frequency 121.5. But sometimes a hard landing will set it off, or it can be accidentally activated during ground operations. More often than not, ELTs are activated in non-emergency situations, and ATC and operators spend a lot of time tracking down false ELT signals. In addition, finding the signal requires homing in to the strength of the signal – a difficult and inaccurate task when the signal accuracy is only limited to about 10 miles.

406 MHz
A 406 MHz ELT transmit a digital signal, which allows for a code to be transmitted along with the distress signal. This code has details about the aircraft, including its registration number and a point of contact.

406 MHz ELTs are more accurate, pinpointing the location of a downed aircraft to within one to three miles, decreasing the potential search area drastically from the of a 121.5 transmitter. And false alerts are less of a problem with 406 MHz ELTs, too, meaning authorities can act immediately upon receipt of a distress signal, instead of spending their time trying to determine if it’s a fake signal or not.

Why Ban 121.5?
It’s easy to see why the 406 MHz ELT is better. What’s less obvious is why we should ban the use of 121.5

The NTSB thinks that the use or 406 MHz ELTs should be mandated. In a 2007 Safety Recommendation letter, the NTSB described the downfall of 121.5 emergency locator transmitters and recommended that the FAA mandate the installation and use of 406 MHz transmitters in all aircraft before major search and rescue organizations COSPAS-SARSAT ceased its monitoring. They NTSB believes that without a mandate, pilots will refuse to upgrade to the 406 MHz units, making it more difficult on search and rescue and possibly creating undue risk.

The FAA agrees, but finds it more difficult to mandate. The Aircraft Owners and Pilots Association has stood strong against the 121.5 ban, saying that it’s too costly for the approximately 200,000 general aviation pilots to upgrade, and that the decision regarding which ELT to use should rest with the pilots themselves.

In the meantime, the FCC is also considering a ban on 121.5 ELTs. In 2013, they opened up a comment period regarding the banning of 121.5 ELTs, and again AOPA opposed in this letter, stating that the FCC needs to leave aviation safety matters to the FAA. It remains to be known if the ban will come into play, but pilots should expect it to happen eventually, and more importantly, for their own safety, pilots should probably just upgrade to the 406 MHz ELT of they haven’t already.

Could - or should - the ban of 121.5 ELTs mean the death of the 121.5 frequency altogether? After all, the frequency is used for more than just ELTs. It’s an emergency frequency in which a pilot can declare an emergency, and it’s still monitiored by FAA facilities, Flight service stations and the civil air patrol. And many pilots still monitor it, which can be helpful to other pilots and ATC if they do hear something on that frequency. And pilots are taught to switch to 121.5 if they’re intercepted for some reason, such as inadvertent flight through a prohibited area.

What do you think? Should we just accept that new technology is better than the old and move on? Or should we fight to keep 121.5 alive?

What’s in Your Airplane Emergency Kit?

Have you ever looked at the contents of your aircraft survival kit? Have you thought about what might actually be useful in an emergency, and what just takes up space and adds weight?

Most pilots probably don’t give much thought to the contents of their survival kit. It’s there in the back of the airplane – we check during the preflight - and that’s good enough, right? Maybe, but if you're actually stuck in the wilderness after a plane crash, you might wish you'd have given it more thought.

Not all commercially packed survival kits are created equal. And while those that we buy from the store are convenient, chances are good that if you were to find yourself out in the woods, you might find that the contents of these ready-made kits are often cheap and sometimes useless when it comes to actually surviving. Some of them come with a lot of fluff that you don’t need (tongue depressors?) and also lack critical items that you’d clearly want, like a good knife.

Next time you’re stuck on the ground due to icy weather this winter, make good use of your down time by reviewing the contents of your survival kit. Make sure the contents haven’t expired. Change out the batteries in flashlights and check that the ELT is operational and is in compliance with the FARs. Update your kit for any changes in flying habits you’ve made, making sure you take into account the routes you fly most often, as well as the other passengers you might be flying around. Just like your smoke detectors in your house, your aircraft emergency kit should be evaluated often.

Your aircraft survival kit should be tailored to you and your flying needs. You might need to consider weight, including only the very critical elements. You might need to consider water survival gear if you frequently overfly lakes. And if you’re flying in the Alaskan wilderness, your needs will be different than they would be if your flights were within 30 miles of your home airport in the Midwest. Think about your personal needs when putting together your survival kit. Here are a few of the basics that you’ll need.

ELT/PLB
The ELT and PLB are so important that they get their own category here. In the case of a plane crash, your chances of being located increase drastically if you have a working ELT (emergency locator transmitter) and/or a PLB (personal locator beacon). If you’re still flying with an old ELT that transmit on 121.5 MHz, consider getting a 406 MHz ELT. They don’t have the false alarm problem that the 121.5 MHz ELTs are known for, and they increase your chances of being found by a significant amount.

The aircraft you’re flying likely has an ELT installed, but it doesn’t hurt to fly with a PLB, too, which comes in handy if you want to leave the area on foot to try to find help. (It’s usually best to stay with the wreckage after an aircraft accident, by the way, especially if you’re unfamiliar with the terrain and area.) PLBs can be activated manually, and transmit on both 121.5 MHz and 406 MHz frequencies. These days, you can get a really good PLB for a couple hundred dollars – a small price to pay for a chance at survival.

In addition to an ELT, you’ll want to have these items in your emergency kit:

Survival Gear

  • Emergency Blanket
  • Canopy
  • Flares (or, better yet, and emergency strobe)
  • Duct tape
  • Knife
  • Firesticks
  • Rope

Food and Water

  • Food rations and other high-calorie protein snacks
  • Water bottles
  • Water purification tablets
  • Fishing kit

Medical Supplies

  • Bandages (various sizes)
  • Tape
  • Aspirin
  • Scissors
  • Personal Medications

Have you discovered any must-have emergency supplies? Share them with us in the comments!

178 Seconds to Live: A Personal Account of Spatial Disorientation


As a flight instructor, I've always considered myself to be a safe pilot. Bad weather? Not flying. Under the weather? We'll cancel.

So when I found myself in a real-life VFR-into-IFR scenario, I actually wondered how it could happen to me. I was able to get my bearings that night, but not all pilots are so lucky.

I'd always heard about this "VFR into IMC" phenomenon and how bad it was, but I was always under the impression that I wouldn't need to worry about it. After all, if a pilot gets a proper preflight weather briefing, why in earth would he or she fly into bad weather?

The day I flew VFR into IMC was a definitely a lesson in weather and personal minimums and hazardous attitudes, but for me, it was also a blunt reality check. I had comfortably flown hundreds of hours in the Cessna 172, I had a lot of night time, cross country time, multi-engine time, IFR time, and apparently just enough instructor time for me to get slightly over-confident.

I was about to take two private pilot students up for a night flight when I realized I wasn't night current. I decided to start up the Cessna 172 and do my three full-stop take offs and landings before the students arrived. I checked AWOS first, and noted that the temperature/dew point spread was close - within three degrees- but a look at the clouds and sky told me it was a beautiful night.

During the first turn in the pattern I noted that the clouds were, indeed, lowering, and that maybe I should pay closer attention to the temperature and dew point. But it was the second take off that provided the reality check I apparently needed.

I turned crosswind, staying at about 800 feet AGL instead of the usual 1000 feet. I could see the ground, the buildings and lights, but was skimming the bottom of the clouds, and at one point went into IMC. Although brief, it was enough to disorient me. In what I suppose was an attempt to stay below the clouds, I had inadvertently commenced a turning descent during the crosswind turn.

I didn't notice until maybe a minute or two later, when I began a turn downwind and heard the sound of increased engine RPM. It sounded as though I'd increased power, but a quick check of the throttle indicated I hadn't. I knew something wasn't right. The engine sounded louder, faster. Thankfully, my brain was quick enough to tell my body that I was in a descent, headed quickly toward a "controlled flight into terrain" scenario that I'd read about in accident reports.

I was able to land safely that night but not every pilot is as lucky as I was.

An FAA publication from 1993 describes a study in which 20 student pilots flew simulators into instrument weather and all of them "went into graveyard spirals or roller-coaster like oscillations." The time until loss of control after entering IMC varied between 20-240 seconds, with the average being 178 seconds.

This harrowing video made by the Civil Aviation Safety Authority (CASA) shows a common scenario in which a pilot might only have 178 seconds to live after flying VFR into IMC. It's a somber reminder for all of us flying around out there:


Source: 178 Seconds to Live: Spatial Disorientation can be a Killer, by Verdon Kleimenhagen, Ron Keones and James Szajkovics of FAA, and Ken Patz of MN/DOT Office of Aeroanutics, FAA Aviation News, January/February 1993.

Aircraft Spins 101


Photo: H. Rabb/Wikimedia
As mentioned in my previous article on stalls, accidents that occur due to stall/spin scenarios are more fatal than others. According to an AOPA study, stall/spin accidents have a fatality rate of about 28 percent, higher than the overall average fatality rate of 20 percent.

A spin occurs when an airplane stalls in an uncoordinated or aggravated state. If a recovery is not initiated after an uncoordinated stall occurs, the wing that is more stalled than the other will drop and the nose will follow into a spiraling descent. The aircraft will descend rapidly in a corkscrew motion.

According to the Jeppesen Private Pilot Manual, a small airplane will descend about 500 feet for each turn in a spin, so there's not much altitude or time available for a recovery in many cases. Considering stalls and spins often occur at low altitudes to begin with, it's clear why the fatality rate is higher for these accidents.

Stages of a Spin
The FAA has outlined three stages for spins in light aircraft: incipient, fully developed and recovery.

  • Incipient: The incipient phase of a spin is the stall and spin entry, up to about 2 turns in the spin.
  • Fully Developed: When the airspeed and rotation stabilize, the spin is considered fully developed.
  • Recovery: Recovery occurs when the pilot applies rudder and aileron inputs to counter the spin and the aircraft regains lift and control function. Once the inputs are initiated to stop the spin, the aircraft can usually recover in less than one spin.

Types of Spin

  • Erect Spin: Erect spins are the most common type of spin, occurring when the aircraft rolls and yaws in the same direction and the aircraft is upright and in a slightly nose-down attitude.
  • Inverted Spin: An inverted spin occurs when the aircraft spins upside down and yaw and roll occurs in opposite directions.
  • Flat Spin: Getting its name from the flat-like pitch attitude, the flat spin occurs when the aircraft spins at a level pitch attitude around the vertical axis as a result of a yawing motion alone. Flat spins are the most difficult to recover from (and just as difficult to enter in some aircraft!)

 

Spin Recovery
Spin recovery should be initiated at the first sign of a spin. Recovery procedures are specific to the aircraft flown and are found in the pilot operating handbook of each aircraft. In light aircraft, the spin recovery procedures follow a typical pattern and can be remembered by the common acronym PARE.

P - Power: The throttle should be moved to the idle position to reduce thrust.
A - Ailerons: Ailerons should be neutralized.
R - Rudder : Full opposite rudder input should be applied until the rotation is stopped. If the aircraft is rotating to the left, right rudder should be applied. Once the spinning stops, the rudder should be neutralized.
E - Elevator: Quick forward pressure should be applied to break the stall and gain airflow over the wings. Once the aircraft gains lift, back pressure should be applied gradually so as not to stall again.

Training aircraft are stable by design. They're meant to recover from unusual attitudes without much external control input from the pilot. A Cessna 172, for example, is actually somewhat difficult to perform an intentional spin in. But this doesn't mean that pilots of training aircraft are immune to spins.

While intentional spins are not always demonstrated during training, stall and spin awareness should always be emphasized with flight students. Many pilots tend to become confident in stall recovery, but all pilots would be wise to remain familiar with spin entry characteristics and recovery procedures for their specific aircraft.

How Well Do You Know Your Stalls & Spins?


Image: Theresa Knott/Wikimedia Commons

For new flight students and passengers, an aircraft stall can often be a source of fear. What is a stall? Will the airplane fall out of the sky? Does the engine quit?

And while stalls shouldn't be something that pilots fear, they should be taken seriously. Aircraft stalls and spins remain a leading cause of general aviation accidents - causing ten percent of general aviation accidents, according to one AOPA study. And stall/spin accidents result in more fatalities than other types of aircraft accidents. Private and commercial pilots are most likely to enter a stall, while student pilots and ATPs are less likely to stall, according to AOPA.

A 2012 advisory circular claims that loss of control accidents are a growing problem and that inappropriate reactions to stall indications are part of that problem.

What's a Stall?
Let's start with the basics. For those of you non-pilots, you need to know that an aircraft stall has absolutely nothing to do with the engine (unless we're talking about compressor stalls - an entirely different topic). Instead, an aircraft stalls when the airflow over the wing is disrupted enough to cause a loss of lift.

Stalls are dangerous because control surfaces become inadequate to control the flight, and if a recovery is not initiated, the aircraft will quickly lose altitude. And then there's that deadly spin: If uncoordinated, a stall can develop into a spin.

The FAA defines an aircraft stall as "an aerodynamic loss of lift caused by exceeding the airplane’s critical angle of attack."

The critical angle of attack is the key phrase here. The angle of attack is the angle between the chord line of the wing (an imaginary line running from the leading edge of the wing to the trailing edge) and the relative wind. The critical angle of attack is the angle at which maximum lift is produced. An increase in the angle of attack beyond the max coefficient of lift results in a loss of lift, airflow separation over the wing and a subsequent stall.

An aircraft can stall at various airspeeds, altitudes, pitch attitudes, configurations and weights. But the critical angle of attack must be exceeded for a stall to occur.

Types of Stalls

  • Power on stall: A power-on stall occurs during situations in which the aircraft power or thrust is increased quickly, such as during takeoff. Power on stalls usually occur (not always) with gear and flaps up.

  • Power off stall: Power off stalls occur when the aircraft power is decreased or at idle, such as during landing. Power-off stalls tend to occur with gear and flaps down.

  • Elevator trim stall: If the pilot disregards the elevator trim setting, any abrupt change in power or configuration can initiate a stall. This can happen easily during takeoff or go-arounds, when the aircraft trim tab is adjusted for the descent and a go-around is initiated. The aircraft can pitch up quickly and unexpectedly to a high angle of attack.

  • Cross controlled stall: A cross-controlled stall is one of the most dangerous types, as it's an uncoordinated stall and easily transitions to a spin. A cross-controlled stall occurs when the pilot inputs aileron control in one direction and rudder pressure in the opposite direction. Cross controlled stalls are known to occur during turns in the traffic pattern.

  • Accelerated stall: When excessive loads are placed on the airplane (such as during steep turns), an aircraft is capable of stalling at a higher airspeed and/or a lower pitch attitude than the pilot might be accustomed to.

  • Secondary stall: Secondary stalls occur if a pilot attempts to recover from a stall too quickly by pitching up to recover from the dive before obtaining an appropriate airspeed and generating enough lift.

  • Deep stall: Also called a super stall, the deep stall happens in T-tail aircraft, like this Piper Lance II or this King Air 350. It occurs when the airflow over the wing is disrupted and airflow over the tail of the aircraft is also disrupted, rendering both the ailerons and elevator/rudder ineffective at the same time. In a deep stall, recovery is difficult and sometimes, impossible.

Spins
An uncoordinated stall can result in a spin. According to the FAA Airplane Flying Handbook, a spin is an aggravated stall that results in autorotation - a downward corkscrew motion.

The spin is a result of one wing being at a higher angle of attack than the other, often descried as one wing being "more stalled than the other." The difference in angles of attack creates lift on the less stalled wing and drag on the more stalled wing.

Spins are more difficult to recover from, as altitude is lost very quickly and control surfaces may react different than the pilot expects, which is why it's important for pilots to continuously practice stall and spin recovery.