• Saturday Science

I happened to be out on the back porch fiddling with my camera when an aircraft flew over, so I fired off a few frames.

Later, looking at the images in Apple's great iPhoto program, the n-number (registration) on the side of the aircraft tickled a few neurons, and I wondered why. A quick check of the FAA registry told me it was owned by someone in Coronado, and Google told me he was an air traffic controller. No help.

So I googled the n-number and out popped an NTSB report that the aircraft "was substantially damaged" in a landing accident at Hyde Field in 1976. Ah-hah!

I flew out of nearby Oxon Hill airport back in the early '70s when the Navy sent me to work at the Department of Defense Computer Institute in Washington DC. Sure 'nuff, a check of my log book revealed I have 5.7 hours in N3430T in late 1973.

So I asked a friend who works for the FAA to forward the picture and the 'small world' history to the owner via agency e-mail.

Then I started wondering if maybe I'd put whoever was flying it on report by mentioning the aircraft had flown low over the neighborhood and when.

How low, I wondered. Is there any way to tell from the picture? Turns out there is.

Virtually all digital cameras store EXIF data along with the image information. That's short for Exchangeable Image File. Information such as shutter speed, F-number, focal length, ISO number, date and time the image was taken, white balance, lens that was used, resolution, and other details are all saved with each image.

If I have the actual focal length (my darling gave me a fantastic Nikkor zoom lens so it might have been anything from 18 to 200mm), and if I know the size of the aircraft (google knows), I can compute it's distance using a simple ratio.

The image size (IS) of the object in the frame is to focal length (FL) as the object size (OS) is to object distance (OD). In other words


Solving for what we don't know, object distance (OD) we get


So I loaded the image in Photoshop, used the ruler tool, and found the aircraft's image size (744 pixels in 3008 pixel image). The focal length was 200mm, and the size (length) of a Cessna 177 Cardinal is 8.22 meters (27 feet). Do the math, and the bird was 262 meters away.

That's a slant range of 860 feet. If he'd been directly overhead he'd have been 860 feet above the ground. If he'd been level with me he'd have been zero feet above the ground.

We could do some more measuring and more math to determine exactly what the angle was, but let's estimate it at 60 degrees. Now with Pythaogras' help, all we have to do is solve a simple geometry problem, with a little trig thrown in [sin (60 degrees) * h], and what you find is that the aircraft was at about 750 feet.

That's higher that I thought (I guessed about 500-600'), but nevertheless slightly lower than is legal over a populated area (1000'). To be charitable let's say that with measuring error on my part and instrument error on his part—he was close enough for government work.

So what does all this prove? Well, for one thing, don't believe everything you think. Humans are notoriously bad observers and even worse estimators. And if you're a pilot, keep in mind that even a backyard photographer can catch you busting the regs.

You might also conclude that I've effectively proven I have far too much time on my hands.

• Air Pilot Killed At Biddenham

Bedfordshire Times and Independent - Friday 20 August 1920

About 8.20pm on Monday night, an aeroplane, which had been near Biddenham some time, was taken up by its pilot, accompanied by a mechanic. When about 100 feet up the engine stopped and the plane began to descend. In attempting to avoid a barn it crashed.

The pilot, James Gordon Riley, aged 21, of 5, Oak Tree Avenue, Palmer’s Green, London N., was jammed in his seat owing to the front of the engine being crushed in. He received severe head injuries.

Mr Blick, of Ford End road, was first on the scene, and was shortly joined by two of the Beds Constabulary, who were on the riverside patrol at Honey Hills.

The mechanic, named Hamblin, of Brixton, also received injuries about the head. He was the first to receive attention, and was conveyed by boat to Kempston Mill, and later to the County Hospital. The pilot was then removed, and died about five minutes later.

The plane was one of those belonging to the By-Air Co., of Coventry, who were giving passenger flights a few weeks ago.

The first machine sustained damage and this was the second which, it will be remembered, came to grief in a field of growing corn belonging to Mr R Whitworth. It had to wait for removal until the corn was cut, and this accomplished.

Mr Riley and his mechanic got to work upon the machine. On Monday evening we believe it was their intention to fly to Hendon.

The inquest was opened by Mr Gregory Whyley at the ‘Three Tuns’, Biddenham, on Tuesday afternoon.

Riley, a bank clerk, living at the same address as the deceased, identified him as his brother, a civil airman and a shareholder and pilot in the By-Air Co. He took his certificate in 1917 and had served in the RAF.

The inquest was adjourned for a fortnight in order to enable the evidence of the mechanic, who is the only witness who can throw light on the mishap, to be taken.

In a follow-up article covering the inquest proceedings some additional details emerged.

William Roe, of Coventry Road, Bedford, described how on Aug. 16th about 8.15pm, he was in a stubble field at Biddenham, when he heard the engine of an aeroplane. He crawled through the hedge, and saw an aeroplane in the field.

The pilot tested the planes, and then the machine started off. It went about 100 yards along the ground before it began to rise, cleared the hedge, and went up towards some sheds. Near the sheds it circled. It was about 60 or 70 ft up. It then seemed to come down at an angle of 45 degrees. He did not see it strike the ground, as he was behind the hedge.

He ran to the spot, and saw that both men were seriously hurt. He obtained a bicycle and rode into Bedford for a doctor. The passenger, Corporal Hamblin, RAF, stationed at Uxbridge, recovered sufficiently to give evidence.

Mr Riley had wired him on Aug.13th to come to Bedford, and he came the next day. He worked for some time on the engine, which was lying in a field, and put in a new cylinder and piston. The machine was then in good order, except for filling up.

On the morning of the 16th Mr Riley assisted him in changing one of the ground wheels, and getting in stores of oil, etc.

Hamblin did not remember getting into the machine at the start, and had no recollection of what happened afterwards.

Mr Trevor Laker, of Coventry, formerly a pilot, gave evidence as to the history of the machine. He said he had got it down from Hounslow, after some trouble, to Lilbourne Aerodrome near Rugby. The water circulation failed, and he had a forced landing a Lilbourne.

After that the engine was thoroughly overhauled by their ground engineer, and he made several flights before he left the Company, the machine flying perfectly. He tested it on July 16th, when they were flying it at Kempston.

It was then (in his opinion) being flown badly, and he expected to see the pilot crash at any moment. He deduced that the tail trimming was out of order. He went to the field and found that Riley had made a bad landing, and bent his under-carriage.

Witness told Riley that if he made a similar mistake that would be his last. Finally Mr J W Batchelor, aeronautical draughtsman, Coventry, said the machine was passed as air-worthy in July. He had seen Mr Riley’s log book, which showed that he had spent 789 hours in the air, and had sunk a German submarine.

The aircraft involved - if it is the same one as was auctioned (Airco DH6, ex C7815) – did not fly again. Records show that it was withdrawn from use at this date and the registration cancelled. Beyond this little is known as to how the sale went, however two papers in the same file as the poster give some clues ... and raise some questions.

The first is a short note from a Superintendent at Bedford Police Station to Mr Mr H Peacock (Auctioneer in Bedford), dated 1st September 1920. It reads ...

"Dear Sir, I received a request from Mr Whitworth yesterday to move the Aeroplane from his field, as he wanted to put horses in. I did so and it is now at the rear of the “Three Tuns”, Biddenham, as it is a better place and it will not be tampered with. When allowing permits to view kindly put “Three Tuns” instead of Mr Whitworths farm, Honeywells. This is also an easier place to find. I see by this mornings paper that Aeroplanes sold very badly at Cambridge but I should think that probably there were a lot for sale."

The second is a typed letter (carbon copy) from the auctioneers, dated 31st January 1921, to O Bach, Esq. Aberlady NB (near Edinburgh).

"Dear Sir, We offered your Aeroplane last week but were unable to get any bidding at all for the same. We offered it again last Saturday, after advertising, and have sold it for £6, and will render you the account on Wednesday. Yours faithfully / (unsigned)."

The reference to the pilot's WW1 service record in reputedly sinking a submarine is interesting.

It is a little known fact that in the last year of the war the DH6, which had been specifically designed as a trainer, was adapted for use as a submarine hunter and may therefore have been a type on which he had some considerable experience.

DH.6 must hold the record for the number and variety of disrespectful epithets. The “sky hook”, a favorite of Australian airmen, probably referred to its lack of speed, although the shape of the exhaust pipes has also been mentioned. Other nicknames for the type included "crab", "clockwork mouse", "flying coffin" and "dung hunter" (these last two on account of the shape of the plywood cockpit - thought to resemble either a coffin or an outside toilet). The type’s unforgiving nature was probably behind yet another nickname, the "clutching hand", although this may also have been associated with its notorious lack of speed.


Here's a nice piece written in 2003 by a friend for his folks back home. 

I promised to talk about the "sandstorms" we encountered. I finally have time to keep that promise. Seems that supporting all those ground troops with our flights has kept me away from e-mail a bit. I have caught up, so here we go...

I had a mission that took us to the west coast of the Persian Gulf. I'd seen the news networks on the ship's satellite TV that there was a "big sandstorm" approaching from both up north in Iraq and to our west in Saudi Arabia. The news agencies typically will sensationalize things out here, so I didn't pay much attention to it.

Our weather brief before the flight mentioned reduced visibilities on the beach, but that wasn't uncommon as the winds had been blowing fairly hard over the past month. We refer to the "beach" as our divert airfields should we have a situation where landing on the ship isn't preferable. I realized before we took off that there was some windy and bumpy weather to be encountered on my flight as well as a possibility of some reduced visibility. No worries though, we are trained for this stuff and there wasn't anything to indicate that we would have any problems.

After my night catapult off the ship I climbed through some turbulence and got on top of what appeared to be a "haze layer" that was similar to what we have had for the several weeks prior. The moon wasn't very full so it was very dark... so dark that there was no horizon. We are trained to handle this so it didn't bother me or my wingman. As we conducted our mission, I could see that there was something interesting about the ground below. The oil rig lights and fires below were getting more and more dim, with a brown glow. Oil rig fires are normal as they are a process of burning off the unusable gasses from the "stuff" being harvested from the underground wells. I didn't think too much of this as the haze and some suspended dust from the dessert is a common weather pattern here.

Mission complete, time to return to the ship. We transited back home and did everything normal. Once on approach I could hear on the radio that the jets in front of me couldn't see the ship at the normal 3/4 mile 'ball call.' The 'ball call' is 15-20 seconds before you touch down on the back of the ship. The LSO (Landing Signals Officer) was having to verbally talk the pilots down to the back of the ship until they got close enough to see it. The LSO was able to see the light of the airplanes, determine glideslope and relation to runway centerline and therefore talk the pilot into the wires (arresting wires on the ship). The pilot is extremely busy controlling the airplane as well as looking at his instruments and typically doesn't pick up the ship in bad weather as quickly as the LSO can see the plane.

Once it became my turn to 'call the ball' we also didn't see the ship. We called 'CLARA,' meaning I don't see the ship or the visual glideslope reference. The LSO then gave me a good cadence of calls that told me where I was on the glideslope and centerline. I flew for about 10 seconds and then suddenly before me, I saw the lights of the ship. I called, "Ball" over the radio signifying that I saw my visual references and then trapped aboard the ship. I then said, "WOW!" to my right seater, signifying what an interesting ride that past 20 seconds had been. We then were taxied to our parking spot where we shut down the jet and got out.

Upon returning to the readyroom I had learned that the storm had just reached the ship and that each pilot returning had worsening and worsening conditions as each plane trapped. I was the last to land, so thankfully the worst was over... or was it? The next set of airplanes still had yet to land! Up to the LSO platform I went, to help my fellow LSOs land the next set of jets on the flight deck.

After flight operations were over and I had a chance to walk around the flight deck. I took a moment to feel exactly how eerie it was with all this sand suspended in the air. You could taste it in your mouth and could feel the grit in your teeth, not that I have ever purposely munched on a handful of sand before. My eyes were irritated by the sand and you could feel the sand sticking to any part of your body that might have a bit of moisture or sweat on it. It was as if there was a fog of sand that reduced visibility just like when ground fog sets in. I haven't seen anything this bad except for when the visibility goes to almost zero because of ground fog. On the flight deck, you could see where the jets had taxied as there was a slight tire track, as if a light snow had just fallen.

This was some of the most interesting weather I have seen besides my encounter with the thunderstorms out here. I am sure this region has more interesting experiences to offer. I know the heat, for one, is just around the corner!