[V.Narayan]

Originally Posted by moralfibre

Completely with you on this. Would you know if the tail numbers are initials of our current Air chief who was instrumental in getting the Rafales for our air force?

I believe so. Initials of the then Chief are often used to designate projects and tailfin numbers. For example when we ordered the customized Kashin class destroyers/frigates from USSR in 1973 they were called SNFs where SN stood for SN Kohli the then Naval chief and F for frigate.

I don't know about budgetary closure for the full 114.

[skanchan95]

Originally Posted by moralfibre

Found an interesting promo video by Dassault Aviation

All Dassault aircraft in IAF/IN service have fired their weapons in anger and the Indian Air Force (IAF) has never been without a Dassault aircraft since 1953, which is quite remarkable.The saga continue will continue with seven Rafales coming in next month.

Originally Posted by moralfibre

Completely with you on this. Would you know if the tail numbers are initials of our current Air chief who was instrumental in getting the Rafales for our air force?

Single Seat Rafales - BS0XX series serial numbers(after former Air Chief ACM B S Dhanoa)

Twin Seat Rafales - RB00X series serial numbers(after current Air Chief ACM R K Bhadauria)

Can't recall any other IAF fighter being serialized after IAF Chiefs and this may well be the first.

The LCA prototypes( PVs and TDs) were serialized KH series serial numbers by HAL/ADA after Dr Kota Harinaryana - Programme Director and Chief Designer of the LCA Tejas.

I have always been very curious to know how other IAF fighters received their serial number series. Could not find anything about it in the books or references I have.

The initial batch of fighters/bombers that the IAF received certainly had an " I"(for India?) link in their serial numbers. The Vampire FB.52s had IB-XXX series, Vampire NF.54s had ID-XXX series, Gnats had IE-XXXX series, Mysteres had IA-XXXX series, Canberras had IB, IF, IP series, Ouragans had IC-XXX series.

That trend was broken when the Hunters got BA-XXX series and the MiG-21F and PFs got BC-XXX series serial numbers. MiG-21s from FL variant onwards received C-XXXX series and the Su-7s received B-XXX series serial numbers. The HF-24s were probably the only fighter type to receive two different types of serial numbers series - D-XXXX series and BD-XXXX series.

[V.Narayan]

The IAF's selection of the Dassault Ouragan has a story behind it. Till then all IAF aircraft had been British or American. In 1952 or 1951 we were looking for some of the later first generation fighter jets to augment our force of de Havilland Vampires. Looking for something with more punch, climb, acceleration and speed. The then Air Chief Sir Gerald Gibbs {also the last British Air Chief} favoured the de Havilland Venom. It was a logical development of the Vampire and it was British. The IAF officer then in-charge of planning Group Capt Mohan Chaturvedi insisted that as a sovereign nation we should strategically seek to diversify our sources of aircraft and not be over dependent on the British and Americans. The matter went up to the RM. Gibbs was understandably upset. But it is an interesting reflection of the times that Chaturvedi was able to stand his ground and decision making had not yet got completely obfuscated by the bureaucracy. And Chaturvedi's recommendation for the Ouragan prevailed. He later rose to Air Marshal and even served as MD of Air India in the late 1960s.

Source: IAF
Air Marshal Sir Gerald Gibbs. He scored 10 aerial victories in World War One.

Source: Personal archives
Air Marshal Mohan Chaturvedi.

Source:Alec Wilson
The Dassault Ouragan, the aircraft in question. How simple jet fighters were then. Straight through wind pipe, plonk the pilot somewhere in between, unswept wings and four 20mm cannons! The most electronic item was probably the radio! Today this looks natural to us -- but in the late 1940s the shift of the fighters' engine from being up in the nose to behind the pilot in the tail was quite a change and a lot of mathematics and wind tunnel testing was needed to get the aerodynamics and CoG right.

[V.Narayan]

Melting glacier on Mont Blanc reveals remains of Air India flight AI 101 that crashed there on 24th January 1966. The flight was enroute from Bombay to London with a halt at Geneva. The crash occurred during the descent into Geneva. Dr Homi Bhaba, India’s top nuclear & space scientist was killed in this flight. It has been said that the CIA decided to assassinate Dr Homi Bhaba to prevent or delay India’s pursuit of being an independent nuclear power. We may never know. Now old newspapers of January 1966 have been thrown up by the melting glacier!

https://edition.cnn.com/2020/07/13/e...ntl/index.html

Source: CNN
Newspaper from half a century ago.

Photo Copyright: Alan Lawerence

Photo Copyright: Roger McDonald

The aircraft VT-DMN, Boeing 707-420. The 420 series was the standard 707-320 but with the more powerful Rolls Royce Conway low bypass turbofans developing 18,000 lbf versus the 17500 lbf of the P&W JT-4A's that the regular -320 carried. In those days that extra thrust was much needed in the typical hot environment of Indian airports. The -420 on BOAC's insistence also had a taller fin that improved yaw authority and a tail strike avoidance device. These later became standard on all Boeing 707s and were retrofitted on all 707 variants produced earlier.

[skanchan95]

Originally Posted by V.Narayan

Melting glacier on Mont Blanc reveals remains of Air India flight AI 101 that crashed there on 24th January 1966. The flight was enroute from Bombay to London with a halt at Geneva. The crash occurred during the descent into Geneva. Dr Homi Bhaba, India's top nuclear & space scientist was killed in this flight. It has been said that the CIA decided to assassinate Dr Homi Bhaba to prevent or delay India's pursuit of being an independent nuclear power. We may never know. Now old newspapers of January 1966 have been thrown up by the melting glacier!

A Time Capsule!!! Fascinating that the newspaper is in such a remarkably good condition. It almost looks as if it was printed yesterday.

[V.Narayan]

15th July 1954 a day that will live in aviation history for all times

Birth of the Boeing 707

On this day 66 years ago the Boeing prototype 367-80 carrying registration number N70700 put wind beneath its wings for the first time when it took off from Renton airfield near Seattle. The 367-80 was the parent prototype that spawned two whole generation of aircraft – first the -135 series and second the ever famous Boeing 707 family. The -135 consisted of the KC-135 air-to-air refueling tanker and the C-135 military cargo lifter. For the 707s Boeing implemented what is the most difficult structural design modification ie widening the fuselage by 4 inches. This widening allowed the aircraft to seat 6 abreast in reasonable comfort and that fuselage cross section right down to the ribs stayed unchanged through the 727, 737 and 757. The Boeing 707 in turn served as the basis for three more military versions, the E-3 AWACS Sentry, the E-6 Mercury Airborne Command Post and E-8 Target Radar Attack System aircraft.

On that day 66 years ago the 367-80 lifted off at 130 mph and lurched up in a steep climb so much so that by the time it was across the air strip it had climbed to 1200 feet. Its tail fin number gave the marketing boys the idea of using the 707 suffix to market the passenger version. At the controls was Boeing’s Test pilot Alvin ‘Tex’ Johnston.

Boeing had sunk $16 million, a ransom in 1954, to build the prototype. It needed to have a flying prototype backed by an empty order book to convince airlines that jet propulsion was viable for an airliner and that an airliner flying at 35,000 feet at 900 kmph was a safe proposition {the 3 de Havilland Comet crashes had spooked the airlines}.

The prototype Boeing Model 367-80 was operated by a pilot, co-pilot and flight engineer. The airplane’s wing was mounted low on the fuselage and the engine nacelles were mounted on pylons under the wing, as they were on Boeing’s B-47 Stratojet and B-52 Stratofortress. The wings and tail surfaces were swept to 35°. The Dash 80 was 127 feet 10 inches long with a wingspan of 129 feet 8 inches and overall height of 38 feet. Its empty weight was 92,100 pounds (41,775 kilos) and loaded weight was 190,000 pounds (86,182 kilos).

N70700 was powered by four Pratt & Whitney Turbo Wasp JT3C engines. This engine is a civil variant of the military J57 series rated at 11,200 pounds of thrust (49.82 kN), and 13,500 pounds (60.05 kN) with water/methanol injection).

These gave the 367-80 a cruise speed of 550 mph (885 kmph) and a maximum speed of 0.84 Mach (582 mph, 937 kmph) at 25,000 feet (7,620 meters). The service ceiling was 43,000 feet. Its range was 3,530 miles (5,680 kms).

The 367-80 became the second ever commercial jet to fly after the Comet.

The KC-135s are expected to be flown till 2030 and the E-3s and E-6s will fly longer. Some will be flying to celebrate the 80th anniversary of the 367-80's first flight.

{First 3 photos copyright of Boeing; last photo copyright Joe Parke, Source Wikipedia}


15 July 1954: At 2:14 p.m., Boeing test pilots Alvin M. “Tex” Johnston and Richard L. “Dix” Loesch lifted off from Renton Field, south of Seattle, Washington, on the first flight of the Boeing 367–80, FAA registration N70700, a prototype military air tanker and commercial airliner. Note the C-97 military transports and KC-97s the original tanker transport, grandfather of today's MRTT


Boeing 367-80 N70700, photographed during its first flight, 15 July 1954


The 367-80 in colour in a later flight. Note the tail number has been painted out from the wing surface. Note the brown, dark yellow Boeing colours of the time.

[Jeroen]

Lovely write up on what many would still consider one of the prettiest commercial jet airliners. It was also test pilot Tex who barrel rolled a 707 in front of Boeing customer and, not very amused, Boeing Executives!

[Sutripta]

Originally Posted by V.Narayan

The -420 on BOAC's insistence also had a taller fin that improved yaw authority and a tail strike avoidance device. .

How does the tail strike avoidance device work?

Sutripta

[fhdowntheline]

Great post on the Boeing 367/B707. However, I believe the Avro Canada Jetliner was the second jetliner to fly after the de Havilland Comet, which beat it to first flight by a matter of few days. The Avro Canada design, of course did not see commercial service, but is one of the tiny bits of aviation trivia stashed away in history.
But on a side note, the eras of the 50s/60s/70s were so competitive in terms of technology in every aspect of peoples lives. I feel somewhere this generation is missing that intense competition. We have come to a sort of a plateau, largely because of the monopoly of a few giant corporations and a general state of contentment.

[V.Narayan]

Originally Posted by Jeroen

Lovely write up on what many would still consider one of the prettiest commercial jet airliners. It was also test pilot Tex who barrel rolled a 707 in front of Boeing customer and, not very amused, Boeing Executives!

https://www.youtube.com/watch?v=AaA7kPfC5Hk

Here is the link. The one barrel roll watched by a very large number of aviation seniors.

Originally Posted by Sutripta

How does the tail strike avoidance device work?

In case of the 707 it was a simple fin that could absorb some of the 'hit' but would crumple with a stronger strike thus protecting the plane's fuselage. It also helped increase the fin stabilizing area. A tail wheel of a Dakota is also a tail strike device!

Originally Posted by fhdowntheline

Great post on the Boeing 367/B707. However, I believe the Avro Canada Jetliner was the second jetliner to fly after the de Havilland Comet, which beat it to first flight by a matter of few days. The Avro Canada design, of course did not see commercial service, but is one of the tiny bits of aviation trivia stashed away in history.

Yes you are correct. My mistake. The Avro Canada Jetliner was the second jet airliner prototype to take to the air in 1949. Sadly lack of Govt funding and political will resulted in no further prototypes being developed. Poor Canadians we tend to forget about them!

[Sutripta]

Originally Posted by V.Narayan

In case of the 707 it was a simple fin that could absorb some of the 'hit' but would crumple with a stronger strike thus protecting the plane's fuselage.

That is like calling the bumpers of cars 'collision avoidance devices'!
And if the 707 had a propensity towards tail strikes, wouln't this bumper reduce the clearance, and exacerbate the problem?

Sadly lack of Govt funding and political will resulted in no further prototypes being developed. Poor Canadians we tend to forget about them!

The biggest shame IMO was the fate of the Avro Arrow.

Sutripta

[Jeroen]

Originally Posted by Sutripta

That is like calling the bumpers of cars 'collision avoidance devices'!
And if the 707 had a propensity towards tail strikes, wouln't this bumper reduce the clearance, and exacerbate the problem?

Reminds me on the endless debate we have in the Alfa Spider club regarding sump guards. The spider is a low slung car. Especially when going across speed bumps a little too fast and you might scrape the sump. Worse, it is likely to shatter. So many Spideristi will install a sump guard. Which reduces the ground clearance even further, by about 15-20mm. And they will find that they are hitting the speed bump more often with the sump guard fitted than without it.

It’s still worthwhile because when you hit that speed bump way to fast, or it is steeper than you thought, all of a sudden the sump guards will make a lot of sense. You still hear an almighty screech, but nothing else happens. Without it you would have been likely to crack the sump, shear of the sump bolts and damage the lub oil pump.

I reckon this 707 tail strike device is similar. You might bump it occasionally, whereas without it you wont, but on the big bumps it really comes into its own.

Jeroen

[V.Narayan]

Air France Flight 4590, Concorde crash

It is exactly 20 years since the tragic crash of the Concorde at CDG Paris. The aircraft serving the flight (registration F-BTSC) ran over debris on the runway during takeoff, blowing a tyre, and sending debris flying into the underside of the left wing, and into the landing gear bay.

The fuel tank that was inside the left wing was unusually full, and the resulting lack of air space in the tank caused it to rupture and send fuel pouring outward with great force when debris from the tire struck the wing thus creating a shock wave that weakened the tank. Debris, which flew into the landing gear bay, severed power wiring for the landing gear, making it impossible to retract the gear as the aircraft climbed. Sparks produced by the broken wiring ignited fuel from the ruptured fuel tank and along with the fire came a reduction of thrust from engines 1 and 2 on the port side. Lack of thrust, the high drag caused by the inability to retract the gear, along with fire damage to the flight controls, made it impossible to control the aircraft with the result that it crashed into a hotel in nearby two minutes after takeoff, killing all 109 people on board. Unfortunately, it led to the pre-mature demise of Concorde flights. The Concorde crashed for no fault of the aircraft.

Excellent explanation by Allec Ibay below

https://www.youtube.com/watch?v=gDyIgQSVaNY

[Sutripta]

Originally Posted by V.Narayan

Air France Flight 4590, Concorde crash

It is exactly 20 years since the tragic crash of the Concorde at CDG Paris.

Can't believe 20 years have gone by. If suddenly asked, would have replied something like 'happened a few years back'!

Sutripta

Why is this in the Indian Aviation thread?

[neofromcapone]

An sad end to one of mankind's engineering feats.
Hope we can see the Concorde in the skies, in some reborn form.

I think it made one flight to Bombay in the mid-1990's for maybe an Indo-France summit