Saturday, 31 December 2016


The hits recorded on the Aerobility Safety Blog now number close to 4500, and our analysis reveals that a significant number of these have originated from outside the UK, covering a large area of the world, from the Americas through Europe to Russia and the Far East.

This is most encouraging, but indicates that some explanation may be needed for those of you who are unfamiliar with what Aerobility is all about, and so a brief resume follows below.

Aerobility is a UK-based Charitable Trust whose objective is to provide opportunities for life-enrichment to those who live with disability of whatever kind and however caused, so that they can enjoy aviation-related experiences which they perhaps believed were beyond attainment, or which they had not even considered possible. Flight operations are centred at Blackbushe airport (EGLK) to the South-West of London, with other UK areas covered as and when needed.

The organisation is managed on a daily basis by people who from personal circumstance are fully conversant with both disability and flying, supported by a small permanent Administrative Staff, Certificated Flying Instructors, and a team of Volunteers. Our work is largely funded by personal donation and Corporate sponsorship, and we are proud to provide services both to individuals and on behalf of several major UK fund-raising Charities dedicated to helping disabled children or adults, and injured ex-military personnel.

Our range of activities includes amongst other things:
  • ·       One-off ground-based group sessions to introduce aviation to children with physical disabilities or learning difficulties, either self-funded or sponsored by major Organisations which share our ideals and support us in delivering them
  • ·        Multi-session group education programmes for young-person or adult groups, which include ground-school topics and flying experiences both actual and simulated
  • ·        One-off first-flight experiences for individuals from all age-groups using our fleet of training aircraft, available with flight control modifications and full hoisting facilities where needed by those without full use of their lower limbs
  • ·       Full flight training to PPL level for adults with disability. Much of this training is  funded by bursary or scholarship awarded by our Sponsor-Partners

The work involved is highly satisfying and rewarding for us, as we see every day great improvement in self-confidence, social and communication skills and potential exhibited by our service-users.

The above is only meant as a brief outline, and any of you who would like to learn more about us can do so by visiting our main site at

This Safety Blog is simply an add-on intended as a supplementary pool of knowledge and experience derived from various sources, principally for those learning to fly, but also serving as an aide-memoire for those who might require the occasional memory-nudge! So please keep logging on every so often, and trawl back through the various articles, which could one day prove useful to you.


Wednesday, 14 December 2016


Acknowledgements: GASCO Flight Safety/CFI Adele Stephenson

Unlike in commercial aviation, where such things are generally prepared for the pilot by others, the private pilot needs to spend a considerable amount of effort and thought in order to determine a safety altitude for each flight.

The chances are, if the pilot wants to short-cut the process he or she will nominate a height which is too high (“Oh well, two thousand feet will do!”).

So when the unexpected weather appears ahead, what about that 2000 feet? It gives a good margin above high ground and obstructions, so why not slip below it for a bit to see how far ahead this weather extends?

This is the danger point, since once the decision is taken to descend below your nominated safety altitude there are no further limits; only collision with high ground or obstructions. So once you have descended to your nominated safety altitude that is exactly what it is. Either maintain it, or initiate your Plan B. (Ed. Note: You do have one, right?). Return or divert, without any messing about or “ducking below”!

So, your planned safety altitude has to be:
·         realistic, so that it removes all temptation to ignore it
·         set below your cruising altitude (this may seem too obvious to mention, but the advice “if you are lost, climb to your safety altitude … “ is known to have been uttered by at least one instructor! But why would you be flying below it in the first place, even in clear conditions?

There are so many things to consider in advance throughout your planned route, both to destination and selected diversion point, including:
·         the Law
·         low flying restrictions, for noise abatement or any other requirement
·         specified minimum altitudes over built-up areas
·         clearance above charted obstructions
·         high ground
·         topological up-draughts & down-draughts, which have adversely affected many a light aircraft
·         is your flight routed upwind of or on the lee side of high ground?
·         do you need to work to different safety altitudes for different sectors of your flight?
·         how far on either side of your planned track do you need your safety altitude to cover in order to account for divergence?

The time spent in pre-flight consideration of the ground conditions over which and close to which you will be flying will be well-spent in the event of need, so please give your safety altitude the respect it deserves, and once off the ground discipline yourself to honour it - it may even save your life!


Monday, 5 December 2016


Acknowledgements: AOPA & David J. Kenny
Fans of the British comedy troupe Monty Python share a particular fondness for the character of Ron Obvious, the first man ever to try to jump the English Channel. 
“How far is it across the Channel?” asks an interviewer (John Cleese).
“Oh, about 21 miles from Dover to Calais,” replies Mr. Obvious (Terry Jones).
“And what’s the farthest you’ve managed to jump in practice?”
“A little over six feet.”
Sure enough, the record jump attempt proves … anticlimactic!

The sketch provided a particularly sly reminder that willpower and optimism come out second best when they take on the laws of physics.

In general aviation, this is proven the hard way year after year by a tiny minority of aviators who feel that an immediate need to complete the flight outweighs the very real risk that they won’t. Making the attempt in the face of known mechanical problems, hazardous weather, or simple inexperience can vastly increase the cost of not reaching that destination.

Consider the following accident report and decide what you would/would not have done ……

The Cessna stopped for fuel at Columbia, Missouri on the way from Jackson, Tennessee to Sioux City, Iowa. It took on 26 gallons. While on the ground, its pilot called to get a weather briefing for the final leg. The briefer advised that Sioux City was IFR and expected to remain so. Low clouds covered much of the route, including northern Missouri and western Iowa, with tops reported between 2,500 and 4,500 feet. Weather in eastern Nebraska was “beautiful,” but instrument conditions also were expected to develop there around his ETA; temperature/dew point spreads were already narrow and decreasing. The pilot responded that his job and vehicle were in Sioux City, so the briefer identified Wayne, Nebraska, 28 nautical miles west-southwest, as the nearest airport reporting clear conditions.

They discussed the option of flying VFR over the cloud deck, but because the pilot was not instrument rated, the briefer suggested flying northwest to Kansas City, then turning north on the west side of the Missouri River. He also recommending stopping at Omaha to reassess the situation. The pilot replied that he’d decided to fly direct to Sioux City above the clouds, diverting to Wayne if conditions required. The briefer advised him to get weather updates en-route and provided him with a list of the appropriate frequencies.

The Cessna took off at 3:40 p.m., an hour and a half before sunset. The moon had gone down in mid-afternoon. The pilot requested and received flight following. Around 6:30 he reported clear skies and good visibility above the clouds to the Sioux City approach controller. The controller asked him to “let me know when you get ground contact” and advised that Sioux City was under a 700-foot overcast. Wayne and Norfolk, Nebraska, still reported clear skies. The pilot responded that he was beginning his descent without ground contact, adding “I’m sure I’m getting fairly close,” and said he planned to land on Runway 36 at Wayne.

Descending through 2,000 feet, less than 600 feet above ground level, he still could not see the ground. The controller provided an updated observation from 10 minutes earlier that included a 200-foot scattered layer at Wayne. The pilot continued to descend, reporting negative ground contact at 1,800 feet. Acknowledgement of the loss of radar contact was the last transmission received from him.

The wreckage was found in a small area at the end of a short debris path, suggesting a steep angle of impact. The next METAR from Wayne, six minutes after the accident, listed the ceiling as overcast at 200 feet. Norfolk, another 25nm southwest, stayed clear with good visibility for two more hours.

If he’d recognized his peril, made a second diversion and landed safely at Norfolk, he might have learned a vital lesson in risk assessment. A VFR pilot flying over a low overcast has nowhere to go in the event of engine trouble, illness, or anything else unexpected. It only gets worse at night. If he’d chosen a route that got him as close to home as possible while avoiding the clouds, whatever it is he needed to do still might not have got done the next day, but at least he’d have had a chance to do it the day after.


Tuesday, 29 November 2016


For those who haven’t had the opportunity to read the whole thing, here’s a summary:

      Stay out of icing conditions for which the aircraft has NOT been cleared.

    Note freezing level in the aviation weather forecast. Don’t go unless the aircraft is equipped for the conditions.

    Have warm clothing available for pre-flight and in case of heater failure or forced landing.

    Mud, snow and slush will lengthen take-off and landing runs. Work out your distances in advance.

     Remove all frost, ice and snow from the aircraft – there is no such thing as a little ice!

      Check carefully that all essential electrical services, especially pitot heat, are working properly.

    Check that the heater and demister are effective. Watch out for any signs of carbon monoxide poisoning.

        Be extra vigilant for carb ice.

      If ice does start to form, act promptly, get out of the conditions by descending (beware of high ground), climbing or diverting.

       If you encounter ice, tell ATC so that others can be warned.

      During the approach if you suspect tail-plane ice, or suffer a severe pitch down, RETRACT THE FLAPS.

   If you have to land with an iced-up aeroplane, add at least 20% to the approach speed.

      Snow-covered, icy or muddy runways will make crosswinds harder to handle.



Airspace infringements continue to be one of the UK’s main aviation safety risks. The UK Civil Aviation Authority (CAA), through its Airspace Infringements Working Group, is currently working with industry to tackle the issue. The Group has issued a list of top ten tips to avoid an infringement:

1. Navigation is a skill which needs to be practised regularly, both in planning a flight and conducting it. Safety Sense Leaflet 5 (available on the CAA website and in the LASORS publication) contains good advice on VFR navigation, but it only works if you read and apply it!

2. If you plan a route through controlled airspace, remember that a crossing clearance may not always be possible and consider that route as your ‘secondary’ plan. Your primary plan should avoid controlled airspace - and don’t forget to make your overall time and fuel calculations using the longer, primary route!

3. Where possible, avoid planning to fly close to controlled airspace boundaries. If you do need to do so, be very careful. A small navigational error or distraction of any sort can lead to an infringement – and it doesn’t take much to ruin your day!

4. Pilot workloads rise rapidly in less than ideal weather - and so do infringements. If the weather starts to deteriorate, consider your options early and if necessary divert or turn back in good time.

5. If you wish to transit controlled airspace, think about what you need to ask for in advance and call the appropriate Air Traffic Control (ATC) unit at least 10 nautical miles or five minutes flying time from the airspace boundary. This gives the controller time to plan ahead.

6. Thinking before you press the transmit switch and using the correct radio phraseology helps air traffic control to help you - and sounds more professional!

7. Be aware that ATC may be busy when you call them – just because the frequency doesn’t sound busy doesn’t mean that the controller isn’t busy on another frequency or on landlines.

8. Remember - the instruction ‘Standby’ means just that; it is not an ATC clearance and not even a precursor to a clearance. The controller is probably busy, so continue to plan to fly around the airspace. Only fly across the airspace if the controller issues a crossing clearance.

9. Your planned route through controlled airspace may appear simple on your chart but the traffic patterns within that airspace may make it unrealistic in practice. Be prepared for a crossing clearance which does not exactly match your planned route but which will allow you to transit safely.

10. Don’t be afraid to call ATC and use the transponder when lost or uncertain of your position - overcoming your embarrassment may prevent an infringement which may in turn prevent an Airprox (or worse).



It’s that time of year again, so a summary of the CAA’s advice on the above ….

      Icing forms stealthily.
      Some aircraft/engine combinations are more susceptible than others.
      Icing may occur in warm humid conditions and is a possibility at any time of the year in the UK.
      MOGAS makes carb icing more likely.
      Low power settings, such as in a descent or in the circuit, are more likely to produce carb icing.
      Warming up the engine before take-off improves the effectiveness of any carb body heat.
      Use full carb hot air frequently when flying in conditions where carb icing is likely.
      Remember the RPM gauge is the primary indication for a fixed pitch propeller; manifold pressure for variable pitch.
      Treat the carb hot air as an ON/OFF control – either full hot or full cold.
      It takes time for the heat to work and the engine may run roughly while ice is clearing.
      Timely use of appropriate procedures can PREVENT THIS PROBLEM.

Finally, In the event of carb heat system failure in flight:

      Avoid likely carb icing conditions.
      Maintain high throttle settings – full throttle if possible.
      Weaken the mixture slightly.

      Land as soon as reasonably possible.


Wednesday, 16 November 2016


Acknowledgements:  FAA GA Joint Steering Committee Safety Enhancement Topic

Maintenance-related problems are one of the most deadly causes of accidents in general aviation. Contributing to this is a pilot’s failure to identify maintenance discrepancies because of a lack of knowledge and improper techniques used during the pre-flight of the aircraft.

In July 2014, the pilot of a Piper PA-12 Super Cruiser airplane was fatally injured after his airplane pitched up steeply during take-off and crashed. The investigation found that the elevator control cables were installed incorrectly such that the elevator moved in the direction opposite to that commanded. The pre-flight checklist for the airplane required the pilot to verify that the flight controls were free and correct. HE DIDN'T!

What the FAA Regulations Say …
·    The pilot in command of a civil aircraft is responsible for determining whether that aircraft is in condition for safe flight
·    No person may operate any aircraft that has undergone maintenance unless it has been approved for return to service and is logged as such in the aircraft records
·    An operational check flight is required for any maintenance that may appreciably change the aircraft’s flight characteristics or substantially affect its operation in flight

Advanced Pre-Flight …
This refers to the conducting of a pre-flight that goes beyond the normal pre-flight checklist. This is accomplished by obtaining a valuable maintenance history of the aircraft and developing an additional items checklist. While this requires some time, once you have developed the additional items checklist it can be used in conjunction with the aircraft’s pre-flight checklist for all future pre-flight inspections.

Some Tips for Advanced Checks …
  •      Become familiar with flight controls or systems prior to maintenance. It is easier to determine what becomes “abnormal” if you are familiar with how it should operate
  •      Locate and review all of the aircraft’s records, including additional documents such as receipts, work orders, Major Repair and Alteration forms, and approval for return to service tags
  •      Also locate any Supplemental Type Certificate (STC) data, including data on items no longer installed on or in the aircraft
  •      Coordinate with your mechanic before flying aircraft that have recently been maintained to get a clear determination as to what has been accomplished
  •      After maintenance, check all systems more thoroughly than the normal pre-flight checklist implies
  •      Pay particular attention to aircraft components that may have been affected by recent maintenance
  •      Avoid becoming distracted or being interrupted in the middle of the pre-flight to ensure you do not accidentally miss or skip a step
  •      Be prepared to abort take-off if something goes wrong or just doesn’t feel right

                                                   FLY SAFE!


Acknowledgements: FAA GA Joint Steering Committee Safety Enhancement Topic

Accident investigations have discovered causal factors resulting from unreasonable expectations of aircraft performance – especially when operating at the edges of the aircraft weight and balance envelope. That’s why the Loss of Control Work Group suggests improvement in pilots’ understanding and calculation of aircraft performance. When we speak of aircraft performance we’re usually answering three basic questions:
·            How much can I carry?
·            How far can I go?
·            How long will it take me?
It sounds simple, but a specific set of interdependent variables must be considered in order to answer each of these questions. Most of these variables have to do with aircraft performance, but the greatest variable does not.

Weight and Balance
·    Decide how much weight you want to carry to what destination. If crew, passengers and cargo alone exceed your aircraft’s capability, make multiple trips or get a bigger aircraft.
·   Once you know your payload, you will know how much fuel you can take and that, together with your weather information, will tell you how far you can go. If you have enough to get to the destination plus alternate and reserve, great. If not, pre-plan an en-route fuel stop.

Take-off and Landing Distance
·  Consider your departure and arrival airports’ runway lengths, obstructions, and expected density altitude. If the field is short and/or obstructed you may not be able to safely fly with a full load.
·     Just because the book says the aircraft can do it doesn’t mean you can do it. Pilot skill and experience count for a lot, so be conservative when you calculate your performance. Some pilots add 50% to their take-off and landing calculations for safety.

The Greatest Variable … the pilot!
The POH figures and all of our calculations don’t mean much if we can’t duplicate them in our flying. That’s why it’s important to document your performance capability at least yearly with an Instructor.
·   In order to know what performance you and your flying machine are (or are not) capable of you’ll need to establish a baseline which co-relates pilot and aircraft performance under a given set of environmental circumstances on a given day.
·    Human factors such as fatigue and environmental factors such as higher density altitudes will result in performance below the baseline,
·    Proficiency training and lighter loading will likely result in above baseline performance.
·   The key point to remember is that for any given flight you need to pre-determine how you and your aircraft will perform.
·  To establish your baseline, load your aircraft with a typical mix of fuel, cargo, and passengers. (We recommend that one of those passengers be your Instructor.) Calculate your test weight and note runway condition, elevation, density altitude, wind direction and speed.
·   Also note what rotation and climb speeds you intend to use and calculate 70 % of the rotation speed. More on that later.
·    Fly several take-offs and landings noting your performance on each trial. When you’re done you can average your performance figures and complete your baseline chart.

Rules of Thumb for Take-off Distance
·   For a fixed pitch prop, add 15% to your calculated take-off distance for each 1,000 feet increase in density altitude up to 8,000 feet (12% per 1,000 feet up to 6,000 feet for constant speed prop).
·   When planning take-off from short unobstructed runways, establish a landmark at 50% of your calculated take-off distance. On the take-off roll you should have 70% of your rotation speed at that point. If you don’t, the safest thing to do is to abort the take-off.
·    If your plan can’t meet the above requirement, reduce weight or wait for more favourable wind and temperature conditions.
·    If you need to clear obstructions on take-off, you’ll need to have 70% of your rotation speed by the time you’ve travelled 30% of your available take-off distance.

Approach and Landing
You’ll want to be stabilised on final approach with full flaps at 1.3 times the stalling speed in landing configuration. Don’t cut your final short. Make it long enough to be stable and go around if you’re unstable.